EDITEK INC
8-K, 1996-02-07
IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES
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                                    FORM 8-K

                       SECURITIES AND EXCHANGE COMMISSION


                             Washington, D.C. 20549





                                 CURRENT REPORT


                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934



       Date of Report (Date of earliest event reported): January 30, 1996




                                  EDITEK, INC.
             (Exact name of registrant as specified in its charter)


                                    Delaware
                 (State or other jurisdiction of incorporation)


        1-11394                                          95-3863205
(Commission File Number)                     (IRS Employer Identification No.)


1238 Anthony Road
Burlington, North Carolina                                        27215
(Address of principal executive offices)                       (Zip Code)


                                 (910) 226-6311
              (Registrant's telephone number, including area code)


<PAGE>


Item 2.  Acquisition or Disposition of Assets.

         The  Registrant   entered  into  an  agreement  (the  "Asset   Purchase
Agreement")  dated as of July 1, 1995, as amended by Amendment  Agreements dated
as of  January  2,  1996 and  January  30,  1996  (the  "Amendment  Agreements")
(collectively,   the  "Purchase  Agreement")  with  MedTox  Laboratories,   Inc.
("MedTox"), a Minnesota corporation involved in the performance of toxicological
testing services,  including forensic,  medical,  biological and pharmacological
toxicology,  to acquire  substantially all of the assets of MedTox. By agreement
dated as of January 10, 1996, the Registrant assigned its rights to purchase the
assets to Psychiatric Diagnostic Laboratories of America, Inc.  ("Psychiatric"),
a Delaware  corporation  and a wholly-owned  subsidiary of Princeton  Diagnostic
Laboratories  of  America,  Inc.,  a  Delaware  corporation  and a  wholly-owned
subsidiary  of the  Registrant.  On January  30, 1996 (the  "Closing  Date") the
Registrant closed the MedTox acquisition.

         The  Registrant  intends  to use the  assets  acquired  from  MedTox to
continue the toxicological testing business formerly conducted by MedTox.  The
Registrant believes that the acquisition of the MedTox assets will enable the
Registrant to expand substantially its toxicological testing presence in the 
United States and Canada and to obtain cost savings from the Registrant's 
current laboratory operations. The Registrant has hired 247 former employees 
of MedTox, which brings to 362 the number of employees of the Registrant.

         The terms of the MedTox  Transaction  and the related  Preferred  Stock
financing were negotiated at arms' length, and no material  relationship  exists
between MedTox and the Registrant or between MedTox and Psychiatric.

         Set  forth  below is a  summary  of some of the  material  terms of the
Purchase Agreement and other  transactions  related thereto  (collectively,  the
"MedTox Transaction"), which summary should be read in conjunction with the full
terms of the Purchase  Agreement and other related  agreements,  copies of which
are included as exhibits hereto and are incorporated herein in their entirety.

         Upon  closing,  the  Registrant's   assignee,   Psychiatric,   acquired
substantially  all of the  assets of  MedTox,  including  all the  tangible  and
intangible  assets (other than cash in bank accounts)  owned by MedTox as of the
closing, including,  without limitation, all accounts receivable, all inventory,
equipment,  contracts, leases, subleases, licenses, customer and supplier lists,
certain  business  records,  trade  secrets,  tradenames  and  marks  and  other
intellectual property. Certain of the liabilities of MedTox were also assumed by
the Registrant and Psychiatric in connection with the acquisition, as more fully
described in the Agreement.

         The Purchase  Agreement  provides  for a purchase  price for the MedTox
assets  of  $24,000,000,  of  which  (i)  $19,000,000  was paid in cash and (ii)
$5,000,000  was paid in the form of 2,517,306  shares  ("MedTox  Shares") of the
Common Stock of the Registrant, par value $.15 per share (the "Common Stock"),
which number of shares is subject to upward  adjustment  as  described  below in
"Additional  Shares For MedTox  Shareholders."  The cash portion of the purchase
price was  financed  by the  Registrant  through  sale of 380 shares of Series A
Convertible

<PAGE>


Preferred  Stock  ("Series A Preferred  Stock") and debt  financing
from Heller Financial, Inc. ("Heller") (the "Debt Financing.") In
addition, the Registrant sold an  additional  235,295 shares of common
stock to Dr. Harry McCoy, a Medtox shareholder, (the "McCoy Shares"), and
27 shares of Series A  Convertible  Preferred  Stock for working capital
purposes  bringing the total number of Series A Preferred Shares sold to
407. The material  terms of the Series A Preferred  Stock and the Debt
Financing are described below.

Additional Shares For MedTox Shareholders

         The Purchase  Agreement  provides  that,  if after the Closing Date the
market value of the Common  Stock of the  Registrant  declines  below $1.986 per
share, the Registrant will issue additional shares of Common Stock  ("Additional
Shares")  to  shareholders  of MedTox who retain  their  shares of Common  Stock
through four specified  dates (the  "Repricing  Dates") to compensate the MedTox
shareholders  for decreases  after the closing of the MedTox  Transaction in the
market price of the Common Stock of the Registrant  below $1.986 per share.  The
Repricing  Dates are the fifth  trading day  following  the date the  Registrant
issues  press  releases  announcing  its  financial  performance  for the fiscal
quarters ending on March 31, 1996, September 30, 1996 and September 30, 1997 and
the fiscal year ending on December  31, 1996.  Because the number of  Additional
Shares that may become  issuable is tied to decreases in the market price of the
Common  Stock,  the  number  of  Additional  Shares  issuable  in the  future in
connection  with the MedTox  Transaction  cannot be  determined at this time and
will depend upon changes in the market price of the Common Stock, as well as the
extent to which  MedTox  shareholders  retain the  MedTox  shares on each of the
Repricing  Dates.  Substantial  sales of shares of  Common  Stock by the  MedTox
shareholders  or  purchasers  of Series A  Preferred  Stock may have a  material
adverse effect on the market price of the Common Stock of the Registrant,  which
would increase the number of Additional  Shares issuable to MedTox  shareholders
on the Repricing Dates.

Debt Financing

         To obtain funds  necessary to complete  the MedTox  Transaction  and to
provide for the  Registrant's  working  capital  needs,  the  Registrant and its
affiliated  entities,  Psychiatric and diAGnostix,  Inc., a Delaware corporation
and a wholly-owned subsidiary of the Registrant,  entered into a credit facility
consisting  of two term  loans in the  amount of  $2,000,000  each,  one with an
eighteen-month  term and the other with a three-year  term, and a revolving line
of credit of up to $7,000,000 (the "Credit  Facility") with the amount available
under the  Credit  Facility  dependent  upon the amount of assets  available  to
secure   borrowings  under  the  Credit   Facility.   As  of  January  30,  1996
approximately  $2,900,000  million was available under the Credit  Facility,  of
which  approximately  $1,000,000  has been  drawn  down by the  Registrant.  The
closing for the term loans and the Credit Facility occurred on January 30, 1996.

         In  connection  with  the  Debt  Financing,   the  Registrant  and  its
subsidiaries  have granted Heller a security interest in substantially all their
assets and have agreed to comply with many financial and other  covenants  which
restrict  operations  of the  Registrant  and its  subsidiaries,  including  the
ability to pay dividends.  These security  interests and covenants are contained
in agreements attached as exhibits hereto. 

<PAGE>


Series A Preferred Stock

         The 407 shares of Series A  Preferred  Stock were sold for  $50,000 per
share with the  initial  sales  occurring  on  January  30,  1996 (the  "Initial
Issuance  Date").  Each share of Series A Preferred  Stock is  convertible  into
shares of Common  Stock,  at any time on or after  March 30, 1996 (60 days after
the Initial  Issuance Date). On the second  anniversary of the Initial  Issuance
Date conversion  rights terminate and any remaining shares of Series A Preferred
Stock will be automatically converted, unless the holder provides the Registrant
with prior written notice that conversion is not desired.

         The number of shares of Common  Stock  issuable  upon  conversion  of a
share of Series A Preferred  Stock will equal the number derived by dividing (i)
the purchase  price of the Series A Preferred  Stock ($50,000 per share) by (ii)
the lower of (x)  $2.775 or (y) 75% of the Market  Price of the Common  Stock on
the day the shares of Preferred  Stock are converted into Common Stock.  "Market
Price" is defined  for this  purpose as the daily  average  of the  closing  bid
prices  quoted on the  American  Stock  Exchange or other  exchange on which the
Common Stock is traded for the five trading days immediately  preceding the date
the shares are converted.  Accordingly,  a minimum of 7,333,333 shares of Common
Stock are issuable upon conversion of the 407 outstanding shares of Series A
Preferred Stock. However, the actual number of shares of Common Stock issuable
upon conversion of the Series A Preferred  Stock will not be known  until the
time of  issuance  of such  Common Stock. Substantial  sales  of  Common  Stock
by the  MedTox  shareholders  and purchasers of Series A Preferred Stock may
have a material adverse effect on the market price of the Registrant's  Common
Stock,  which would increase the number of shares of Common Stock  issuable upon
conversion  of the Series A Preferred Stock.

         The Series A  Preferred  Stock has a  liquidation  preference  and a 9%
annual dividend  (cumulative  until December 31, 1997) and very limited voting
rights,  as described in the Amended  Certificate of Designations of Preferred
Stock, a copy of which is attached as an Exhibit hereto.

Resales of Securities

         The Registrant has issued the 2,517,306 MedTox Shares, 235,295 McCoy
Shares and 104 shares of Series  A  Preferred  Stock  pursuant  to an  exemption
from  the  registration requirements of the Securities Act of 1933, as amended
(the 1933 Act"), afforded by Regulation D of the Securities and Exchange
Commission (the "Commission").

         The Registrant has agreed to use its best efforts to register for 
resale with the Commission the Common Stock issuable upon  conversion of such 
shares of Series A Preferred  Stock (the "Conversion Shares"), the MedTox 
Shares, the Additional Shares (as defined above), the McCoy Shares and 586,667
shares of Common Stock issuable pursuant to warrants issued as compensation to
Shoreline Pacific for investment banking services in connection with sales of 
Series A Preferred Stock.

         In  addition,  303 shares of Series A Preferred  Stock were sold by the
Registrant pursuant to Regulation S of the Commission (the "Offshore Offering").
The Registrant does not expect to file a registration  statement with respect to
these shares of Series A Preferred Stock.

<PAGE>


         Regulation S generally provides that offers or sales that occur outside
the United  States  and in  compliance  with the  requirements  thereof  are not
subject  to  the  registration  requirements  of the  Act.  Subject  to  certain
restrictions  and conditions  set forth  therein,  Regulation S is available for
offers and sales to investors  that are not in the U.S. Such offshore  investors
who  purchase the shares of Series A Preferred  Stock in the  Offshore  Offering
pursuant to Regulation S are not permitted to transfer such shares or Conversion
Shares to a U.S.  Person  (defined  generally  as a resident  of the U.S.  or an
entity  organized  under  the laws of the U.S.) for a period of at least 40 days
after  February 2, 1996, the closing of the Offshore  Offering (the  "Restricted
Period"). Resales to buyers who are not U.S Persons are permitted at any time.

         After the expiration of the Restricted Period,  investors who purchased
shares of Series A Preferred Stock in the Offshore Offering may sell such shares
or Conversion  Shares in the U.S.,  but only if such shares are registered or an
exemption from  registration is available.  Accordingly,  beginning on March 30,
1996 (the  first day any  investor  will be able to  convert  shares of Series A
Preferred  Stock into shares of Common  Stock),  to the extent that any offshore
investors  have converted  their shares of Series A Preferred  Stock into Common
Stock,  such offshore  investors  will also be able to sell such Common Stock in
the U.S. if the shares are registered or an exemption is available.

         The investors  participating in the Offshore Offering who can resell in
accordance  with  Regulation  S do not have  registration  rights to require the
Registrant to register for resale the Conversion Shares issuable upon conversion
of shares of Series A Preferred Stock. Therefore, sales of Conversion Shares for
such  offshore  investors  must be made in  compliance  with an  exemption  from
registration.  The stock certificates for the Conversion Shares will not contain
restrictive securities legends. Consequently, the Registrant will not be able to
prevent  resales of Series A Preferred  Stock or  Conversion  Shares by offshore
investors and each offshore  investor  will make its own  determination  whether
such sales qualify for exemptions from registration.

         If substantial sales of the Registrant's Common Stock occur, whether by
the  investors in the  Offshore  Offering or by U.S.  investors  pursuant to the
registration  statement or otherwise,  such sales could have a material  adverse
affect on the market price of the Registrant's Common Stock.

Item 5.  Other Events.

         Effective January 31, 1996, the Board of Directors of the Registrant
elected two additional members to the Board of Directors of the Registrant,
bringing the total number of Directors to six. Dr. Harry McCoy was the President
and  Co-Founder of MedTox.  Dr. McCoy received his Bachelors  Degree in Biology
from the University of  California,  San Diego and a Doctorate in Pharmacy  from
the  University  of California,  San Francisco. He conducted his clinical
internship at the Stanford Medical  Center,   University  of  California  and
pursued  his   Post-Doctoral Fellowship in  Pharmacokinetics  with the
University of Minnesota  where he held joint faculty  appointments  at the
University of Minnesota  College of Pharmacy and the Section of Clinical
Pharmacology at the St. Paul-Ramsey Medical Center.


<PAGE>

         Mr. George  Masters is Vice  Chairman,  President  and Chief  Executive
Officer of Seragen, Inc. Mr. Masters has spent his entire business career in the
healthcare   industry,   including  20  years  with   Warner-Lambert.   He  left
Warner-Lambert in 1983 as a Group President,  and for the past 12 years has held
senior  management  positions  with a number  of  biotechnology  companies.  Mr.
Masters has been a board  member of  approximately  fifteen  medically  oriented
companies  and  currently  serves as a member of the Board of Directors  of: CME
Telemetrix,  Hemosol,  Inc., ImmuCell Corporation,  Intelligent Medical Imaging,
and  Seragen.  Mr.  Masters is on the Board of  Directors  of the  Biotechnology
Industry  Organization in Washington,  DC and serves on its Executive Committee.
He is on the Board of Visitors of Boston  University  School of Medicine and the
Board of Associates of the Whitehead  Institute for Biomedical  Research at MIT.
He also acts as an investment advisor to three venture capital funds.

Item 7.  Financial Statements and Exhibits.

         (a)      Financial statements.

                  Audited Consolidated Balance Sheets, Statements of Operations
                  and Cash Flows for MedTox Laboratories, Inc. for fiscal years
                  ended  December 31, 1993 and December 31, 1994.  (Incorporated
                  by reference to the Registrant's Proxy Statement dated 
                  September 25, 1995.)

                  Interim Consolidated Balance Sheets, Statements of Operations
                  and Cash Flows for MedTox Laboratories, Inc. for the nine 
                  months ended September 30, 1995.

         (b)      Pro Forma Financial Information.

                  EDITEK, Inc. and MedTox Laboratories, Inc. Pro Forma Condensed
                  Balance  Sheet as of September 30, 1995 and Statements of 
                  operations for fiscal year ended December 31, 1994 and Nine 
                  Months ended September 30, 1995.

         (c)      Exhibits.

                  3.1      Amended  Certificate  of  Designations  of  Series  A
                           Convertible Preferred Stock.

                  10.1     Asset  Purchase  Agreement  dated as of July 1,  1995
                           between EDITEK, Inc. and MedTox Laboratories, Inc.

                  10.2     Amendment  Agreement  dated  as of  January  2,  1996
                           between EDITEK, Inc. and MedTox Laboratories, Inc.

<PAGE>

                  10.3     Amendment  Agreement  dated as of  January  30,  1996
                           among the Registrant,  MedTox Laboratories,  Inc. and
                           Psychiatric Diagnostic Laboratories of America, Inc.

                  10.4     Loan  and  Security  Agreement   (together  with  the
                           Exhibits  and  Schedules  thereto) by and between the
                           Registrant,  Psychiatric  Diagnostic  Laboratories of
                           America, Inc., diAGnostix, Inc. and Heller Financial,
                           Inc., dated January 30, 1996.

                  10.5     Term Note A executed by the  Registrant,  Psychiatric
                           Diagnostic   Laboratories   of  America,   Inc.   and
                           diAGnostix in favor of Heller Financial,  Inc., dated
                           January 30, 1996.

                  10.6     Term Note B executed by the  Registrant,  Psychiatric
                           Diagnostic   Laboratories   of  America,   Inc.   and
                           diAGnostix in favor of Heller Financial,  Inc., dated
                           January 30, 1996.

                  10.7     Assignment  for  Security  (Patents)  executed by the
                           Registrant in favor of Heller Financial,  Inc., dated
                           January 30, 1996.

                  10.8     Assignment   for   Security  -  EDITEK   (Trademarks)
                           executed  by  the   Registrant  in  favor  of  Heller
                           Financial, Inc., dated January 30, 1996; and

                  10.9     Assignment  for  Security  -  Princeton  (Trademarks)
                           executed  by  Princeton  Diagnostic  Laboratories  of
                           America,  Inc.  in favor of Heller  Financial,  Inc.,
                           dated January 30, 1996.

                  10.10    Lease Agreement between MedTox Laboratories, Inc.
                           and Phoenix Home Life Mutual Insurance Company, dated
                           April 1, 1992, and amendments to such lease.





<PAGE>




                                   SIGNATURES

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.


                                    EDITEK, INC.



Date:  February 7, 1996          By:      /s/ Peter J. Heath
                                 Name:    Peter J. Heath
                                 Title:   Vice President of Finance
                                          and Chief Financial Officer



<PAGE>



                                  EXHIBIT INDEX

<TABLE>
<CAPTION>


  Exhibit No.                                      Description                                      
<S>               <C>                                                                               
      (a)         Interim Consolidated Balance Sheets, Statements of Operations and Cash Flows for MedTox
                  Laboratories, Inc. for the nine months ended September 30, 1995.

      (b)         EDITEK, Inc. and MedTox Laboratories, Inc. Pro Forma Condensed Balance Sheet as of 
                  September 30, 1995 and Statements of Income for fiscal year ended December 31, 1994 
                  and Nine Months ended September 30, 1995.

      3.1         Amended Certificate of Designations of Series A Convertible Preferred Stock.

      10.1        Asset Purchase Agreement dated as of July 1, 1995 between EDITEK, Inc. and MedTox
                  Laboratories, Inc.

      10.2        Amendment Agreement dated as of January 2, 1996 between EDITEK, Inc. and MedTox
                  Laboratories, Inc.

      10.3        Assignment Agreement dated as of January 10, 1996 among the Registrant, MedTox
                  Laboratories, Inc. and Psychiatric Diagnostic Laboratories of America, Inc.

      10.4        Loan and Security  Agreement  (together  with the Exhibits and Schedules  thereto) by  and
                  between the Registrant, Psychiatric Diagnostic Laboratories of America, Inc., diAGnostix,
                  Inc. and Heller Financial, Inc., dated January 30, 1996.

      10.5        Term Note A executed by the Registrant, Psychiatric Diagnostic Laboratories of America,
                  Inc. and diAGnostix in favor of Heller Financial, Inc., dated January 30, 1996.

      10.6        Term Note B executed by the Registrant, Psychiatric Diagnostic Laboratories of America,
                  Inc. and diAGnostix in favor of Heller Financial, Inc., dated January 30, 1996.

      10.7        Assignment for Security  (Patents)  executed by the Registrant in favor of 
                  Heller Financial, Inc., dated January 30, 1996.

      10.8        Assignment for Security - EDITEK (Trademarks) executed by the Registrant in favor of
                  Heller Financial, Inc., dated January 30, 1996.

      10.9        Assignment for Security - Princeton (Trademarks) executed by Princeton Diagnostic
                  Laboratories of America, Inc. in favor of Heller Financial, Inc., dated January 30, 1996.

     10.10        Lease Agreement between MedTox Laboratories, Inc. and Phoenix Home Life Mutual Insurance
                  Company, dated April 1, 1992, and amendments to such lease.

</TABLE>

<PAGE>
Exhibit (a)

                           MEDTOX LABORATORIES, INC.
                                 AND SUBSIDIARY
                           Consolidated Balance Sheet

<TABLE>
<CAPTION>


                                                                     9/30/95            12/31/94
                                                                 --------------------------------
                                                                   (unaudited)
<S>                                                                 <C>             <C>         
Current assets:
     Cash and cash equivalents                                      $  2,034,921    $    526,512
     Accounts receivable, less allowance for
       doubtful accounts                                               3,438,523       2,966,466
     Laboratory supplies                                                 310,395         413,301
     Prepaid expenses and other current assets                           179,386         107,622
                                                                 --------------------------------
     Total current assets                                              5,963,225       4,013,901

Property and equipment:
     Laboratory equipment                                              4,736,097       4,108,629
     Office furniture and fixtures                                       372,764         370,685
     Leasehold improvements                                              543,277         426,017
     Transportation equipment                                            315,819         304,891
                                                                 --------------------------------

     Total property and equipment                                      5,967,957       5,210,222
     Less accumulated depreciation                                   (4,169,368)     (3,700,312)
                                                                 --------------------------------
     Net property and equipment                                        1,798,589       1,509,910

Other assets, net of related amortization:
     Software                                                             66,505          84,242
     Goodwill                                                              5,331           9,022
     Deposits and other                                                   18,629          19,596
                                                                 --------------------------------
     Total other assets                                                   90,465         112,860
                                                                          
                                                                 --------------------------------

     Total assets                                                   $  7,852,279    $  5,636,671
                                                                 ================================

Current Liabilities

     Accounts payable                                              $     639,451   $      98,218
     Accrued salary and wages                                            287,724         335,120
     Accrued expenses                                                  1,114,215         761,700
     Restructuring accrual, current portion                              258,070         258,070
     Current portion of long-term debt                                   501,710         437,755
                                                                 --------------------------------
     Total current liabilities                                         2,801,170       1,890,863

Restructuring accrual, long-term portion                                 514,173         659,795
Long-term debt (net of current portion)                                  591,525         518,563
Minority interest in subsidiary
                                                                             210             210
                                                                 --------------------------------

     Total liabilities                                                 3,907,078       3,069,431

Stockholder's equity:
     Common stock, $1 par value per share, 50,000 shares
       authorized; 29,658 issued and outstanding                          29,658          29,658
     Additional paid-in capital                                          600,033         600,032
     Retained earnings                                                 3,315,510       1,937,550
                                                                 --------------------------------
     Total stockholders' equity                                        3,945,201       2,567,240

Total liabilities and stockholders' equity                          $  7,852,279    $  5,636,671
                                                                 ================================
</TABLE>


<PAGE>

                           MEDTOX LABORATORIES, INC.
                                 AND SUBSIDIARY
                 Unaudited Consolidated Statement of Operations


<TABLE>
<CAPTION>


                                                 Nine Months      Nine Months
                                                    Ended            Ended
                                                   9/30/95          9/30/94
                                               ---------------------------------
<S>                                           <C>                <C>      
Revenues                                            $17,019,777     $16,575,770
Pass through costs                                  (1,669,418)     (1,664,776)
                                               ---------------------------------
Net revenues                                         15,350,359      14,910,994

Cost of revenues:
     Supplies                                         3,013,015       3,233,910
     Direct labor                                     2,652,051       2,201,928
     Laboratory overhead                              1,259,848
                                                                              -
                                               ---------------------------------
Total cost of sales                                   6,924,914       5,435,838

Gross profit                                          8,425,445       9,475,156

Operating expenses:
     Distribution expenses                            1,839,941               -
     Sales and marketing expenses                       707,987         638,483
     Client support expenses                          1,413,822       2,557,649
     MIS expenses                                       144,980         103,800
     General and administrative expenses              1,616,389       3,709,373
                                               ---------------------------------
     Total operating costs                            5,723,119       7,009,305

Other income (expense)
     Other Income                                         1,112           4,000
     Interest expense                                 (139,156)       (109,410)
                                               ---------------------------------
     Total other income (expense)                     (138,044)       (105,410)

                                               ---------------------------------

Net income                                         $  2,564,282    $  2,360,441
                                               =================================


Pro forma income data:
     Net income as reported                        $  2,564,282    $  1,613,686
     Pro forma adjustment to record
         provision for income taxes                     971,863         611,587
                                               ---------------------------------

     Pro forma net income                          $  1,592,419    $  1,002,099
                                               =================================

     Pro forma net income per share              $        53.71    $      33.95
                                               =================================
</TABLE>

<PAGE>

                          MEDTOX LABORATORIES, INC.
                               AND SUBSIDIARY
                Unaudited Consolidated Statement of Cash Flows


<TABLE>
<CAPTION>



                                                                           Nine Months      Nine Months
                                                                              Ended            Ended
                                                                             9/30/95          9/30/94
                                                                        -----------------------------------

<S>                                                                         <C>              <C>          
Reconciliation of net income to net cash provided by operating activities:
        Net income                                                          $   2,564,282    $   2,360,441
        Adjustment to reconcile net income to net cash
           provided by operating activities:
              Depreciation and amortization                                       536,659          468,000
              (Gain) loss on sale of assets                                       (1,112)          (4,000)
        Changes in operating assets and liabilities:
              Accounts receivable                                               (472,057)        (311,655)
              Laboratory supplies                                                 102,906          167,056
              Prepaid and other current assets                                   (71,764)          168,965
              Accounts payable                                                    517,707        (848,245)
              Accrued expenses, salaries and wages                                183,020          558,706
                                                                        -----------------------------------

Net cash provided by operating activities                                   $   3,359,641    $   2,559,268

Cash flows from investing activities:
     Purchases of property and equipment                                   $    (670,928)   $    (462,248)
     Purchases of intangible assets and software                                (132,982)         (33,335)
     Proceeds from sale of equipment                                                1,112            4,000
     Decrease in deposits and other assets                                            967           19,157
                                                                        -----------------------------------

Net cash used in investing activities                                      $    (801,831)   $    (472,426)

Cash flows from financing activities:
     Proceeds from long-term debt                                           $     478,000    $     124,619
     Net decrease in line of credit                                                     -         (500,000)
     Payments on long-term debt                                                 (341,083)        (724,890)
     Proceeds from the issuance of common stock                                         -           31,200
     Distributions to stockholders                                            (1,186,318)                -
                                                                        -----------------------------------

Net cash used in financing activities                                      $  (1,049,401)   $  (1,069,071)

Net increase in cash and cash equivalents                                   $   1,508,409    $   1,017,771
Cash and cash equivalents, beginning of year                                $     526,512   $       27,977
                                                                        -----------------------------------

Cash and cash equivalents, end of year                                      $   2,034,921    $   1,045,748
                                                                        ===================================
</TABLE>


EXHIBIT (b)

The following unaudited pro forma consolidated balance sheet as of September 30,
1995, and the unaudited pro forma consolidated  statements of operations for the
nine months ended  September 30, 1995 and the year ended December 31, 1994, give
effect to the  acquisition  of MEDTOX by EDITEK using the purchase  method.  The
unaudited  pro  forma  consolidated   financial  information  is  based  on  the
historical  financial  information of EDITEK and MEDTOX as of September 30, 1995
and the pro forma adjustments  described in the notes thereto.  There are no pro
forma  adjustments  to  other  amounts  reflected  in the  historical  financial
statements of MEDTOX as management  believes that the historical  costs assigned
to MEDTOX assets and liabilities approximate fair value.

         Information  was  prepared  as if the  acquisition  was  effected as of
September 30, 1995 in the case of the unaudited pro forma  consolidated  balance
sheet;  as of January 1, 1994 in the case of the September 30, 1995 and December
31, 1994 unaudited pro forma  statements of operations.  The unaudited pro forma
financial  statements  may not be indicative of the results that actually  would
have occurred if the  acquisition  had been in effect on the dates  indicated or
which  may  be  obtained  in the  future.  The  unaudited  pro  forma  financial
information  should be read in  conjunction  with the financial  statements  and
other financial data of EDITEK and MEDTOX.


<PAGE>

                               EDITEK AND MEDTOX
                     UNAUDITED CONSOLIDATED BALANCE SHEETS
                               September 30, 1995
                     (In Thousands except per share amounts)


<TABLE>
<CAPTION>
                                                                      Historical                             Proforma
                                                      -------------------------------   ------------------------------------
                                                         EDITEK           MEDTOX          Adjustments        Consolidated
                                                      -------------    --------------   ----------------   -----------------
<S>                                                   <C>              <C>              <C>                <C>
ASSETS:
Cash and Cash Equivalents                               $      416        $    2,035      $         934 (a)  $        3,385
Accounts Receivable, net                                     1,308             3,439                  -               4,747
Inventory and Supplies                                         868               310                  -               1,178
Other Current Assets                                           741               179               (500)(a)             420
                                                      -------------------------------   ----------------   -----------------
      Total Current Assets                                   3,333             5,963                434               9,730

Property and Equipment                                       7,512             5,968                  -              13,480
Accumulated Depreciation                                   (6,704)           (4,169)                  -            (10,873)
                                                      -------------------------------   ----------------   -----------------
     Property & Equipment, net                                 808            1,799                -               2,607

Other Assets                                                     -                85                  -                  85
Goodwill, net                                                3,241                 5             22,202 (c)          25,448
                                                      -------------------------------   ----------------   -----------------

     Total Non-Current Assets                                4,049             1,889             22,202              28,140
                                                      -------------------------------   ----------------   -----------------
Total Assets                                            $    7,382        $    7,852       $     22,636       $      37,870
                                                      =============    ==============   ================   =================


LIABILITIES AND STOCKHOLDERS' EQUITY:
Revolving line of credit                                $        -        $        -       $        990 (a)       $     990
Accounts Payable                                             1,139               639                  -               1,778
Accrued Expenses                                               333             1,402                112 (h)           1,847
Current Maturities of Long Term Debt                            82               502                831 (b)           1,415
Restructuring Accrual, Current Portion                           -               258                  -                 258
Other Current Liabilities                                       13                 -                  -                  13
                                                      -------------    --------------   ----------------   -----------------
      Total Current Liabilities                              1,567             2,801              1,933               6,301

Long Term Debt Obligations                                       -               592              2,075 (b)           2,667
Restructuring Accrual, Long Term Portion                         -               514                  -                 514
                                                                 -
Other Long Term Liabilities                                      -                 -                  -                   -
                                                      -------------    --------------   ----------------   -----------------
      Total Liabilities                                      1,567             3,907              4,008               9,482

Common Stock                                                 1,532                30                348 (e)           1,910
Addt. Paid-in Capital                                       33,631               600              2,595 (e)          36,826
Preferred Stock                                                  -                 -             19,000 (e)          19,000
Retained Earnings (Deficit)                               (29,172)             3,315            (3,315) (e)        (29,172)
                                                      -------------    --------------   ----------------   -----------------
                                                             5,991             3,945             18,628              28,564
Less: Treasury Stock and Other Contra Equity                  (176)                 -                  -               (176)
                                                      -------------    --------------   ----------------   -----------------
      Total Stockholders' Equity                             5,815             3,945             18,628              28,388
                                                      -------------    --------------   ----------------   -----------------
Total Liabilities and Shareholders' Equity              $    7,382        $    7,852       $     22,636       $      37,870
                                                      =============    ==============   ================   =================
</TABLE>

See notes to unaudited pro forma consolidated financial statements

<PAGE>


                           EDITEK AND MEDTOX
            UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS
                  Nine Months Ended September 30, 1995
                (In Thousands except per share amounts)


<TABLE>
<CAPTION>

                                                            Historical                              Proforma
                                                 ---------------------------------   ----------------------------------------

                                                     EDITEK           MEDTOX           Adjustments           Consolidated
                                                 ---------------------------------   -----------------     ------------------
<S>                                              <C>                <C>              <C>                   <C>
Revenues                                           $       5,663    $      15,351      $           -                  21,014
Cost of sales                                              4,800            6,925              1,985 (g)              13,710
                                                 ---------------------------------   -----------------     ------------------
       Gross margin                                          863            8,426             (1,985)                  7,304

Operating expenses
   Research and development                                  669                -                   -                    669
   Selling, general and administrative                     2,852            5,723              (1,985) (g)             6,590
   Amortization                                              111                -                 833 (d)                944
                                                 ---------------------------------   -----------------     ------------------
       Total operating expenses                                                               (1,152)
                                                           3,632            5,723                                      8,203

Income (loss) before interest
   and other income                                      (2,769)            2,703               (833)                  (899)

Other income                                                   -                1                   -                      1
Interest expense                                            (21)            (139)               (206) (b)              (366)
                                                 ---------------------------------   -----------------     ------------------
      Net income (loss)                                  (2,790)            2,565            (1,039)                  (1,264)
Preferred stock dividend                                       -                -             1,283   (f)              1,283
                                                 ---------------------------------   -----------------     ------------------

Net income (loss) applicable to common
    shareholders                                  $      (2,790)   $        2,565     $       (2,321)       $        (2,546)
                                                 =================================   =================     ==================

Income (Loss) per common share                    $       (0.28)   $        86.51                           $         (0.20)
                                                 =================================                         ==================

Weighted average number of common
     shares outstanding                                9,915,427           29,650                                 12,432,733
                                                 =================================                         ==================
</TABLE>

See notes to unaudited pro forma consolidated financial statements


<PAGE>

                           EDITEK AND MEDTOX
            UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS
                      Year Ended December 31, 1994
                (In Thousands except per share amounts)

<TABLE>
<CAPTION>

                                                                 Historical                             Proforma
                                                         ----------------------------    ---------------------------------------

                                                            EDITEK        MEDTOX            Adjustments          Consolidated
                                                         ----------------------------     ----------------     -----------------


<S>                                                      <C>             <C>              <C>                  <C>
Revenues                                                   $     6,593    $   19,651        $     37 (g)          $       26,281
Cost of sales                                                    6,044         8,714           2,635 (g)                  17,393
                                                         ----------------------------     ----------------     -----------------
       Gross margin                                                549        10,937           (2,598)                 8,888

Operating expenses
   Research and development                                        729             -                    -                   729
   Selling, general and administrative                           3,194         7,576              (2,617) (g)             8,153
   Amortization                                                    147             -                1,110 (d)             1,257
   Restructuring costs                                               -           568                    -                   568
                                                         ----------------------------     ----------------     -----------------
       Total operating expenses                                  4,070         8,144              (1,507)                10,707

Income (loss) before interest
   and other income                                            (3,521)         2,793              (1,091)               (1,819)
Other income                                                         -            19                 (19) (g)                 -
Interest income(expense)                                          (25)         (218)                (368) (a)             (611)
                                                         ----------------------------     ----------------     -----------------
      Net income (loss)                                        (3,546)         2,594              (1,478)               (2,430)

Preferred stock dividend                                             -             -                1,710 (f)             1,710
                                                         ----------------------------     ----------------     -----------------

Net income (loss) applicable to common
    shareholders                                          $    (3,546)   $     2,594            $ (3,188)       $        (4,140)
                                                         ============================     ================     =================
Income (Loss) per common share                            $     (0.49)  $     87.87                             $         (0.43)
                                                         ============================                          =================

Weighted average number of common
     shares outstanding                                      7,204,244        29,520                                  9,595,685
                                                         ============================                          =================
</TABLE>

See notes to unaudited pro forma consolidated financial statements

<PAGE>


                                          EDITEK AND MEDTOX
                                         NOTES TO UNAUDITED
                             PRO FORMA CONSOLIDATED FINANCIAL STATEMENTS


a) EDITEK was able to close the $24 million  acquisition of MEDTOX by raising
$19 million from the issuance of 380 shares of Preferred  Stock,  borrowing
approximately $5 million in the form of two term loans and a revolving line
of credit and  issuing $5  million  of Common  Stock of the  Company to the
shareholders of MEDTOX in the form of 2,517,306 shares of Common Stock. The
Company did not acquire  the cash on hand at MEDTOX at  September  30, 1995
and was required to pay off the existing loans of MEDTOX and  approximately
$1.2 million in financing costs.

                                       Cash and Cash Equivalents
                                      (dollar amounts in thousands)

     Proceeds from issuance of
     Series A Preferred Stock                   $19,000
     Proceeds from debt:
           Term Loans                             4,000
           Credit Facility                          990

     Compensation to Investment
     Bankers                                     ( 1,262)

     Compensation for Placement
     of Debt                                    (    165)

     Payment of MedTox Notes:
              Current Portion                   (    502)
              Long Term Portion                 (    592)

     Payment to MedTox
     Shareholders                                (18,500)

     MedTox distribution of cash
     on hand at Medtox                          (  2,035)
                                             --------------
                                               $      934

Reduction of $500 in other Current Assets represents deposit previously
paid to Medtox.

(b) Pro Forma adjustment to long term debt accounts are summarized as follows:

                                             Current         Long Term
                                             Portion         Portion

Elimination of Medtox's
  long term debt                            $ (502)          $  (592)
Issuance of term loans                       1,333             2,667
                                             -----------------------
                                            $  831           $ 2,075

The interest rates on the loans are as follows:

  Term Loan A            2.0% above Prime Rate
  Term Loan B            2.5% above Prime Rate
  Credit Facility        1.5% above Prime Rate


<PAGE>


c) Goodwill representing the excess of the purchase price of $24 million over
     the fair value of the  identifiable net assets of MedTox has been reflected
     and is comprised of the following:

                                         (dollar amounts in thousands)

Purchase price ............................................            $ 24,000
Costs related to acquisition ..............................                 400
Net assets acquired @ 9/30/95 .............................              (2,198)
                                                                       --------
                                                                       $ 22,202

     The  allocation of the total amount of excess  purchase price over the fair
     value of the assets is a  preliminary  allocation  absent an  appraisal  of
     certain intangible assets.

d) Amortization is based on an effective date of the acquisition of MEDTOX of
     January 1, 1994 amortized over a twenty year period.

e) Pro Forma  adjustment to  stockholder's  equity accounts are summarized as
follows:

<TABLE>
<CAPTION>

                                                      (dollar amounts in thousands)
                                                                        Additional
                                            Common      Preferred        Paid In         Retained
                                            Stock         Stock          Capital         Earnings

<S>                                     <C>           <C>           <C>               <C>        
Elimination of MEDTOX'S equity accounts $       (30)  $         -   $         (600)   $   (3,315)
Issuance of Preferred Stock                        -         19,000          (1,427)           -
Issuance of Common Stock                         378           -              4,622           -
                                         -----------   ---------    ----------------  ----------
                                         $       348   $ 19,000     $        2,595    $  ( 3,315)

</TABLE>

f) Dividend of 9%  declared  for $19 million of  Preferred  Stock  issued and
outstanding.

g) Adjustments   to  reclassify   certain   expenses  of  MEDTOX,   including
     distribution  expenses to conform with the historical  presentation  of the
     financial statements of EDITEK. These  reclassifications  have no impact on
     the operating income of MEDTOX.


h)  Adjustment  to  reflect  Acquisition  costs are  expected  to  approximate
$400,000.


<PAGE>





<PAGE>




             AMENDED CERTIFICATE OF DESIGNATIONS OF PREFERRED STOCK
                                       OF
                                  EDITEK, INC.

     Pursuant to Section 151 of the Delaware  Corporation Law,  EDITEK,  Inc., a
Delaware  corporation  (the  "Corporation"),  does hereby  submit  this  Amended
Certificate of  Designations  of Preferred Stock for the purpose of amending the
powers,  preferences,  limitations  and  rights  of  the  Series  A  Convertible
Preferred Stock of the  Corporation,  as determined by the Board of Directors of
the Corporation  pursuant to the authority vested in it by the provisions of the
Certificate of  Incorporation  of the Corporation and as originally set forth in
the  Certificate  of  Designations  of  Preferred  Stock filed with the Delaware
Secretary of State on January 10, 1996.  There have been no shares of the Series
A Convertible Preferred Stock issued.

     The Board of Directors of the Corporation unanimously adopted the following
resolutions,  effective  as of  January  25,  1996,  with  respect to up to Four
Hundred Eighty (480) shares of Series A Convertible  Preferred  Stock, par value
$1.00 per share, of the Corporation:

     RESOLVED:

          The Series A  Convertible  Preferred  Stock of the  Corporation  shall
     consist  of Four  Hundred  Eighty  (480)  shares  of  Series A  Convertible
     Preferred Stock, par value $1.00 per share ("Series A Stock"),  the powers,
     preferences,   privileges,   rights,   qualifications,    limitations   and
     restrictions of which are as follows:

          Section 1.Dividends.

          On December  31st of each year  commencing  on December  31,  1996,  a
     dividend equal to Four Thousand Five Hundred Dollars  ($4,500.00) per share
     shall accrue on each share of Series A Stock issued and outstanding on such
     date.  Such  dividend  shall  be  payable  out of funds  legally  available
     therefor,   when  and  as  declared  by  the  Board  of  Directors  of  the
     Corporation.  Such  dividends  are  hereinafter  referred to as  "Preferred
     Dividends." Preferred Dividends which accrue on or before December 31, 1997
     shall be cumulative,  but Preferred  Dividends  accruing after December 31,
     1997 shall not be cumulative.  No dividends  shall be payable on the shares
     of Common Stock of the  Corporation  (the "Common Stock") until all accrued
     cumulative  Preferred Dividends have been fully paid. The Corporation shall
     have no  obligation  to pay any dividend  until the dividend is declared by
     the Board of Directors of the Corporation.

          Section 2.Liquidation, Dissolution or Winding Up.

          (a) (i) In the event of any liquidation,  dissolution or winding up of
     the  Corporation,   whether  voluntary  or  involuntary,   the  holders  of
     outstanding shares of Series A Stock,  subject to the provisions of Section
     2(b)  hereof,  shall  be  entitled  to be  

<PAGE>


     paid out of the assets of the  Corporation  available for  distribution  to
     stockholders,  whether such assets are capital,  surplus, or earnings,  and
     before any additional  payment shall be made to the holders of any class of
     Common  Stock  or of  any  other  class  or  series  of  stock  ranking  on
     liquidation  junior to the Series A Stock,  a liquidation  preference in an
     amount,  for each  share of Series A Stock  held,  equal to Fifty  Thousand
     Dollars  ($50,000.00),  plus all  accrued but unpaid  cumulative  Preferred
     Dividends and all accrued noncumulative  Preferred Dividends that have been
     declared but which remain unpaid (the "Series A Liquidation Preference").

               (ii) If, upon any  liquidation,  dissolution or winding up of the
     Corporation,  the  assets  to be  distributed  pursuant  to  the  Series  A
     Liquidation  Preference  set forth  above shall be  insufficient  to permit
     payment  in full of such  Series A  Liquidation  Preference  and the Parity
     Preferred Liquidation  Preference which may be payable to holders of Parity
     Preferred Stock (both as defined in subsection (b) below),  then the Series
     A Liquidation  Preference shall entitle the holders of Series A Stock to be
     distributed  that portion of the assets  available for  distribution as (x)
     the Series A  Liquidation  Preference  bears to (y) the sum of the Series A
     Liquidation  Preference plus the Parity  Preferred  Liquidation  Preference
     (which amount shall be distributed pro rata to each owner of Series A Stock
     based on the number of shares owned by each).

               (iii)After payment in full of the Series A Liquidation Preference
     and the  Parity  Preferred  Liquidation  Preference  payable  to holders of
     Parity Preferred Stock (as defined in subsection (b) below) (or after funds
     necessary for such payment shall have been set aside by the  Corporation in
     trust  for the  account  of such  holders  so as to be  available  for such
     payment),   any  assets  remaining  available  for  distribution  shall  be
     distributed  to the  holders of the Common  Stock  and/or  other  series or
     classes of stock, and no further  distribution shall be made to the holders
     of Series A Stock.

          (b) The  Corporation  shall have the right to create a series or class
     (or  series  or  classes)  of  Preferred  Stock  of  the  Corporation  with
     liquidation  rights and  preferences  which are equal,  but not senior,  to
     those  of the  Series  A  Stock,  and  the  Series  A Stock  shall  rank in
     liquidation on a parity with any such series or class of preferred stock of
     the  Corporation  ("Parity  Preferred  Stock")  to the extent of the Parity
     Preferred  Liquidation  Preference  if the rights of such Parity  Preferred
     Stock  indicate  that it is equal to the Series A Stock.  The term  "Parity
     Preferred  Liquidation  Preference"  shall  mean the sum of (i) the  lowest
     purchase  price  paid  to the  Corporation  upon  issuance  of  the  Parity
     Preferred  Stock,  plus  (ii) all  accrued  cumulative  dividends  (up to a
     maximum  annual  dividend  per share of nine  percent  (9%) of the purchase
     price per share of the Parity  Preferred  Stock)  payable to the holders of
     the Parity Preferred Stock ("Parity  Dividends")  which remain unpaid,  and
     all accrued  noncumulative  Parity  Dividends  that have been  declared but
     which remain unpaid.

          (c) A  consolidation  or  merger  of  the  Corporation  (other  than a
     subdivision,  combination,  reclassification or exchange of shares provided
     for elsewhere in Section 4 hereof) or a sale of all or substantially all of
     the  assets  of the  Corporation  (other  than a 

<PAGE>



     transaction  to which the provisions of Section 4(e) hereof apply) shall be
     regarded as a liquidation,  dissolution or winding up of the affairs of the
     Corporation within the meaning of this Section 2; provided,  however, that,
     except  in the  case  of a sale of  substantially  all  the  assets  of the
     Corporation,  each  holder of Series A Stock  shall have the right to elect
     the benefits of the  provisions of Section 4(e) hereof in lieu of receiving
     payment  in  liquidation,  dissolution  or  winding  up of the  Corporation
     pursuant  to this  Section  2. For  purposes  of this  Section 2, a sale of
     substantially all of the assets of the Corporation  shall include,  without
     limitation,  the sale or other disposition of more than 50% of such assets,
     as determined  by reference to either (i) the book value,  or (ii) the fair
     market value, of such assets.

          (d) In the event of a  liquidation,  dissolution  or winding up of the
     Corporation  resulting  in the  availability  of assets other than cash for
     distribution  to the  holders  of Series A Stock,  the  holders of Series A
     Stock shall be entitled to a  distribution  of cash and/or  assets equal in
     value to the Series A Liquidation Preference,  subject to the provisions of
     Section 2(a). In the event that such  distribution to the holders of Series
     A Stock shall include any assets other than cash, the Board of Directors of
     the Corporation  shall determine the value of such assets to be distributed
     for such  purpose  and shall  notify all  holders of Series A Stock of such
     determination.  The value of such assets for  purposes of the  distribution
     under this  Section 2(d) shall be the value as  determined  by the Board of
     Directors of the Corporation in good faith. The  determination of the Board
     of Directors shall be final and binding.

          Section 3.Voting Power.  Except as otherwise expressly provided herein
     or as required  by law,  the holders of Series A Stock shall have no voting
     power,  and the holders of the Common Stock shall  exclusively  possess all
     voting power for the election of directors and for all other purposes.

          Section  4.Conversion.The  holders  of Series A Stock  shall  have the
     following conversion rights:

          (a) Subject to and in compliance  with the  provisions of this Section
     4, during the  Conversion  Period (as defined in Section  4(c)  hereof),  a
     share of Series A Stock may be converted into fully-paid and  nonassessable
     shares of Common  Stock.  The  number of shares of Common  Stock to which a
     holder  of  Series  A Stock  shall be  entitled  upon  conversion  shall be
     obtained by  multiplying  the  Applicable  Conversion  Rate  (determined as
     provided in Section  4(b) hereof) by the number of shares of Series A Stock
     being converted.

          (b) The number of shares of Common Stock  issuable upon  conversion of
     each share of the Series A Stock (the "Applicable  Conversion  Rate") shall
     equal  the  quotient  obtained  by  dividing  (i)  Fifty  Thousand  Dollars
     ($50,000.00)  by (ii) 75% of the Market Price per share of the Common Stock
     on the Conversion Date (as defined in Section 4(f) below).  Notwithstanding
     the  foregoing,  in no event shall the Applicable  Conversion  Rate be less
     than the number of shares of Common Stock equal to the quotient obtained by

<PAGE>


     dividing (i) Fifty Thousand  Dollars  ($50,000.00) by (ii) $2.775.  "Market
     Price" shall mean for this  purpose the daily  average for the five trading
     days  immediately  prior to the First Issuance Date or the Conversion Date,
     as the case may be, of the closing bid prices quoted on the American  Stock
     Exchange,  Nasdaq  National Market System or other  securities  exchange on
     which the Common Stock is traded.

          (c) A holder of Series A Stock shall have no right to convert Series A
     Stock into Common Stock (A) from the date the first share of Series A Stock
     is  issued  by the  Corporation  (the  "First  Issuance  Date")  until  the
     beginning  of the  Conversion  Period  (as  defined  below),  and  (B)  all
     conversion rights terminate and the Series A Stock ceases to be convertible
     on the  second  anniversary  of the First  Issuance  Date (the  "Conversion
     Termination  Date").  The  period  commencing  on the  sixtieth  (60th) day
     following the First Issuance Date and ending on the Conversion  Termination
     Date shall be referred to herein as the "Conversion  Period." All shares of
     Series A Stock not theretofore  converted shall  automatically be converted
     into  shares  of  Common  Stock on the last day of the  Conversion  Period,
     unless  prior to 5:00 P. M. on the last day of the  Conversion  Period  the
     holder of such shares of Series A Stock  delivers to the principal  offices
     of the Corporation  written notice executed by such holder  instructing the
     Corporation  not to  convert  the  Series  A  Stock  of  such  holder.  The
     Corporation   shall  not  be   required  to  deliver   stock   certificates
     representing  shares of Common  Stock  until  the  holder of the  converted
     Series A Stock  surrenders the stock  certificates  evidencing the Series A
     Stock as required by Section 4 (f) hereof.  In determining the commencement
     of a  holder's  right  to  convert  shares  of  Series  A  Stock,  the  day
     immediately following the First Issuance Date shall be counted as the first
     day.

          (d) If, during the Conversion  Period,  the Common Stock issuable upon
     the  conversion  of the Series A Stock  shall be  changed  into the same or
     different  number of shares of any class or  classes  of stock,  whether by
     reclassification  or  otherwise  (other  than  a  reorganization,   merger,
     consolidation  or sale of assets provided for elsewhere in this Section 4),
     then and in each  such  event the  holder  of each  share of Series A Stock
     shall have the right  thereafter  to  convert  such share into the kind and
     amount of shares of stock and other securities and property receivable upon
     such  reorganization,  reclassification  or other change, by holders of the
     number of shares of Common  Stock into which such Series A Stock might have
     been converted  immediately prior to such reorganization,  reclassification
     or change.

          (e) If at any time or from time to time during the  Conversion  Period
     there shall be a capital  reorganization  of the Common Stock (other than a
     reclassification  or  exchange of shares  provided  for  elsewhere  in this
     Section 4) or a merger or  consolidation  of the  Corporation  with or into
     another  Corporation,  then,  as a  part  of  and  as a  condition  to  the
     effectiveness of such reorganization,  merger or consolidation,  lawful and
     adequate  provision  shall  be made so that if the  Corporation  is not the
     surviving corporation, any shares of Series A Stock shall be converted into
     preferred stock of the surviving  corporation ("New  Corporation  Preferred
     Stock") having equivalent preferences,  rights and privileges to the Series
     A Stock, except that in lieu of being able to convert into 

<PAGE>


     shares of Common Stock, the holders of the New Corporation  Preferred Stock
     shall  thereafter  be  entitled  to  receive  upon  conversion  of the  New
     Corporation  Preferred  Stock  the  number  of  shares  of  stock  or other
     securities or property of the  Corporation or of the successor  corporation
     resulting  from  such  merger  or  consolidation,  to which a holder of the
     number of shares of Common Stock  deliverable upon conversion of the Series
     A  Stock   immediately  prior  to  the  capital   reorganization,   merger,
     consolidation   or  sale  would  have  been   entitled   on  such   capital
     reorganization, merger or consolidation.

          Each  holder  of  Series A Stock  upon  the  occurrence  of a  capital
     reorganization,  merger or  consolidation of the Corporation as such events
     are more fully set forth in the first paragraph of this Section 4(e), shall
     have the option of electing  treatment of the shares of Series A Stock held
     by such holder  under  either this  Section  4(e) or Section  2(c)  hereof,
     except as otherwise provided in said Section 2(c), notice of which election
     shall be submitted in writing to the  Corporation at its principal  offices
     no later  than ten (10)  days  before  the  effective  date of such  event,
     provided  that any such notice  shall be  effective if given not later than
     fifteen (15) days after the date of the Corporation's  notice,  pursuant to
     Section 6, with respect to such event.

          (f) To exercise the conversion  privilege,  a holder of Series A Stock
     shall  surrender the certificate or  certificates  representing  the shares
     being converted to the Corporation at its principal office,  and shall give
     written  notice  (which  notice  may be  made  by fax,  telecopy  or  other
     electronic transmission) to the Corporation at that office that such holder
     elects to convert  such  shares.  Such notice  shall also state the name or
     names (with address or addresses) in which the  certificate or certificates
     for shares of Common Stock issuable upon such  conversion  shall be issued.
     The  certificate or certificates  for shares of Series A Stock  surrendered
     for conversion  shall be accompanied  by proper  assignment  thereof to the
     Corporation  or in blank.  The date when such written notice is received by
     the Corporation shall be the "Conversion Date" with respect to such shares.
     Within three (3) trading days after the Conversion  Date,  the  Corporation
     shall issue and shall deliver to the holder of the shares of Series A Stock
     being  converted,  or on written order from such holder,  a certificate  or
     certificates  as such  holder may  request for the number of full shares of
     Common Stock  issuable upon the conversion of such shares of Series A Stock
     in accordance with the provisions of this Section 4 and cash as provided in
     Section  4(g),  in  respect  of any  fraction  of a share of  Common  Stock
     issuable upon such  conversion;  provided,  however,  that the  Corporation
     shall not be required to deliver stock certificates  representing shares of
     Common Stock until its receipt of the surrendered  stock  certificates  for
     the Series A Stock from the holder of the  converted  Series A Stock.  Such
     conversion shall be deemed to have been effected  immediately  prior to the
     close of business on the  Conversion  Date,  and at such time the rights of
     the holder as holder of the converted  shares of Series A Stock shall cease
     and the  person  or  persons  in whose  name or names  any  certificate  or
     certificates  for  shares  of  Common  Stock  shall be  issuable  upon such
     conversion  shall be deemed to have  become the holder or holders of record
     of shares of Common Stock represented thereby.

          (g) No  fractional  shares  of  Common  Stock  or  scrip  representing
     fractional  

<PAGE>


     shares shall be issued upon  conversion  of Series A Stock.  Instead of any
     fractional  shares of Common Stock which would  otherwise be issuable  upon
     conversion of Series A Stock,  the  Corporation  shall pay to the holder of
     the shares of Series A Stock  which were  converted  a cash  adjustment  in
     respect of such  fraction  in an amount  equal to the same  fraction of the
     Market Price (as defined in Section  4(b)) per share of the Common Stock on
     the Conversion Date.

          (h) In the  event  some but not all of the  shares  of  Series A Stock
     represented  by a certificate or  certificates  surrendered by a holder are
     converted,  the Corporation shall execute and deliver to or on the order of
     the  holder,  at  the  expense  of  the  Corporation,   a  new  certificate
     representing  the  number  of  shares  of  Series  A Stock  which  were not
     converted.

          (i) The  Corporation  shall at all times during the Conversion  Period
     reserve and keep  available out of its  authorized  but unissued  shares of
     Common  Stock,  solely for the purpose of effecting  the  conversion of the
     shares of Series A Stock,  such  number  of its  shares of Common  Stock as
     shall  from time to time be  sufficient  to effect  the  conversion  of all
     outstanding  shares  of  Series A Stock,  and if at any time the  number of
     authorized  but unissued  shares of Common Stock shall not be sufficient to
     effect the conversion of all then outstanding shares of Series A Stock, the
     Corporation  shall take such corporate action as may, in the opinion of its
     counsel,  be necessary to increase its  authorized  but unissued  shares of
     Common  Stock to such  number  of shares  as shall be  sufficient  for such
     purpose.

          Section 5.No Reissuance of Series A Stock.No share or shares of Series
     A Stock  acquired by the  Corporation  by reason of  redemption,  purchase,
     conversion  or otherwise  shall be  reissued,  and all such shares shall be
     cancelled,  retired,  and eliminated  from the shares which the Corporation
     shall be authorized to issue.  The  Corporation  may from time to time take
     such  appropriate  corporate  action  as may be  necessary  to  reduce  the
     authorized number of shares of Series A Stock accordingly.

          Section  6.Notices  of Record  Date.In  the event (a) the  Corporation
     establishes  a  record  date to  determine  the  holders  of any  class  of
     securities who are entitled to receive any dividend or other  distribution,
     or (b) there  occurs any capital  reorganization  of the  Corporation,  any
     reclassification   or   recapitalization   of  the  capital  stock  of  the
     Corporation,  any  merger  or  consolidation  of the  Corporation,  and any
     transfer of all or  substantially  all of the assets of the  Corporation to
     any other  corporation,  or any other entity or person, or any voluntary or
     involuntary dissolution,  liquidation or winding up of the Corporation, the
     Corporation  shall  mail to each  holder of Series A Stock at least  twenty
     (20) days prior to the record date specified  therein,  a notice specifying
     (i) the  date of such  record  date for the  purpose  of such  dividend  or
     distribution and a description of such dividend or  distribution,  (ii) the
     date  on  which  any  such  reorganization,   reclassification,   transfer,
     consolidation,  merger, dissolution,  liquidation or winding up is expected
     to become effective, and (iii) the time, if any, that is to be fixed, as to
     when the holders of record of Common Stock (or other  securities)  

<PAGE>


     shall be  entitled  to  exchange  their  shares of  Common  Stock (or other
     securities)  for  securities  or  other  property   deliverable  upon  such
     reorganization,    reclassification,   transfer,   consolidation,   merger,
     dissolution, liquidation or winding up.

          Section  7.No  Preemptive  Rights.The  holders of Series A Stock shall
     have no preemptive  rights or other right to purchase  additional shares of
     capital  stock or other  securities of the  Corporation  by reason of their
     ownership  of shares of Series A Stock,  except as may from time to time be
     specified in a written  contract  between such  holder(s) of Series A Stock
     and the Corporation.

          Section 8.Other  Rights.Except as otherwise  provided herein or in the
     Certificate of  Incorporation,  each share of Series A Stock and each share
     of Common  Stock shall be identical  in all  respects,  shall have the same
     powers,  preferences  and rights,  without  preference of any such class or
     share over any other such class or share,  and shall be treated as a single
     class of stock for all purposes.


     IN  WITNESS  WHEREOF,  the  Corporation  has  caused  this  Certificate  of
Designations  to be executed on its behalf by James D. Skinner,  its  President,
and Peter J. Heath, its Secretary,  as of this 25th day of January, 1996, hereby
declaring and certifying  that this is the act and deed of the  Corporation  and
that the facts stated herein are true.

                         EDITEK, INC.

[CORPORATE SEAL]

                         By:   /s/ James D. Skinner
                         James D. Skinner

ATTEST:


   /s/ Peter J. Heath
Peter J. Heath, Secretary







<PAGE>






                    ASSET PURCHASE AGREEMENT



                             Between



                          EDITEK, INC.



                               and



                    MEDTOX LABORATORIES, INC.







                  Dated Effective July 1, 1995


<PAGE>

                        TABLE OF CONTENTS

ARTICLE I      ASSET SALE. . . . . . . . . . . . . . . . . . .  1

     Section 1.1    Asset Sale . . . . . . . . . . . . . . . .  1
     Section 1.2    Affiliates . . . . . . . . . . . . . . . .  1

ARTICLE II     LIABILITIES . . . . . . . . . . . . . . . . . .  1

     Section 2.1    Assumed Liabilities. . . . . . . . . . . .  1
     Section 2.2    Retained Liabilities . . . . . . . . . . .  2
     Section 2.3    Litigation Administration. . . . . . . . .  2

ARTICLE III    CONSIDERATION PAYABLE BY PURCHASER. . . . . . .  3

     Section 3.1    Purchase Price . . . . . . . . . . . . . .  3

ARTICLE IV     CLOSING . . . . . . . . . . . . . . . . . . . .  3

     Section 4.1    Closing. . . . . . . . . . . . . . . . . .  3
     Section 4.2    Conditions to Each Party's Obligation to
                    Close. . . . . . . . . . . . . . . . . . .  4
     Section 4.3    Conditions to Obligation of Seller to
                    Close. . . . . . . . . . . . . . . . . . .  4
     Section 4.4    Conditions to Obligation of Purchaser to
                    Close. . . . . . . . . . . . . . . . . . .  5

ARTICLE V      REPRESENTATIONS AND WARRANTIES OF PURCHASER . .  6

     Section 5.1    Corporate Organization and Good
                    Standing . . . . . . . . . . . . . . . . .  6
     Section 5.2    Authorization; Binding Agreement . . . . .  6
     Section 5.3    Certain Fees . . . . . . . . . . . . . . .  7

ARTICLE VI     REPRESENTATIONS AND WARRANTIES OF SELLER. . . .  7

     Section 6.1    Corporate Organization and Good
                    Standing . . . . . . . . . . . . . . . . .  7
     Section 6.2    Authorization; Binding Agreement . . . . .  8
     Section 6.3    Capitalization of Seller . . . . . . . . .  8
     Section 6.4    Subsidiaries; Investments. . . . . . . . .  8
     Section 6.5    Financial Statements . . . . . . . . . . .  8
     Section 6.6    Absence of Certain Changes . . . . . . . .  9
     Section 6.7    Certain Fees . . . . . . . . . . . . . . .  9
     Section 6.8    Consents and Approvals; No Violations. . .  9
     Section 6.9    Litigation . . . . . . . . . . . . . . . . 10
     Section 6.10   Certain Employment Matters . . . . . . . . 10
     Section 6.11   Employee Benefit Plans . . . . . . . . . . 11
     Section 6.12   Tax Matters. . . . . . . . . . . . . . . . 14
     Section 6.13   Assets.. . . . . . . . . . . . . . . . . . 14
     Section 6.14   Intellectual Property. . . . . . . . . . . 15
     Section 6.15   Contracts, Minutes and Other Instruments
                    and Information. . . . . . . . . . . . . . 15
     Section 6.16   Permits and Licenses . . . . . . . . . . . 15

<PAGE>

     Section 6.17   Real Property; Environmental Matters . . . 16
     Section 6.18   Related Party Transactions . . . . . . . . 17
     Section 6.19   Customers. . . . . . . . . . . . . . . . . 17
     Section 6.20   Insurance. . . . . . . . . . . . . . . . . 17
     Section 6.21   Material Statements or Omissions . . . . . 17

ARTICLE VII    CONDUCT OF BUSINESS PENDING THE CLOSING . . . . 18

     Section 7.1    Conduct of Business by Seller Pending the
                    Closing. . . . . . . . . . . . . . . . . . 18
     Section 7.2    Enforcement. . . . . . . . . . . . . . . . 20

ARTICLE VIII   ADDITIONAL AGREEMENTS . . . . . . . . . . . . . 20

     Section 8.1    Access to Information. . . . . . . . . . . 20
     Section 8.2    Shareholders' Approval . . . . . . . . . . 20
     Section 8.3    Employees. . . . . . . . . . . . . . . . . 21
     Section 8.4    Expenses . . . . . . . . . . . . . . . . . 21
     Section 8.5    Agreement to Cooperate . . . . . . . . . . 21
     Section 8.6    Public Statements. . . . . . . . . . . . . 21
     Section 8.7    Allocation of Purchase Price . . . . . . . 22

ARTICLE IX     POST CLOSING COVENANTS. . . . . . . . . . . . . 22

     Section 9.1    Names and Marks. . . . . . . . . . . . . . 22
     Section 9.2    Trade Secrets. . . . . . . . . . . . . . . 22
     Section 9.3    Good Will and Customers. . . . . . . . . . 22
     Section 9.4    Noncompetition . . . . . . . . . . . . . . 23
     Section 9.5    Contract Rights. . . . . . . . . . . . . . 23
     Section 9.6    Title; Liens; Assignments. . . . . . . . . 23

ARTICLE X      TERMINATION, AMENDMENT AND WAIVER . . . . . . . 23

     Section 10.1   Termination. . . . . . . . . . . . . . . . 23
     Section 10.2   Effect of Termination. . . . . . . . . . . 24
     Section 10.3   Amendment. . . . . . . . . . . . . . . . . 24
     Section 10.4   Waiver . . . . . . . . . . . . . . . . . . 24

ARTICLE XI     CONFIDENTIALITY . . . . . . . . . . . . . . . . 24

     Section 11.1   Confidential Information . . . . . . . . . 24

ARTICLE XII    INDEMNIFICATION . . . . . . . . . . . . . . . . 25

     Section 12.1   Indemnification. . . . . . . . . . . . . . 25
     Section 12.2   Indemnification of Seller. . . . . . . . . 26
     Section 12.3   Other Remedies . . . . . . . . . . . . . . 27
     Section 12.4   Setoff . . . . . . . . . . . . . . . . . . 27
     Section 12.5   Knowledge of Breach. . . . . . . . . . . . 27

                                  ii

<PAGE>

ARTICLE XIII   GENERAL PROVISIONS. . . . . . . . . . . . . . . 28

     Section 13.1   Survival of Representations, Warranties
                    and Agreements . . . . . . . . . . . . . . 28
     Section 13.2   Notices. . . . . . . . . . . . . . . . . . 28
     Section 13.3   Miscellaneous. . . . . . . . . . . . . . . 29
     Section 13.4   Dispute Resolution . . . . . . . . . . . . 29
     Section 13.5   Counterparts . . . . . . . . . . . . . . . 30
     Section 13.6   Parties in Interest. . . . . . . . . . . . 30



Disclosure Schedules

Exhibit A -    Escrow Agreement with Henson & Efron, P.A. as
               Escrow Agent (3.1 (a))
Exhibit B -    Escrow Agreement with Petree Stockton, L.L.P as
               Escrow Agent (3.1 (b))
Exhibit C -    Form of Opinion of Petree Stockton, L.L.P. (4.3
               (b))
Exhibit D -    Form of Opinion of Henson & Efron, P. A. (4.4 (b))
Exhibit E -    Form of Noncompetition Agreements (4.4 (f))
Exhibit F-     Financial Statements of Seller (6.5)
Exhibit G -    Form of Opinion of Henson & Efron, P. A. (8.2)
                                  iii
<PAGE>

                    ASSET PURCHASE AGREEMENT

     AGREEMENT, dated effective July 1, 1995 (the "Agreement"),
between EDITEK, Inc., a Delaware corporation ("Purchaser") and
MedTox Laboratories, Inc., a Minnesota corporation ("Seller").

     WHEREAS, Seller desires to sell to Purchaser all the assets of
Seller, and Purchaser desires to purchase all the assets of Seller,
pursuant to the terms and conditions set forth in this Agreement.

     NOW, THEREFORE, in consideration of the premises and the
representations, warranties, covenants and agreements contained
herein, the parties hereto, intending to be legally bound hereby,
agree as follows:


                            ARTICLE I
                           ASSET SALE

     Section 1.1    Asset Sale.  Seller agrees to sell, and
Purchaser agrees to purchase, all the tangible and intangible
assets (other than cash in bank accounts) owned by Seller as of the
Closing Date (as hereinafter defined), including, without
limitation, all accounts receivable, all inventory, equipment,
contracts, leases, subleases, licenses, customer and supplier
lists, business records (other than Seller's minute books and stock
ledger), trade secrets, tradenames and marks and other intellectual
property (collectively, the "Assets").  Schedule 1.1 hereto
contains a list of all Assets of Seller on May 31, 1995.  Until the
Closing Date Seller shall not incur any liabilities or transfer any
Assets without the prior consent of Purchaser, which shall not
unreasonably be withheld, except that Seller may sell inventory and
incur trade payables in the ordinary course of business consistent
with its prior practices as explained to Purchaser.  All assets to
be sold by Seller hereunder, whether or not listed on Schedule 1.1
hereto, are hereinafter referred to as the "Assets." 

     Section 1.2    Affiliates.  The term "Affiliates" shall mean
all of the current officers and directors of Seller.

                           ARTICLE II
                           LIABILITIES

     Section 2.1    Assumed Liabilities.  In addition to payment of
the purchase price payable pursuant to Section 3.1, Purchaser shall
undertake and assume on the Closing Date (as hereinafter defined)
to satisfy, perform or discharge, to the extent not satisfied,
performed, paid or discharged prior to the Closing Date, the
following liabilities and obligations of Seller (the "Assumed
Liabilities") to the extent such liabilities are not retained
liabilities covered by Section 2.2 hereof:

<PAGE>

          (a)  All contractual liabilities and obligations of
Seller set forth on, reflected on or reserved against the unaudited
balance sheet of Seller furnished pursuant to Section 6.5 below,
including without limitation all trade payables, bank debt and
other long term liabilities;

          (b)  All contractual liabilities and obligations of
Seller accruing on or after the Closing Date or the performance of
which arises on or after the Closing Date under agreements, leases,
contracts and commitments (i) which are disclosed to Purchaser
pursuant to Section 6.15, or (ii) which are (A) entered into in the
ordinary course of Seller's business (or are consented to by
Purchaser) after the date hereof and prior to the Closing Date and
(B) if it is "material" (as defined in Section 6.15 hereof), it is
disclosed in writing to Purchaser at or prior to the Closing Date;
and

          (c)  All obligations of Seller under the Change in
Control and Employment Agreements set forth in Disclosure Schedule
2.1(c) ("Employee Agreements") for employees who are terminated by
Seller immediately prior to the Closing, provided that no
obligation of Seller is assumed by Purchaser under this Section 2.1
with respect any claim by any employee of Seller that the
termination of employment with Seller constitutes a termination of
employment for purposes of Section 3 of any such Employee
Agreement, unless Purchaser shall fail to offer to employ such
employee on terms that would not constitute a "Good Reason" as
defined in the Employee Agreements.

     Section 2.2    Retained Liabilities.  Except as provided in
Section 2.1 hereof, Purchaser assumes no liabilities of Seller and
Seller retains all its liabilities, including, without limitation:

          (a)  all federal, state and other income, withholding,
social security, workman's compensation and similar tax liabilities
of Seller and any associated interest or penalties;

          (b)  all liability for any lawsuits and claims asserted
against Seller, disclosed pursuant to Sections 6.9 and 6.10; and

          (c)  all liability for any law suits, claims or
administrative actions arising out of, or related to, acts or
omissions of Seller prior to the Closing, whether or not asserted
prior to the Closing and whether or not disclosed to Purchaser,
whether based on breach of contract, tort, fiduciary duty, strict
liability or any other theory, except suits to collect contractual
obligations assumed by Purchaser pursuant to Section 2.2 hereof.

     Section 2.3    Litigation Administration.  The parties agree
that defending suits, claims and actions may be difficult for
Seller after the Closing due to the Seller ceasing to conduct an
active business.  Solely to facilitate defense by Seller of any


                                  2
<PAGE>

minor suits, claims or actions for which Seller has retained
liability hereunder, until the first anniversary of the Closing,
Purchaser will, upon written request by Seller, assist Seller to
defend any suit, claim or action with potential liability of less
than Twenty Five Thousand ($25,000) for any single suit, claim or
action, provided that all such suits, claims and actions in the
aggregate do not exceed Fifty Thousand ($50,000) Dollars.  Seller
shall pay to Purchaser all reasonable amounts incurred by Purchaser
in defense or settlement of any matter on which Seller requests
assistance as provided herein.  At the option of Purchaser,
Purchaser may have such amounts paid to it from the Escrowed
Purchase Price.


                           ARTICLE III
               CONSIDERATION PAYABLE BY PURCHASER

     Section 3.1    Purchase Price.  In addition to assumption of
the Assumed Liabilities, Purchaser shall pay Seller an aggregate
purchase price of Twenty-Four Million ($24,000,000) Dollars for the
Assets, as follows:

          (a)  Upon execution hereof, $500,000 earnest money,
deposited into escrow with legal counsel to Seller, as escrow
agent, to be held pursuant to the terms of the Escrow Agreement
attached hereto as Exhibit A, and delivered to Seller, together
with any interest or other income therefrom, upon the closing of
the transactions contemplated herein;

          (b)  At Closing, the sum of $500,000 to be deposited in
escrow (the "Escrowed Purchase Price") with legal counsel to
Purchaser to be held and delivered pursuant to the terms of the
Escrow Agreement attached hereto as Exhibit B; and

          (c)  At Closing, the remainder of the Purchase Price
shall be paid by wire transfer to Seller's bank account in
Minneapolis, Minnesota.


                           ARTICLE IV
                             CLOSING

     Section 4.1    Closing.  The Closing for the transactions
contemplated hereby shall be held on a date designated by Purchaser
within twenty (20) business days following approval of the
transactions contemplated hereby by the stockholders of the
Purchaser (but no later than the Seller Termination Date if Seller
exercises its termination rights under Section 10.1 hereof) or on
another mutually agreeable date (the "Closing Date") at a location
and time mutually agreeable to the parties.

                                  3
<PAGE>

     At the Closing, Seller shall deliver to Purchaser such bills
of sale, deeds, assignments and such other instruments of
conveyance as shall be effective to vest in Purchaser good and
marketable title to the Assets, free and clear of all liens, claims
and encumbrances, other than Permitted Liens (as defined in Section
4.4 (c)).  Seller shall from and after the Closing Date, upon
request of Purchaser, execute, acknowledge and deliver, or cause to
be, executed, acknowledged or delivered, all such further acts,
deeds, assignments, transfers or conveyances as may be reasonably
required to assign, transfer, grant or convey to Purchaser, or to
aid in reducing to possession of Purchaser, title to and possession
of Purchaser, title to or possession of any of the Assets to be
transferred pursuant to this Agreement.

     Section 4.2    Conditions to Each Party's Obligation to Close. 
The respective obligations of each party to close the transactions
contemplated by this Agreement shall be subject to the fulfillment
at or prior to the Closing of the following conditions:

          (a)  This Agreement and the transactions contemplated
hereby shall have been approved and adopted by the requisite vote
of the shareholders and the Board of Directors of Seller and the
Board of Directors of Purchaser and the shareholders of Purchaser
shall have approved of the issuance of securities required to
finance the purchase of the Assets, under applicable law and
applicable listing requirements;

          (b)  No preliminary or permanent injunction or other
order or decree by any court which prevents the consummation of the
transactions contemplated hereby shall have been issued and remains
in effect (each party agreeing to use all best efforts to have any
such injunction, order or decree lifted); and

          (c)  All governmental consents and approvals required by
law for the consummation of the transactions contemplated hereby
shall have been obtained and be in effect on the Closing Date on
terms and conditions that would not have a material adverse effect
on the prospects of the business operated by Seller.

     Section 4.3    Conditions to Obligation of Seller to Close. 
The obligation of Seller to close the transactions contemplated by
this Agreement shall be subject to the fulfillment at or prior to
the Closing Date of the following additional conditions:

          (a)  Purchaser shall have performed in all material
respects its agreements contained in this Agreement required to be
performed on or prior to the Closing Date and the representations
and warranties of Purchaser contained in this Agreement shall be
true and correct in all material respects on and as of the date of
this Agreement and at and as of the Closing Date as if made on and
as of such date or time, except as contemplated or permitted by
this Agreement, and Seller shall have received a certificate of the

                                  4
<PAGE>

Chief Executive Officer and Chief Financial Officer of Purchaser to
that effect;

          (b)  Seller shall have received an opinion addressed to
Seller from Petree Stockton, L.L.P., or other legal counsel
selected by Purchaser and reasonably satisfactory to Seller, dated
the Closing Date, substantially in the form set forth in Exhibit C
hereto; and

          (c)  Purchaser shall be ready, willing and able to pay
the Purchase Price in full as contemplated by Article III hereof. 

     Section 4.4    Conditions to Obligation of Purchaser to Close. 
The obligation of Purchaser to close the transactions contemplated
by this Agreement shall be subject to the fulfillment at or prior
to the Closing Date of the additional following conditions:

          (a)  Seller shall have performed in all material respects
its agreements contained in this Agreement required to be performed
at or prior to the Closing Date, and the representations and
warranties of Seller contained in this Agreement shall be true and
correct in all material respects on and as of the date of this
Agreement and at and as of the Closing Date as if made on and as of
such date or time, except as contemplated or permitted by this
Agreement, and Purchaser shall have received a Certificate of the
Chief Executive Officer and Chief Financial Officer of Seller to
that effect;

          (b)  Purchaser shall have received an opinion addressed
to Purchaser from Henson & Efron, P.A., or other legal counsel
selected by Seller and reasonably satisfactory to Purchaser, dated
as of the Closing date, substantially in the form set forth in
Exhibit D hereto;

          (c)  Seller shall have executed and delivered bills of
sale assignments, consents to assignment and transfer, waivers of
liens and other documents of title and related documents as
Purchaser shall reasonably request, in any event sufficient to
convey to Purchaser good and marketable title to all the Assets
free and clear of all liens, charges, claims and encumbrances of
any nature whatsoever, other than the liens, claims and
encumbrances set forth on Disclosure Schedule 4.4(c) (the
"Permitted Liens");

          (d)  Seller and Petree Stockton, L.L.P., as Escrow Agent,
shall have executed and delivered to Purchaser an Escrow Agreement
substantially in the form set forth in Exhibit B hereto;

          (e)  Purchaser shall be reasonably satisfied that the key
employees of Seller identified on Disclosure Schedule 4.4(e) are
willing to become employed by Purchaser on terms and conditions

                                  5

<PAGE>

acceptable to Purchaser and as generally described on Disclosure
Schedule 4.4(e);

          (f)  Seller and the key employees of Seller listed on
Disclosure Schedule 4.4 (f) hereto shall have executed and
delivered to Purchaser Noncompetition Agreements in substantially
the form of Exhibit E hereto;

          (g)  Seller and its officers, directors and key employees
shall have executed and delivered to Purchaser such other
certificates and other similar documents as Purchaser shall
reasonably request;

          (h)  Purchaser shall have raised at least Thirty Million
($30,000,000) Dollars from the sale of debt and/or equity
securities from the date of this Agreement through the Closing
Date; and

          (i)  No material adverse change shall have occurred in
the business of Seller, the business prospects of Seller or the
Assets.

                            ARTICLE V
           REPRESENTATIONS AND WARRANTIES OF PURCHASER

     Purchaser hereby represents and warrants to Seller as follows:

     Section 5.1    Corporate Organization and Good Standing.
Purchaser is a corporation duly organized, validly existing and in
good standing under the laws of Delaware, with all requisite
corporate power and authority to own, operate and lease its
properties and to carry on its business as it is now being
conducted, and is qualified or licensed to do business and is in
good standing in each jurisdiction in which the ownership or
leasing of property by it or the conduct of its business requires
such licensing or qualification, except for such failures to be so
qualified or licensed which would not have a material adverse
effect on Purchaser.  

     Section 5.2    Authorization; Binding Agreement.  Purchaser
has all requisite corporate power and authority to execute and
deliver this Agreement and to perform its obligations hereunder. 
The execution, delivery and performance of this Agreement by
Purchaser, and the consummation by Purchaser of the transactions
contemplated hereby, have been duly authorized by Purchaser's Board
of Directors, and no other corporate action or proceeding on the
part of Purchaser is necessary for the execution, delivery and
performance of this Agreement by Purchaser and the consummation of
the transactions contemplated hereby, other than approval by the
stockholders of Purchaser of the issuance of securities to finance
the transactions contemplated hereby.  This Agreement has been duly
and validly executed and delivered by Purchaser and is a legal,

                                  6
<PAGE>

valid and binding obligation of Purchaser, enforceable against
Purchaser in accordance with its terms except as enforceability may
be limited by bankruptcy, insolvency, reorganization, moratorium
and other similar laws relating to or affecting creditors' rights
generally, and by general equitable principles (regardless of
whether such enforceability is considered in a proceeding in equity
or at law).

     Section 5.3    Certain Fees.  Neither Purchaser, any
subsidiary of Purchaser nor any of their officers, directors,
employees or agents has employed any broker or finder or incurred
any liability for any financial advisory, brokerage or finder's fee
or commissions in connection with the transactions contemplated
herein.  Purchaser agrees to indemnify and hold harmless Seller
from and against any and all claims, suits, liabilities, costs and
expenses, including reasonable attorneys' fees, resulting from any
claims that may be made against the parties by any broker or person
claiming a commission, fee or other compensation on the basis of
any communication or agreement such broker may have had or entered
into with Purchaser or any of its subsidiaries, officers,
directors, shareholders, employees or agents.

     The representations and warranties made by Purchaser shall
survive the Closing and Seller shall be entitled to rely upon such
representations and warranties for a period of two years
notwithstanding any due diligence investigations of Purchaser
conducted by Seller or any other person or any statements made by
Purchaser or any other person or entity outside this Agreement or
any Disclosure Schedule, subject to Section 12.5 (a) hereof.


                           ARTICLE VI
            REPRESENTATIONS AND WARRANTIES OF SELLER

     The terms "to the knowledge of Seller" and "Seller is not
aware of" and other similar terms include the knowledge and
awareness of any Affiliate of Seller.  If Seller has any subsidiary
or parent corporations or other entities, the representations and
warranties set forth herein shall apply to such entities to the
same extent they apply to Seller.  Seller hereby represents and
warrants to Purchaser as follows:

     Section 6.1    Corporate Organization and Good Standing. 
Seller is a corporation duly organized, validly existing and in
good standing under the laws of Minnesota, with all requisite
corporate power and authority to own, operate and lease its
properties and to carry on its business as it is now being
conducted, and is qualified or licensed to do business and is in
good standing in each jurisdiction in which the ownership or
leasing of property by Seller or the conduct of its business
requires such licensing or qualification.

                                  7
<PAGE>

     Section 6.2    Authorization; Binding Agreement.  Seller has
all requisite corporate power and authority to execute and deliver
this Agreement and to perform its obligations hereunder.  The
execution, delivery and performance of this Agreement by Seller,
and the consummation by Seller of the transactions contemplated
hereby, have been duly authorized by the Board of Directors of
Seller and no other corporate action or proceeding on the part of
Seller is necessary for the execution, delivery and performance of
this Agreement and the transactions contemplated hereby, other than
approval by Seller's shareholders, which shall be obtained prior to
the Closing.  This Agreement has been duly and validly executed and
delivered by Seller and constitutes legal, valid and binding
obligations of Seller, enforceable against Seller in accordance
with its terms except as enforceability may be limited by
bankruptcy, insolvency, reorganization, moratorium and other
similar laws relating to or affecting creditors' rights generally
and by general equitable principles (regardless of whether such
enforceability is considered in a proceeding in equity or at law). 

     Section 6.3    Capitalization of Seller.  The authorized
capital stock of Seller consists of 50,000 shares of Common Stock,
$1.00 par value per share.  There are issued and outstanding 29,658
shares of Common Stock.  There are no outstanding options,
warrants, subscriptions, conversion rights or other rights,
agreements or commitments obligating Seller to issue any additional
shares of the capital stock of Seller or any other securities
convertible into, exchangeable for or evidencing the right to
subscribe for or acquire from Seller or any of its subsidiaries any
shares of the capital stock of Seller, or any stock appreciation
rights.  The names of each shareholder and the number of shares
owned by each are set forth on Disclosure Schedule 6.3 hereto.  To
Seller's knowledge, no one other than the owner disclosed herein
has the right to vote any shares of capital stock of Seller, except
by duly executed proxy voted at a shareholders' meeting.

     Section 6.4    Subsidiaries; Investments.  Except as set forth
on Disclosure Schedule 6.4, Seller does not own, directly or
indirectly, any capital stock or other equity securities of any
corporation or have any direct or indirect equity or ownership
interest in any other business.  Seller has no obligations or
commitments to invest any funds in any business or entity.

     Section 6.5    Financial Statements.  Attached as Exhibit F
hereto are true and complete copies of the audited financial
statements of Seller for the two fiscal years ended December 31,
1993 and 1994 and unaudited financial statements for the five-month
period ended May 31, 1995 (the "Financial Statements").  The
Financial Statements (including any related notes) were prepared in
conformity with generally accepted accounting principles applied on
a consistent basis (except as otherwise stated in such financial
statements), and present fairly the consolidated financial
position, results of operations and cash flows of Seller as of the

                                  8
<PAGE>

dates and for the periods indicated, subject, in the case of
unaudited interim financial statements to condensation, the absence
of certain notes thereto and normal year-end audit adjustments. 
The financial records of Seller are sufficient to allow the
accountants of Purchaser to audit the Financial Statements of
Seller for the periods covered by the Financial Statements.

     Section 6.6    Absence of Certain Changes.  Since the end of
the period covered by the Financial Statements (i) no material
adverse changes have occurred with respect to Seller or its
business or the Assets, (ii) Seller has not taken action or failed
to act, nor has any event occurred or failed to occur, which action
or event or failure is likely to result in a material adverse
effect on the business of Seller or the Assets compared to the
business and Assets reflected on the unaudited Financial Statements
or on the ability of Seller to perform this Agreement and close the
transactions contemplated hereby.

     Section 6.7    Certain Fees.  Neither Seller nor any of its
officers, directors, employees or agents has employed any broker or
finder or incurred any liability for any financial advisory,
brokerage or finder's fee or commissions in connection with the
transactions contemplated herein.  No other agent or broker or
other person is entitled to any commission or finder's fee in
connection with the transaction contemplated by this Agreement. 
Seller agrees to indemnify and hold harmless Purchaser from and
against any and all claims, suits, liabilities, costs and expenses,
including reasonable attorneys' fees, resulting from any claims
that may be made against the parties by any broker or person
claiming a commission, fee or other compensation on the basis of
any communication or agreement such broker may have had or entered
into with Seller, or any of its officers, directors, shareholders,
employees or agents.

     Section 6.8    Consents and Approvals; No Violations.

          (a)  Seller is not in violation in any material respect,
of any applicable law, statute, ordinance, order, rule or
regulation promulgated or judgment, decree, order, concession,
grant, permit, license or other governmental authorization or
approval, issued or entered by, any federal, state or local, court
or governmental authority relating to or affecting the operation,
conduct or ownership of the property or business of Seller.

          (b)  No filing or registration with, no notice to and no
permit, authorization, consent or approval of any public or
governmental body or authority is necessary for the consummation by
Seller of the transactions contemplated by this Agreement or to
enable Purchaser after the Closing Date to continue to conduct the
same business conducted by Seller in a manner which is consistent
with that in which it is presently conducted by Seller.

                                  9
<PAGE>

          (c)  Seller has provided Purchaser with true, complete
and correct copies of the Articles of Incorporation and Bylaws of
Seller, both as amended to date.  Neither the execution and
delivery of this Agreement by Seller, the performance by Seller of
its obligations hereunder nor the consummation by Seller of the
transactions contemplated hereby will (i) conflict with or result
in any breach of any provision of the Articles of Incorporation or
By-laws of Seller, (ii) subject to obtaining any necessary
consents, all of which shall have been obtained by Seller prior to
the Closing Date unless waived by Purchaser, result in a violation
or breach of, or constitute (with or without due notice or lapse of
time or the happening or occurrence of any other event) a default
by Seller, or permit the termination of, or result in the
acceleration of, or entitle any party to accelerate (or give rise
to the creation of any lien, charge, security interest or
encumbrance upon any properties or assets of Seller), under, or
violate or breach, any of the terms, conditions or provisions of
any contract, note, bond, mortgage, indenture, license, agreement
or other instrument or obligation to which Seller is a party or by
which Seller or any of its properties or assets may be bound or
(iii) violate any order, writ, injunction, decree, statute, rule or
regulation of any court or governmental authority applicable to
Seller, or any of its properties or assets, provided that if Seller
is not named therein, this clause (iii) shall be to the knowledge
of Seller.

     Section 6.9    Litigation.  Except as set forth on Disclosure
Schedule 6.9 hereof, there is no action, suit, set of related
actions or suits concerning a common issue, complaint, arbitration,
inquiry, proceeding or investigation pending or, to the knowledge
of Seller, threatened against or involving Seller, or any
properties or rights of Seller, before any court, arbitrator or
administrative or governmental body, and there is no judgment,
decree, injunction, rule or order of any court, governmental
department, commission, agency, instrumentality or arbitrator
outstanding against Seller which would individually or in the
aggregate, if adversely determined, have a material adverse effect
on Seller or result in any claim, lien or other encumbrance on any
of the Assets.  There are no actions, suits or proceedings pending
or, to the knowledge of Seller, threatened against Seller arising
out of or in any way related to this Agreement, or any of the
transactions contemplated hereby.

     Section 6.10   Certain Employment Matters.  Except as set
forth in Disclosure Schedule 6.10, there are no written employment
or consulting agreements or contracts in effect between Seller with
any of the employees of Seller, nor any oral contracts or
understandings of employment or consultation, or any applicable
law, which (i) are not terminable upon the giving of notice not to
exceed ten (10) days, or (ii) provide for any severance or other
payments to any employee of Seller upon termination of employment
or upon any change of control of Seller or sale of the assets of

                                 10
<PAGE>

Seller.  Except as set forth on Disclosure Schedule 6.10,  Seller
has complied with all applicable laws, rules and regulations
relating to the employment of labor which could have a material
adverse effect on the business, assets, condition or prospects,
financial or otherwise, of Seller, including without limitation
those relating to wages, hours, collective bargaining, age and sex
discrimination and the payment and withholding of taxes; Seller has
withheld all amounts required by law or agreement to be withheld
from the wages or salaries of employees of Seller and made all
required withholding payments to the appropriate government agency
within the required periods; and Seller has no unaccrued liability
for any arrears of wages or any taxes or penalties for failure to
comply with any of the foregoing with respect to employees of
Seller.  Except as set forth in Disclosure Schedule 6. 10, there
are no controversies pending, threatened or reasonably anticipated
between Seller and any employee or former employee of Seller.  None
of the employees of Seller are represented by a labor union, and no
petition has been filed or proceeding instituted of which Seller
has notice by any employee or group of employees with any labor
relations boards seeking recognition of a bargaining
representative.  There is no material dispute or controversy with
any union or other organization representing employees, and no
arbitration proceeding is pending or threatened involving such a
dispute or controversy.

     Section 6.11   Employee Benefit Plans.  (a)  The following
terms shall have the meanings set forth below:

     (i)  "Benefit Plan" means each plan, program or agreement,
other than an ERISA Plan, providing deferred compensation,
insurance, bonuses or other incentive compensation which is
established or maintained by Seller. 

     (ii) "Code" means the Internal Revenue Code of 1986, as
amended.

     (iii)"ERISA" means the Employee Retirement Income Security Act
of 1974, as amended.

     (iv) "ERISA Plan" means any Pension Plan and any Welfare Plan.

     (v)  "IRS" means the Internal Revenue Service. 

     (vi) "PBGC" means the Pension Benefit Guaranty Corporation.

     (vii)"Pension Plan" means any employee pension benefit plan as
defined in ERISA Section 3(2) which is established or maintained by
Seller.

     (viii)"Plan" means any Benefit Plan, Pension Plan, Welfare
Plan and any ERISA Plan.

                                  11
<PAGE>

     (ix) "Welfare Plan" means any employee welfare benefit plan as
defined in ERISA Section 3(1) which is established or maintained by
Seller or any Subsidiary of Seller.

     (b)  Disclosure Schedule 6.11 (b) lists all Plans established,
maintained or contributed to by Seller during the six-year period
preceding the date of this Agreement.  Each such Plan is correctly
labeled on Disclosure Schedule 6.11 (b) as a Benefit Plan, Pension
Plan or Welfare Plan.  No Pension Plan is a multiemployer plan
within the meaning of ERISA Section 3(37).  Seller has previously
provided to Purchaser true and complete copies of all Plans
together with (i) the three most recent actuarial and financial
reports prepared with respect to each ERISA Plan, (ii) the three
most recent annual reports filed with any government agency for
each ERISA Plan, and (iii) all rulings and determination letters
and any open requests for rulings or letters that pertain to each
ERISA Plan.  Seller has no commitment to create any additional
plan, program, agreement, contract or arrangement that would
constitute a Plan or to amend any Plan so as to increase benefits
thereunder.  

          (c)  Seller has fully complied in all material respects
with all provisions of ERISA and any and all other laws, rules, and
regulations applicable to the Plans.  All reports and descriptions
required by ERISA with respect to the ERISA Plans have been timely
filed and distributed and all notices required by ERISA, the Code,
or any state or federal law or any ruling or regulation of any
state or federal administrative agency with respect to the Plans
have been appropriately given.

          (d)  A favorable determination letter has been issued by
the IRS with respect to each Pension Plan that is intended to be
qualified under Code Section 401 to the effect that such Pension
Plan is qualified under Code Section 401 and that the trust
associated with such Pension Plan is exempt from tax under Code
Section 501.  No such letter has been revoked or threatened to be
revoked and Seller knows of grounds on which such revocation may be
based.  Seller has no material liability under any such plan that
is not reflected on the Financial Statements of Seller. Each such
Plan is and has been administered in accordance with its provisions
and applicable law.

          (e)  All contributions required to be made by Seller on
or prior to the date of this Agreement under the terms of any Plan
have been timely made.  

          (f)  Seller has not incurred any material liability to
the PBGC or the IRS with respect to any Pension Plan except
liabilities to the PBGC pursuant to ERISA Section 4007, all of
which have been fully paid.  No "reportable event" (within the
meaning of ERISA Section 4043(b)) with respect to which notice must
be provided to the PBGC has occurred during the twelve-month period

                                 12
<PAGE>

preceding the date hereof or is continuing with respect to any
Pension Plan, and there exists no condition or set of circumstances
presenting a material risk of the termination or partial
termination of any Pension Plan which could result in a material
liability on the part of Seller to the PBGC.

          (g)  No "prohibited transaction" (within the meaning of
ERISA Section 406 or Code Section 4975 which is not exempt under
ERISA Section 408, Code Section 4975 or an administrative
exemption) has occurred with respect to any Plan (i) which would
result in the imposition, directly or indirectly, of an excise tax
under Code Section 4975, or (ii) the correction of which would have
an adverse effect on the financial condition, results of operations
or business of the Seller.

          (h)  The present value of all benefits, whether or not
vested, under each Pension Plan did not exceed as of the most
recent actuarial valuation date, and will not exceed as of the
Effective Date, the then current fair market value of the assets of
such plan.  For purposes of determining the present value of
benefits under any Pension Plan, the actuarial assumptions and
methods used under such Pension Plan for the most recent actuarial
valuation shall be used, other than any assumptions relating to
employee turnover (as to which it shall be assumed there will be
none).  No Pension Plan has an "accumulated funding deficiency"
(whether or not waived) within the meaning of Code Section 412 or
ERISA Section 302.  Seller has not provided, nor is it required to
provide, security to any Pension Plan pursuant to Code Section
401(a)(29).

          (i)  Neither Seller nor any administrator or fiduciary of
any of such Benefit Plan (or agent or delegate of any of the
foregoing) has engaged in any transaction or acted or failed to act
in any manner which could subject Seller to any direct or indirect
liability for a breach of any fiduciary, co-fiduciary, or other
duty under ERISA, which individually or in the aggregate could
result in liability to Seller.  No oral or written representation
or communication by Seller with respect to any aspect of the
Benefit Plans has been or will be made to employees of Seller prior
to the Closing which is not in accordance with the written or
otherwise preexisting terms and provisions of such Benefit Plans in
effect immediately prior to the Closing.  There are no unresolved
claims or disputes under the terms of, or in connection with, the
Benefit Plans and no action, legal or otherwise, has been commenced
with respect to any claim.

          (j)  Each Welfare Plan providing health benefits, and any
plan providing health benefits that is maintained by an entity
which is a member of a group described in Code Section 414(b),(c),
(m) or (o) that includes the Seller, has been maintained in form
and in operation in compliance with the continuation coverage

                                  13

<PAGE>

requirements of Code Section 4980B, the corresponding provisions of
ERISA and any applicable state laws or regulations.  

          (k)  Except as set forth on Disclosure Schedule 6.11 (k),
Seller is not obligated to provide any post-retirement welfare
benefits to its employees, including post-retirement health or life
insurance coverage.

          (l)  No liability under Subtitle C or D of Title IV of
ERISA has been, or is expected to be, incurred by the Seller with
respect to any ongoing, frozen or terminated "single-employer plan"
(within the meaning of ERISA Section 4001(a)(15)) currently or
formerly maintained by the Seller. 

     Section 6.12   Tax Matters.  Seller and each of its
subsidiaries, if applicable, has filed all federal, state and other
tax returns and reports required to be filed for all periods on or
before the due dates (as extended by any valid extensions of time)
and has paid all taxes shown to be due by said returns.  Such
returns reflect all taxes due and payable with respect to the
periods covered thereby and there are no liabilities, claims,
interest or penalties pending, assessed, asserted or threatened
against Seller or any of its subsidiaries in connection with any
such taxes and no basis therefor.  The reserves for taxes (federal,
state and local) reflected in Seller's Financial Statements are
adequate to cover any and all taxes, including deferred taxes, and
any interest and penalties in connection therewith which may be
assessed with respect to the property, business and operations of
Seller or any of its subsidiaries up to the date of Seller's
Financial Statements and all prior periods.  Seller has fully
complied with all withholding, social security and other similar
tax laws.  Neither Seller nor any of its subsidiaries has given or
been requested to give waivers of any statutes of limitations
relating to the payment of taxes for any taxable period.  No fact
exists which could constitute grounds for assessment of any tax
liability or lien against Purchaser or any of the Assets on account
of any tax liability of Seller.

     Section 6.13   Assets.  Seller has good title to all the
Assets to be sold to Purchaser hereunder free and clear of any
claim, lien or encumbrance of any third person or entity of any
nature whatsoever other than the Permitted Liens.  All of the
equipment comprising the Assets is in good operating condition,
reasonable wear and tear excepted, and the use and operation of all
the Assets in the business of Seller comply in all material
respects to all applicable rules and other regulations of any
regulatory body having jurisdiction and all applicable building,
zoning and other laws, ordinances, regulations, permits, licenses
and certificates, and Seller has not received any notice of non-
compliance therewith (except for any non-compliance that has been
cured). 

                                  14

<PAGE>

     Section 6.14   Intellectual Property.  Seller has good title
to all the patents, trademarks, trade names, service marks,
copyrights, trade secrets and other intellectual property set forth
in Disclosure Schedule 6.14 ("Seller Intellectual Property"), free
and clear of all liens, charges or encumbrances of any nature
whatsoever, except for Permitted Liens.  Seller has not granted any
person or entity any license or other rights to the Seller
Intellectual Property.  Seller is not aware of any basis for any
claim by any other person or entity that Seller is infringing upon
any patent, trademark, trade name, copyright, publication right or
other intellectual property right of any other person or entity. 
No infringement claim has been asserted by any other person against
Seller.  Seller has no liability for, nor has Seller given any
indemnification for, patent, trademark or copyright infringement as
to any equipment, materials, services, products or supplies
manufactured, produced, used or sold by Seller.  No rights of
Seller under any agreement regarding ownership, protection or
confidentiality of any trade secret or other intellectual property
of Seller have been waived by Seller.  Seller has taken all
reasonable measures to protect its trade secrets, such trade
secrets have not been disclosed to others except pursuant to
reasonable confidentiality agreements and Seller has no reason to
believe any confidentiality agreement involving its trade secrets
has been breached.

     Section 6.15   Contracts, Minutes and Other Instruments and
Information.  Disclosure Schedule 6.15 lists all material contracts
and agreements.  For purposes of this Agreement, the phrase
"material contracts and agreements" shall mean all leases for real
and personal property and all contracts, agreements and license to
which Seller is a party or by which Seller is bound (i) which have
a term longer than six months or (ii) which involve payment of
consideration in excess of $25,000 (including all similar
agreements which in the aggregate exceed $25,000).  Seller has made
available to Purchaser true, correct and complete copies of all
such material contracts.  Except as set forth on Disclosure
Schedule 6.15, all such material contracts and agreements are
assignable to Purchaser without the consent of the other parties
thereto.  Seller is in compliance in all material aspects with all
such material contracts and agreements, and to the knowledge of
Seller, no other party is in breach thereof and no other party is
incapable of performing, or unwilling to perform, their obligations
thereunder.  True, correct and complete copies of all minutes
and/or consents of all actions taken by the shareholders and Board
of Directors of Seller and all committees of the Board, all of
which are contained in the minute books of Seller or in other
records of Seller made available to Purchaser.

     Section 6.16   Permits and Licenses.  Seller has acquired and
currently holds all permits, licenses, franchises, authorizations,
approvals and other certificates of authority (the "Licenses") as
are required for Seller to conduct its business, and copies of all

                                  15
<PAGE>

such documents have been provided to Purchaser.  Except as
disclosed on Disclosure Schedule 6.16, Seller is in material
compliance with all the terms thereof, the Licenses are
transferable and are being transferred to Purchaser with the Assets
and Seller is not aware of any reason which any such License could
not be renewed on terms at least as advantageous to Purchaser as
the current License held by Seller.  Seller is not aware of any
change in any law, rule or regulation, whether or not yet
effective, which is likely to require Purchaser to obtain in the
future any additional License to conduct the business currently
conducted by Seller.  Seller has been certified by the Substance
Abuse and Mental Health Services Administration ("SAMSHA") and the
organizations and agencies listed on Disclosure Schedule 6.16
hereto, which certifications are in good standing and will be in
good standing as of the Closing Date.  Pursuant to such
certifications, Seller has designated the persons listed on
Disclosure Schedule 6.16 to be the responsible parties where
responsible parties are required for such certifications.  Seller
has made available to Purchaser all material correspondence and
other documents relating to such certifying organizations.

     Section 6.17   Real Property; Environmental Matters.  Seller
does not own any real property and is not a party to any agreement
to acquire ownership of any real property or any interests in real
property, and does not occupy or otherwise use any real property,
other than real property subject to lease(s) to which Seller is a
party and are being assigned to Purchaser as part of the Seller
Assets, copies of which have been provided to Purchaser.  Seller
has not (either with or without negligence) caused or permitted the
escape, disposal or release in violation of applicable law of any
biologically active or other hazardous substances, or materials
causing harm in or on any real property occupied or utilized by
Seller in conducting its business (the "Premises").  Seller has not
allowed the storage or use of such substances or materials in any
manner not sanctioned by law or by commercially reasonable
standards in the industry for the storage and use of such
substances or materials.  Seller has not allowed to be brought onto
the Premises any such materials or substances except to use in the
ordinary course of Seller's business.  During the use and occupancy
of the Premises by Seller, Seller has kept and maintained the
Premises so as to be in material compliance with all then existing
statutes, laws, rules, ordinances, orders, permits and regulations
of all governmental and regulatory authorities, agencies and bodies
pertaining to environmental matters, or regulating, prohibiting or
otherwise having to do with asbestos and all other toxic,
radioactive or hazardous wastes or materials.  Seller is not aware
of any hazardous waste, toxic material, asbestos or other
environmental or health problem associated with the Premises,
whether or not caused by Seller or any other person or entity, and
whether or not pre-dating Seller's occupancy of the Premises.  

                                  16
<PAGE>

     Section 6.18   Related Party Transactions.  Set forth on
Disclosure Schedule 6.18 hereto, is a true and complete list of all
transactions between the Seller and any Interested Party (i) which
have been agreed to in the immediately preceding twelve months, or
(ii) which all or any part have been performed in the immediately
preceding twelve months or (iii) which all or any part are to be
performed in the future.  True, complete and accurate copies of all
documents relating to the transactions so disclosed have been
provided to Purchaser.  "Interested Party" shall mean:  (i) any
director, officer or employee of Seller; (ii) any current nominee
for election as a director or officer of Seller; (iii) any security
holder of Seller owning (including options, warrants or other
rights to acquire) more than five (5%) percent of any class of
Seller's securities; (iv) any member of the immediate family of any
of the foregoing persons; and (v) any entity in which any person
described in any of the preceding clauses of this sentence is an
officer, director, partner, nominee, or ten (10%) percent owner.

     Section 6.19   Customers.     All customers of Seller, who in
any of the three preceding fiscal years of Seller was responsible
for more than two (2%) percent of the gross revenues of Seller, are
listed on Disclosure Schedule 6.19, together with the volume of
business each such year.  No such customer has notified Seller of
its intention to reduce or terminate its business with Seller or
demanded to change the terms (including price) of its business, and
Seller is not otherwise aware of any reason any such customer would
decide to terminate or reduce its business with Seller.  

     Section 6.20   Insurance.  Disclosure Schedule 6.20 hereto
contains a list of all insurance policies maintained by Seller,
true, complete and correct copies of which have been provided to
Purchaser.  Copies of all claims and correspondence with any
insurer during the past three years have been provided to
Purchaser.  Seller has paid all premiums due under all such
policies and no circumstances exist which could justify any insurer
denying the coverage stated in such policies.

     Section 6.21   Material Statements or Omissions.  Seller has
fully described to Purchaser all facts that are material to
understanding the business of Seller, has not misstated any facts
material to understanding the business of Seller and has not
omitted any fact which is necessary to understand the facts that
have been disclosed, or which is necessary to avoid having any of
the facts disclosed be misleading in any respect.

     The representation and warranties made by Seller shall survive
the Closing and Purchaser shall be entitled to rely upon such
representations and warranties for a period of two years
notwithstanding any due diligence investigations of Seller
conducted by Purchaser or any other person or any statements made
by Seller or any other person or entity outside this Agreement or
any Disclosure Schedule, subject to Section 12.5 (a) hereof.

                                  17
<PAGE>

                           ARTICLE VII
             CONDUCT OF BUSINESS PENDING THE CLOSING

  
     Section 7.1    Conduct of Business by Seller Pending the
Closing.  Except as otherwise expressly contemplated hereby, after
the date hereof and prior to the Closing or earlier termination of
this Agreement, unless Purchaser shall otherwise agree in writing
or as otherwise expressly contemplated by this Agreement, Seller
shall:

          (a)  conduct its business only in the ordinary and usual
course of business and consistent with past practice as previously
disclosed to Purchaser;

          (b)  use its best efforts to:  preserve intact its
business organization and goodwill, keep available the services of
its present officers and key employees, and preserve the goodwill
and business relationships with suppliers, distributors, customers,
employees and others having business relationships with Seller;

          (c)  confer on a regular and frequent basis with one or
more representatives of Purchaser to discuss operational matters of
materiality and the general status of ongoing operations of Seller,
provided that Seller need not follow any course of action requested
by Purchaser;

          (d)  promptly notify Purchaser of any significant changes
in the business, properties, assets, condition (financial or other)
or results of operations of Seller;

          (e)  not directly or indirectly, (i) sell, lease,
encumber or otherwise transfer any Assets or stock of Seller,
(including, any merger, consolidation or similar transactions)
other than sales of nonmaterial amounts of inventory in the
ordinary course of business ("Prohibited Transactions"), (ii) enter
into or negotiate any agreement with respect to any Prohibited
Transaction, (iii) submit to any other person or entity any offer
or proposal for, or provide any information useful for, or relating
to, any Prohibited Transaction, (iv) solicit or encourage any offer
from any third party for any Prohibited Transaction, (v) otherwise
participate in discussions or take any other action that is
designed to promote any Prohibited Transaction or (vi) take any
other action that is inconsistent with a good faith attempt to
fulfill the purposes of this Agreement;

          (f)  not enter into any material contract, agreement or
lease; 

          (g)  not increase the salary or other compensation of any
employee of Seller or enter into or amend any employment,
noncompetition, severance, bonus, special pay arrangement with

                                  18
<PAGE>

respect to termination of employment or other similar arrangements
or agreements other than pursuant to normal annual reviews
consistent with past practice of Seller as previously disclosed to
Purchaser;

          (h)  not adopt, enter into or amend any bonus, profit
sharing, compensation, stock option, pension, retirement, deferred
compensation, health care, employment or other employee benefit
plan, agreement, trust, fund or arrangement for the benefit or
welfare of any employee or retiree of Seller, except (i) as
required to comply with changes in applicable law occurring after
the date hereof and (ii) with respect to all plans other than in
the ordinary course of business and consistent with past practice
as previously disclosed to Purchaser; 

          (i)  maintain and pay premiums for all insurance policies
in effect on the date of this Agreement until the Closing and at
the option of the Purchaser for a period of thirty (30) days
following the Closing, provided Purchaser pays all post-closing
premiums.

          (j)  use reasonable efforts to obtain any consent or
approval required to assign any of the contracts and agreements
being assigned to Purchaser hereunder;

          (k)  not take any action that a reasonable person would
have reason to believe may harm the good will or reputation of the
business purchased from Seller by Purchaser or relationship with
customers, suppliers or employees of Seller;

          (l)  take all reasonable actions requested by Purchaser,
but not including the expenditure of any money, to extend the term
of any contract or agreement being assigned to Purchaser hereunder;

          (m)  not disclose any of its trade secrets to others,
except in the ordinary course of its business, consistent with past
practice as previously disclosed to Seller, and shall cooperate
with Purchaser to protect against further use of such trade secrets
by others;

          (n)  maintain normal levels of inventory and conduct
normal levels of equipment maintenance consistent with past
practice as previously disclosed to Purchaser;

          (o)  not accelerate collection of account receivables
faster than past practice as previously disclosed to Purchaser;

          (p)  pay all trade payables, employment withholding,
social security, workmen's compensation, sales and other taxes,
pension plan, 401 (k), health and other contributions, and other
obligations as and when due consistent with past practice as
previously disclosed to Purchaser; and

                                  19
<PAGE>

          (q)  not agree orally or in writing, or otherwise, to
take any of the foregoing actions or any other action which would
make any representation or warranty contained in Article VI untrue
or incorrect in any material respect as of the time of the Closing.

     Section 7.2    Enforcement.  Purchaser shall be entitled to
obtain an injunction or other restraining order requiring
compliance with this Article VII.  In the event Seller or any of
its Affiliates shall engage in any activity prohibited by Section
7.1 (e) hereof, if Seller consummates a sale with the person or
entity involved in such activity, Seller shall pay Purchaser the
sum of Eight Hundred Fifty Thousand ($850,000) Dollars as a break-
up fee in addition to expense reimbursement pursuant to Section 8.4
hereof.


                          ARTICLE VIII
                      ADDITIONAL AGREEMENTS

          Section 8.1    Access to Information.  (a)  Seller shall
afford to Purchaser and its accountants, counsel, investment
bankers, potential investors and other representatives reasonable
access during normal business hours and upon reasonable notice
throughout the period prior to the Closing to all properties,
books, contracts, commitments and records related to the business
of Seller or the Assets and all other information concerning the
businesses, properties and personnel of Seller as Purchaser may
reasonably request.  Seller shall promptly advise Purchaser in
writing of any change or occurrence of any event after the date of
this Agreement having, or which, insofar as can reasonably be
foreseen, in the future may have, a material adverse affect on
Seller.

     Section 8.2    Shareholders' Approval.  Seller in accordance
with applicable law, shall promptly submit this Agreement and the
transactions contemplated hereby for the approval of its respective
Board of Directors and shareholders.  Purchaser shall not be
required to solicit proxies from its shareholders until this
Agreement and the transactions contemplated hereby have been
approved by the Board of Directors and the shareholders of Seller. 
If both such approvals are not obtained, or if an opinion of
Seller's legal counsel with respect to such approvals in
substantially the form attached as Exhibit G hereto is not
delivered to Purchaser within twenty (20) days after the date of
this Agreement, the date of the Seller Termination Date pursuant to
Section 10.1(b) and the time afforded Purchaser to raise funds as
provided in Section 10.1(d) shall be extended by the amount of the
delay in obtaining such approvals or delivering such opinion. 
Purchaser shall use its best efforts to submit its preliminary
proxy materials to the Securities and Exchange Commission within
thirty (30) days after this Agreement is executed and delivered by
Seller and Purchaser, but notwithstanding the foregoing, Purchaser

                                  20
<PAGE>

shall not be required to file such proxy materials until fifteen
(15) days after the earlier of the (i) Purchaser's receipt of
notice that Seller's shareholders have approved the transactions
contemplated hereby or (ii) Purchaser's receipt of an opinion from
Seller's legal counsel in the form specified above.

     Section 8.3    Employees.  Seller agrees to take efforts
reasonably requested by Purchaser to encourage Seller's employees
to accept employment with Purchaser.  Purchaser has no obligation
to hire any employee of Seller, provided, that if Purchaser shall
hire any of Seller's employees, Purchaser shall assume any and all
obligations of Seller accruing after the Closing Date under any
employment agreement between Seller and such employee if such
agreement has been disclosed and provided to Seller prior to the
date of this Agreement.  Purchaser covenants that if the
transactions contemplated hereby are not consummated for any
reason, it will not, for a period of one year from the date of this
Agreement, solicit the employment of any employee of Seller.

     Section 8.4    Expenses.   All costs and expenses incurred in
connection with this Agreement and the transactions contemplated
hereby shall be paid by the party incurring such expenses, except
that if either party breaches this Agreement causing the Closing
not to be held the breaching party shall pay the expenses of the
nonbreaching party, including any expenses of Purchaser associated
with fundraising, provided that any recovery by Purchaser for
fundraising expenses shall not exceed One Hundred Fifty Thousand
($150,000) Dollars.

     Section 8.5    Agreement to Cooperate.  Subject to the terms
and conditions herein provided, each of the parties hereto shall
use reasonable efforts to take, or cause to be taken, all action to
do, or cause to be done, all things necessary, proper or advisable
under applicable laws and regulations to consummate and make
effective the transactions contemplated by this Agreement.

     Section 8.6    Public Statements.  Purchaser shall have the
right to issue a press release immediately following execution and
delivery of this Agreement and/or file a Report on Form 8-K with
the Securities and Exchange Commission, which press release and
report may disclose this Agreement and the transactions
contemplated hereby.  Purchaser shall also have the right to make
disclosures in accordance with proxy solicitation and other
securities rules and regulations.  Seller and its legal counsel
shall have the right to review and comment upon such statements
before they are released provided such comments shall not
unreasonably be delayed.  Seller and Purchaser shall consult with
each other prior to issuing any other public announcement or
statement with respect to this Agreement or the transactions
contemplated hereby and shall not issue any such public
announcement or statement prior to such consultation, except as may
be required by law or any listing agreement with the American Stock

                                  21
<PAGE>

Exchange or other national securities exchange, in which case prior
oral or written notice shall be sent to Seller.  No public
statement by either party shall be made for the purpose of harming
the business of the other party.

     Section 8.7    Allocation of Purchase Price.  The purchase
price shall be allocated among the Assets in accordance with
Schedule 8.7 attached hereto, subject to adjustment as shall be
appropriate to reflect changes in the Assets between the date
hereof and the Closing Date.

                           ARTICLE IX
                     POST CLOSING COVENANTS

     Section 9.1    Names and Marks.  From and after the Closing
Date neither Seller nor any of its Affiliates shall use the names
or marks sold to Purchaser nor any name or mark similar to any name
or mark sold to Purchaser.  Within ten (10) days after the Closing
Date, Seller shall have amended its corporate charter to change its
corporate name.  All rights to use names and marks shall be
assigned to Purchaser and on the Closing Date, or at any time after
the Closing Date, Seller shall execute such documents as are
requested by Purchaser to allow Purchaser to use such names and
marks.  Where any name or mark is registered or otherwise
protected, Seller shall so inform Purchaser and facilitate transfer
of such registration or other protection to Purchaser.

     Section 9.2    Trade Secrets.  From and after the Closing
Date, neither Seller nor any of its Affiliates shall use or
disclose, whether orally or in writing, the trade secrets or other
intellectual property sold to Purchaser.  Seller has delivered to
Purchaser a list of all the trade secrets of Seller, any license
of, and copies of, such trade secrets and on or prior to the
Closing Date Seller shall deliver to Purchaser the information
required to enable Purchaser to utilize such trade secrets.  All
copies of such information in whatever form not delivered to
Purchaser shall be destroyed.  From and after the date hereof,
Seller (i) shall not disclose such trade secrets to others, whether
orally or in writing, and (ii) shall cooperate with Purchaser to
protect against future use of such trade secrets by others.

     Section 9.3    Good Will and Customers.  As Purchaser is
paying for the goods of Seller as a going concern, from and after
the date hereof neither Seller nor any of its Affiliates shall take
any action that a reasonable person would have reason to believe
may harm the good will or reputation of the business purchased from
Seller by Purchaser or relationships with customers, suppliers or
employees of Seller.  For a period of sixty (60) days after the
Closing Date, Seller and the Affiliates of Seller shall, without
additional compensation, assist Purchaser to encourage the
customers of Seller to become customers of Purchaser.

                                  22
<PAGE>

     Section 9.4    Noncompetition.  For a period of two (2) years
following the Closing, Seller shall not directly or indirectly
engage in the business conducted by Seller prior to the Closing,
nor any other similar business at any location in the United States
or at any location outside the United States if such business
solicits customers located in the United States.

     Section 9.5    Contract Rights.  To the extent that any of the
Assets include contracts, licenses, sublicenses, leases or other
agreements ("Contract Rights") that require the consent or approval
of any other parties thereto, Seller and its Affiliates shall
arrange for the consent or approval of the assignment of all such
Contract Rights to Purchaser in form and substance acceptable to
Purchaser, unless Purchaser executes a waiver of this requirement.

     Section 9.6    Title; Liens; Assignments.  After the Closing
Seller shall execute and deliver any and all documents reasonably
requested by Purchaser to evidence transfer of title to the Assets
to Purchaser and to remove any liens.  Seller shall also assist
Purchaser to obtain consents from any person whose consent is
required to assign any contract, license or other agreement
assigned by Seller to Purchaser, unless Purchaser executes a waiver
of this requirement.

                            ARTICLE X
                TERMINATION, AMENDMENT AND WAIVER

     Section 10.1   Termination.  This Agreement may be terminated
and the transactions contemplated hereby may be abandoned at any
time prior to the Closing:

          (a)  by mutual consent of Seller and Purchaser; or

          (b)  by Seller, if Purchaser shall have breached any of
its material obligations under this Agreement, if any material
representation or warranty of Purchaser shall have been untrue when
made or shall have subsequently become untrue as of any date prior
to the Closing or if the Closing shall not have been consummated on
or before one hundred twenty days (120) after the date of this
Agreement (the "Seller Termination Date") through no fault of
either Seller or any of its Affiliates; or

          (c)  by Purchaser, if Seller shall have breached any of
its material obligations under this Agreement, any material
representation or warranty of Seller shall have been untrue when
made or shall have subsequently become untrue as of any date prior
to the Closing or if the Closing shall not have been consummated on
or before one hundred twenty days after the date of this Agreement
(the "Purchaser Termination Date") without breach of this Agreement
by Purchaser; or

                                  23
<PAGE>

          (d)  by Seller or Purchaser, if within one hundred twenty
(120) days following the date of this Agreement Purchaser, or the
investment bankers or other agents of Purchaser on behalf of
Purchaser, do not have in its possession an amount of cash equal to
the full Purchase Price, provided that in the event the proxy
materials for the stockholders meeting of Purchaser to be called to
approve the transactions contemplated hereby are not approved by
the Securities and Exchange Commission within thirty (30) days
after the filing of preliminary proxy materials with the
Commission, the Seller Termination Date pursuant to Section 10.1(b)
hereof and such 120-day period shall automatically be extended by
the number of days delay in obtaining approval from the Commission. 
Purchaser agrees to seek to move expeditiously in obtaining
approval of the proxy materials.

     Section 10.2   Effect of Termination.  In the event of
termination of this Agreement, as provided in Section 10.1, this
Agreement shall forthwith become void, and there shall be no
obligation hereunder on the part of any party, except pursuant to
Sections 7.2, 8.4, 11.1 and 13.4 hereof and the Escrow Agreement in
the form of Exhibit A hereto.  Nothing in this Section 10.2 shall
relieve any party from liability for any breach of this Agreement.

     Section 10.3   Amendment.  This Agreement may be amended by
the parties hereto at any time but only by an instrument in writing
signed by each of the parties hereto.

     Section 10.4   Waiver.  At any time prior to the Closing, the
parties hereto may (i) extend the time for the performance of any
of the obligations or other acts of the other parties hereto,
(ii) waive any inaccuracies in the representations and warranties
contained herein or in any document delivered pursuant hereto and
(iii) waive compliance with any of the agreements or conditions
contained herein; provided, however, that waiver of compliance with
any agreements or conditions herein shall not limit the parties'
obligations to comply with all other agreements or conditions
herein.  Any agreement on the part of a party hereto to any such
extension or waiver shall be valid if set forth in an instrument in
writing signed on behalf of such party.

                           ARTICLE XI
                         CONFIDENTIALITY

     Section 11.1   Confidential Information.     The parties agree
that in the event the transactions contemplated by this Agreement
are not consummated, all information of one another (i) shall be
treated in accordance with the existing nondisclosure agreements
executed by the parties prior to this Agreement and (ii) all
recorded evidence thereof shall be delivered to Seller together
with a certificate to the effect that no copies thereof remain in
possession of Purchaser or Purchaser's agents, affiliates, counsel
or auditors except to the extent required by any party to document

                                  24
<PAGE>

a justifiable termination of this Agreement, breach by the other
party of this Agreement or to assert any legal right or to defend
against the assertion of any legal right.  The obligations of the
parties under this Article XI shall survive the termination of this
Agreement.

                           ARTICLE XII
                         INDEMNIFICATION

          Section 12.1   Indemnification.  (a)  From and after the
Closing, Seller will indemnify and hold Purchaser and its
subsidiaries, divisions, affiliates, officers, directors, agents
and employees (the "Purchaser Parties") harmless from and against
any damage, loss, liability or expense, including reasonable
attorneys' fees and court costs (collectively, "Indemnifiable
Damages") incurred as a result of, or in connection with, any
untruth, inaccuracy, violation or breach of any representations,
warranties, or covenants of Seller set forth in this Agreement. 
Purchaser shall have the right to defend or compromise any claim,
proceeding or other action by any third party in its sole
discretion.  Prior to settling any claim, Purchaser shall consult
with Seller.  Purchaser need not follow any course of action
suggested by Seller, unless Seller deposits into escrow with legal
counsel for Purchaser under the terms of the escrow agreement to
which such legal counsel, Seller and Purchaser are parties, the
amount of potential liability and estimated defense expenses
associated with the claim, in which case Purchaser shall follow the
reasonable suggestions of Seller with respect to settlement of
claims.  Seller shall not be required to make such deposits until
Excess Claims (as defined in Section 12.1 (e) hereof) exist.

     (b)  Purchaser hereby agrees not to make any claim for
indemnity hereunder except in good faith and for reasonable cause. 
Purchaser will give Seller notice of each time that Purchaser
becomes aware of any fact or circumstance which may give rise to an
obligation of the Seller to indemnify any Purchaser Parties under
this Section, which notice shall be accompanied by a copy of any
claim made which may result in such indemnification obligation.
Notice shall be given as promptly as possible, but in no event more
than thirty (30) days after Purchaser becomes aware of the facts or
circumstances giving rise to the potential indemnification
obligation.  Failure to provide timely notice as required by this
Paragraph (b) shall not relieve Seller of its indemnification
obligations hereunder, unless such notice is not provided within
one hundred twenty (120) days after Purchaser becomes aware of the
facts or circumstances giving rise to the potential indemnification
obligation.

     (c)  Except with respect to any matter (i) which results from
the fraud or willful misconduct of Seller or any of its Affiliates,
or (ii) which involves the reporting, payment or liability for
federal, state, local and foreign taxes, or (iii) which involves

                                  25
<PAGE>

the title of Seller to the Assets, including any lien, encumbrance
or other claim against the Assets, Seller will have no obligation
to indemnify Purchaser hereunder, unless written notice of claim is
received by Seller no later than the first anniversary of the
Closing.  With respect to claims for indemnification involving the
matters which survive the first anniversary of the Closing
described in subclauses (i), (ii) and (iii) of this Section
12.1(c), no claim may be made later than the running of all
applicable statutes of limitation, after giving effect to any
tolling or waiver of any time periods or statutes of limitation
granted by Seller or any third party, if any.

     (d)  Any recovery by Purchaser for Indemnifiable Damages shall
be limited as follows: (i) Purchaser shall not be entitled to
recover any Indemnifiable Damages under this Article XII until the
aggregate amount of Purchaser's Indemnifiable Damages shall exceed
Fifty Thousand ($50,000) Dollars in the aggregate (the
"Deductible"), except that Purchaser shall be entitled to recover
Indemnifiable Damages for any claim that exceeds Twenty Five
Thousand ($25,000) Dollars notwithstanding that aggregate claims do
not exceed the Deductible; and (ii) in no event shall Seller be
liable for indemnification for an amount greater than the Purchase
Price.

     (e)  Purchaser shall be entitled to recover any Indemnifiable
Damages from funds other than the funds held by the Escrow Agent
only if Excess Claims exist.  "Excess Claims" shall be deemed to
exist if the aggregate unpaid claims of Purchaser for Indemnifiable
Damages (including Purchaser's estimate of the cost of defense of
any claim), that have not been resolved against Purchaser pursuant
to arbitration hereunder, exceed the amount then held by the escrow
agent for the purpose of compensating Purchaser for Indemnifiable
Damages.

     Section 12.2   Indemnification of Seller.  (a) From and after
the Closing, Purchaser will indemnify and hold Seller and its
subsidiaries, officers, directors, shareholders, agents and
employees (the "Seller Parties") harmless from and against any
Indemnifiable Damages incurred as a result of, or in connection
with, any untruth, inaccuracy, violation or breach of any
representations, warranties or covenants of Purchaser set forth in
this Agreement or out of the failure of Purchaser to pay, discharge
or perform any liability or obligation assumed by Purchaser
hereunder.

          (b)  Seller hereby agrees not to make any claim for
indemnity hereunder except in good faith and for reasonable cause. 
Seller will give Purchaser notice of each time that Seller becomes
aware of any fact or circumstance which may give rise to an
obligation of the Purchaser to indemnify any Seller Parties under
this Section, which notice shall be accompanied by a copy of any
claim made which may result in such indemnification obligation. 

                                  26
<PAGE>

Notice shall be given as promptly as possible but in no event more
than thirty (30) days after Seller becomes aware of the facts or
circumstances giving rise to the potential indemnification
obligation.  Failure to provide timely notice as required by this
Paragraph (b) shall not relieve Purchaser of its indemnification
obligations hereunder, unless such notice is not provided within
one hundred twenty (120) days after Seller becomes aware of the
facts or circumstances giving rise to the potential indemnification
obligation.

          (c)  Purchaser shall have no liability for any claim,
unless Seller has complied with the notice provisions of Section
12.2 (b) prior to the first anniversary of the Closing Date.  The
liability of Purchaser for indemnity hereunder shall be limited to
the actual direct damages suffered as a result of the untruth,
inaccuracy, violation or breach by Purchaser.  Seller shall not be
entitled to recover any Indemnifiable Damages under this Article
XII until the aggregate amount of Seller's Indemnifiable Damages
shall exceed Fifty Thousand ($50,000) Dollars in the aggregate (the
"Deductible"), except that Seller shall be entitled to recover
Indemnifiable Damages for any claim that exceeds Twenty Five
Thousand ($25,000) Dollars notwithstanding that aggregate claims do
not exceed the Deductible.  Notwithstanding the foregoing, in the
case of any breach by Purchaser of its obligations to pay Assumed
Liabilities (as defined in Section 2.1 hereof), the Deductible and
the one-year notice of claim requirement contained in this Section
12.2 (c) shall not apply to any claim for Indemnifiable Damages
made by Seller.

          Section 12.3   Other Remedies.  The remedies provided for
in this Article XII and the Escrow Agreement shall be in addition
to and not in lieu of any other remedies available to Purchaser
under this Agreement or otherwise.  Seller acknowledges that the
amount Purchaser is entitled to claim as Indemnifiable Damages is
not limited by the amount of the Escrowed Purchase Price.  All
claims of Purchaser or Seller under this Article XII shall be
deemed to be a "claim" for purposes of the Minnesota Uniform
Fraudulent Transfer Act.  Minn St. Section 513.41 (3).

          Section 12.4   Setoff.  Purchaser may withhold payment of
any obligation due to Seller to the extent Purchaser has reason to
believe (i) it is entitled to indemnification hereunder and (ii)
the amount of the indemnity obligation is equal to or greater than
the amount withheld.  Upon determination of such indemnification
rights, the indemnity obligation may be set-off against the
obligation for which payment was withheld or any other obligation
of Purchaser to Seller.

          Section 12.5   Knowledge of Breach  (a)  In the event any
party to whom a representation or warranty is made (the "Warranty
Receiving Party") pursuant to Article V or VI hereof has actual
knowledge on the Closing Date that the representation or warranty

                                  27
<PAGE>

is materially inaccurate or incomplete, the Warranty Receiving
Party shall not be entitled to Indemnifiable Damages caused by such
breached representation or warranty, unless the party making such
breached representation or warranty had actual knowledge at the
time the representation or warranty was made of the inaccuracy or
incompleteness of the representation or warranty.  Notwithstanding
that the Warranty Receiving Party is not entitled to Indemnifiable
Damages, the representation or warranty in question will be deemed
to have been breached for all purposes of this Agreement other than
the collection of Indemnifiable Damages, including the
determination whether conditions to closing by the Warranty
Receiving Party contained in Article IV hereof have been satisfied.

     (b)  The failure of any party to comply with any covenant or
agreement of such party pursuant to this Agreement shall entitle
the other party (the "Covenant Receiving Party") to Indemnifiable
Damages caused by such breach if the Covenant Receiving Party
decides to close the transactions contemplated hereby
nothwithstanding knowledge by the Covenant Receiving Party of the
breach by the other party.  Notwithstanding that Indemnifiable
Damages are available if the Covenant Receiving Party decides to
close the transactions contemplated hereby, the breach shall be
considered in determining whether conditions to closing by the
Covenant Receiving Party contained in Article IV hereof have been
satisfied.

                          ARTICLE XIII
                       GENERAL PROVISIONS

          Section 13.1   Survival of Representations, Warranties
and Agreements.  All representations, warranties and agreements in
this Agreement shall survive the Closing for a period of two years.

          Section 13.2   Notices.  All notices and other
communications hereunder shall be in writing and shall be deemed
given and effective (i) when delivered personally to the persons
named below at any location or (ii) when delivered by any means
(including Fax, mail or expedited delivery service, such as Federal
Express) to the locations provided below, addressed as follows:


     (a)  If to Purchaser to:

               EDITEK, Inc.
               1238 Anthony Rd.
               Burlington, NC 27215
               Attention:  James D. Skinner

               with copies to:

               Petree Stockton, L. L. P.
               4101 Lake Boone Trail, Suite 400

                                  28

<PAGE>

               Raleigh, NC  27607
               Attention:  James F. Verdonik, Esq.

     (b)  If to Seller, to:

               Medtox Laboratories, Inc.
               402 West County Road D
               New Brighton, MN  55112
               Attention: James S. Arrington

               with a copy to:


               Henson & Efron, P.A.
               1200 Title Insurance Building
               400 Second Avenue South
               Minneapolis, MN  55401
               Attention:  Alan C. Eidness, Esq.

     Any party hereto may change the address provided hereinabove
or the person to whom notice is to be given by giving notice to the
other parties in the manner hereinabove provided.


     Section 13.3   Miscellaneous.  This Agreement (including the
documents and instruments referred to herein) (a) constitutes the
entire agreement and supersedes all other prior agreements and
understandings, both written and oral, among the parties, or any of
them, with respect to the subject matter hereof; (b) shall not be
assigned except that Purchaser may assign this agreement to any
Affiliate of Purchaser or any subsequent purchaser of all or any
substantial part of the Assets, provided such assignment shall not
relieve Purchaser of any obligation of Purchaser hereunder; and (c)
shall be governed in all respects, including validity,
interpretation and effect, by the laws of the State of Minnesota
(without giving effect to the provisions thereof relating to
conflicts of law).  The invalidity or unenforceability of any
provision of this Agreement shall not affect the validity or
enforceability of any other provision of this Agreement, which
shall remain in full force and effect.

     Section 13.4   Dispute Resolution.  Any controversy or claim
between Seller and Purchaser arising out of or in connection with
this Agreement, other than a matter under one of the two escrow
agreements which shall be arbitrated as provided in such
agreements, shall be settled in binding arbitration in Chicago,
Illinois or at another location acceptable to both Seller and
Purchaser.  Seller or Purchaser may initiate arbitration by sending
notice of such initiation to the other party and to the American
Arbitration Association ("AAA").  Such arbitration shall be
conducted before a panel of three arbitrators (one appointed by
Seller, one appointed by Purchaser, and one appointed by the other

                                  29
<PAGE>

two so appointed all of which appointments shall be made within
twenty (20) days after arbitration is instituted) in accordance
with the then-current commercial arbitration rules of the AAA.  The
arbitrators shall make their determination within forty-five (45)
days after their appointment and the determination of the
arbitrator(s) shall be final, binding and nonappealable.  No party
shall be precluded hereby from seeking provisional remedies in the
courts of any jurisdiction, including, without limitation,
temporary restraining orders and preliminary injunctions, nor shall
the pursuit of such provisional relief constitute a waiver of such
party's right to arbitrate a dispute arising under this Agreement,
unless such waiver is expressed in writing and signed by such
party.  The losing party shall bear all costs of the arbitration.

     Section 13.5   Counterparts.  This Agreement may be executed
in two or more counterparts, each of which shall be deemed to be an
original, but all of which shall constitute one and the same
agreement.  Facsimile signatures shall be binding on all parties
upon delivery thereof.

     Section 13.6   Parties in Interest.  This Agreement shall be
binding upon and inure solely to the benefit of each party hereto
and nothing in this Agreement, express or implied, is intended to
confer upon any other person any rights or remedies of any nature
whatsoever under this Agreement.

          [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]
                                  30
<PAGE>

     IN WITNESS WHEREOF, Seller and Purchaser have caused this
Agreement to be signed by their respective officers thereunto duly
authorized as of the date first written above.


                         PURCHASER:


                         EDITEK, INC.

                         By:_________________________________
                         Title:______________________________
ATTEST:

[SEAL]


_______________________
          Secretary


                         MEDTOX LABORATORIES, INC.


                         By:_________________________________
                         Title:______________________________
ATTEST:

[SEAL]


_________________________
          Secretary

                                  31

<PAGE>

                                    EXHIBIT A

                                ESCROW AGREEMENT

         THIS  ESCROW  AGREEMENT  ("Agreement")  is  made  by and  among  MedTox
Laboratories,  a Minnesota  corporation  ("Seller"),  EDITEK,  Inc.,  a Delaware
corporation  ("Purchaser"),  and Henson & Efron, P.A., a Minnesota  professional
association (the "Escrow Agent").

         WHEREAS,  Seller and  Purchaser  have  executed and  delivered an Asset
Purchase  Agreement,  dated  effective  as of July 1, 1995 (the "Asset  Purchase
Agreement"),  pursuant  to which  Purchaser  is to  purchase  all the  assets of
Seller; and

         WHEREAS, Seller desires to have Purchaser deposit with the Escrow Agent
the amount of Five Hundred  Thousand Dollars  ($500,000)  Dollars to demonstrate
the good faith of Purchaser (the "Escrowed  Funds") for the Escrow Agent to hold
and deliver in accordance with the provisions of this Agreement.

         NOW, THEREFORE,  in consideration of the foregoing premises, the mutual
promises  contained  herein,  and other  good and  valuable  consideration,  the
receipt and  sufficiency  of which are hereby  acknowledged,  the parties hereto
agree as follows:

         1.  Deposits.  Immediately  upon  execution  and  delivery of the Asset
Purchase  Agreement,  Purchaser  shall deliver the Escrowed  Funds to the Escrow
Agent to hold and deliver in accordance with the provisions of this Agreement.

         2. Escrow Agent.  The Escrow Agent agrees to accept the Escrowed  Funds
from Purchaser and to hold and deliver the Escrowed Funds in accordance with the
provisions  of this  Agreement.  The Escrow  Agent  shall  issue to  Purchaser a
receipt for the Escrowed Funds and shall deliver to Seller a written notice that
the Escrowed Funds have been received by the Escrow Agent.  The Escrow Agent may
require any person to whom the Escrowed Funds are delivered to execute a receipt
therefor  as a  condition  to  delivery.  The  Escrow  Agent  is,  and  shall be
considered, an independent contractor, and not an agent of Seller or Purchaser.

         3.  Investment.  The Escrow  Agent shall hold the  Escrowed  Funds in a
trust account,  which may be interest bearing or noninterest bearing in the sole
discretion  of the Escrow  Agent.  In the event the Escrow  Agent is delivered a
written notice  executed by Seller and Purchaser,  which specifies an investment
of the Escrowed  Funds,  the Escrow Agent shall invest the Escrowed Funds in the
investment  specified in such written  notice.  The Escrow Agent shall implement
any order to sell or otherwise  change the  investment  contained in any written
notice executed by Seller and Purchaser.  If the investment expires prior to the
Escrow Agent  delivering  the Escrowed  Funds,  the Escrow Agent shall renew the
investment  in the same type of  investment,  unless the Escrow  Agent  receives
written notice executed by Seller and Purchaser  instructing the Escrow Agent to
not renew such investment, in which case the Escrow Agent shall


<PAGE>



implement such instructions. The Escrow Agent shall have no liability whatsoever
for any losses  associated  with  investment of the Escrowed  Funds or delays in
implementing  investment  instructions.  Any  interest,  gains or  other  income
derived from investment of the Escrowed Funds shall constitute Escrowed Funds to
be held and delivered by the Escrow Agent in accordance  with the  provisions of
this  Agreement.  The  Escrow  Agent  shall  pay any  expenses  associated  with
investments from the Escrowed Funds.

         4.  Notices.  The Escrow  Agent shall be  protected  in acting upon any
written  notice  request,  waiver,  consent,  receipt or other paper or document
furnished  to it in  accordance  with the terms of this  Agreement,  not only in
assuming its due execution and the validity and effectiveness of its provisions,
but also as to the truth and acceptability of any information therein contained,
which it in good faith believes to be genuine and what it purports to be.

         5. Additional Duties or Liabilities. In no event shall the Escrow Agent
be liable for any act or failure to act under the provisions of this  Agreement,
except where its acts are the result of its gross negligence or malfeasance. The
Escrow  Agent shall have no duties  except those which are  expressly  set forth
herein,  and it shall  not be bound by any  notice of a claim,  or  demand  with
respect  thereto,  or  any  waiver,  modification,   amendment,  termination  or
rescission  of this  Agreement,  unless  received  in writing by it, and, if its
duties or liabilities herein are affected,  unless it shall have given its prior
written consent thereto.

         6.  Indemnity.  The  parties  to  this  Agreement  hereby  jointly  and
severally  indemnify  the Escrow Agent  against any loss,  liability,  or damage
(other  than any caused by the gross  negligence  or  malfeasance  of the Escrow
Agent),  including reasonable costs of litigation and counsel fees, arising from
or in connection with the performance of its duties under this Agreement.

         7. Conditions to Release of Escrowed Funds. Seller and Purchaser hereby
agree that the  Escrowed  Funds shall be owned,  held and  delivered as provided
below:

(a)      The Escrowed Funds shall be owned by Purchaser until such time as it is
         determined  pursuant  to the terms of this  Section 7 or Section 8 that
         the Escrowed Funds are owned by Seller.

(b)      If the transactions contemplated by the Asset Purchase Agreement close,
         Five Hundred  Thousand  Dollars  ($500,000)  (or such lesser  amount if
         investment  losses and expenses have reduced the Escrowed Funds or such
         greater  amount if interest or other income has been earned),  shall be
         delivered  by  the  Escrow  Agent  to  Seller  at  the  closing  of the
         transactions  contemplated by the Asset Purchase  Agreement as a credit
         against the purchase price payable by Purchaser in connection  with the
         Asset Purchase Agreement.

(c)      Purchaser shall have the right to have the Escrowed Funds delivered to
         Purchaser, or to any designee of Purchaser, and all claims of Seller to
         the Escrowed Funds 
                                                         2

<PAGE>




         shall terminate,  upon the earlier to occur of (i) failure of Seller to
         satisfy all conditions to Purchaser's  obligation to close set forth in
         Sections 4.1, 4.2 and 4.4 of the Asset Purchase  Agreement on or before
         the Purchaser  Termination  Date (as defined in Section  10.1(c) of the
         Asset Purchase Agreement) or (ii) Purchaser's or Seller's determination
         not to close  the asset  purchase  contemplated  by the Asset  Purchase
         Agreement,  except  under the  circumstances  described in Section 7(d)
         hereof.

(d)      Seller  shall have the right to have the  Escrowed  Funds  delivered to
         Seller,  or a designee of Seller,  and all claims of  Purchaser  to the
         Escrowed  Funds shall  terminate,  if all the following  conditions are
         satisfied (i) all conditions to Purchaser closing set forth in Sections
         4.1, 4.2 and 4.4 of the Asset Purchase  Agreement,  have been satisfied
         on or before  the  Purchaser  Termination  Date (as  defined in Section
         10.1(c) of the Asset Purchase Agreement),  (ii) following  satisfaction
         of such conditions,  Purchaser shall fail to notify Seller on or before
         the Seller Termination Date (as defined in Section 10.1(b) of the Asset
         Purchase Agreement that Purchaser is ready,  willing and able to close,
         (iii)  Seller  terminates  the Asset  Purchase  Agreement  pursuant  to
         Section  10.1(b)  of the  Asset  Purchase  Agreement  before  Purchaser
         notifies  Seller that  Purchaser  is ready,  willing and able to close,
         (iv)  Purchaser's  failure to notify  Seller as to its ability to close
         was caused  solely by the failure of the  Purchaser  to raise an amount
         equal to the purchase price  pursuant to the Asset  Purchase  Agreement
         from sales of securities or loans and (v) Purchaser's  failure to raise
         such amount of funds was not caused,  in whole or in part,  directly or
         indirectly,  by Seller or any Affiliate of Seller other than by (x) any
         action of Seller taken after the date of this Agreement in the ordinary
         course of its business as previously  disclosed to Seller,  if such act
         would  not  breach  the Asset  Purchase  Agreement,  (y) any  aspect of
         Seller's financial condition or results of operations,  if the same has
         been disclosed to Purchaser by Seller in the Asset  Purchase  Agreement
         or in the due diligence  review of Seller by Purchaser  conducted prior
         to the date of the Asset  Purchase  Agreement  and (z) any  nonmaterial
         change in the  financial  condition or results of operations of Seller,
         if such nonmaterial  change was caused by any action of Seller (A) that
         is taken after the date of this  Agreement  in the  ordinary  course of
         business as  previously  disclosed to Purchaser  and (B) that would not
         breach the Asset Purchase Agreement. Notwithstanding clause (iv) of the
         preceding  sentence,  if Purchaser raises $24,000,000 (the amount equal
         to the purchase  price  pursuant to the Asset  Purchase  Agreement) and
         fails to raise  $30,000,000,  which is a condition to Purchaser closing
         pursuant to Section  4.4 (h) of the Asset  Purchase  Agreement,  and if
         Purchaser  shall  fail to  waive  such  Section  4.4  (h) of the  Asset
         Purchase  Agreement prior to the Seller  terminating the Asset Purchase
         Agreement  pursuant to Section  10.1 (b)  thereof,  Purchaser  shall be
         deemed not to have raised the  $24,000,000  for purposes of clause (iv)
         of the preceding sentence.
                                                    3

<PAGE>



(e)      Purchaser  shall have the right to have the Escrowed Funds delivered to
         Purchaser, or a designee of Purchaser,  and all claims of Seller to the
         Escrowed   Funds  shall   terminate,   upon   Purchaser's  or  Seller's
         determination not to close the asset purchase contemplated by the Asset
         Purchase Agreement except under the circumstances  described in Section
         7 (d) hereof.

(f)      Upon determination by Purchaser that Purchaser or Seller is entitled to
         delivery of the  Escrowed  Funds as provided  above in this  Section 7,
         Purchaser  may  instruct  the  Escrow  Agent in  writing  either (i) to
         deliver all or part of the Escrowed Funds to Seller,  in which case the
         Escrow Agent shall  deliver the specified  Escrowed  Funds to Seller as
         soon as practicable after receipt of such notice from Purchaser or (ii)
         to deliver all or part of the  Escrowed  Funds to  Purchaser,  in which
         case the Escrow Agent shall afford Seller the  opportunity to object to
         such  delivery as follows.  As soon as practical  after  receipt of the
         written  instructions from Purchaser,  the Escrow Agent shall provide a
         copy of such written instructions to Seller. Unless within fifteen (15)
         days  following the date the Escrow Agent sends to Seller a copy of the
         instructions  of  Purchaser,  the Escrow Agent  receives  from Seller a
         written notice executed by Seller objecting to delivery of the Escrowed
         Funds to  Purchaser,  the Escrow Agent shall  deliver to Purchaser  the
         Escrowed  Funds  specified  in  Purchaser's  notice,  and all claims of
         Seller to such specified Escrowed Funds shall terminate notwithstanding
         the  underlying  reasons  for the  failure to close the asset  purchase
         contemplated  by the Asset Purchase  Agreement.  Seller's rights to the
         Escrowed Funds shall survive delivery of such funds to the Purchaser.

(g)      Upon  determination  by Seller that Seller or  Purchaser is entitled to
         delivery of the  Escrowed  Funds as provided in this  Section 7, Seller
         may instruct  the Escrow Agent in writing  either (i) to deliver all or
         part of the Escrowed Funds to Purchaser, in which case the Escrow Agent
         shall  deliver the  specified  Escrowed  Funds to  Purchaser as soon as
         practicable  after receipt of such instructions from Seller, or (ii) to
         deliver all or part of the Escrowed Funds to Seller,  in which case the
         Escrow Agent shall afford  Purchaser the  opportunity to object to such
         delivery  as follows.  As soon as  practical  after  receipt of written
         instructions from Seller, the Escrow Agent shall provide a copy of such
         written  instructions  to Purchaser.  Unless  within  fifteen (15) days
         following  the date the Escrow  Agent sends to  Purchaser a copy of the
         instructions  of Seller,  the Escrow  Agent  receives a written  notice
         executed by Purchaser  objecting  to delivery of the Escrowed  Funds to
         Seller,  the Escrow Agent shall  deliver to Seller the  Escrowed  Funds
         specified in Seller's notice, and any balance owed to Purchaser and all
         claims of Purchaser to such specified  Escrowed  Funds shall  terminate
         notwithstanding  the  underlying  reasons  for the failure to close the
         asset purchase contemplated by the Asset Purchase Agreement.

(h)      Seller  and  Purchaser  hereby  agree  not to make  any  claim  for the
         Escrowed  Funds,  and not to dispute any claim for the  Escrowed  Funds
         made by the other party, except in good faith and for reasonable cause.

(i)      In performing  its duties as escrow agent  hereunder to hold or deliver
         the Escrowed  Funds,  the Escrow Agent shall follow the  provisions set
         forth  above and shall not allow any  

                                                         4

<PAGE>



         independent  judgment  it may form about the  validity of any claims of
         either  Seller  or  Purchaser  to the  Escrowed  Funds  to  affect  its
         performance  hereunder,  notwithstanding any independent  knowledge the
         Escrow Agent may have of the validity or invalidity of such claims.

         8. Dispute Resolution.  Any controversy or claim between Seller and the
Escrow  Agent or  Purchaser  and the Escrow  Agent (but not any dispute  between
Purchaser and Seller,  which shall be arbitrated  pursuant to the Asset Purchase
Agreement)  arising out of or in connection with this Agreement shall be settled
in binding  arbitration in the City of  Minneapolis,  Minnesota.  Any of Seller,
Purchaser or the Escrow Agent may initiate arbitration by sending notice of such
initiation  to  the  other  parties  hereto  and  to  the  American  Arbitration
Association ("AAA"). Such arbitration shall be conducted before a panel of three
arbitrators  (one  appointed  by Seller,  one  appointed by  Purchaser,  and one
appointed by the other two so appointed, all of which appointments shall be made
within twenty (20) days after  arbitration is instituted) in accordance with the
then-current commercial arbitration rules of the AAA. The arbitrators shall make
their  decision  within  forty-five  (45) days after their  appointment  and the
determination of the arbitrator(s) shall be final, binding and nonappealable. No
party shall be precluded hereby from seeking provisional  remedies in the courts
of any jurisdiction, including, without limitation, temporary restraining orders
and preliminary  injunctions,  nor shall the pursuit of such provisional  relief
constitute a waiver of such party's  right to arbitrate a dispute  arising under
this  Agreement,  unless such waiver is  expressed in writing and signed by such
party.  The Escrow  Agent,  upon receipt of any order of any court or arbitrator
shall hold or deliver the  Escrowed  Funds in  accordance  with such order.  The
Escrow Agent shall not question  the  jurisdiction  or authority of the court or
arbitrator or whether the order is appealable.  The losing party,  if other than
the Escrow Agent, shall bear all costs of the arbitration.

         9. Payment of Fees. The Escrow Agent shall be entitled to reimbursement
of expenses,  plus a fee at its normal  hourly  rates,  for  performance  of its
duties  hereunder.  Fees and  expenses  shall be paid 50% by  Seller  and 50% by
Purchaser,  provided  that any fees or expenses of the Escrow  Agent  associated
with the  preparation  or  negotiation  of this  Agreement,  or any amendment or
modification for this Agreement shall be the exclusive responsibility of Seller.
The Escrow  Agent  shall not be  entitled  to deduct  expenses  or fees from the
Escrowed  Funds (except as provided  above with respect to expenses  incurred in
connection  with  investing the Escrowed  Funds),  nor shall the Escrow Agent be
entitled  to delay  delivery  of the  Escrowed  Funds on account of any  party's
failure to pay its fees or expenses.

         10.  Termination.  This Agreement  shall terminate upon delivery of the
Escrowed  Funds  pursuant to Section 7 hereof or pursuant to an order entered by
the arbitrator(s) pursuant to Section 8.

         11. Resignation or Removal of the Escrow Agent. The Escrow Agent may at
any time resign,  which  resignation  shall be effective on the thirtieth (30th)
day following the effective date of written notice of resignation sent to Seller
and  Purchaser.  Upon such  resignation,  the Escrow  Agent  shall  deliver  the
Escrowed  Funds to a substitute  Escrow  Agent  designated  in a written  
                                                         5

<PAGE>



notice  executed by both Seller and  Purchaser.  If Seller and Purchaser fail to
provide   written  notice  of  the  same   substitute   Escrow  Agent  prior  to
effectiveness of resignation,  the Escrow Agent shall deliver the Escrowed Funds
to a  substitute  Escrow  Agent of its own  choice and shall  notify  Seller and
Purchaser  of same.  The Escrow  Agent may be  removed at any time upon  written
notice  executed by both Seller and Purchaser,  whereupon the Escrow Agent shall
deliver the Escrowed Funds in accordance with the instructions set forth in such
notice.  Upon  delivery of the  Escrowed  Funds,  the duties of the Escrow Agent
hereunder shall immediately terminate.

         12.      Miscellaneous.

                  12.1 Entire Agreement.  This Agreement  constitutes the entire
agreement  between the parties hereto with respect to the subject matter hereof,
and  supersedes  any and all prior  agreements,  understandings,  promises,  and
representations  concerning the subject  matter hereof and the terms  applicable
thereto other than those expressly set forth herein.

                  12.2 Amendments.  This Agreement may not be modified, amended,
altered,  or supplemented  except by a written instrument executed and delivered
by all of the parties hereto.

                  12.3 Assignments:  Binding Effect. This Agreement shall not be
assigned by operation of law or otherwise  without the prior written  consent of
the other parties.  Subject to the preceding  sentence,  this Agreement shall be
binding upon, inure to the benefit of, and be enforceable by, the parties hereto
and their respective successors and assigns.

                  12.4  Severability.  If any  term or other  provision  of this
Agreement is invalid,  illegal,  or  unenforceable  by any rule of law or public
policy, all other conditions and provisions of this Agreement shall nevertheless
remain in full force and effect so long as the  economic or legal  substance  of
the  transactions  contemplated  hereby  is not  affected  in a manner  which is
materially  adverse  to any  party.  Upon  determination  that any term or other
provision  is invalid,  illegal,  or  unenforceable,  the parties  hereto  shall
negotiate  in good faith to modify this  Agreement  so as to effect the original
intent of the parties.

                  12.5 Notice.  Unless otherwise  expressly provided herein, all
notices and other  communications to be given or made pursuant to this Agreement
shall be in writing and if sent by the Escrow Agent shall be deemed to have been
received,  effective (i) on the third day following deposit in the United States
Mail, postage prepaid,  certified,  return receipt requested,  or (ii) or on the
day following  delivery to Federal  Express,  Express Mail, or other  nationally
recognized  expedited  mail or  package  service,  next day  delivery,  delivery
prepaid, addressed to the parties as follows:

If to Seller:                       Medtox Laboratories, Inc.
                                    402 West County Road D
                                    New Brighton, MN  55112
                                    Attn:  James S. Arrington


                                                         6

<PAGE>






With a copy to:                     Henson & Efron, P.A.
                                    1200 Title Insurance Building
                                    400 Second Avenue South
                                    Minneapolis, MN  55401
                                    Attn:  Alan C. Eidsness, Esq.

If to Purchaser:                    EDITEK, Inc.
                                    1238 Anthony Road
                                    Burlington, NC  27215
                                    Attn:  James D. Skinner

With a copy to:                     Petree Stockton, L.L.P.
                                    4101 Lake Boone Trail
                                    Suite 400
                                    Raleigh, NC  27607
                                    Attn: James F. Verdonik, Esq.

If to Escrow Agent:                 Henson & Efron, P.A.
                                    1200 Title Insurance Building
                                    400 Second Avenue South
                                    Minneapolis, MN  55401
                                    Attn:  Alan C. Eidsness, Esq.

                  Any notice sent by a party to the Escrow Agent shall be deemed
to have been  received by the Escrow  Agent when it is actually  received by the
Escrow  Agent at the  address  indicated  above.  Any  notice  sent by Seller or
Purchaser  to the other shall be subject to the notice  provisions  of the Asset
Purchase Agreement.

                  Any party hereto may change the address  provided  hereinabove
or the person to whose  attention  the notice is to be given by giving notice to
the other parties in the manner hereinabove provided.

                  12.6  Headings.  The headings  contained in this Agreement are
for  reference  purposes  only,  and shall not affect in any way the  meaning or
interpretation of this Agreement.

                  12.7 Governing  Law. This Agreement  shall be governed by, and
construed in  accordance  with,  the  substantive  law of the State of Minnesota
without giving effect to the principles of conflicts of law thereof.

                  12.8.  Counterparts.  This Agreement may be executed in one or
more counterparts,  each of which shall be deemed an original,  but all of which
shall together constitute one and the same instrument.
                                                         7

<PAGE>



                 

                  12.9  Waivers.  The failure of any party hereto to insist,  in
any one or more  instances,  upon the  performance  of any  term,  covenant,  or
condition of this Agreement,  or to exercise any rights hereunder,  shall not be
construed as a waiver or  relinquishment  of the future  performance of any such
term,  covenant,  or condition,  or the future  exercise of such right,  but the
obligations of the non-performing  party with respect to such future performance
shall continue in full force and effect.

                  12.10 Further Assurances.  The parties hereto will execute and
deliver all such further documents and instruments, and take all further actions
as may be necessary to consummate the transactions contemplated hereby.

                  12.11  Escrow  Agent  Representation  of Seller;  Conflict  of
Interest.  The  parties  hereby  acknowledge  that the  Escrow  Agent  regularly
represents  Seller as legal counsel and has acted as legal counsel for Seller in
connection  with  the  negotiation  of the  Asset  Purchase  Agreement  and this
Agreement.  Purchaser  agrees that it will not raise any objection to any future
representation  of Seller by the Escrow  Agent on  account  of the Escrow  Agent
acting as escrow agent pursuant to the Agreement, including, without limitation,
in connection with any dispute arising out of, or in connection  with, the Asset
Purchase Agreement or this Agreement.


                                                         8

<PAGE>


         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed as of this ___ day of June, 1995.


[CORPORATE SEAL]                      MEDTOX LABORATORIES, INC.


ATTEST:                               By:______________________________
                                         Name:_________________________
                                         Title:__________________________
By:_________________________
   ______________, Secretary

[CORPORATE SEAL]                      EDITEK, INC.

ATTEST:                               By:______________________________
                                         Name:_________________________
                                         Title:________________________
By:_________________________
   ______________, Secretary

                                      ESCROW AGENT:
                                      HENSON & EFRON, P.A.

                                      By:______________________________
                                         Name:_________________________
                                         Title:________________________


                                          9


<PAGE>
                                 EXHIBIT B

                             ESCROW AGREEMENT

     THIS ESCROW AGREEMENT ("Agreement") is made by and among MedTox
Laboratories, a Minnesota corporation ("Seller"), EDITEK, Inc., a
Delaware corporation ("Purchaser"), and Petree Stockton, L. L. P., a
North Carolina Limited Liability Partnership (the "Escrow Agent").

     WHEREAS, Seller and Purchaser have executed and delivered an Asset
Purchase Agreement dated effective as of July 1, 1995 (the "Asset
Purchase Agreement"), pursuant to which Purchaser is to purchase all the
assets of Seller; and

     WHEREAS, Article XII of the Asset Purchase Agreement provides for
Seller to indemnify Purchaser for Indemnifiable Damages (as defined in
the Asset Purchase Agreement); and

     WHEREAS, the Asset Purchase Agreement provides for Five Hundred
Thousand ($500,000) of the Purchase Price to be delivered into escrow by
Purchaser at the Closing to be held and delivered pursuant to this
Agreement (the "Escrowed Funds") for the Escrow Agent to provide a ready
source of payment to Purchaser should there be any Indemnifiable
Damages.

     NOW, THEREFORE, in consideration of the foregoing premises, the
mutual promises contained herein, and other good and valuable
consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

     1.    Deposits.  At the Closing Purchaser shall deliver the
Escrowed Funds to the Escrow Agent to hold and deliver in accordance
with the provisions of this Agreement.

     2.    Escrow Agent.  The Escrow Agent agrees to accept the Escrowed
Funds from Purchaser and to hold and deliver the Escrowed Funds in
accordance with the provisions of this Agreement.  The Escrow Agent
shall issue to Purchaser a receipt for the Escrowed Funds and shall
deliver to Seller a written notice that the Escrowed Funds have been
received by the Escrow Agent.  The Escrow Agent may require any person
to whom the Escrowed Funds are delivered to execute a receipt therefor
as a condition to delivery.  The Escrow Agent is, and shall be
considered, an independent contractor, and not an agent of Seller or
Purchaser.

     3.    Investment.  The Escrow Agent shall hold the Escrowed Funds
in a trust account, which may be interest bearing or noninterest bearing
in the sole discretion of the Escrow Agent. In the event the Escrow
Agent is delivered a written notice executed by Seller and Purchaser,
which specifies an investment of the Escrowed Funds, the Escrow Agent
shall invest the Escrowed Funds in the investment specified in such
written notice.  The Escrow Agent shall implement any order to sell or
otherwise change the investment contained in any written notice executed
by Seller and Purchaser.  If the investment expires prior to the Escrow
Agent delivering the Escrowed Funds, the Escrow Agent shall renew the
investment in the same type of investment, unless the Escrow Agent
receives written notice executed by Seller and Purchaser



<PAGE>


instructing the Escrow Agent to not renew such investment, in which case
the Escrow Agent shall implement such instructions.  The Escrow Agent
shall have no liability whatsoever for any losses associated with
investment of the Escrowed Funds, or delays in implementing investment
instructions.  Any interest, gains or other income derived from
investment of the Escrowed Funds shall constitute Escrowed Funds to be
held and delivered by the Escrow Agent in accordance with the provisions
of this Agreement.  The Escrow Agent shall pay any expenses associated
with investments from the Escrowed Funds.

     4.    Notices.  The Escrow Agent shall be protected in acting upon
any written notice request, waiver, consent, receipt or other paper or
document furnished to it in accordance with the terms of this Agreement,
not only in assuming its due execution and the validity and
effectiveness of its provisions, but also as to the truth and
acceptability of any information therein contained, which it in good
faith believes to be genuine and what it purports to be.

     5.    Additional Duties or Liabilities.  In no event shall the
Escrow Agent be liable for any act or failure to act under the
provisions of this Agreement, except where its acts are the result of
its gross negligence or malfeasance.  The Escrow Agent shall have no
duties except those which are expressly set forth herein, and it shall
not be bound by any notice of a claim, or demand with respect thereto,
or any waiver, modification, amendment, termination or rescission of
this Agreement, unless received in writing by it, and, if its duties or
liabilities herein are affected, unless it shall have given its prior
written consent thereto.

     6.    Indemnity.  The parties to this Agreement hereby jointly and
severally indemnify the Escrow Agent against any loss, liability, or
damage (other than any caused by the gross negligence or malfeasance of
the Escrow Agent), including reasonable costs of litigation and counsel
fees, arising from or in connection with the performance of its duties
under this Agreement.

     7.    Conditions to Release of Escrowed Funds.  Seller and
Purchaser hereby agree that the Escrowed Funds shall be owned, held and
delivered as provided below:

(a)  The Escrowed Funds shall be owned by Seller until such time as it
     is determined pursuant to the terms of this Section 7 or Section 8
     that the Escrowed Funds are owned by Purchaser.

(b)  In the event Purchaser has any claims for Indemnifiable Damages for
     which Seller may be responsible pursuant to the Asset Purchase
     Agreement, the following procedures shall be followed:

     (i)   Purchaser shall give written notice to Seller, and shall send
           a copy of such notice to the Escrow Agent, which notice shall
           set forth a detailed description of the claimed breach and
           the amount of loss, damage, cost or expense which Purchaser
           claims to have sustained by reason thereof;

                                   2

<PAGE>

     (ii)  The Escrow Agent shall pay to Purchaser the amount of such
           claim from the Escrowed Purchase Price upon the expiration of
           thirty (30) days from the date a copy of such notice is
           received by the Escrow Agent (the "Notice of Contest Period")
           if a written notice of dispute from Seller is not received by
           the Escrow Agent prior to expiration of the Notice of Contest
           Period; and

     (iii) If, prior to the expiration of the Notice of Contest Period,
           Seller shall notify Purchaser in writing of an intention to
           dispute the claim and if such dispute is not resolved by
           agreement of both Purchaser and Seller delivered to the
           Escrow Agent within 30 days after expiration of such Period
           (the "Resolution Period"), then any party may submit the
           dispute to arbitration pursuant to Section 8 hereof.

     (iv)  If a written notice of dispute from Seller is received by the
           Escrow Agent prior to expiration of the Notice of Contest
           Period, the Escrow Agent shall pay Purchaser the amount (i)
           set forth in any written instruction executed by Seller and
           Purchaser and/or (ii) set forth in any arbitration award or
           order pursuant to Section 8 hereof.

(c)  On the first anniversary of the date of this Agreement, the Escrow
     Agent shall pay to Seller the amount, if any, by which (i) the
     Escrowed Funds then held by the Escrow Agent on such date exceed
     (ii) the amount of claims against the Escrowed Funds made by
     Purchaser that have not been either paid from the Escrowed Funds or
     determined against Purchaser pursuant to Section 8 hereof.

(d)  Seller and Purchaser hereby agree not to make any claim for the
     Escrowed Funds, and not to dispute any claim for the Escrowed Funds
     made by the other party, except in good faith and for reasonable
     cause.

(e)  In performing its duties as escrow agent hereunder to hold or
     deliver the Escrowed Funds, the Escrow Agent shall follow the
     provisions set forth above and shall not allow any independent
     judgment it may form about the validity of any claims of either
     Purchaser or Seller to the Escrowed Funds under the terms of the
     Asset Purchase Agreement to affect its performance hereunder,
     notwithstanding any independent knowledge the Escrow Agent may have
     of the validity of such claims.

     8.    Dispute Resolution.  Any controversy or claim between Seller
and the Escrow Agent or between Purchaser and the Escrow Agent (but not any
dispute between Seller and Purchaser, which shall be arbitrated pursuant to the
Asset Purchase Agreement) arising out of or in connection with this
Agreement shall be settled in binding arbitration in the City of
Raleigh, North Carolina. Any of Seller, Purchaser or the Escrow Agent
may initiate arbitration by sending notice of such initiation to the
other parties hereto and to the American Arbitration Association
("AAA").  Such arbitration shall be conducted before a panel of three
arbitrators (one appointed by Seller, one appointed by Purchaser, and
one appointed by the other two so appointed all of which appointments
shall be made within twenty (20) days after arbitration is instituted) in

                                   3
<PAGE>

accordance with the then-current commercial arbitration rules of the
AAA.  The arbitrators shall make their decision within forty-five (45)
days after their appointment and the determination of the arbitrator(s)
shall be final, binding and nonappealable.  No party shall be precluded
hereby from seeking provisional remedies in the courts of any
jurisdiction, including, without limitation, temporary restraining
orders and preliminary injunctions, nor shall the pursuit of such
provisional relief constitute a waiver of such party's right to
arbitrate a dispute arising under this Agreement, unless such waiver is
expressed in writing and signed by such party.  The Escrow Agent, upon
receipt of any order of any court or arbitrator shall hold or deliver
the Escrowed Funds in accordance with such order.  The Escrow Agent
shall not question the jurisdiction or authority of the court or
arbitrator or whether the order is appealable.  The losing party, if
other than the Escrow Agent, shall bear all costs of the arbitration.

     9.    Payment of Fees.  The Escrow Agent shall be entitled to
reimbursement of expenses, plus a fee at its normal hourly rates, for
performance of its duties hereunder.  Fees and expenses shall be paid
50% by Seller and 50% by Purchaser, provided that any fees or expenses
of the Escrow Agent associated with the preparation or negotiation of
this Agreement, or any amendment or modification for this Agreement
shall be the exclusive responsibility of Purchaser. The Escrow Agent
shall not be entitled to deduct expenses or fees from the Escrowed Funds
(except as provided above with respect to expenses incurred in
connection with investing the Escrowed Funds), nor shall the Escrow
Agent be entitled to delay delivery of the Escrowed Funds on account of
any party's failure to pay its fees or expenses.

     10.   Termination.  This Agreement shall terminate upon delivery of
the Escrowed Funds pursuant to Section 7 hereof or pursuant to an order
entered by the arbitrator(s) pursuant to Section 8.

     11.   Resignation or Removal of the Escrow Agent.  The Escrow Agent
may at any time resign, which resignation shall be effective on the
thirtieth (30th) day following the effective date of written notice of
resignation sent to Seller and Purchaser.  Upon such resignation, the
Escrow Agent shall deliver the Escrowed Funds to a substitute Escrow
Agent designated in a written notice executed by both Seller and
Purchaser.  If Seller and Purchaser fail to provide written notice of
the same substitute Escrow Agent prior to effectiveness of resignation,
the Escrow Agent shall deliver the Escrowed Funds to a substitute Escrow
Agent of its own choice and shall notify Seller and Purchaser of same.
The Escrow Agent may be removed at any time upon written notice executed
by both Seller and Purchaser, whereupon the Escrow Agent shall deliver
the Escrowed Funds in accordance with the instructions set forth in such
notice.  Upon delivery of the Escrowed Funds, the duties of the Escrow
Agent hereunder shall immediately terminate.

     12.   Miscellaneous.

           12.1  Entire Agreement.  This Agreement constitutes the
entire agreement between the parties hereto with respect to the subject
matter hereof, and supersedes any and all prior agreements,
understandings, promises, and representations concerning the subject
matter hereof and the terms applicable thereto other than those
expressly set forth herein.

                                   4
<PAGE>


           12.2  Amendments. This Agreement may not be modified,
amended, altered, or supplemented except by a written instrument
executed and delivered by all of the parties hereto.

           12.3  Assignments: Binding Effect.  This Agreement shall not
be assigned by operation of law or otherwise without the prior written
consent of the other parties.  Subject to the preceding sentence, this
Agreement shall be binding upon, inure to the benefit of, and be
enforceable by, the parties hereto and their respective successors and
assigns.

           12.4  Severability.  If any term or other provision of this
Agreement is invalid, illegal, or unenforceable by any rule of law or
public policy, all other conditions and provisions of this Agreement
shall nevertheless remain in full force and effect so long as the
economic or legal substance of the transactions contemplated hereby is
not affected in a manner which is materially adverse to any party.  Upon
determination that any term or other provision is invalid, illegal, or
unenforceable, the parties hereto shall negotiate in good faith to
modify this Agreement so as to effect the original intent of the
parties.

           12.5  Notice.  Unless otherwise expressly provided herein,
all notices and other communications to be given or made pursuant to
this Agreement shall be in writing and if sent by the Escrow Agent shall
be deemed to have been received, effective (i) on the third day
following deposit in the United States Mail, postage prepaid, certified,
return receipt requested, or (ii) or on the day following delivery to
Federal Express, Express Mail, or other nationally recognized expedited
mail or package service, next day delivery, delivery prepaid, addressed
to the parties as follows:

If to Seller:         Medtox Laboratories, Inc.
                      402 West County Road D
                      New Brighton, MN  55112
                      Attn:  James S. Arrington

With a copy to:       Henson & Efron, P.A.
                      1200 Title Insurance Building
                      400 Second Avenue South
                      Minneapolis, MN  55401
                      Attn:  Alan C. Eidsness, Esq.


If to Purchaser:      EDITEK, Inc.
                      1238 Anthony Road
                      Burlington, NC  27215
                      Attn:  James D. Skinner

With a copy to:       Petree Stockton, L.L.P.
                      4101 Lake Boone Trail
                      Suite 400

                                   5
<PAGE>

                      Raleigh, NC  27607
                      Attn: James F. Verdonik, Esq.


If to Escrow Agent:   Henson & Efron, P.A.
                      1200 Title Insurance Building
                      400 Second Avenue South
                      Minneapolis, MN  55401
                      Attn:  Alan C. Eidsness, Esq.

     Any notice sent by a party to the Escrow Agent shall be deemed to
have been received when it is actually received by the Escrow Agent at
the address indicated above.  Any notice sent by Seller or Purchaser to
the other shall be subject to the notice provisions of the Asset
Purchase Agreement.

     Any party hereto may change the address provided hereinabove or the
person to whose attention the notice is to be given by giving notice to
the other parties in the manner hereinabove provided.

           12.6  Headings. The headings contained in this Agreement are
for reference purposes only, and shall not affect in any way the meaning
or interpretation of this Agreement.

           12.7  Governing Law.  This Agreement shall be governed by,
and construed in accordance with, the substantive law of the State of
North Carolina without giving effect to the principles of conflicts of
law thereof.

           12.8. Counterparts.  This Agreement may be executed in one or
more counterparts, each of which shall be deemed an original, but all of
which shall together constitute one and the same instrument.

           12.9  Waivers.  The failure of any party hereto to insist, in
any one or more instances, upon the performance of any term, covenant,
or condition of this Agreement, or to exercise any rights hereunder,
shall not be construed as a waiver or relinquishment of the future
performance of any such term, covenant, or condition, or the future
exercise of such right, but the obligations of the non-performing party
with respect to such future performance shall continue in full force and
effect.

           12.10 Further Assurances.  The parties hereto will execute
and deliver all such further documents and instruments, and take all
further actions as may be necessary to consummate the transactions
contemplated hereby.

           12.11  Escrow Agent Representation of Purchaser; Conflict of
Interest.  The parties hereby acknowledge that the Escrow Agent
regularly represents Purchaser as legal counsel and has acted as legal
counsel for Purchaser in connection with the Asset Purchase Agreement
and this Agreement.  Seller agrees that it will not raise any objection
to any future representation of


                                   6

<PAGE>


Purchaser by the Escrow Agent on account of the Escrow Agent acting as
escrow agent pursuant to the Agreement, including, without limitation,
in connection with any dispute arising out of, or in connection with,
the Asset Purchase Agreement or this Agreement.

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement
to be duly executed as of this ___ day of June, 1995.

[CORPORATE SEAL]                  MEDTOX LABORATORIES, INC.
ATTEST:                           By:______________________________
                                     Name:_________________________
                                     Title:__________________________
By:_________________________
   ______________, Secretary

[CORPORATE SEAL]                  EDITEK, INC.
ATTEST:                           By:______________________________
                                     Name:_________________________
                                     Title:________________________
By:_________________________
   ______________, Secretary
                                  ESCROW AGENT:

                                  PETREE STOCKTON, L. L. P.

                                  By:______________________________
                                     Name:_________________________
                                     Title:________________________


<PAGE>

                                    EXHIBIT C


                                                ______________, 1996


MedTox Laboratories, Inc.
402 West County Road D
New Brighton, MN  55112

         Re:      Sale of Certain Assets of MedTox Laboratories, Inc.

Gentlemen:

         This opinion letter is being delivered  pursuant to paragraph 4.3(b) of
that  certain  Asset  Purchase  Agreement  dated  effective  July 1, 1995 by and
between  MedTox  Laboratories,  Inc., a Minnesota  corporation  ("Seller"),  and
EDITEK, Inc., a Delaware corporation  ("Purchaser"),  as amended by an Amendment
Agreement  dated as of  December  1, 1995  (the  "Purchase  Agreement"),  in our
capacity as counsel to Purchaser in connection with the  negotiation,  execution
and  delivery of the  Purchase  Agreement  and the  closing of the  transactions
contemplated by the Purchase Agreement.

         Capitalized  terms used in this  opinion  letter and not  defined in it
have the respective meanings given to those terms in the Purchase Agreement.

         In our  capacity  as  such  counsel,  we  have  reviewed  the  Purchase
Agreement (including the exhibits and schedules thereto), agreements in the form
attached  as  Exhibits  to the  Purchase  Agreement,  as amended  ("the  Exhibit
Agreements"),   the  Certificate  of  Incorporation  (as  amended),  Bylaws  (as
amended),  and minutes of meetings of the Board of Directors and stockholders of
Purchaser and such other  documents,  records,  agreements and  certificates and
have made such inquiries as we deemed appropriate.  We have relied as to factual
matters upon  certificates  of officers of  Purchaser,  but we have no reason to
believe the facts stated  therein are incorrect,  incomplete or misleading,  and
upon certificates or statements or both of various  governmental  officials.  In
all  examinations  of  such  documents,  we  have  assumed  the  genuineness  of
signatures on original documents and the conformity to original documents of all
copies submitted to us as certified, conformed or 

<PAGE>



photographic  copies,  the legal  competence  of  natural  persons  and that the
Purchaser  Delivered  Documents (as defined below) are  enforceable  against all
parties thereto (other than Purchaser). As to certificates or statements or both
of public  officials,  we have assumed that they have been properly given and to
be accurate.

         Except as set forth in the following  sentence,  the opinions set forth
in this  letter are based upon and limited to (i) the laws of the State of North
Carolina,  (ii) the General Corporation Law of the State of Delaware,  and (iii)
the  federal  laws of the United  States of  America,  and we express no opinion
herein concerning the laws of any other jurisdiction.  The opinions set forth in
numbered  paragraphs  1, 2(a) and 2(b) below are also based upon and  limited to
the Delaware General Corporation Law.

         Based  upon  the  foregoing  and  subject  to  the  qualifications  and
limitations set forth herein, we are of the following opinions:

                           1.  Purchaser  is a  corporation  duly  incorporated,
         organized  and  entitled  to  conduct  business  under,  and is validly
         existing and in good standing under, the laws of the State of Delaware.

                           2. With  respect to the  Purchase  Agreement  and any
         other agreements,  instruments and documents  executed and delivered by
         Purchaser  pursuant to the Purchase Agreement  (collectively,  together
         with the Purchase Agreement, the "Purchaser Delivered Agreements"):

                                    (a)  Buyer  has  the  corporate   power  and
                  authority  to execute  and  deliver  the  Purchaser  Delivered
                  Agreements and to consummate the transactions contemplated by,
                  and otherwise to comply with and perform under, them;

                                    (b) the  execution and delivery by Purchaser
                  of the Purchaser  Delivered  Agreements,  the  consummation by
                  Purchaser  of  the  transactions   contemplated  by  them  and
                  Purchaser's  other  compliance with or performance  under them
                  have been duly authorized by all necessary corporate action on
                  the part of  Purchaser  in  compliance  with any  governing or
                  applicable   agreements,   

<PAGE>


                  instruments or other documents  (including  without limitation
                  its  Certificate of  Incorporation  and Bylaws) and applicable
                  law; and

                  (c) Buyer has duly executed and delivered the Buyer  Delivered
                  Agreements.

                           3.  The  Purchaser  Delivered  Agreements  constitute
         valid and binding agreements of Purchaser that are enforceable  against
         it in accordance with their terms.

                           4. Neither the execution and delivery by Purchaser of
         the Purchaser Delivered Agreements nor the consummation by Purchaser of
         the  transactions  contemplated  thereby nor other  compliance  with or
         performance  under them will (with the passage of time or the giving of
         notice or both)  constitute a violation of (i) any term or provision of
         the  Certificate  of  Incorporation  or Bylaws of  Purchaser,  (ii) any
         permit,  judgment,  decree or order of any governmental authority known
         to us or (iii) any  applicable  law which in our experience is normally
         applicable  to  the  transactions  of  the  type  contemplated  in  the
         Purchaser Delivered Agreements.

                           5. No consent,  approval,  order or authorization of,
         or registration, declaration of filing with, any governmental authority
         or other person on the part of Purchaser is required in connection with
         Purchaser's  execution  or delivery of the  Purchase  Agreement  or the
         other Purchaser Delivered  Agreements,  or Purchaser's  consummation of
         the transactions  contemplated by them or Purchaser's  other compliance
         with or performance  under them,  including the issuance of the Closing
         Shares and the Additional  Shares,  except that offers and sales of the
         Closing Shares and the Additional  Shares may require filings with, and
         approvals  by state  securities  regulators  following  the Closing and
         Purchaser is required to file a Form D with the Securities and Exchange
         Commission   following   the  Closing  and  the   performance   of  the
         Registration  Rights Agreement will require filings with, and approvals
         by, the Securities and Exchange Commission and various state securities
         regulators.

                           6. Upon issuance in accordance with the provisions of
         the Purchase  Agreement,  the Closing Shares and the Additional  Shares
         will constitute duly and validly authorized, fully-

<PAGE>


         paid and nonassessable shares of Common Stock of the Purchaser

         The   foregoing   opinions  are  further   subject  to  the   following
qualifications and assumptions:

                           Our opinions as to enforceability (i) are given as if
         the laws of the State of North Carolina govern the Purchase  Agreement,
         the  other  Purchaser  Delivered  Agreements  (ii)  may be  limited  by
         applicable  bankruptcy,  insolvency and other laws  (including  without
         limitation  fraudulent conveyance and other laws of similar import), by
         equitable principles affecting creditors' rights generally,  and by the
         discretion of the courts in granting equitable remedies  (regardless of
         whether such  enforceability is considered in a proceeding at law or in
         equity and  regardless  of whether  such  limitations  are derived from
         constitutions, statutes, judicial decisions or otherwise). In addition,
         no  opinion  is  expressed  herein  as to  the  enforceability  of  any
         provision   in   the   Registration    Rights    Agreement    regarding
         indemnification,  contribution or related matters set forth in Sections
         6 and 7 of the Registration Rights Agreement.

         In addition,  and subject to the  qualifications  and  assumptions  set
forth  previously  in this  letter,  we confirm to you that to our  knowledge no
litigation  or  other  proceeding  against  Purchaser  has  been  instituted  or
threatened to restrain or prohibit any of the  transactions  contemplated by the
Purchase Agreement.

         This opinion letter is delivered in connection with the consummation of
the transactions contemplated in the Purchase Agreement, may be relied upon only
by you and your counsel in connection  therewith,  may not be relied upon by you
for any other purpose or by anyone else for any purpose,  and may not be quoted,
published or otherwise disseminated without our prior written consent.

                                               Very truly yours,



                                               PETREE STOCKTON, L.L.P.

<PAGE>

                            EXHIBIT C


                      ______________, 1995


MedTox Laboratories, Inc.
402 West County Road D
New Brighton, MN  55112

     Re:  Sale of Certain Assets of MedTox Laboratories, Inc.

Gentlemen:

     This opinion letter is being delivered pursuant to paragraph
4.3(b) of that certain Asset Purchase Agreement (the "Purchase
Agreement") dated effective July 1, 1995 by and between MedTox
Laboratories, Inc., a Minnesota corporation ("Seller"), and EDITEK,
Inc., a Delaware corporation ("Purchaser"), in our capacity as
counsel to Purchaser in connection with the negotiation, execution
and delivery of the Purchase Agreement and the closing of the
transactions contemplated by the Purchase Agreement.

     Capitalized terms used in this opinion letter and not defined
in it have the respective meanings given to those terms in the
Purchase Agreement.

     In our capacity as such counsel, we have reviewed the Purchase
Agreement (including the exhibits and schedules thereto),
agreements in the form attached as Exhibits to the Purchase
Agreement ("the Exhibit Agreements") the Certificate of
Incorporation (as amended), Bylaws (as amended), and minutes of
meetings of the Board of Directors and stockholders of Purchaser
and such other documents, records, agreements and certificates and
have made such inquiries as we deemed appropriate.  We have relied
as to factual matters upon certificates of officers of Purchaser,
but we have no reason to believe the facts stated therein are
incorrect, incomplete or misleading, and upon certificates or
statements or both of various governmental officials.  In all
examinations of such documents, we have assumed the genuineness of
signatures on original documents and the conformity to original
documents of all copies submitted to us as certified, conformed or
photographic copies, the legal competence of natural persons and
that the Purchaser Delivered Documents (as defined below) are
enforceable against all parties thereto (other than Purchaser).  As
to certificates or statements or both of public officials, we have
assumed that they have been properly given and to be accurate.

     Except as set forth in the following sentence, the opinions
set forth in this letter are based upon and limited to (i) the laws
of the State of North Carolina, (ii) the General Corporation Law of
the State of Delaware, and (iii) the federal laws of the United
States of America, and we express no opinion herein concerning the

<PAGE>

MedTox Laboratories, Inc.
                 , 1995
Page 2


laws of any other jurisdiction.  The opinions set forth in numbered
paragraphs 1, 2(a) and 2(b) below are also based upon and limited
to the Delaware General Corporation Law.

     Based upon the foregoing and subject to the qualifications and
limitations set forth herein, we are of the following opinions:

          1.   Purchaser is a corporation duly incorporated,
     organized and entitled to conduct business under, and is
     validly existing and in good standing under, the laws of the
     State of Delaware.

          2.   With respect to the Purchase Agreement and any other
     agreements, instruments and documents executed and delivered
     by Purchaser pursuant to the Purchase Agreement (collectively,
     together with the Purchase Agreement, the "Purchaser Delivered
     Agreements"):

               (a)  Buyer has the corporate power and authority to
          execute and deliver the Purchaser Delivered Agreements
          and to consummate the transactions contemplated by, and
          otherwise to comply with and perform under, them;

               (b)  the execution and delivery by Purchaser of the
          Purchaser Delivered Agreements, the consummation by
          Purchaser of the transactions contemplated by them and
          Purchaser's other compliance with or performance under
          them have been duly authorized by all necessary corporate
          action on the part of Purchaser in compliance with any
          governing or applicable agreements, instruments or other
          documents (including without limitation its Certificate
          of Incorporation and Bylaws) and applicable law; and

               (c)  Buyer has duly executed and delivered the Buyer
          Delivered Agreements.

          3.   The Purchaser Delivered Agreements constitute valid
     and binding agreements of Purchaser that are enforceable
     against it in accordance with their terms.

          4.   Neither the execution and delivery by Purchaser of
     the Purchaser Delivered Agreements nor the consummation by
     Purchaser of the transactions contemplated thereby nor other
     compliance with or performance under them will (with the
     passage of time or the giving of notice or both) constitute a
     violation of (i) any term or provision of the Certificate of
     Incorporation or Bylaws of Purchaser, (ii) any permit,
     judgment, decree or order of any governmental authority known
     to us or (iii) any applicable law which in our experience is

<PAGE>

MedTox Laboratories, Inc.
                 , 1995
Page 3


     normally applicable to the transactions of the type
     contemplated in the Purchaser Delivered Agreements.

          5.   No consent, approval, order or authorization of, or
     registration, declaration of filing with, any governmental
     authority or other person on the part of Purchaser is required
     in connection with Buyer's execution or delivery of the
     Purchase Agreement or the other Purchaser Delivered
     Agreements, or Purchaser's consummation of the transactions
     contemplated by them or Purchaser's other compliance with or
     performance under them.

     The foregoing opinions are further subject to the following
qualifications and assumptions:

               Our opinions as to enforceability (i) are given as
     if the laws of the State of North Carolina govern the Purchase
     Agreement, the other Purchaser Delivered Agreements (ii) may
     be limited by applicable bankruptcy, insolvency and other laws
     (including without limitation fraudulent conveyance and other
     laws of similar import), by equitable principles affecting
     creditors' rights generally, and by the discretion of the
     courts in granting equitable remedies (regardless of whether
     such enforceability is considered in a proceeding at law or in
     equity and regardless of whether such limitations are derived
     from constitutions, statutes, judicial decisions or
     otherwise).

     In addition, and subject to the qualifications and assumptions
set forth previously in this letter, we confirm to you that to our
knowledge no litigation or other proceeding against Purchaser has
been instituted or threatened to restrain or prohibit any of the
transactions contemplated by the Purchase Agreement.

     This opinion letter is delivered in connection with the
consummation of the transactions contemplated in the Purchase
Agreement, may be relied upon only by you and your counsel in
connection therewith, may not be relied upon by you for any other
purpose or by anyone else for any purpose, and may not be quoted,
published or otherwise disseminated without our prior written
consent.

                                   Very truly yours,



                                   PETREE STOCKTON, L.L.P.




<PAGE>

                          EXHIBIT D



                          _______, 1996








EDITEK, Inc.
1238 Anthony Road
Burlington, NC  27215

     Re:  Sale of Certain Assets of MedTox Laboratories

Gentlemen:

     This opinion letter is being delivered pursuant to paragraph
4.4(b) of that certain Asset Purchase Agreement dated effective
July 1, 1995 by and between MedTox Laboratories, a Minnesota
corporation ("Seller"), and EDITEK, Inc., a Delaware corporation
("Purchaser"), as amended by an Amendment Agreement dated as of
December 1, 1995 (the "Purchase Agreement"), in our capacity as
counsel to Seller in connection with the negotiation, execution
and delivery of the Purchase Agreement and the closing of the
transactions contemplated by the Purchase Agreement.

     Capitalized terms used in this opinion letter and not
defined in it have the respective meanings given to those terms
in the Purchase Agreement.

     In our capacity as such counsel, we have reviewed the
Purchase Agreement, as amended (including the exhibits and
schedules thereto), the Articles of Incorporation (as amended),
Bylaws (as amended), and minutes books of Seller and such other
documents, records, agreements and certificates and have made
such inquiries as we deemed appropriate.  We have relied as to
factual matters upon a certificate of an officer of Seller, but
we have no reason to believe the facts stated therein are
incorrect, incomplete or misleading, and upon certificates or
statements or both of various governmental officials.  In all
examinations of such documents, we have assumed the genuineness
of signatures on original documents and the conformity to
original documents of all copies submitted to us as certified,
conformed or photographic copies, the legal competence of natural
persons and that the Seller Delivered Agreements (as defined
below) are enforceable against all parties thereto (other than
Seller).  As to certificates or statements or both of public

<PAGE>

EDITEK, Inc.
           , 1996
Page 2

officials, we have assumed that they have been properly given and
to be accurate.

     Except as set forth in the following sentence, the opinions
set forth in this letter are based upon and limited to (i) the
laws of the State of Minnesota and (ii) the federal laws of the
United States of America, and we express no opinion herein
concerning the laws of any other jurisdiction.  

     Based upon the foregoing and subject to the qualifications
and limitations set forth herein, we are of the following
opinions:

          1.   Seller and The Forensic Resource Group, Inc.
("Subsidiary") are corporations duly incorporated, organized and
entitled to conduct business under, and are validly existing and
in good standing under the laws of the State of Minnesota.

          2.   Seller and Subsidiary have all requisite corporate
power and authority to own, operate and lease their properties
and to carry on their businesses as conducted on the date hereof. 
Seller is qualified or licensed to do business in the States of
Illinois, California, New Jersey and Connecticut.

          3.   With respect to the Purchase Agreement and any
other agreements, instruments and documents executed and
delivered by Seller, pursuant to the Purchase Agreement
(collectively, together with the Purchase Agreement, the "Seller
Delivered Agreements"):

               (a)  Seller has the corporate power and authority
to execute and deliver the Seller Delivered Agreements to which
it is a party and to consummate the transactions contemplated by,
and otherwise to comply with and perform under, them;

               (b)  The execution and delivery by Seller of the
Seller Delivered Agreements, the consummation by Seller of the
transactions contemplated by them and Seller's other compliance
with or performance under them have been duly authorized by all
necessary corporate action on the part of Seller in compliance
with any governing or applicable agreements, instruments or other
documents (including without limitation its Articles of
Incorporation and Bylaws) and applicable law, and no other
corporate action or proceeding on the part of Seller or any of
its shareholders, directors or officers is necessary for the
execution, delivery and performance of the Seller Delivered

<PAGE>


EDITEK, Inc.
           , 1996
Page 3

Agreements by Seller and the consummation of the transactions
contemplated hereby.  

               (c)  Seller has duly executed and delivered the
Seller Delivered Agreements; and

               (d)  the transfer instruments included in the
Seller Delivered Agreements effectively convey to Purchaser all
of Seller's right, title and interest to and in the Assets.

          4.   The Seller Delivered Agreements (including without
limitation the transfer instruments delivered by Seller with
respect to the Assets) constitute valid and binding obligations
of Seller enforceable against it in accordance with their terms, 
except as enforceability may be limited by bankruptcy,
insolvency, reorganization, moratorium and other similar laws
relating to or affecting creditors' rights generally, by general
equitable principles and by discretion of the courts in granting
equitable remedies (regardless of whether such enforceability is
considered in a proceeding in equity or at law).  In addition, no
opinion is expressed herein as to the enforceability of any
provision in the Registration Rights Agreement regarding
indemnification, contribution or related matters set forth in
Sections 6 and 7 of the Registration Rights Agreement.

          5.   The Noncompetition Agreements have been duly
executed and delivered by Harry G. McCoy and D. Gary Hemphill and
constitute valid and binding obligations of each of them
enforceable against them in accordance with their respective
terms, except as enforceability may be limited by bankruptcy,
insolvency, reorganization, moratorium and other similar laws
relating to or affecting creditors' rights generally, by general
equitable principles and by discretion of the courts in granting
equitable remedies (regardless of whether such enforceability is
considered in a proceeding in equity or at law).

          6.   Except as set forth in the Purchase Agreement,
neither the execution or delivery of the Seller Delivered
Agreements nor the consummation by Seller of the transactions
contemplated thereby nor other compliance with or performance
under them will (with the passage of time or the giving of notice
or both):

               (a)  constitute a violation of, constitute a
default or require any payment under, permit a termination of, or
result in the creation or imposition of any security interest,
lien or other encumbrance or adverse claim against Seller or upon

<PAGE>

EDITEK, Inc.
           , 1996
Page 4

any of the Assets (with or without due notice or lapse of time or
the happening or occurrence of any other event) under (i) any
term or provision of the Articles of Incorporation (as amended)
or Bylaws (as amended) of Seller, or (ii) any applicable law
which in our experience is normally applicable to transactions of
the type contemplated by the Purchase Agreement; or

               (b)  create, or cause the acceleration of the
maturity of, any indebtedness, obligation, or liability of Seller
known to us.

          7.   Except for any notice or filing which may be
required in connection with licenses and permits which are
identified by Seller in Schedule 6.16 to the Purchase Agreement,
no consent, approval, order or authorization of, or registration,
declaration or filing with, any governmental authority or other
person on the part of Seller is required in connection with
Seller's execution or delivery of the Purchase Agreement or the
other Seller Delivered Agreements, Seller's consummation of the
transactions contemplated by them, or Seller's other compliance
with or performance under them.

          8.   Except as set forth in the Disclosure Schedule to
the Purchase Agreement, to the best of our knowledge upon due
inquiry, (i) there is no action, suit, set of related actions or
suits concerning a common issue, complaint, arbitration, inquiry,
proceeding or investigation pending or threatened against or
involving Seller, Subsidiary or any of the Assets, before any
court, arbitrator or administrative or governmental body, and
there is no judgment, decree, injunction, rule or order of any
court, governmental department, commission, agency,
instrumentality or arbitrator outstanding against Seller,
Subsidiary or any of the Assets, which would, individually or in
the aggregate, if adversely determined against Seller or
Subsidiary, subject Seller or Subsidiary to liability in excess
of $25,000 for any single event or $50,000 for all events in the
aggregate, or result in a claim lien or other encumbrance on any
of the Assets; and (ii) there are no actions, suits or
proceedings pending or threatened against Seller, Subsidiary or
any of the Assets arising out of or in any way related to the
Seller Delivered Agreements, or any of the transactions
contemplated thereby.  We have not conducted any investigation to
determine whether, and Seller has not provided us with any
information that would cause us to, advise Seller that it is in
violation of any applicable material law, statute, ordinance,
order, rule or regulation promulgated or judgment, decree, order,
concession, grant, permit, license or other governmental

<PAGE>

EDITEK, Inc.
           , 1996
Page 5

authorization or approval, issued or entered by, any federal,
state or local, court or governmental authority relating to or
affecting the operation, conduct or ownership of the property or
business of Seller or Subsidiary.

          9.   The authorized capital stock of Seller consists of
50,000 shares of Common Stock, $1.00 par value per share, of
which 29,658 shares are issued and outstanding.  The authorized
capital stock of Subsidiary consists of 25,000 shares of Common
Stock, $1.00 par value per share, of which 1,000 shares are
issued and outstanding.  To the best of our knowledge upon due
inquiry, (i) there are no outstanding options, warrants,
subscriptions, conversion rights or other rights, agreements or
commitments obligating Seller or Subsidiary to issue any
additional shares of the capital stock of Seller or any other
securities convertible into, exchangeable for or evidencing the
right to subscribe for or acquire from Seller or Subsidiary or
any stock appreciation rights; (ii) no one other than the owner
disclosed in the Purchase Agreement has the right to vote any
shares of capital stock of Seller or Subsidiary; and (iii)
neither Seller nor Subsidiary owns, directly or indirectly, any
capital stock or other equity securities of any corporation or
have any direct or indirect equity or ownership interest in any
other business other than Subsidiary.

          10.  We have not conducted any investigation to
determine whether, and Seller has not provided us with any
information that would cause us to, advise Seller that it is in
violation of any provisions of ERISA or any other law, rule, or
regulation applicable to Seller's Plans.

          11.  Except as set forth in the Purchase Agreement, to
our actual knowledge, (i) Seller has good title to all the
Assets, free and clear of all liens, charges or encumbrances of
any nature whatsoever; and (ii) neither Seller nor Subsidiary has
granted any person or entity any license or other rights to the
Seller Intellectual Property.  Seller has not sought our advice
with respect to any claims by any other person or entity that the
business conducted by Seller and/or Subsidiary infringes the
intellectual property of any other person or entity and no person
or entity has asserted any such infringement claim and Seller has
not otherwise advised of any such claim or of any basis for any
such claim.

          12.  We have not conducted any investigation to
determine whether, and Seller has not provided us with any

<PAGE>

EDITEK, Inc.
           , 1996
Page 6


information that would cause us to, advise Seller that it is in
violation of any material Licenses.

          13.  To our actual knowledge, there are no false
statements by Seller in the Purchase Agreement or in any of the
Disclosure Schedules thereto.

     This opinion letter is delivered in connection with the
consummation of the transactions contemplated in the Purchase
Agreement, may be relied upon only by you and your counsel in
connection therewith, may not be relied upon by you for any other
purpose or by anyone else for any purpose, and may not be quoted,
published or otherwise disseminated without our prior written
consent.

                              Very truly yours,


                              

                              HENSON & EFRON, P.A.

<PAGE>

                               EXHIBIT D



                             _______, 1995








EDITEK, Inc.
1238 Anthony Road
Burlington, NC  27215

     Re:  Sale of Certain Assets of MedTox Laboratories

Gentlemen:

     This opinion letter is being delivered pursuant to paragraph
4.4(b) of that certain Asset Purchase Agreement (the "Purchase
Agreement") dated effective July 1, 1995 by and between MedTox
Laboratories, a Minnesota corporation ("Seller"), and EDITEK,
Inc., a Delaware corporation ("Purchaser"), in our capacity as
counsel to Seller in connection with the negotiation, execution
and delivery of the Purchase Agreement and the closing of the
transactions contemplated by the Purchase Agreement.

     Capitalized terms used in this opinion letter and not
defined in it have the respective meanings given to those terms
in the Purchase Agreement.

     In our capacity as such counsel, we have reviewed the
Purchase Agreement (including the exhibits and schedules
thereto), the Articles of Incorporation (as amended), Bylaws (as
amended), and minutes books of Seller and such other documents,
records, agreements and certificates and have made such inquiries
as we deemed appropriate.  We have relied as to factual matters
upon a certificate of an officer of Seller, but we have no reason
to believe the facts stated therein are incorrect, incomplete or
misleading, and upon certificates or statements or both of
various governmental officials.  In all examinations of such
documents, we have assumed the genuineness of signatures on
original documents and the conformity to original documents of
all copies submitted to us as certified, conformed or
photographic copies, the legal competence of natural persons and
that the Seller Delivered Agreements (as defined below) are
enforceable against all parties thereto (other than Seller).  As
to certificates or statements or both of public officials, we
have assumed that they have been properly given and to be
accurate.

<PAGE>

EDITEK, Inc.
            , 1995
Page 2

     Except as set forth in the following sentence, the opinions
set forth in this letter are based upon and limited to (i) the
laws of the State of Minnesota and (ii) the federal laws of the
United States of America, and we express no opinion herein
concerning the laws of any other jurisdiction.  

     Based upon the foregoing and subject to the qualifications
and limitations set forth herein, we are of the following
opinions:

          1.   Seller and The Forensic Resource Group, Inc.
("Subsidiary") are corporations duly incorporated, organized and
entitled to conduct business under, and are validly existing and
in good standing under the laws of the State of Minnesota.

          2.   Seller and Subsidiary have all requisite corporate
power and authority to own, operate and lease their properties
and to carry on their businesses as conducted on the date hereof. 
Seller is qualified or licensed to do business in the States of
Illinois, California, New Jersey and Connecticut.

          3.   With respect to the Purchase Agreement and any
other agreements, instruments and documents executed and
delivered by Seller, pursuant to the Purchase Agreement
(collectively, together with the Purchase Agreement, the "Seller
Delivered Agreements"):

               (a)  Seller has the corporate power and authority
to execute and deliver the Seller Delivered Agreements to which
it is a party and to consummate the transactions contemplated by,
and otherwise to comply with and perform under, them;

               (b)  The execution and delivery by Seller of the
Seller Delivered Agreements, the consummation by Seller of the
transactions contemplated by them and Seller's other compliance
with or performance under them have been duly authorized by all
necessary corporate action on the part of Seller in compliance
with any governing or applicable agreements, instruments or other
documents (including without limitation its Articles of
Incorporation and Bylaws) and applicable law, and no other
corporate action or proceeding on the part of Seller or any of
its shareholders, directors or officers is necessary for the
execution, delivery and performance of the Seller Delivered
Agreements by Seller and the consummation of the transactions
contemplated hereby.

<PAGE>

EDITEK, Inc.
            , 1995
Page 3

               (c)  Seller has duly executed and delivered the
Seller Delivered Agreements; and

               (d)  the transfer instruments included in the
Seller Delivered Agreements effectively convey to Purchaser all
of Seller's right, title and interest to and in the Assets.

          4.   The Seller Delivered Agreements (including without
limitation the transfer instruments delivered by Seller with
respect to the Assets) constitute valid and binding obligations
of Seller enforceable against it in accordance with their terms,
except as enforceability may be limited by bankruptcy,
insolvency, reorganization, moratorium and other similar laws
relating to or affecting creditors' rights generally, by general
equitable principles and by discretion of the courts in granting
equitable remedies (regardless of whether such enforceability is
considered in a proceeding in equity or at law).

          5.   The Noncompetition Agreements have been duly
executed and delivered by Harry G. McCoy and D. Gary Hemphill and
constitute valid and binding obligations of each of them
enforceable against them in accordance with their respective
terms, except as enforceability may be limited by bankruptcy,
insolvency, reorganization, moratorium and other similar laws
relating to or affecting creditors' rights generally, by general
equitable principles and by discretion of the courts in granting
equitable remedies (regardless of whether such enforceability is
considered in a proceeding in equity or at law).

          6.   Except as set forth in the Purchase Agreement,
neither the execution or delivery of the Seller Delivered
Agreements nor the consummation by Seller of the transactions
contemplated thereby nor other compliance with or performance
under them will (with the passage of time or the giving of notice
or both):

               (a)  constitute a violation of, constitute a
default or require any payment under, permit a termination of, or
result in the creation or imposition of any security interest,
lien or other encumbrance or adverse claim against Seller or upon
any of the Assets (with or without due notice or lapse of time or
the happening or occurrence of any other event) under (i) any
term or provision of the Articles of Incorporation (as amended)
or Bylaws (as amended) of Seller, or (ii) any applicable law
which in our experience is normally applicable to transactions of
the type contemplated by the Purchase Agreement; or

<PAGE>

EDITEK, Inc.
            , 1995
Page 4

               (b)  create, or cause the acceleration of the
maturity of, any indebtedness, obligation, or liability of Seller
known to us.

          7.   Except for any notice or filing which may be
required in connection with licenses and permits which are
identified by Seller in Schedule 6.16 to the Purchase Agreement,
no consent, approval, order or authorization of, or registration,
declaration or filing with, any governmental authority or other
person on the part of Seller is required in connection with
Seller's execution or delivery of the Purchase Agreement or the
other Seller Delivered Agreements, Seller's consummation of the
transactions contemplated by them, or Seller's other compliance
with or performance under them.

          8.   Except as set forth in the Disclosure Schedule to
the Purchase Agreement, to the best of our knowledge upon due
inquiry, (i) there is no action, suit, set of related actions or
suits concerning a common issue, complaint, arbitration, inquiry,
proceeding or investigation pending or threatened against or
involving Seller, Subsidiary or any of the Assets, before any
court, arbitrator or administrative or governmental body, and
there is no judgment, decree, injunction, rule or order of any
court, governmental department, commission, agency,
instrumentality or arbitrator outstanding against Seller,
Subsidiary or any of the Assets, which would, individually or in
the aggregate, if adversely determined against Seller or
Subsidiary, subject Seller or Subsidiary to liability in excess
of $25,000 for any single event or $50,000 for all events in the
aggregate, or result in a claim lien or other encumbrance on any
of the Assets; and (ii) there are no actions, suits or
proceedings pending or threatened against Seller, Subsidiary or
any of the Assets arising out of or in any way related to the
Seller Delivered Agreements, or any of the transactions
contemplated thereby.  We have not conducted any investigation to
determine whether, and Seller has not provided us with any
information that would cause us to, advise Seller that it is in
violation of any applicable material law, statute, ordinance,
order, rule or regulation promulgated or judgment, decree, order,
concession, grant, permit, license or other governmental
authorization or approval, issued or entered by, any federal,
state or local, court or governmental authority relating to or
affecting the operation, conduct or ownership of the property or
business of Seller or Subsidiary.

          9.   The authorized capital stock of Seller consists of
50,000 shares of Common Stock, $1.00 par value per share, of


<PAGE>

EDITEK, Inc.
            , 1995
Page 5

which 29,658 shares are issued and outstanding.  The authorized
capital stock of Subsidiary consists of 25,000 shares of Common
Stock, $1.00 par value per share, of which 1,000 shares are
issued and outstanding.  To the best of our knowledge upon due
inquiry, (i) there are no outstanding options, warrants,
subscriptions, conversion rights or other rights, agreements or
commitments obligating Seller or Subsidiary to issue any
additional shares of the capital stock of Seller or any other
securities convertible into, exchangeable for or evidencing the
right to subscribe for or acquire from Seller or Subsidiary or
any stock appreciation rights; (ii) no one other than the owner
disclosed in the Purchase Agreement has the right to vote any
shares of capital stock of Seller or Subsidiary; and (iii)
neither Seller nor Subsidiary owns, directly or indirectly, any
capital stock or other equity securities of any corporation or
have any direct or indirect equity or ownership interest in any
other business other than Subsidiary.

          10.  We have not conducted any investigation to
determine whether, and Seller has not provided us with any
information that would cause us to, advise Seller that it is in
violation of any provisions of ERISA or any other law, rule, or
regulation applicable to Seller's Plans.

          11.  Except as set forth in the Purchase Agreement, to
our actual knowledge, (i) Seller has good title to all the
Assets, free and clear of all liens, charges or encumbrances of
any nature whatsoever; and (ii) neither Seller nor Subsidiary has
granted any person or entity any license or other rights to the
Seller Intellectual Property.  Seller has not sought our advice
with respect to any claims by any other person or entity that the
business conducted by Seller and/or Subsidiary infringes the
intellectual property of any other person or entity and no person
or entity has asserted any such infringement claim and Seller has
not otherwise advised of any such claim or of any basis for any
such claim.

          12.  We have not conducted any investigation to
determine whether, and Seller has not provided us with any
information that would cause us to, advise Seller that it is in
violation of any material Licenses.

          13.  To our actual knowledge, there are no false
statements by Seller in the Purchase Agreement or in any of the
Disclosure Schedules thereto.

<PAGE>

EDITEK, Inc.
            , 1995
Page 6

     This opinion letter is delivered in connection with the
consummation of the transactions contemplated in the Purchase
Agreement, may be relied upon only by you and your counsel in
connection therewith, may not be relied upon by you for any other
purpose or by anyone else for any purpose, and may not be quoted,
published or otherwise disseminated without our prior written
consent.

                              Very truly yours,




                              HENSON & EFRON, P.A.



<PAGE>

                            EXHIBIT E

                FORM OF NONCOMPETITION AGREEMENT



     NONCOMPETITION AGREEMENT ("this Agreement") dated __________ ___,
1995 by and among EDITEK, INC., a Delaware corporation ("Purchaser") and
__________________ ("Employee").

     The parties to this Agreement, in consideration of the mutual
agreements set forth below in this Agreement (the mutuality, adequacy,
receipt and sufficiency of which are hereby acknowledged), hereby agree
as follows:

     1.   Background.  This Agreement is being executed and delivered
contemporaneously with and as a condition to the acquisition by
Purchaser of substantially all the assets of MedTox Laboratories, Inc.,
a Minnesota corporation ("Seller") the Company (the "Acquisition").
Seller is in the business of forensic, medical, clinical, biological
and/or pharmacological toxicology (the "Business").  Employee is
_______________________ of Seller. Employee understands that Purchaser
will not consummate such acquisition without the assurance that Employee
will not engage in the activities prohibited by this Agreement, and in
order to induce the Purchaser to consummate the acquisition and other
transactions contemplated by the acquisition agreement, Employee agrees
to restrict his actions as provided in this Agreement. Employee
acknowledges and agrees that such restrictions are reasonable in light
of the business of Seller and the direct and substantial benefits of the
acquisition to Employee.

     2.   Territory.  Employee acknowledges and agrees that Seller sells
its services throughout the United States (the "Territory") and that
Purchaser intends to continue and to increase its sales and operations
throughout the Territory.

     3.   Noncompetition Period.  The Noncompetition Period commences on
the date of this Agreement and shall terminate on the later of (i) the
second anniversary of the closing date of the Acquisition or (ii) the
first anniversary of termination of employment with Purchaser.

     4.   Noncompetition.  Employee agrees that during the
Noncompetition Period, he will not, directly or indirectly, either:

          (a)  have any interest in (whether as proprietor, officer,
          director or otherwise),

          (b)  enter the employment of,

          (c)  act as agent, broker, or distributor for or adviser or
          consultant to, or

<PAGE>

          (d)  provide information useful in conducting the Business to,
solicit customers or employees on behalf of or otherwise provide any
substantial assistance useful in conducting the Business to any person,
firm, corporation or business entity which is engaged, or which Employee
reasonably knows is undertaking to become engaged, in the Territory in
the Business or outside the Territory if sales are solicited from
customers located inside the Territory.

     Notwithstanding the foregoing, Employee shall not be prohibited
from (i) being employed by or acting as an agent, broker or distributor
for or advisor or consultant to any Non-Business Affiliate of a person,
division, firm, corporation, a business entity ("Parent") which
("Parent"), as one of its businesses, is or may become engaged in the
Business so long as (x) Employee has no relationship or contact with any
portion of Parent which is competitive with the Business, (y) Employee's
activities are not described in clause (d) above and (z) the Business
does not constitute more than ten (10%) of the aggregate revenues of
Parent on a consolidated basis; or (ii) owning not more than 1% of the
issued and outstanding securities of a publicly traded entity which may
be engaged in whole or in part in the Business.  A Non-Business
Affiliate is a person, division, firm, corporation or business entity
which does not, and is not preparing to, engage in the Business.

     5.   No Interference with Purchaser Customers.  Employee agrees
that during the Noncompetition Period, he will not, directly or
indirectly:

          (a)  solicit, divert or take away, or attempt to solicit,
divert or take away, the business of any Purchaser Customer; or

          (b)  attempt or seek to cause any of the Purchaser Customers
to refrain, in any respect, from maintaining or acquiring from or
through the Purchaser any product or service of the Business sold (or
offered for sale) to such Purchaser Customer by Seller or Purchaser
during the twelve-month period prior to the date of this Agreement or
during the Noncompetition Period.

     As used in this section, "Purchaser Customer" means any customer of
Seller or Purchaser located in the Territory served or solicited by
Seller or Purchaser within the twenty-four (24) month period prior to
termination of employment with Purchaser.

     6.   No Interference With Employees.  Employee agrees that for the
Noncompetition Period, he will not, directly or indirectly, request or
induce any employee of Purchaser to terminate his employment with
Purchaser or accept employment with another business entity engaged in
the Business in the Territory or which is located outside the Territory
if sales are solicited from customers located inside the Territory.

     7.   Notice to Others.  Employee hereby agrees that Purchaser may
disclose the provisions of this Agreement to any person or entity,
including without limitation one that at the time employs or is
considering employing Employee.

                                   2

<PAGE>

     8.   Remedies.  Employee acknowledges that any violation of this
Agreement may cause irreparable harm to Purchaser and that damages are
not an adequate remedy.  Employee therefore agrees that Purchaser shall
be entitled to injunctive relief, including temporary, preliminary and
permanent injunctions, by an appropriate court in the appropriate
jurisdiction, enjoining, prohibiting and restraining Employee from the
continuance of any such violation, in addition to any monetary damages
which might occur by reason of the violation of this Agreement.  The
remedies provided in this Agreement are cumulative and shall not exclude
any other remedies to which any party to this Agreement may be entitled
under this Agreement or applicable law, and the exercise of a remedy
shall not be deemed an election excluding any other remedy (any such
claim by the other party to this Agreement being hereby waived).

     9.   Modification.  It is understood and agreed by the parties
hereto that should any portion, provision or clause of the foregoing be
deemed too broad to permit enforcement to its full extent, then it shall
be enforced to the maximum extent permitted by law, and the Employee
hereby consents and agrees that such scope may be judicially modified
accordingly in any proceeding brought to enforce such restriction.

     10.  Independent.  The covenants and agreements set forth in this
Agreement shall be deemed, and shall be construed as, separate and
independent covenants and agreements, and should any part or provision
of such covenants or agreements be held invalid, void or unenforceable
by any court of competent jurisdiction, such invalidity, voidness or
unenforceability shall in no way render invalid, void or unenforceable
any other part or provision thereof or any separate covenant not
declared invalid, void or unenforceable; and this Agreement shall in
that case be construed as if the void, invalid or unenforceable
provisions were omitted.

     11.  Miscellaneous.

          (a)  Notice.  All notices under this Agreement shall be in
writing and given either in person, by express overnight service (with
all fees prepaid) or sent by registered or certified mail, return
receipt requested, postage prepaid, to the address of the party to this
Agreement set forth below his or its signature or to such other address
as a party to this Agreement may furnish to the other as provided in
this sentence, and shall be deemed received on the date of personal
delivery, on the first business day after sent by express overnight
service or on the date of delivery or attempted delivery as indicated by
the return receipt if sent by registered or certified mail; and if
notice is given pursuant to the foregoing of a permitted successor or
assign, then notice shall thereafter be given pursuant to the foregoing
to such permitted successor or assign.

          (b)  Assignment; Binding Effect.  No assignment, transfer or
delegation of any rights or obligations under this Agreement by a party
shall be made without the prior written consent of the other parties to
this Agreement (which shall not be unreasonably withheld.)  This
Agreement shall be binding upon the parties to this Agreement and their
respective legal representatives, heirs, devisees, legatees or other
successors and assigns, and shall inure to the benefit of the parties to
this Agreement and their respective permitted legal representatives,
heirs, devisees, legatees or other permitted successors and assigns.

                                  3
<PAGE>

          (c)  Gender; Captions.  Whenever the context so requires, the
singular number shall include the plural and the plural shall include
the singular, and the gender of any pronoun shall include the other
genders.  Titles and captions of or in this Agreement are inserted only
as a matter of convenience and for reference and in no way affect the
scope of this Agreement or the intent of its provisions.

          (d)  Certain Definitions.  The parties agree that "applicable
law" means all provisions of any constitution, statute, law, rule,
regulation, decision, order, decree, judgment, release, license, permit,
stipulation or the official pronouncement enacted, promulgated or issued
by any governmental authority or arbitrator or arbitration panel; that
"governmental authority" means any legislative, executive, judicial,
quasi-judicial or other public authority, agency, department, bureau,
division, unit, court or other public body, person or entity; and that
"including" and other words or phrases of inclusion, if any, shall not
be construed as terms of limitation, so that references to "included"
matters shall be regarded as non-exclusive, non- characterizing
illustrations.

          (e)  Entire Agreement.  This Agreement constitutes the entire
agreement of the parties to this Agreement with respect to its subject
matter, supersedes all prior agreements, if any, of the parties to this
Agreement with respect to its subject matter, and may not be amended
except in writing signed by the party to this Agreement against whom the
change is being asserted.

          (f)  No Waiver.  The failure of any party to this Agreement at
any time or times to require the performance of any provisions of this
Agreement shall in no manner affect the right to enforce the same; and
no waiver by any party to this Agreement of any provision (or of a
breach of any provision) of this Agreement, whether by conduct or
otherwise, in any one or more instances, shall be deemed or construed
either as a further or continuing waiver of any such provision or breach
or as a waiver of any other provision (or of a breach of any other
provision) of this Agreement.

          (g)  Governing Law.  This Agreement shall be governed by,
construed and enforced in accordance with the laws of the State of
Minnesota.

          (h)  Counterparts.  This Agreement may be executed in two or
more copies, each of which shall be deemed an original, and it shall not
be necessary in making proof of this Agreement or its terms to produce
or account for more than one of such copies.



     DULY EXECUTED and delivered by the parties to this Agreement, under
seal, on _____________, 1995.


THE EMPLOYEE:

                                 4
<PAGE>

                              __________________________________(SEAL)


                              Address:
                              __________________________________
                              __________________________________

THE PURCHASER:           EDITEK, INC.

                              By:________________________________
                              Name:______________________________
                              Title:_____________________________

                              Address:
                              __________________________________
                              __________________________________


                             5
<PAGE>



                               EXHIBIT G

                             _______, 1995



EDITEK, Inc.
1238 Anthony Road
Burlington, NC  27215

     Re:  Sale of Certain Assets of MedTox Laboratories

Gentlemen:

     This opinion letter is being delivered pursuant to paragraph
8.2 of that certain Asset Purchase Agreement (the "Purchase
Agreement") dated effective July 1, 1995 by and between MedTox
Laboratories, a Minnesota corporation ("Seller"), and EDITEK,
Inc., a Delaware corporation ("Purchaser"), in our capacity as
counsel to Seller in connection with the negotiation, execution
and delivery of the Purchase Agreement and the closing of the
transactions contemplated by the Purchase Agreement.

     Capitalized terms used in this opinion letter and not
defined in it have the respective meanings given to those terms
in the Purchase Agreement.

     In our capacity as such counsel, we have reviewed the
Purchase Agreement (including the exhibits and schedules
thereto), the Articles of Incorporation (as amended), Bylaws (as
amended), and minutes books of Seller and such other documents,
records, agreements and certificates and have made such inquiries
as we deemed appropriate.  We have relied as to factual matters
upon a certificate of an officer of Seller, and we have no reason
to believe the facts stated therein are incorrect, incomplete or
misleading.  In all examinations of such documents, we have
assumed the genuineness of signatures on original documents and
the conformity to original documents of all copies submitted to
us as certified, conformed or photographic copies, the legal
competence of natural persons and that the Seller Delivered
Agreements (as defined below) are enforceable against all parties
thereto (other than Seller).  As to certificates or statements or
both of public officials, we have assumed that they have been
properly given and to be accurate.

     Except as set forth in the following sentence, the opinions
set forth in this letter are based upon and limited to (i) the
laws of the State of Minnesota and (ii) the federal laws of the
United States of America, and we express no opinion herein
concerning the laws of any other jurisdiction.

<PAGE>

            , 1995
Page 2

     Based upon the foregoing and subject to the qualifications
and limitations set forth herein, we are of the following
opinion:

     The Purchase Agreement and any other agreements, instruments
and documents to be executed and delivered by Seller, pursuant to
the Purchase Agreement are hereinafter collectively referred to
as the "Seller Delivered Agreements").

     The execution and delivery by Seller of the Seller Delivered
Agreements, the consummation by Seller of the transactions
contemplated by them and Seller's other compliance with or
performance under them have been duly authorized by all necessary
corporate action on the part of Seller, including approval by
Seller's Board of Directors on ________, 1995 and approval by
Seller's shareholders on ________, 1995.

     This opinion letter is delivered in connection with the
consummation of the transactions contemplated in the Purchase
Agreement, may be relied upon only by you and your counsel in
connection therewith, may not be relied upon by you for any other
purpose or by anyone else for any purpose, and may not be quoted,
published or otherwise disseminated without our prior written
consent.

                              Very truly yours,




                              HENSON & EFRON, P.A.





                               AMENDMENT AGREEMENT

         AGREEMENT   dated  as  of  January  2,  1996   between   EDITEK,   Inc.
("Purchaser") and MedTox Laboratories, Inc. ("Seller").

                                   WITNESSETH:

         WHEREAS,  Seller and Purchaser are parties to a certain Asset  Purchase
Agreement dated July 1, 1995 (the "Purchase Agreement"), and desire to delay the
closing of the  transactions  contemplated by the Purchase  Agreement until 1996
and to change the nature of the consideration to be paid to Seller by Purchaser.

         NOW,  THEREFORE,  in  consideration  of the  premises  and  the  mutual
promises of the parties set forth below, the parties hereby agree as follows:

(1)      The  Purchase  Agreement  is  hereby  amended  so that  (i) the  Seller
         Termination  Date  referred  to in  Section  10.1  (b),  the  Purchaser
         Termination  Date  referred  to  in  Section  10.1  (c)  and  the  date
         contemplated  by Section  10.1 (d) of the  Purchase  Agreement  are all
         changed to January 15,  1996,  and (ii) Section 4.1 is changed to allow
         Purchaser  to set a Closing Date to be not earlier than January 1, 1996
         and not later than the new Seller Termination Date.

(2)      The Escrow Agent is hereby authorized  pursuant to the Escrow Agreement
         attached   to  the   Purchase   Agreement   as   Exhibit   A   executed
         contemporaneously with the Purchase Agreement between Seller, Purchaser
         and Henson & Efron, P. A., as Escrow Agent (the "Escrow  Agreement") to
         deliver to Seller the funds  deposited into escrow by Purchaser and all
         interest thereon. The amount delivered shall constitute a nonrefundable
         deposit to be credited  against the purchase price in the  transactions
         contemplated by the Purchase  Agreement.  If the Purchase  Agreement is
         terminated by either party for any reason,  Seller shall be entitled to
         retain  the funds  delivered  to Seller  and being  held by Seller as a
         nonrefundable deposit. All obligations and
         rights of the parties to the Escrow Agreement are hereby terminated.

(3)      Article III of the Purchase  Agreement is hereby amended to read in its
         entirety as follows:


<PAGE>

                                   ARTICLE III
                       CONSIDERATION PAYABLE BY PURCHASER


                  Section 3.1 Cash Purchase  Price. In addition to assumption of
the Assumed  Liabilities,  Purchaser shall pay Seller an aggregate cash purchase
price of Nineteen Million ($19,000,000) Dollars for the Assets as follows:

                  (a) Upon  execution of this Amendment  Agreement,  $509,569.90
nonrefundable  deposit delivered to Seller by legal counsel to Seller,  formerly
held  pursuant to the terms of the Escrow  Agreement  attached  to the  Purchase
Agreement as Exhibit A;

                  (b) At Closing, the remainder of the cash Purchase Price shall
be paid by wire transfer to Seller's bank account in Minneapolis, Minnesota.

                  Section 3.2  Definitions.  The following  terms shall have the
definitions set forth below:

                  (a)  "Additional  Shares" shall mean shares of Common Stock of
Purchaser issued pursuant to Section 3.4 of this Agreement.

                  (b) "Closing Date Market Price" shall mean the average for the
five  Trading  Days  immediately  preceding  the Closing Date of the mean of the
daily  high and low  sales  prices of the  Common  Stock on the  American  Stock
Exchange, Inc.

                  (c)  "Closing  Shares"  shall mean  shares of Common  Stock of
Purchaser  issued to Seller at the Closing of the  transactions  contemplated by
the Purchase Agreement.

                  (d) "Common Stock" shall mean shares of the Common Stock,  par
value $0.15 per share, of Purchaser

                  (e) "Holder" shall mean Seller or the shareholder of Seller to
whom Seller distributes the Closing Shares.

                  (f) "Price  Protection  Price" shall mean the lower of (i) the
Purchase  Price or (ii) the lowest  Repricing Date Market Price for any previous
Repricing Date.

                  (g)  "Purchase  Price" shall mean Seventy (70%) Percent of the
Closing Date Market Price of a share of Common Stock of Purchaser.

                  (h) "Release Date(s)" shall mean the calendar date(s) on which
Purchaser  issues a press release  announcing its financial  performance for (i)
the fiscal quarter that ends on March 31, 1996, but not later than May 14, 1996,
(ii) the fiscal  

                                   2
<PAGE>


quarter that ends on September  30, 1996,  but not later than November 14, 1996,
(iii) the fiscal year that ends on December 31,  1996,  but not later than March
31, 1997 and (iv) the fiscal  quarter that ends on September  30, 1997,  but not
later than November 14, 1997.

                  (i)  "Repricing   Date"  shall  mean  the  fifth  Trading  Day
following  each Release  Date,  with the Trading Day  immediately  following the
Release Date constituting the first Trading Day.

                  (j)  "Repricing  Date Market  Price" shall mean the average on
the Repricing  Date and four Trading Days  preceding  the Repricing  Date of the
mean  between  the  daily  high and low  sales  prices  of the  Common  Stock of
Purchaser  on the  national  securities  exchange  or NASDAQ on which the Common
Stock of Purchaser is listed or quoted.

                  (j)  "Trading  Day" shall mean any day on which at least 1,000
shares of Common Stock of Purchaser are sold on any national securities exchange
or NASDAQ;  provided,  however, if for any applicable period there are more than
two  consecutive  trading  days when there are fewer than 1,000 shares of Common
Stock sold, then each trading day thereafter shall be deemed to be a Trading Day
regardless of the number of shares of Common
Stock sold.

                  Section  3.3  (a)  Equity   Purchase  Price.  At  Closing  the
Purchaser  shall  issue to Seller a number of  shares of Common  Stock  ("Common
Stock") of Purchaser equal to the quotient obtained by dividing (i) Five Million
(5,000,000), by (ii) Seventy (70%) Percent of the Closing Date Market Price of a
share of Common Stock of Purchaser. No fractional shares shall be issued.
Purchaser shall have the option to pay cash or to issue a whole share in lieu of
fractional shares.

                  (b)  Escrowed  Shares.  At Closing,  a number of the shares of
Common Stock  issuable  pursuant to Section 3.3 (a) having a Closing Date Market
Price equal to Two Hundred Fifty Thousand  ($250,000) Dollars shall be deposited
in escrow (the "Escrowed  Shares") with legal counsel to Purchaser with executed
stock powers  acceptable to Purchaser to be held and  delivered  pursuant to the
terms of the escrow agreement  attached to the Purchase  Agreement as Exhibit B;
and

                  Section 3.4  Additional  Shares of Common Stock.  To encourage
retention of the Closing  Shares,  Purchaser  hereby  agrees to  compensate  the
Holders of Closing  Shares for  declines in the market price of the Common Stock
of Purchaser  below the Purchase  Price as follows.  To the extent  necessary to
compensate  a Holder for  declines  in the market  price of the Common  Stock of
Purchaser below the Purchase Price, Purchaser shall issue to the Holder a number
of Additional Shares such that after issuance of any such Additional Shares, the
Closing  Shares and the  Additional 


                                          3
<PAGE>

Shares held by Holder on the  Repricing  Date are equal in value  (valued at the
applicable Repricing Date Market Price) to the product determined by multiplying
(a) the number of Closing Shares and Additional  Shares held by the Holder after
the close of trading on the day immediately preceding the Repricing Date, by (b)
the Price Protection Price.

                  Additional  Shares shall be issued  within ten (10) days after
the Repricing Date. No fractional  shares shall be issued.  Purchaser shall have
the option to pay cash or to issue a whole share in lieu of fractional shares.

                  Notwithstanding  the foregoing,  no Additional Shares shall be
issued to any Holder who at any time prior to the Repricing Date shall engage in
any short sales of the Common Stock of Purchaser, acquire any put option or sell
any call  option on the  Common  Stock of  Purchaser,  loan any shares of Common
Stock to any other person or entity who Holder knows has a short position in the
Common Stock of Purchaser or who Holder knows has any put or call options on the
Common Stock of Purchaser,  sell any shares of Common Stock of Purchaser  during
the  period  between  any  Release  Date  and the  following  Repricing  Date or
encourage  or assist  any other  person or entity to engage in any such  trading
activity.

         Section 3.6       Tax Liability.

         (a) In the event Seller  distributes  Closing Shares to any shareholder
and a Sales Window does not occur between the date Purchaser  notifies Seller in
writing that the Closing  Shares and  Additional  Shares are  registered and are
sellable under  securities  laws and April 10,1997,  Purchaser shall pay the Tax
Liability to each of Seller's shareholders who received Closing Shares.

         The  term  "Tax  Liability"   shall  mean  the  amount   determined  by
multiplying  (i) the  amount by which  the  Purchase  Price of a  Closing  Share
exceeds the Market  Price of a share of Common  Stock of  Purchaser on April 10,
1997, by (ii) the quotient  derived by dividing (x) the Federal and state income
tax  liability  associated  with Seller's  shareholder's  receipt of the Closing
Shares (but not any penalties or  interest),  by (y) the Market Price of a share
of Common Stock of Purchaser  on April 10,  1997,  provided  that in the event a
shareholder of Seller does not sell any Closing  Shares or Additional  Shares to
pay such taxes, clause (y) of the foregoing calculation
shall read as follows: "(y) the Purchase Price."

         The term "Sales Window" shall mean a period of twenty (20)  consecutive
Trading Days in which the aggregate Tax  Liability  Price of the Closing  Shares
and Additional  Shares issued by Purchaser  equals or exceeds the Purchase Price
for the Closing Shares of such shareholder.

                                      4
<PAGE>


         The term "Tax Liability Price" for any shareholder of Seller shall mean
the sum of the following:
                           (i) the  aggregate  average  Market  Price during the
                  Trading  Window of all Closing  Shares and  Additional  Shares
                  held by such  shareholder  of Seller  throughout  the  Trading
                  Window;

                           (ii) if during or prior to the  Trading  Window  such
                  shareholder  sells any Closing Shares or Additional Shares for
                  a price that is less than the average  Market Price during the
                  Trading Window,  the aggregate average Market Price during the
                  Trading  Window of the Closing  Shares and  Additional  Shares
                  sold by such shareholder; and

                           (iii)if  during or prior to the  Trading  Window such
                  shareholder  sells any Closing Shares or Additional Shares for
                  a price  that is equal to or  greater  than the  Market  Price
                  during the  Closing  Window,  the sales  price of the  Closing
                  Shares and Additional Shares sold by such shareholder.

         The term  "Market  Price" shall mean the mean of the high and low sales
prices on the date in question of the Common  Stock of Purchaser on any national
securities exchange or NASDAQ on which the Common Stock of
Purchaser is listed or quoted.

         (b) The  obligations  of  Purchaser  to pay the  Tax  Liability  to any
shareholder of Seller shall be subject to such shareholder  providing  Purchaser
with  proof  reasonably  satisfactory  to  Purchaser  of the  amount  of the Tax
Liability,  including  (i) the date and  sales  price of any  Closing  Shares or
Additional Shares and (ii) continued  ownership of Closing Shares and Additional
Shares during the applicable period.

         (c) Purchaser shall pay its Tax Liability  hereunder on or before April
15, 1997,  provided  that  Purchaser may delay payment of all or part of its Tax
Liability  hereunder to the extent payment is not permissible under law or under
any  covenant  or  agreement  with the  lender(s)  providing  financing  for the
acquisition of the assets of Seller,  including any covenant or agreement in any
line of credit extended in connection with the acquisition  loans. If all or any
part of payment of the Tax Liability is delayed by reason of the foregoing,  (i)
Purchaser  shall  notify  Seller of the  basis for the delay and (ii)  Purchaser
shall pay the  delayed the Tax  Liability  payment to the extent  payment  later
becomes  permissible  under such legal or  contractual  restriction  on payment,
provided  that in the  event at any  time  prior to  additional  payment  of Tax
Liability becoming  permissible

                                        5
                                          
<PAGE>

a Sales Window occurs,  Purchaser shall cease to have any further  obligation to
pay the tax liability that has not previously  been paid. The ability to pay Tax
Liability  shall  be  measured  as of the  last day of each  fiscal  quarter  of
Purchaser.

         (d) In the  event  of any  partial  payment  of the  Tax  Liability  by
Purchaser,  all persons  entitled to Tax Liability  payments shall be paid their
pro rata  share  based on the number of Closing  Shares  distributed  to them by
Seller.

         Section 3.6 Stock Dividends,  Splits, Combinations etc. In the event of
any stock, dividend,  split,  combination,  reorganization or similar event with
respect to the shares of Common Stock of Purchaser, (i) shares issued on account
of or in exchange for Closing Shares shall be Closing Shares, (ii) shares issued
on account of or in exchange for  Additional  Shares shall be Additional  Shares
and  (iii)  stock  prices  shall  be  proportionately  adjusted  to  the  extent
adjustment is required to fulfill the original intention of the parties.

         Section 3.7       Transfer Restrictions.

         (a) Holders of Closing Shares shall not sell or otherwise  transfer any
Closing  Shares  until  the  sixtieth  (60th)  day after the  Closing  Date.  In
determining  a  Holder's  right  to sell  Closing  Shares,  the day  immediately
following the Closing Date shall be Day One.

         Notwithstanding  the foregoing,  nothing  contained in this Section 3.7
(a) shall prohibit  transfer by Seller of Closing  Shares to any  shareholder of
Seller who shall  execute and deliver to  Purchaser  an agreement to comply with
the provisions of this Section 3.7.

         (b) Because the Closing Shares and the Additional  Shares have not been
registered under the Securities Act of 1933, as amended (the  "Securities  Act")
or applicable state securities laws,  Seller cannot dispose of any or all of the
Closing  Shares or the  Additional  Shares  unless such shares are  subsequently
registered under the Securities Act, and/or applicable state securities laws, or
exemptions from such  registration  are available.  Purchaser shall register the
Closing Shares and the Additional Shares as provided in the Registration  Rights
Agreement  attached  as  Exhibit  A  hereto.  Seller  further  understands  that
Purchaser,  as a  condition  to the  transfer  of any of the  Closing  Shares or
Additional  Shares,  may require that the request for transfer be accompanied by
an opinion of  counsel  satisfactory  to the  Purchaser,  in form and  substance
satisfactory  to the  Purchaser  and preceded by prior  written  notice,  to the
effect that the proposed transfer does not result in violation of the Securities
Act or applicable state  securities laws,  unless such transfer is covered by an
effective  registration  statement 

                                          6
<PAGE>


under the  Securities  Act and all  applicable  state  securities  laws.  Seller
understands that each certificate representing the Closing Shares and Additional
Shares and any securities  issued on account of ownership  thereof will bear the
following legend or one substantially similar thereto:

         The securities represented by this certificate have not been registered
         under the Securities Act of 1933, as amended (the "Securities Act"), or
         the securities laws of any state.  These  securities have been acquired
         for investment and not with a view to distribution  or resale,  and may
         not be sold, mortgaged,  pledged, hypothecated or otherwise transferred
         without an effective  registration  statement for such shares under the
         Securities Act and applicable  state  securities laws, or an opinion of
         counsel  satisfactory  to  the  corporation  that  registration  is not
         required under the Securities Act and applicable state securities laws.


                  Section 3.8 Representations  and Agreements of Seller.  Seller
hereby represents, warrants and agrees as follows:

                  (a) Seller has a total of thirty-five (35)  shareholders.  The
name and address of each shareholder are set forth on Schedule 3.8 hereto.

                  (b) Prior to the meeting of  shareholders of Seller to approve
this Amendment Agreement,  Seller shall distribute to all shareholders of Seller
a copy of the Private  Placement  Memorandum  (and all exhibits  thereto) and an
Investor Questionnaire furnished by Purchaser to Seller.

                  (c)  Seller   agrees  to  furnish  to   Purchaser   any  other
information about Seller reasonably requested by Purchaser to allow Purchaser to
comply  with  securities  laws and that no shares of Common  Stock of  Purchaser
shall be  distributed to any  shareholder  (i) who fails to deliver to Purchaser
and/or  Seller  prior to the  Closing  a  completed  Investor  Questionnaire  of
Purchaser, or (ii) who alone or together with their Purchaser Representative (as
defined in Rule 501 (h) of Regulation  D), fails to furnish prior to the Closing
such  information  or  assurances  necessary  for Purchaser to conclude that the
issuance and delivery of the Closing Shares to Seller as contemplated herein, is
exempt from registration under Federal and state securities laws. Determinations
of  information  required  and whether the  conditions  to  exemption  have been
satisfied shall be made jointly in good faith by both Purchaser and Seller.

(4)      All  representations  and  warranties  made  by  Seller  and  Purchaser
         Sections in 5.2 and 6.2 of the Purchase  Agreement are hereby  extended
         to this Amendment  

                                    7
<PAGE>


         Agreement and the  Registration  Rights  Agreement and the transactions
         contemplated hereby and thereby.

(5)      Sections 5.4 and 5.5,  which shall read in their  entirety as set forth
         below, are hereby added to the Purchase Agreement:

                  Section 5.4 Closing Shares and Additional  Shares. The Closing
Shares and the Additional  Shares will upon issuance in accordance  with Article
III of the Purchase  Agreement be duly and validly  authorized,  fully-paid  and
nonassessable shares of Common Stock of Purchaser,  except that the shareholders
of  Purchaser  are  not  required  to  approve  this  Amendment  Agreement,  the
Registration  Rights  Agreement  or  the  transactions  contemplated  hereby  or
thereby.  Purchaser has obtained  confirmation  from the American Stock Exchange
("AMEX")  that the vote of the  shareholders  of  Purchaser at a meeting held on
October  26,  1995 is  sufficient  to satisfy  AMEX  rules  with  respect to the
transactions contemplated by this Amendment Agreement. No filing or registration
with,  no notice to and no permit,  authorization,  consent or  approval  of any
public body or authority is necessary for the  consummation  by Purchaser of the
transactions contemplated by this Amendment Agreement or the Registration Rights
Agreement,  except that (i) offers and/or sales of Closing Shares and Additional
Shares may require filings with, and approvals by, state securities  regulators,
which  filings  and  approvals  will be made and  obtained by  Purchaser  at its
expense  prior to issuance of the Closing  Shares and  Additional  Shares;  (ii)
Purchaser  will file a Form D at its expense  with the  Securities  and Exchange
Commission  following the Closing;  and (iii)  performance  of the  Registration
Rights Agreement will require filings with, and approvals by, the Securities and
Exchange Commission and various State securities regulators, with the expense of
such filings to be allocated as set forth in the Registration Rights Agreement.

                  Section  5.5  Securities  Documents.   The  Private  Placement
Memorandum  delivered by Purchaser to Seller and the documents  incorporated  by
reference  therein do not contain any untrue  statements of material fact and do
not omit to state any material fact necessary to make the statements of material
fact  therein,  in light of the  circumstances  under which they were made,  not
misleading.  This representation shall not apply to any statements contained in,
or  omitted  from,  such  documents  to the  extent  the  statement  is based on
information supplied to Purchaser by Seller.

(6)      Article IV of the Purchase  Agreement is hereby  amended to add Section
         4.2 (d), 4.3 (d), (e) and (f), and Section 4.4 (j), which shall read in
         their entirety as follows:

         4.2 (d) All  shareholders  of Seller shall have completed and delivered
         to Purchaser and Seller the Investor Questionnaire in the form attached
         as Exhibit A hereto,  and 

                                   8
<PAGE>



         together with their  Purchaser  Representative  (as defined in Rule 501
         (h) of Regulation  D), shall satisfy the  conditions  for exempting the
         offer and sale by  Purchaser  of shares of Common  Stock to such person
         under Federal or state securities laws.

         4.3 (d)  Purchaser  shall have  executed  and  delivered  to Seller the
         Registration Rights Agreement in the Form attached as Exhibit B to this
         Amendment Agreement.

         4.3 (e)  Shareholders  of Seller shall have  approved the execution and
         delivery  of  this  Amendment  Agreement  and the  consummation  of the
         transactions contemplated by the Purchase Agreement, as amended by this
         Amendment Agreement.

         4.3 (f) No holders of the  outstanding  shares of stock of Seller shall
         have  elected to  exercise  their  dissenters  rights  under  Minnesota
         Statutes Sections 302A.471 and 302A.473.

         4.4 (j) Seller  shall have  executed and  delivered  to  Purchaser  the
         Registration Rights Agreement in the Form attached as Exhibit B to this
         Amendment Agreement.

(7)      The opinion  letters to be  delivered by attorneys  for  Purchaser  and
         attorneys  for Seller  pursuant to Sections  4.3 (b) and 4.4 (b) of the
         Purchase  Agreement  shall be changed to read in their  entirety as set
         forth on Exhibit C and Exhibit D hereto.

(8)      Section  8.4 of the  Purchase  Agreement  is hereby  amended to add the
         following:

         Purchaser shall pay at Closing all reasonable attorneys fees, costs and
         expenses  incurred by Seller on or after  November 16, 1995 through the
         Closing Date, and amounts reasonably estimated to be incurred after the
         Closing  Date up to a maximum  of  $25,000  in  post-Closing  fees,  in
         connection with the negotiation, preparation, documentation, execution,
         delivery and performance of the Purchase Agreement,  as amended by this
         Amendment  Agreement,  and the Registration Rights Agreement,  provided
         that  Purchaser  shall not be liable for  amounts  related to work that
         would have been performed had the Purchase Agreement closed without the
         changed terms contained in the Amendment Agreement.

(9)      Article VIII of the Purchase Agreement is hereby amended to add Section
         8.8, which shall read in its entirety as follows:

         Purchaser shall continue to have its Common Stock listed for trading on
         a national securities exchange or quoted on the Automated Quotation 
         System of the

                                       9

<PAGE>


         National Association of Securities Dealers, Inc. until the last 
         Repricing Date.

(10)     Except  as  set  forth  above,  the  Purchase  Agreement  shall  remain
         unchanged and in full force and effect.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


                                       10
<PAGE>


         IN WITNESS WHEREOF, the parties have caused this Amendment Agreement to
be signed by their  respective  officers  thereto duly authorized as of the date
first written above.


[CORPORATE SEAL]                    MEDTOX LABORATORIES, INC.
 

ATTEST:                                By:______________________________
                                                  Name:_________________________
 
Title:_______________________
By:_________________________
   ______________, Secretary

[CORPORATE SEAL]                    EDITEK, INC.

ATTEST:                                By:______________________________
                                                   Name:_______________________
                                                   Title:______________________
By:______________________
   ______________, Secretary

                                              11
<PAGE>


                          REGISTRATION RIGHTS AGREEMENT


         THIS REGISTRATION RIGHTS AGREEMENT,  dated as of January __, 1996 (this
"Agreement"),  is made between Editek,  Inc., a corporation  organized under the
laws of Delaware (the "Company"),  and MedTox Laboratories,  Inc., a corporation
organized under the laws of the State of Minnesota (the "Initial Investor").

                              W I T N E S S E T H:

         WHEREAS, in connection with the Asset Purchase  Agreement,  dated as of
July 1, 1995, as amended by the Amendment Agreement dated as of December 1, 1995
between the Initial  Investor and the Company (the  "Purchase  Agreement"),  the
Company has agreed, upon the terms and subject to the conditions of the Purchase
Agreement,  to issue and sell to the Initial  Investor shares of Common Stock at
the closing of the  transactions  contemplated  by the Purchase  Agreement  (the
"Closing  Shares"),  and,  under  certain  conditions  described in the Purchase
Agreement to issue without  additional  cost  additional  shares of Common Stock
(the "Additional Shares"); and

         WHEREAS, the Company is agreeing to provide certain registration rights
under the  Securities  Act of 1933,  as amended,  and the rules and  regulations
thereunder,  or any similar  successor  statute  (collectively,  the "Securities
Act"),  and applicable  state securities laws with respect to the Closing Shares
and the Additional Shares (the "Shares");

         NOW,  THEREFORE,  in  consideration  of the  premises  and  the  mutual
covenants  contained  herein  and other  good and  valuable  consideration,  the
receipt and  sufficiency of which are hereby  acknowledged,  the Company and the
Initial Investor hereby agree as follows:

         1.       Definitions.

                  (a)      As used in this Agreement, the following terms shall
have the following meanings:

                           (i)      "Register," "registered," and "registration"
refer to a registration effected by preparing  and filing a  Registration
Statement or  Statements in compliance with the Securities Act on such
appropriate registration form promulgated by the Commission as shall be selected
by the Company and the  declaration  or ordering of effectiveness of such
Registration  Statement by the United States Securities and Exchange Commission
("SEC") and applicable state laws.

<PAGE>

                           (ii)     "Registrable Securities" means the Closing
Shares and the Additional Shares.

                           (iii)    "Registration Statement"  means  a
registration statement under the Securities Act registering securities of the
Company.

         (b) As used in this  Agreement,  the  term  Investor  includes  (i) the
Initial  Investor  (as  defined  above) and (ii) each  person who is a permitted
transferee or assignee of the  Registrable  Securities  pursuant to Section 9 of
this Agreement.


         2.       Registration.

                  (a)  Piggy-Back  Registrations.  Subject to the  provisions of
Sections 3 and 4 hereof,  if at any time the Company shall  determine to prepare
and file with the SEC a Registration Statement relating to an offering under the
Securities  Act of any of its  equity  securities  for  its own  account  or the
account of others,  other than on Form S-4 or Form S-8 or their then equivalents
relating  to equity  securities  to be  issued  solely  in  connection  with any
acquisition  of  any  entity  or  business  or  equity  securities  issuable  in
connection with stock option or other employee  benefit plans, the Company shall
send to each Investor who owns  Registrable  Securities  written  notice of such
determination and, if within twenty (20) days after receipt of such notice, such
Investor  shall so  request  in  writing,  the  Company  shall  include  in such
Registration  Statement all or any part of the Investor's Registrable Securities
that such Investor requests to be registered, except that if, in connection with
any  underwritten  public  offering  for the account of the Company the managing
underwriter(s)  thereof  shall  impose a  limitation  on the number of shares of
Common Stock which may be included in the  Registration  Statement  because,  in
such underwriter(s)' judgment, such limitation is necessary to effect an orderly
public  distribution,  then the Company  shall be  obligated  to include in such
Registration  Statement only such limited  portion,  if any, of the  Registrable
Securities  with  respect  to  which  such  Investor  has  requested   inclusion
hereunder.  Any exclusion of Registrable  Securities and other securities having
registration  rights  shall be made pro  rata  among  the  Investors  and  other
shareholders seeking to include Registrable Securities and other securities have
registration  rights and in proportion to the number of  Registrable  Securities
and other securities  having  registration  rights sought to be included in such
registration;  provided,  however,  that  the  Company  shall  not  exclude  any
Registrable  Securities  unless the Company has first  excluded all  outstanding
securities  the holders of which are not entitled to inclusion of  securities in
such Registration  Statement. No right to registration of Registrable Securities
under this Section 2(a) shall be  construed to limit any  registration  required
under  Section 2(b) hereof.  The  obligations  of the Company under this Section
2(a) may be waived by Investors  holding Eighty (80%) Percent in interest of the
Registrable  Securities  and shall  terminate (i) after the Company has afforded
the  opportunity  for the Investors to exercise  registration  rights under this
Section 2(a) for two  registrations;  provided,  however,  that any Investor who
shall

                                       2

<PAGE>

have  had any  Registrable  Securities  excluded  from  any  Registration
Statement in  accordance  with this Section 2(a) shall be entitled to include in
an  additional  Registration  Statement  filed by the  Company  the  Registrable
Securities  so excluded,  or (ii) after the  expiration of three years after the
Closing Date of the transactions contemplated by the Purchase Agreement.

                  (b)  Immediate  Registration.  Subject  to the  provisions  of
Sections 3 and 4 hereof,  the  Company  shall  prepare  and file a  Registration
Statement  with the SEC within fifteen (15) business days after the Closing Date
of the transactions contemplated by the Purchase Agreement;  provided,  however,
that such registration  statement need not be filed until five (5) business days
after all persons  having the right to include  shares therein have provided the
Company with all information  reasonably  requested by the Company in connection
with such  registration.  The Registration  Statement required by this Section 2
(b) shall cover a number of  Registrable  Securities  of  Investor  equal to the
number of Closing Shares issued at the Closing of the transactions  contemplated
by the Purchase  Agreement,  plus an equal number of Additional  Shares.  In the
event the Company  becomes  obligated to issue a number of Additional  Shares in
excess of the number covered by such Registration  Statement,  the Company shall
either amend the Registration  Statement to cover the extra Additional Shares or
file a new  Registration  Statement to cover the extra Additional  Shares.  Such
amendment or new  Registration  Statement  shall be filed a number of days after
the issuance of such Additional  Shares as the first  Registration  Statement is
required to be filed after the Closing Date of the transactions  contemplated by
the Purchase Agreement.

                  (c) If any  registration  is  underwritten,  the Investors who
hold the Registrable  Securities to be included in such  underwriting  shall pay
all  underwriting  discounts and commissions  with respect to their  Registrable
Securities and the fees and expenses of legal counsel selected by the Investors.

                  (d)  Nothing  herein  shall  limit the right of the Company to
grant registration rights to any other person or entity and to include shares of
such person or entity on any Registration Statement.

         3.       Obligations of the Company.  In connection with the
registration of the Registrable Securities under this Agreement, the Company
shall:

                  (a) prepare promptly and file with the SEC promptly (but in no
event later than 15 business  days after the  Closing  Date of the  transactions
contemplated by the Purchase  Agreement) a Registration  Statement or Statements
with  respect  to  all  Registrable  Securities  to  be  included  therein,  and
thereafter  use its best efforts to cause the  Registration  Statement to become
effective as soon as reasonably possible after such filing. If such Registration
Statement is filed pursuant to Rule 415, the Company shall keep the Registration
Statement  effective pursuant to Rule 415 at all times until such date as is two
years after the date such  Registration  Statement is first ordered effective by
the SEC. In any case, the  Registration

                                     3

<PAGE>

Statement  (including any amendments or supplements  thereto and  prospectuses
contained  therein) filed by the Company shall not contain  any untrue statement
of a material  fact or omit to state a material fact required to be stated
therein, or necessary to make the statements therein,  in light of the
circumstances in which they were made, not misleading; provided,  however, that,
subject to the  conditions set forth in Section 4(a) below, each Investor may
notify the Company in writing that it wishes to exclude all or a portion of its
Registrable Securities from such Registration Statement.

                  (b) prepare and file with the SEC such  amendments  (including
post-effective amendments) and supplements to the Registration Statement and the
prospectus  used  in  connection  with  the  Registration  Statement  as  may be
necessary to keep the Registration  Statement  effective at all times until such
date as is two years after the date such Registration Statement is first ordered
effective by the SEC, and, during such period, comply with the provisions of the
Securities Act with respect to the disposition of all Registrable  Securities of
the Company covered by the Registration Statement until such time as all of such
Registrable Securities have been disposed of by the Investors in accordance with
the  intended  methods  of  disposition  by the  Investors  as set  forth in the
Registration Statement.

                  (c) furnish to each Investor whose Registrable  Securities are
included in the Registration  Statement,  such number of copies of a prospectus,
including a preliminary  prospectus,  and all amendments and supplements thereto
promptly  upon  approval  thereof  by the SEC and such other  documents  as such
Investor may reasonably  request in order to facilitate  the  disposition of the
Registrable  Securities owned by such Investor; The Company shall provide copies
of all such  documents  upon  approval  thereof  by the SEC to  counsel  for the
Initial Investor at such address designated in writing by the Initial Investor;

                  (d)  (i)  register  or  qualify,   or  obtain  exemption  from
registration or  qualification  for, the Registrable  Securities  covered by the
Registration  Statement  under  such other  securities  or blue sky laws of such
jurisdictions as required for sale of the Registrable Securities by the investor
as the Investors who hold a majority in interest of the  Registrable  Securities
being offered reasonably  request,  (ii) prepare and file in those jurisdictions
such amendments  (including  post-effective  amendments) and supplements,  (iii)
take such other  actions as may be necessary to maintain such  registrations  or
qualifications  in effect at all times  until such date as is the earlier of two
years after the date such  Registration  Statement is first ordered effective by
the SEC or is two years after the Initial Investor  acquired the Shares and (iv)
take all  other  actions  reasonably  necessary  or  advisable  to  qualify  the
Registrable Securities for sale in such jurisdictions or to otherwise permit the
Holders to dispose of the Registrable  Securities;  provided,  however, that the
Company shall not be required in connection  therewith or as a condition thereto
to (I) qualify to do business in any  jurisdiction  where it would not otherwise
be required to qualify but for this Section 3(d), (II) subject itself to general
taxation in any such  jurisdiction,  (III) file a general  consent to service of
process  in any such  jurisdiction,  (IV)  make any  change  in its  charter  or
by-laws,  which in each case the

                                     4

<PAGE>

Board of Directors of the Company determines to be contrary to the best
interests  of the Company and its  stockholders  or (V) subject  any  officer,
director  or  shareholder  to any  penalty  or  risk  of forfeiture  other than
those penalties and risks to which officers and directors are ordinarily liable
in a public offering of securities;

                  (e) in the event  Investors who hold a majority in interest of
the Registrable  Securities being offered pursuant to Section 2(b) hereof select
underwriters for the offering,  or an underwritten  public offering is conducted
pursuant to Section 2(a) hereof, enter into and perform its obligations under an
underwriting   agreement  in  usual  and  customary  form,  including,   without
limitation,  customary  indemnification and contribution  obligations,  with the
managing underwriter of such offering;

                  (f) as promptly as  practicable  after  becoming aware of such
event, notify each Investor who holds Registrable Securities being sold pursuant
to such  registration  of the  happening  of any event of which the  Company has
knowledge,  as a result of which the  prospectus  included  in the  Registration
Statement, as then in effect, contains an untrue statement of a material fact or
omits to state a material  fact  required to be stated  therein or  necessary to
make the statements therein, in light of the circumstances under which they were
made, not misleading,  and use its best efforts promptly to prepare a supplement
or amendment to the  Registration  Statement to correct such untrue statement or
omission, and deliver a number of copies of such supplement or amendment to each
Investor as such Investor may reasonably request;

                  (g) as promptly as  practicable  after  becoming aware of such
event, notify each Investor who holds Registrable Securities being sold pursuant
to such registration (or, in the event of an underwritten offering, the managing
underwriters)  of the issuance by the SEC of any stop order or other  suspension
of effectiveness of the Registration Statement at the earliest possible time;

                  (h)  permit a single  firm of  counsel  designated  as selling
Investors'  counsel by the  Investors  who hold a majority  in  interest  of the
Registrable  Securities  being sold pursuant to such  registration to review the
Registration  Statement and all amendments and supplements  thereto a reasonable
period of time prior to their  filing with the SEC, and not file any document in
a form to which such counsel reasonably objects,  provided that any unreasonable
delay by such counsel  shall  automatically  extend the period  provided in this
Agreement for filing the Registration Statement;

                  (i) at the  request of the  Investors  who hold a majority  in
interest of the  Registrable  Securities  being sold pursuant to an underwritten
registration,  furnish on the date that Registrable  Securities are delivered to
an  underwriter  for sale in connection  with the  Registration  Statement (i) a
letter,  dated  such  date,  from the  Company's  independent  certified public
accountants  in form  and  substance  as is  customarily  given  by independent
certified public

                                    5

<PAGE>

accountants to underwriters in an underwriter public offering, addressed to the
underwriters;  and (ii) an  opinion,  dated such  date,  from counsel
representing the Company for purposes of such Registration Statement, in form
and substance as is customarily  given in an underwritten  public offering,
addressed to the underwriters and Investors;

                  (j)  make  available  for  inspection  by any  Investor  whose
Registrable  Securities  are  being  sold  pursuant  to such  registration,  any
underwriter  participating  in any  disposition  pursuant  to  the  Registration
Statement,  and any  attorney,  accountant  or other agent  retained by any such
Investor  or  underwriter  (collectively,   the  "Inspectors"),   all  pertinent
financial and other records, pertinent corporate documents and properties of the
Company  (collectively,  the  "Records"),  as shall be  reasonably  necessary to
enable each  Inspector to exercise its due diligence  responsibility,  and cause
the Company's officers,  directors and employees to supply all information which
any  Inspector  may  reasonably  request  for  purposes  of such due  diligence;
provided,  however,  that each Inspector  shall hold in confidence and shall not
make any disclosure  (except to an Investor) of any Record or other  information
which the  Company  determines  in good faith to be  confidential,  and of which
determination the Inspectors are so notified,  unless (i) the disclosure of such
Records is  necessary  to avoid or correct a  misstatement  or  omission  in any
Registration Statement,  (ii) the release of such Records is ordered pursuant to
a  subpoena  or  other  order  from a court  or  government  body  of  competent
jurisdiction  or (iii) the  information  in such Records has been made generally
available  to the public  other than by  disclosure  in violation of this or any
other agreement.  The Company shall not be required to disclose any confidential
information  in such Records to any  Inspector  until and unless such  Inspector
shall  have  entered  into  confidentiality  agreements  (in form and  substance
satisfactory  to the  Company)  with the  Company  with  respect  thereto.  Each
Investor agrees that it shall,  upon learning that disclosure of such Records is
sought  in or by a court  or  governmental  body of  competent  jurisdiction  or
through other means, give prompt notice to the Company and allow the Company, at
its expense,  to undertake  appropriate  action to prevent  disclosure of, or to
obtain a protective  order for,  the Records  deemed  confidential.  The Company
shall  hold in  confidence  and shall  not make any  disclosure  of  information
concerning an Investor  provided to the Company  pursuant to Section 4(e) hereof
unless (i) disclosure of such information is necessary to comply with federal or
state  securities  laws, (ii) the disclosure of such information is necessary to
avoid or correct a misstatement or omission in any Registration Statement, (iii)
the release of such information is ordered pursuant to a subpoena or other order
from a  court  or  governmental  body of  competent  jurisdiction  or (iv)  such
information  has been made  generally  available  to the  public  other  than by
disclosure in violation of this or any other agreement.  The Company agrees that
it shall,  upon  learning  that  disclosure  of such  information  concerning an
Investor  is  sought  in  or  by a  court  or  governmental  body  of  competent
jurisdiction  or through other means,  give prompt notice to such Investor,  and
allow such Investor,  at its expense, to undertake appropriate action to prevent
disclosure of, or to obtain a protective order for, such information;

                                     6

<PAGE>

                  (k)  use  its  best  efforts  either  to  (i)  cause  all  the
Registrable Securities covered by the Registration Statement to be listed on the
American  Stock  Exchange or another  national  securities  exchange and on each
additional  national  securities  exchange on which similar securities issued by
the  Company  are  then  listed,  if any,  if the  listing  of such  Registrable
Securities  is then  permitted  under the rules of such  exchange or (ii) secure
designation  of all  the  Registrable  Securities  covered  by the  Registration
Statement as a National  Association of Securities Dealers Automated  Quotations
System  ("NASDAQ")  "national market system security" within the meaning of Rule
11Aa2-1 of the SEC under the  Securities  Exchange Act of 1934,  as amended (the
"Exchange Act"),  and the quotation of the Registrable  Securities on the NASDAQ
National Market System or, if, despite the Company's best efforts to satisfy the
preceding  clause (i) or (ii),  the Company is  unsuccessful  in satisfying  the
preceding  clause  (i) or (ii),  to  secure  listing  on a  national  securities
exchange or NASDAQ authorization and quotation for such Registrable Securities;

                  (l)      provide a transfer agent and registrar, which may be
a single entity, for the Registrable Securities not later than the effective
date of the Registration Statement;

                  (m)  cooperate   with  the  Investors  who  hold   Registrable
Securities  being sold  pursuant to  registration  statements  and the  managing
underwriter or  underwriters,  if any, to facilitate the timely  preparation and
delivery of certificates to the transferees to whom such Registrable  Securities
are  being  sold  (not  bearing  any  restrictive   legends)   pursuant  to  the
denominations  or amounts as the case may be, and  registered,  in such names as
the  managing  underwriter  or  underwriters,  if  any,  or  the  Investors  may
reasonably  request;  and,  within  three  business  days  after a  Registration
Statement which includes Registrable Securities is ordered effective by the SEC,
the Company shall deliver,  or shall cause legal counsel selected by the Company
to deliver, to the transfer agent for the Registrable Securities (with copies to
the Investors whose Registrable  Securities are being sold)  instructions to the
transfer  agent  to issue  new  stock  certificates  without  a  legend  to such
transferees and an opinion of such counsel that the shares have been registered;
and

                  (n) take all other  reasonable  actions  necessary to expedite
and  facilitate  disposition  by  the  Investor  of the  Registrable  Securities
pursuant to the Registration Statement.

                  (o)      Notwithstanding the foregoing, the Company's
obligations in connection with the registration of Registrable Securities shall
be limited as follows:

                           (i)      The Company shall not be obligated under
this Agreement to register or include in any registration Registrable Securities
that any Investor has requested to be registered if the Company shall furnish
such Investor with a written  opinion of counsel  reasonably   satisfactory  to
such  Investor,   that  all  Registrable Securities that such Investor holds may
be publicly offered, sold or distributed without  registration under the Act
pursuant to Rule 144 without  restriction as to the amount of securities that
can be sold.

                                      7

<PAGE>

                           (ii)     The Company's obligation to amend,
supplement and cause to continue to be effective any registration statement may
be suspended,  for a reasonable period of time,  not to exceed 45 days,  if the
Company has been  advised in writing by independent  legal  counsel that such
filing would  require the  disclosure of a material  transaction or other facts
and the Board of  Directors of the Company determines  reasonably  and in good
faith  that such  disclosure  would  have a material,  adverse effect on the
Company;  provided,  however,  that the Company shall not under any
circumstances be permitted to exercise such rights more than two (2) times in
any twelve (12) month  period.  The Company  shall  immediately notify in
writing all Investors who hold Registrable  Securities covered by such
registration statement of such determination,  and such Investors shall maintain
the confidentiality of such notice and shall cease all trading in the securities
of the Company  until the Company  notifies  such  Investors in writing that the
circumstances  that caused such suspension or postponement are no longer present
and that the Registration  Statement is currently  effective.  The Company shall
use its best efforts to promptly  take all such  actions  necessary to eliminate
any such suspension or postponement as soon as reasonably possible.

                           (iii)    The Company may in its discretion grant to
any owner of securities of the Company registration rights of any kind or
nature.

                  (p) If  the  Company  shall  fail  to  file  the  Registration
Statement  required to be filed by the Company  pursuant to Section 2 (b) hereof
within the time  provided  therefor,  or if the  Company  shall fail to actively
attempt to obtain  effectiveness  of the Registration  Statement,  the Investors
shall be entitled, at the Company's expense, to prepare a Registration Statement
and/or to attempt to obtain effectiveness of the Registration Statement. In such
event,  the  Company  shall  cause its  directors  and  officers  to provide all
required  information  and to execute all documents as  reasonably  requested by
such  Investors  to  file  such   Registration   Statement   and/or  cause  such
Registration Statement to become effective.

         4.       Obligations of the Investors.  In connection with the
registration of the Registrable Securities, the Investors shall have the
following obligations:

                  (a) It shall be a condition  precedent to the  obligations  of
the Company to take any action  pursuant to this  Agreement with respect to each
Investor that such Investor  furnish to the Company such  information  regarding
itself,  the  Registrable  Securities  held by it and  the  intended  method  of
disposition  of the  Registrable  Securities  held by it as shall be  reasonably
required to effect the  registration of the  Registrable  Securities and execute
such  documents  in  connection  with  such  registration  as  the  Company  may
reasonably  request.  At least fifteen (15) days prior to the first  anticipated
filing  date of the  Registration  Statement,  the  Company  shall  notify  each
Investor of the  information  the Company  requires from each such investor (the
"Requested  Information") if such Investor elects to have any of such Investor's
Registrable  Securities included in the Registration  Statement.  If within five
(5) business days

                                      8

<PAGE>

prior to the filing date the Company has not received a signed writing
containing the Requested Information from an Investor (a "Non-Responsive
Investor"),  then  the  Company  may  file the  Registration  Statement  without
including Registrable Securities of such Non-Responsive Investor;

                  (b)  Each  Investor  by  such  Investor's  acceptance  of  the
Registrable  Securities  agrees to  cooperate  with the  Company  as  reasonably
requested by the Company in connection  with the  preparation  and filing of the
Registration Statement hereunder,  unless such Investor has notified the Company
in  writing  of such  Investor's  election  to  exclude  all of such  Investor's
Registrable Securities from the Registration Statement;

                  (c) In the event the Company or  Investors  holding a majority
in interest of the Registrable  Securities being registered  determine to engage
the services of an  underwriter  in accordance  with Section 2(b) hereof,  or in
connection  with any  underwritten  public  offering  pursuant  to Section  2(a)
hereof,  each  Investor  agrees  to  enter  into  and  perform  such  Investor's
obligations  under an  underwriting  agreement,  in usual  and  customary  form,
including,  without  limitation,   customary  indemnification  and  contribution
obligations,  with the managing underwriter of such offering and take such other
actions as are  reasonably  required  in order to  expedite  or  facilitate  the
disposition of the Registrable Securities, unless such Investor has notified the
Company in writing of such Investor's election to exclude all of such Investor's
Registrable  Securities from the Registration  Statement,  and the Company shall
have no  obligation to register the  Registrable  Securities of any Investor who
fails to comply with this paragraph;

                  (d) Each Investor agrees that, upon receipt of any notice from
the Company of the happening of any event of the kind  described in Section 3(f)
and 3(g), such Investor will immediately  discontinue disposition of Registrable
Securities  pursuant to the  Registration  Statement  covering such  Registrable
Securities  until such Investor's  receipt of the copies of the  supplemented or
amended  prospectus  contemplated by Section 3(f) or 3(g) and, if so directed by
the Company,  such Investor  shall,  at the option of the  Investor,  either (i)
deliver to the Company or (ii) destroy (and deliver to the Company a certificate
of  destruction)  all copies in such  Investor's  possession,  of the prospectus
covering  such  Registrable  Securities  current  at the time of receipt of such
notice; and

                  (e) No Investor may  participate and the Company shall have no
obligation  to  register  the  Registrable  Securities  of any  Investor  in any
underwritten registration hereunder unless such Investor (i) agrees to sell such
Investor's  Registrable  Securities  on the basis  provided in any  underwriting
arrangements  approved  by the  Investors  entitled  hereunder  to approve  such
arrangements,  (ii)  completes  and  executes  all  questionnaires,   powers  of
attorney,  indemnities,  underwriting  agreements and other documents reasonably
required under the terms of such  underwriting  arrangements and (iii) agrees to
pay its pro rata share of all underwriting  discounts and commissions applicable
with  respect  to its  Registrable  Securities,

                                     9

<PAGE>

in each case to the  extent not payable by the Company pursuant to the terms of
this Agreement.

         5.  Expenses of  Registration.  All expenses  (other than  underwriting
discounts and commissions or brokerage  commissions) incurred in connection with
registrations,  filings or  qualifications  pursuant  to  Section 3,  including,
without limitation, all registration, listing and qualifications fees, printers'
and accounting fees and the fees and  disbursements  of counsel for the Company,
shall be borne by the Company; provided,  however, that the Investors shall bear
the fees and  out-of-pocket  expenses of the one legal  counsel  selected by the
Investors pursuant to Section 3(h) hereof.

         6.       Indemnification.  In the event any Registrable Securities are
included in a Registration Statement under this Agreement:

                  (a) To the extent permitted by law, the Company will indemnify
and hold  harmless  each  Investor who holds such  Registrable  Securities,  the
directors,  if any, of such  Investor,  the officers,  if any, of such Investor,
each  person,  if any,  who  controls  any  Investor  within the  meaning of the
Securities  Act  or  the  Exchange  Act,  any  underwriter  (as  defined  in the
Securities Act) for the Investors,  the directors,  if any, of such  underwriter
and the  officers,  if any, of such  underwriter,  and each person,  if any, who
controls any such  underwriter  within the meaning of the  Securities Act or the
Exchange  Act (each,  an  "Indemnified  Person"),  against any  losses,  claims,
damages,  expenses or liabilities (joint or several) (collectively  "Claims") to
which any of them become subject under the  Securities  Act, the Exchange Act or
otherwise, insofar as such Claims (or actions or proceedings,  whether commenced
or  threatened,  in respect  thereof)  arise out of or are based upon any of the
following statements,  omissions or violations in the Registration Statement, or
any post-effective  amendment thereof, or any prospectus  included therein:  (i)
any untrue statement or alleged untrue statement of a material fact contained in
the  Registration  Statement  or any  post-effective  amendment  thereof  or the
omission or alleged  omission to state  therein a material  fact  required to be
stated therein or necessary to make the statements therein not misleading,  (ii)
any untrue statement or alleged untrue statement of a material fact contained in
any  preliminary  prospectus  if  used  prior  to the  effective  date  of  such
Registration  Statement,  or  contained in the final  prospectus  (as amended or
supplemented,  if the Company files any amendment thereof or supplement  thereto
with the SEC) or the omission or alleged  omission to state therein any material
fact  necessary  to  make  the  statements   made  therein,   in  light  of  the
circumstances  under which the  statements  therein were made, not misleading or
(iii) any violation or alleged  violation by the Company of the Securities  Act,
the  Exchange Act or any state  securities  law or any rule or  regulation  (the
matters  in  the  foregoing  clauses  (i)  through  (iii)  being,  collectively,
"Violations").  Subject  to the  restrictions  set  forth in  Section  6(d) with
respect  to the  number  of legal  counsel,  the  Company  shall  reimburse  the
Investors and each such  underwriter  or  controlling  person,  promptly as such
expenses  are  incurred  and are due and  payable,  for any legal  fees or other
reasonable  expenses  incurred  by  them in  connection  with  investigating  or
defending  any such

                                     10

<PAGE>

Claim.  Notwithstanding  anything to the contrary  contained herein, the
indemnification  agreement contained in this Section 6(a) (I) shall not apply to
a Claim  arising out of or based upon a Violation  which  occurs in reliance
upon and in  conformity  with  information  furnished in writing to the Company
by any  Indemnified  Person or underwriter for such Indemnified Person expressly
for  use in  connection  with  the  preparation  of the  Registration Statement,
preliminary prospectus, final prospectus or any amendments thereof or
supplements thereto, if such prospectus was timely made available by the Company
pursuant to Section 3(c) hereof; (II) with respect to any preliminary prospectus
shall not inure to the benefit of any such person from whom the person asserting
any such Claim purchased the Registrable Securities that are the subject thereof
(or  to the  benefit  of any  person  controlling  such  person)  if the  untrue
statement or omission of material fact contained in the  preliminary  prospectus
was  corrected  in the  prospectus,  as then  amended or  supplemented,  if such
prospectus  was timely made  available  by the Company  pursuant to Section 3(c)
hereof;  and (III) shall not apply to amounts paid in settlement of any Claim if
such  settlement is effected  without the prior written  consent of the Company,
which consent shall not be unreasonably withheld. Such indemnity shall remain in
full force and effect  regardless of any  investigation  made by or on behalf of
the  Indemnified  Persons  and shall  survive the  transfer  of the  Registrable
Securities by the Investors pursuant to Section 9.

                  (b) In connection with any Registration  Statement in which an
Investor is  participating,  each such  Investor  agrees to  indemnify  and hold
harmless,  to the same extent and in the same manner set forth in Section  6(a),
the  Company,  each  of its  directors,  each  of its  officers  who  signs  the
Registration Statement, each person, if any, who controls the Company within the
meaning of the Securities Act or the Exchange Act, any underwriter and any other
stockholder selling securities pursuant to the Registration  Statement of any of
its  directors  or  officers  or any person who  controls  such  stockholder  or
underwriter  within  the  meaning  of the  Securities  Act or the  Exchange  Act
(collectively and together with an Indemnified person, an "Indemnified  Party"),
against any Claims to which any of them may become subject, under the Securities
Act, the Exchange Act or otherwise,  insofar as such Claims(s)  arises out of or
is based  upon any  Violation(s),  in each case to the  extent  (and only to the
extent) that such  Violation(s)  occurs in reliance upon and in conformity  with
written information  furnished to the Company by such Investor expressly for use
in connection with such Registration Statement;  and such Investor will promptly
reimburse any legal or other expenses  reasonably incurred by them in connection
with  investigating  or defending any such Claim;  provided,  however,  that the
indemnity  agreement  contained  in this Section 6(b) shall not apply to amounts
paid in settlement of any Claim if such settlement is effected without the prior
written  consent  of such  Investor,  which  consent  shall not be  unreasonably
withheld;  provided,  further,  however, that the Investor shall be liable under
this  Section  6(b) for only that  amount of a Claim as does not  exceed the net
proceeds  to such  Investor  as a result of the sale of  Registrable  Securities
pursuant to such  Registration  Statement.  Such indemnity  shall remain in full
force and effect  regardless of any  investigation  made by or on behalf of such
Indemnified  Party and shall survive the transfer of the Registrable  Securities
by the Investors

                                     11

<PAGE>

pursuant to Section 9. Notwithstanding anything to the contrary herein,  the
indemnification  agreement  contained  in this  Section  6(b) with respect  to
any  preliminary  prospectus  shall not inure to the  benefit of any
Indemnified Party if the untrue statement or omission of material fact contained
in the preliminary prospectus was corrected on a timely basis in the prospectus,
as then amended or supplemented.

                  (c) The Company shall be entitled to receive  indemnities from
underwriters,  selling brokers,  dealer managers and similar securities industry
professionals participating in any distribution,  to the same extent as provided
above,  with respect to information such persons so furnished in writing by such
persons expressly for inclusion in the Registration Statement.

                  (d)  Promptly  after  receipt  by  an  Indemnified  Person  or
Indemnified  Party  under this  Section 6 of notice of the  commencement  of any
action  (including  any  governmental   action),   such  Indemnified  Person  or
Indemnified Party shall, if a Claim in respect thereof is to be made against any
indemnifying  party under this  Section 6, deliver to the  indemnifying  party a
written notice of the commencement thereof and the indemnifying party shall have
the right to  participate  in,  and,  to the  extent the  indemnifying  party so
desires,  jointly with any other indemnifying party similarly noticed, to assume
control  of the  defense  thereof  with  counsel  mutually  satisfactory  to the
indemnifying  parties;   provided,   however,  that  an  Indemnified  Person  or
Indemnified Party shall have the right to retain its own counsel,  with the fees
and expenses to be paid by the indemnifying party, if, in the reasonable opinion
of counsel  retained  by the  indemnifying  party,  the  representation  by such
counsel of the  Indemnified  Person or  Indemnified  Party and the  indemnifying
party would be  inappropriate  due to actual or  potential  differing  interests
between such Indemnified  Person or Indemnified Party and indemnifying  party in
such  proceeding.  The Company shall pay for only one separate legal counsel for
such of the Investors as may become Indemnified Parties or Indemnified  Persons;
such legal  counsel  shall be  selected by the  Investors  holding a majority in
interest of the Registrable Securities. The failure to deliver written notice to
the indemnifying  party within a reasonable time of the commencement of any such
action  shall  not  relieve  such  indemnifying  party of any  liability  to the
Indemnified  Person or  Indemnified  Party  under this  Section 6, except to the
extent that the  indemnifying  party is prejudiced in its ability to defend such
action. The indemnification required by this Section 6 shall be made by periodic
payments  of the  amount  thereof  during  the  course of the  investigation  or
defense,  as such expense,  loss, damage or liability is incurred and is due and
payable.

                  (e) Any Holder  required to indemnify  the Company as provided
in this  Section  6 shall  cease to have the right to  participate  in any other
registration pursuant to this Agreement.

         7. Contribution.  To the extent any indemnification provided for herein
is  prohibited  or limited by law,  the  indemnifying  party  agrees to make the
maximum contribution

                                    12

<PAGE>

with respect to any amounts for which it would otherwise be liable  under
Section  6 to the  fullest  extent  permitted  by law;  provided, however, that
(a) no contribution shall be made under  circumstances  where the maker would
not have been liable for  indemnification  under the fault standards set  forth
in  Section  6, (b) no  Holder of  Registrable  Securities  guilty of fraudulent
misrepresentation  (within  the  meaning  of  Section  11(f)  of the Securities
Act) shall be entitled to contribution from any Holder of Registrable Securities
who was not  guilty  of such  fraudulent  misrepresentation  and (c)
contribution by any Holder of Registrable  Securities shall be limited in amount
to the net amount of  proceeds  received  by such  Holder  from the sale of such
Registrable Securities.

         8. Reports under  Exchange Act. With a view to making  available to the
Investors  the benefits of Rule 144 or any other  similar rule or  regulation of
the SEC that may at any time  permit the  Investors  to sell  securities  of the
Company to the public  without  registration,  until such time as the  Investors
have sold all the Registrable Securities held by them pursuant to a Registration
Statement or Rule 144 or otherwise, the Company agrees to:

                  (a)      make and keep public information available, as those
terms are understood and defined in Rule 144;

                  (b)      file with the SEC in a timely manner all reports and
other documents required of the Company under the Securities Act and the
Exchange Act; and

                  (c)  furnish to each  Investor so long as such  Investor  owns
Registrable  Securities,  promptly upon request,  (i) a written statement by the
Company that it has complied  with the reporting  requirements  of Rule 144, the
Securities  Act and the Exchange  Act,  (ii) a copy of the most recent annual or
quarterly report of the Company and such other reports and documents so filed by
the Company and (iii) such other  information as may be reasonably  requested to
permit  the  Investors  to sell such  securities  pursuant  to Rule 144  without
registration.

         9.  Assignment  of the  Registration  Rights.  The  rights  to have the
Company  register  Registrable  Securities  pursuant  to this  Agreement  may be
assigned by the Initial  Investor to any shareholder of the Initial  Investor to
whom the Initial Investor  transfers any Closing Shares or Additional Shares if:
(a) the Company is, within a reasonable  time after such transfer or assignment,
furnished with written notice of (i) the name and address of such  transferee or
assignee and (ii) the securities with respect to which such registration  rights
are being  transferred or assigned,  (b) immediately  following such transfer or
assignment  the further  disposition  of such  securities  by the  transferee or
assignee is restricted  under the Securities Act and applicable state securities
laws,  and (c) at or before the time the Company  receives  the  written  notice
contemplated by clause (a) of this sentence the transferee or assignee agrees in
writing with the Company to be bound by all of the provisions  contained

                                    13
<PAGE>

herein. Except for transfers to  shareholders  of the Initial  Investor that
comply with the requirements of this Section, registration rights are not
transferable.

         10. Amendment of Registration  Rights.  Any provision of this Agreement
may be amended and the observance  thereof may be waived (either generally or in
a particular instance and either retroactively or prospectively),  only with the
written  consent of the Company and Investors who hold a majority in interest of
the Registrable Securities.  Any amendment or waiver effected in accordance with
this Section 10 shall be binding upon each Investor and the Company.

         11.      Miscellaneous.

                  (a) A person or entity is deemed to be a holder of Registrable
Securities  whenever  such  person or entity  owns of  record  such  Registrable
Securities.  If  the  Company  receives  conflicting  instructions,  notices  or
elections  from  two or more  persons  or  entities  with  respect  to the  same
Registrable  Securities,  the Company shall act upon the basis of  instructions,
notice  or  election  received  from the  registered  owner of such  Registrable
Securities.

                  (b) Notices  required or permitted to be given hereunder shall
be in writing (including facsimile) and shall be deemed to be sufficiently given
and delivered when personally delivered,  faxed (with a copy sent by first class
mail) or when sent by registered mail, return receipt  requested,  addressed (i)
if to the  Company,  at EDITEK,  Inc.,  1238  Anthony  Road,  Burlington,  North
Carolina 27215,  Attention:  Peter J. Heath, Chief Financial Officer, (ii) if to
the Initial Investor, at the address set forth in the Purchase Agreement, with a
copy to Henson & Efron,  P. A.,  1200  Title  Insurance  Building,  Minneapolis,
Minnesota  55401,  Attention  Alan C.  Eidsness,  Esq. and (iii) if to any other
Investor, at such address as such Investor shall have provided in writing to the
Company,  or at such other address as each such party  furnishes by notice given
in accordance  with this Section  11(b),  with a copy to Henson & Efron,  P. A.,
1200 Title Insurance Building,  Minneapolis,  Minnesota 55401, Attention Alan C.
Eidsness, Esq., and shall be effective, when personally delivered, upon receipt,
when faxed, the day after transmission, and when so sent by certified mail, four
business days after deposit with the United States Postal Service.

                  (c) Failure of any party to exercise any right or remedy under
this  Agreement,  or otherwise,  or delay by a party in exercising such right or
remedy, shall not operate as a waiver thereof.

                  (d)  This  Agreement  shall  be  enforced,   governed  by  and
construed in accordance with the laws of the State of New York applicable to the
agreements  made and to be performed  entirely  within such state.  In the event
that any  provision  of this  Agreement  is invalid or  unenforceable  under any
applicable  statute  or  rule  of law,  then  such  provision  shall

                                   14

<PAGE>

be  deemed inoperative  to the extent that it may  conflict therewith and shall
be deemed modified to conform with such statute or rule of law. Any provision
hereof which may prove invalid or  unenforceable  under any law shall not affect
the validity or enforceability of any other provision hereof.

                  (e) This Agreement  constitutes the entire agreement among the
parties  hereto  with  respect  to  the  subject  matter  hereof.  There  are no
restrictions,  promises, warranties or undertakings,  other than those set forth
or  referred to herein.  This  Agreement  supersedes  all prior  agreements  and
understandings  among the  parties  hereto with  respect to the  subject  matter
hereof.

                  (f)  Subject to the  requirements  of  Section 9 hereof,  this
Agreement  shall inure to the benefit of and be binding upon the  successors and
assigns of each of the parties hereto.

                  (g)      All pronouns and any variations thereof refer to the
masculine, feminine or neuter, singular or plural, as the context may required.

                  (h)      The headings in the Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

                  (i)  This   Agreement   may  be   executed   in  two  or  more
counterparts,  each of which shall be deemed an original  but all of which shall
constitute one and the same agreement. This Agreement, once executed by a party,
may be  delivered  to  the  other  party  hereto  by  telephone  line  facsimile
transmission  of a copy of this Agreement  bearing the signature of the party so
delivering this Agreement.


         IN WITNESS  WHEREOF,  the parties have caused this Agreement to be duly
executed by their  respective  officers  thereunto duly authorized as of day and
year first above written.

EDITEK, INC.                                         MEDTOX LABORATORIES, INC.


By: _______________________                          By:_______________________
Title:_____________________                          Title:____________________


                                    15

<PAGE>


                           EDITEK, INC. QUESTIONNAIRE


         As partial  consideration  for the acquisition of substantially  all of
the  assets of  MedTox  Laboratories,  Inc.  ("MedTox")  by  EDITEK,  Inc.  (the
"Company"),  shares (the "Shares") of the common stock, par value $.15 per share
("Common  Stock"),  of the  Company are being  offered to MedTox,  at a purchase
price and on the terms described in the Company's Private  Placement  Memorandum
(the "Offering").

         The Shares are being offered without  registration under the Securities
Act of 1933,  as amended  (the  "Securities  Act"),  or the  securities  laws of
certain  states,  in reliance on the exemption  contained in Section 4(2) of the
Securities  Act and on Regulation D promulgated  by the  Securities and Exchange
Commission  pursuant to the Securities Act ("Regulation  D"), and in reliance on
applicable  exemptions  claimed under certain applicable state laws. The Company
has  agreed  to file a  registration  statement  on Form S-3 (the  "Registration
Statement")  with the  Securities  and Exchange  Commission to  registering  for
resale the Shares.


                         PURPOSES OF THIS QUESTIONNAIRE


         PART I:   Suitability Requirements and General Solicitation 
Restrictions.

         Under the  Securities  Act,  Regulation D and certain  state laws,  the
Company must determine that an individual meets certain suitability requirements
before selling (or, in some states,  offering) the Shares to such individual and
must ensure that no general solicitation occurs in connection with the Offering.
This  Questionnaire does not constitute an offer to sell or a solicitation of an
offer  to sell or a  solicitation  of an offer to buy the  Shares  or any  other
security.

         THE COMPANY WILL NOT OFFER OR SELL SHARES TO ANY INDIVIDUAL WHO HAS NOT
         COMPLETED AND EXECUTED THIS QUESTIONNAIRE.

         PART II: Stock Ownership.

         Certain information regarding ownership of the Company's securities and
the  intended  plan of  distribution  of the Shares is  necessary to prepare the
Registration  Statement and other securities  documents which may be required in
connection with the  Registration  Statement to be filed by the Company with the
Securities  and  Exchange  Commission  to  register  for resale the  Shares,  in
accordance  with the rights granted to you pursuant to the  Registration  Rights
Agreement between the Company and MedTox (the "Registration Rights Agreement").

         Because the information provided herein will be used in connection with
the  preparation  of  documents to be filed with state or federal  agencies,  it
should be accurate,  complete  and true,  and not omit any material or important
information.


<PAGE>


         One copy of this  questionnaire  should be completed  and  delivered to
Editek, Inc., 1238 Anthony Road, Burlington, NC 27215, Attn: Peter J. Heath.

         SHARES WILL NOT BE INCLUDED IN THE REGISTRATION UNLESS YOU COMPLETE 
         THIS QUESTIONNAIRE.



                                     PART I

INSTRUCTIONS TO PART I:

         PLEASE ANSWER ALL  QUESTIONS.  If the  appropriate  answer is "None" or
"Not Applicable," so state.  Please print or type your answers to all questions.
Attach additional sheets if necessary to complete your answers to
any item.

         Your answers to Part I will be kept strictly confidential at all times;
however,  the Company may present this  Questionnaire to such parties (including
lenders or  governmental  entities) as it deems  appropriate  in order to assure
itself and such entities that the offer and sale of the Units will not result in
a violation of the registration  provisions of the Securities Act or a violation
of Regulation D or the securities laws of any state.

         NOTE:  Individuals  responding  to  this  questionnaire  should  answer
questions 1 through 3.2 of Part I. Partnerships,  corporations,  trusts or other
entities responding to this questionnaire  should answer questions 4 through 7.2
of Part I.

A.       INDIVIDUALS

         1.       Name and Address.


Name:_____________________________________     Date of Birth:__________________
Residence Address (include Zip Code):__________________________________________

- ------------------------------------------------------------------------------

Business Address (include Zip Code)____________________________________________

- ------------------------------------------------------------------------------
                                        2

<PAGE>

Telephone Nos. Res.:_______________________          Bus.:_____________________
Preferred Mailing Address: [  ] Residence   [  ] Business

Citizenship:      [  ] U.S.   [  ] Other (specify)_____________________________

State of Residence:____________________________________________________________

Social Security No.:___________________________________________________________

Marital Status:________________________________________________________________


         2.  Financial   Condition.   Please  answer  the  following   questions
concerning your financial condition by marking the appropriate response box.

         2.1      Did your  individual  annual  gross  income  (net of  expenses
                  directly related to the production of such income) during each
                  of 1993 and 1994 exceed $200,000, and do you reasonably expect
                  your individual annual income during 1995 to exceed $200,000?

                                                                   [ ]   [ ] 
                                                                   Yes    No

         2.2      Did your joint annual gross income (together with your spouse)
                  (net of expenses  directly  related to the  production of such
                  income) during each of 1993 and 1994 exceed  $300,000,  and do
                  you reasonably  expect your joint annual income during 1995 to
                  exceed $300,000?
                                                                     [ ]  [ ]
                                                                     Yes    No

         2.3     Does your  individual  or joint  (together  with your  spouse) 
                 net worth 1 exceed $1,000,000?
                                                                   
                                                                     [ ]   [ ]
                                                                     Yes    No

1 For this purpose, a person's net worth is the excess of all of the person's 
assets over all of the person's liabilities, based upon current fair market 
value.

                                        3
<PAGE>


         3.                Sophistication:

         3.1               (a) Do  you  consider  yourself  to  have  sufficient
                           knowledge  and  experience  in financial and business
                           matters  to enable  you to  evaluate  the  merits and
                           risks of an investment in the Shares?

                                                                     [ ]    [ ]
                                                                     Yes     No

                  (b)      If the answer to 3.1(a) is "No," you will be required
                           to have an attorney,  accountant or other  investment
                           adviser serve as your purchaser  representative(s) to
                           evaluate   and  advise  you  with   respect  to  your
                           prospective  investment  in  the  Shares.  Each  such
                           person  must  complete,   and  you  must  review  and
                           acknowledge,   a  separate  Purchaser  Representative
                           Questionnaire    and    Disclosure    Statement   and
                           Acknowledgement which must be returned to the Company
                           prior to the sale of any Shares to you.

         3.2      In  connection  with your  proposed  investment in the Shares,
                  will you seek advice from any attorney, accountant, investment
                  adviser or other person or persons?

                                                                   
                                                                     [ ]   [ ]
                                                                     Yes    No

                  If yes,  please set forth the name,  profession or occupation,
                  business address and telephone number of each such prospective
                  adviser and, if more than one, explain briefly the division of
                  responsibilities between them:

                  --------------------------------------------------------------

                  --------------------------------------------------------------

                  --------------------------------------------------------------

                  --------------------------------------------------------------

                                                4
<PAGE>


B.       PARTNERSHIPS, CORPORATIONS, TRUSTS OR OTHER ENTITIES

         4.       Name and Address.

Name of entity: ________________________________________________________________



Indicate type of entity:
                           [   ]   General Partnership
                           [   ]   Limited Partnership
                           [   ]   Corporation
                           [   ]   Trust
                           [   ]   Other ____________________________________
                                                      (Specify)

Taxpayer identification number:___________________

Business address:______________________________________________________________
(Street)
- ------------------------------------------------------------------------------
                  (City)            (State)          (Zip Code)

Business telephone number:_______________________________________
                                    (Area Code)           (Number)

State in which organized or incorporated:
- ------------------------------------------------------------------------------

Date of organization or incorporation:
- ------------------------------------------------------------------------------

Was this partnership, corporation, trust or other entity formed for the specific
purpose of investing in the Shares?

                           [   ]  Yes                         [   ]  No


         5.       Business

         Please describe the nature of the business the entity conducts.
         ----------------------------------------------------------------------

                                        5
<PAGE>

         ----------------------------------------------------------------------



         6.       Financial Condition:

         6.1      Please answer Questions 6.1.1 through 6.1.6 by checking the 
                  appropriate box or boxes below:

                  6.1.1 The  undersigned  entity is (a) a bank,  as  defined  in
                  Section 3(a)(2) of the Securities Act os 1933, as amended (the
                  "Act"), or a savings and loan association or other institution
                  as defined in Section 3(a)(5)(A) of the Act, whether acting in
                  its individual or fiduciary  capacity;  (b) a broker or dealer
                  registered  pursuant to Section 15 of the Securities  Exchange
                  Act of 1934, as amended (the "Exchange Act"); (c) an insurance
                  company,  as  defined  in  Section  2(13) of the  Act;  (d) an
                  investment company registered under the Investment Partnership
                  Act of 1940 (the "1940 Act") or a business development company
                  as  defined  in  Section  310(c) or (d) of the Small  Business
                  Investment Act of 1958; (e) a plan  established and maintained
                  by a  state,  it  political  subdivision,  or  any  agency  or
                  instrumentality of a state or its political subdivisions,  for
                  the benefit of its  employees if such plan has total assets in
                  excess of $5,000,000;  or an employee  benefit plan within the
                  meaning of the Employee Retirement Income Security Act of 1974
                  ("ERISA"),  if  the  investment  decision  is  made  by a plan
                  fiduciary,  as  defined  in  Section  3(21) of ERISA,  that is
                  either a bank, savings and loan association, insurance company
                  or registered  investment  adviser, or if the employee benefit
                  plan has  total  assets  in  excess  of  $5,000,000  or,  if a
                  self-directed  plan, with investment  decisions made solely by
                  persons that are accredited investors.

                                                                      
                                                                      [ ]   [ ]
                                                                      Yes    No




                  6.1.2  The   undersigned   entity  is  a   "private   business
                  development  company" as defined in Section  202(a)(22) of the
                  Investment Advisers Act of 1940.


                                                                      
                                                                      [ ]   [ ]
                                                                      Yes    No

                  6.1.3 The undersigned  entity is an organization  described in
                  Section 501(c)(3) of the Internal Revenue Code, a corporation,
                  a Massachusetts  or similar  business trust, or a partnership,
                  not formed for the specific  purpose of making the investment,
                  with total assets in excess of $5,000,000.

                                                                   
                                                                      [ ]   [ ]
                                                                      Yes    No

                                        7
<PAGE>


                  6.1.4 The undersigned  entity is a trust, with total assets in
                  excess of $5,000,000,  not formed for the purpose of investing
                  in the Shares.

                                                                         
                                                                       [ ]   [ ]
                                                                       Yes    No

                  6.1.5 The undersigned is an entity and each partner (including
                  general  and  limited  partners),  shareholder,  grantor  of a
                  revocable  trust or  other  equity  owner  of the  undersigned
                  entity (a) has a net worth,  individually  or jointly with his
                  or her spouse, of at least  $1,000,000;  (b) had an individual
                  income  in  excess  of  $200,000  in each of 1993 and 1994 and
                  reasonably  expects such individual  income to exceed $200,000
                  in 1995 (or with his or her spouse, had and expects to have an
                  income of  $300,000  for such  periods;  (c) is an  officer or
                  director of the Company;  or (d) meets the requirements of any
                  of categories 6.1.1, 6.1.2, 6.1.3, 6.1.4 above.

                                                                       
                                                                       [ ]  [ ]
                                                                       Yes   No

                  6.1.6  The  undersigned  entity  does  not  meet  any  of  the
                  standards set forth in the categories  listed in 6.1.1 through
                  6.1.5 above.

                                                                    
                                                                      [ ]   [ ]
                                                                      Yes    No

         7.       Sophistication

         7.1               (a) Does the entity  have  sufficient  knowledge  and
                           experience  in  financial  and  business  matters  to
                           enable  it to  evaluate  the  merits  and risks of an
                           investment in the Shares?

                                                                     
                                                                     [ ]    [ ]
                                                                     Yes     No

                  (b)      If the answer to 7.1(a) is "No," the  entity  will be
                           required  to have an  attorney,  accountant  or other
                           investment    adviser    serve   as   its   purchaser
                           representative(s)  to  evaluate  and  advise  it with
                           respect to the prospective  investment in the Shares.
                           Each such person must  complete,  and the entity must
                           review  and   acknowledge,   a   separate   Purchaser
                           Representative Questionnaire and Disclosure Statement
                           and  Acknowledgement  which must be  returned  to the
                           Company  prior  to  the  sale  of any  Shares  to the
                           entity.

                                              8
<PAGE>



         7.2      In connection with the proposed investment in the Shares, will
                  the  entity  seek  advice  from  any   attorney,   accountant,
                  investment adviser or other person or persons?

                                                                          
                                                                      [ ]   [ ]
                                                                      Yes    No

                  If yes,  please set forth the name,  profession or occupation,
                  business address and telephone number of each such prospective
                  adviser and, if more than one, explain briefly the division of
                  responsibilities between them:

                  --------------------------------------------------------------

                  --------------------------------------------------------------

                  --------------------------------------------------------------

                  --------------------------------------------------------------

                                           9

<PAGE>



                                     PART II



INSTRUCTIONS TO PART II:

         Please answer each question  fully,  giving the most exact and accurate
answers possible and provide  information as of December 1, 1995.  Certain terms
used in Part II are defined in Appendix A hereto, which should be referred to in
completing this part of the questionnaire.

         For purposes of the questions in Part II, references to "you" or "your"
refer equally to individuals and entities responding to this questionnaire.

         1.       General.

                  State  your  name  as  it  should  appear  in  any  securities
registration filings made.

                  NAME:________________________________________________________

                  If an entity, indicate principal contact for questions:

                  NAME:________________________________________________________

                  TELEPHONE:___________________________________________________

         2.       Business.

                  Please  describe the nature of the business your  organization
conducts.

- ------------------------------------------------------------------------------

- ------------------------------------------------------------------------------

                                        10
<PAGE>


         3.       Relationship with the Company.

                  Please  state  your  (or  the  undersigned  entity's)  current
position  or  relationship   with  the  Company  (or  its  affiliates)  and  any
relationship with the Company (or its affiliates) during the past three years:
- ------------------------------------------------------------------------------

- ------------------------------------------------------------------------------

         4.       Security Holdings.

                  (a) Please state below the respective numbers of shares of the
Company's Common Stock (or any other class of equity securities),  excluding the
shares  of the  Company's  Common  Stock  offered  by  the  Company  as  partial
consideration  for the  acquisition of the assets of MedTox,  owned of record or
beneficially*, directly or indirectly, by you or members of your family, or by a
group* of which you are a member, or by an associate* of yours, as indicated, as
of __________________  (the "Non-MedTox Shares"). For purposes of this question,
your family members include your spouse, your minor children and any relative of
you or your spouse who lives with you.

<TABLE>
<CAPTION>

                                    Class & Number of       Name and               Amount and
                                    Non-MedTox Shares       Address of             Nature of
                                    Currently Owned         Beneficial Owner*      Beneficial Ownership2
<S>                                 <C>                    <C>                   <C> 


Non-MedTox Shares owned
by you, both of record
and beneficially*

Non-MedTox Shares owned
by you, of record only

Non-MedTox Shares owned
by you, beneficially* only

Non-MedTox  Shares owned
of record or beneficially*  
by your spouse,  your 
minor children and  
relatives of yours or
of your spouse  
(including  adult  children)
living in your home
</TABLE>

2 State whether this is by (1) sole voting power, (2) shared voting power, (3)
sole investment power, (4) shared investment power, or any combination of the 
foregoing.

                                    11
<PAGE>

<TABLE>
<CAPTION>


                                    Class & Number of         Name and          Amount and
                                    Non-MedTox Share          Address of        Nature of
                                    Currently Owned           Beneficial Owner* Beneficial Ownership3
<S>                              <C>                         <C>                <C>

Non-MedTox Shares owned
by a group* of which you
are a member, both of
record and beneficially*

Non-MedTox Shares owned
by a group* of which
you are a member,
of record only

Non-MedTox Shares owned
by a group* of which
you are a member,
beneficially* only

Non-MedTox  Shares  
which  you  have a 
right to  acquire  
pursuant  to  options,
warrants or otherwise  
within 60 days of 
 _____________,  1995 
(please  describe
arrangements on reverse 
side of this page)
</TABLE>


         (b) Are any of the shares of stock or notes of the Company owned by you
subject to any pledge or other contractual arrangement*?

                           No _____                  Yes _____

                  If yes,  please  explain  such  pledge  or  other  contractual
arrangement*:

3 State whether this is by (1) sole voting power, (2) shared voting power, 
(3) sole investment power, (4) shared investment power, or any combination
of the foregoing.

                                    12

<PAGE>


- ------------------------------------------------------------------------------

- ------------------------------------------------------------------------------



         (c) Please  describe  any other  rights to purchase  securities  of the
Company that you have:
- ------------------------------------------------------------------------------

- ------------------------------------------------------------------------------

         5. Plan of Distribution. Attached as Appendix B hereto is a description
of a plan of  distribution  that  is  intended  to be  used in the  Registration
Statement.  Please indicate  whether anything stated in Appendix B is inaccurate
or misleading with respect to any plan you may have to distribute the securities
owned by you or  whether  Appendix B omits to state any  information  about such
plan of distribution.

                           No _____                  Yes _____

                  If yes, describe below  specifically in what manner Appendix B
is  inaccurate  or  misleading.   Please  also  describe  below  any  additional
information  about any plan you may have to distribute the  securities  that you
own.

- ------------------------------------------------------------------------------

- ------------------------------------------------------------------------------

- ------------------------------------------------------------------------------
                                    13


<PAGE>


                                  CERTIFICATION


         The  undersigned  hereby  affirms  that the  preceding  information  is
correct as of the date hereof.  The undersigned will promptly notify the Company
or its  legal  counsel  of any  changes  in such  information.  The  undersigned
understands and agrees that this  Questionnaire,  as completed,  and any further
communications  by the undersigned  regarding the matters  contemplated  herein,
will be relied  upon,  in  connection  with the  offering  by the Company of the
Shares and the filings related to the  Registration  Statement,  by the Company,
its legal counsel,  and the  representatives  of the  underwriters  (if any) and
their counsel.

                 -----------------------------------------------
                             Signature of Investor 4

                 ----------------------------------------------
                   Please type or print name and title, if any

                  ---------------------------------------------
                                      Date

4 If this Questionnaire is being completed by or on behalf of a person* other 
than an individual, the entity on whose behalf the Questionnaire is being 
completed should be stated.

                                          14
<PAGE>



                                   APPENDIX A


1.       Affiliate,  Affiliated  Company.  The term  "affiliate"  or "affiliated
         company"  means any person* that directly or indirectly  through one or
         more intermediaries  controls,  or is controlled by, or is under common
         control with a specific entity,  by means of possession of the power to
         direct or cause the direction of its management  and policies,  whether
         through ownership or otherwise. Persons who have acted or are acting on
         behalf  or  for  the  benefit  of  any  entity  include,  but  are  not
         necessarily  limited  to,  directors,   officers,   employees,  agents,
         consultants and sales representatives.

2.       Associate.  The term "associate" means:

         (a)      Any  corporation or  organization,  except the Company and its
                  subsidiaries, of which you are an executive officer or partner
                  or of which you,  together with other officers or directors of
                  the Company, are, directly or indirectly, the beneficial owner
                  of 10% or more of any class of equity securities.

         (b)      Any  trust or other  estate  in which  you have a  substantial
                  beneficial  interest or as to which you serve as trustee or in
                  a similar fiduciary capacity.

         (c)      Any  relative,  your spouse or any relative of your spouse who
                  resides  with  your or who is a  director  of  officer  of the
                  Company or its subsidiaries.

3.       Beneficial Owner. A "beneficial owner" of securities is any person who,
         directly   or   indirectly,   through   any   contract,    arrangement,
         understanding, relationship or otherwise has or shares:

         (i)      Voting power,  which  includes the power to vote, or to direct
                  the voting of, such security; and/or,

         (ii)     Investment  power,  which  includes  the power to  dispose  or
                  direct the disposition of, such security.

         Furthermore, a "beneficial owner" of a security includes any person who
         has the right to acquire  beneficial  ownership of such security at any
         time within sixty (60) days. The right to acquire beneficial  ownership
         could (but need not  necessarily)  be through  (i) the  exercise of any
         option,  warrant or right,  (ii) the conversion of a security,  (iii) a
         power to  revoke or  automatic  termination  of a trust,  discretionary
         account, or similar arrangement, or otherwise.


                                         15
<PAGE>


         A  "beneficial  owner"  also  includes  any  person  who,  directly  or
         indirectly,  creates or uses a trust, proxy, power of attorney, pooling
         arrangement  or any other  contract,  arrangement,  or device  with the
         purpose or effect of divesting such person or beneficial ownership of a
         security or preventing the vesting of such beneficial ownership as part
         of a plan to evade the reporting  requirements  of any federal or state
         securities act.

         Securities owned beneficially would include not only securities held by
         you for your own benefit,  whether in bearer form or registered in your
         own name or otherwise, but would also include securities held by others
         for your benefit  (regardless  of whether or how they are  registered),
         such  as,  for  example,  securities  held  for you by  banks  or other
         custodians,  brokers  (whether  in your name,  their name or in "street
         name"),  executors,  administrators,  or trustees  (including trusts in
         which you have only a remainder  interest) and securities held for your
         account by pledges,  and securities owned by a partnership in which you
         are a member,  and securities owned by any corporation in which you and
         your associates* own 10% or more of the stock. A person is deemed to be
         the beneficial  owner of securities  beneficially  owned by his spouse,
         his minor children, or any relative sharing his home.

         "Indirectly", when used to refer to beneficial ownership of securities,
         means  ownership  through  another  such as a  controlled  corporation,
         member of the family, estate, trust, partnership or other entity.

4.       Family  Member.  The term "family  member" means your spouse,  parents,
         children,    siblings,    mothers   and   fathers-in-law,    sons   and
         daughters-in-law, and brothers and sisters-in-law.

5.       Family   Relationship.   The  term  "family   relationship"  means  any
         relationship by blood, marriage or adoption, not more remote than first
         cousin.

6.       Group.  The term  "group"  means  any two or more  persons  acting as a
         partnership, limited partnership, syndicate or otherwise.

7.       Person. The term "person" means a natural person, company, partnership,
         joint venture, limited partnership, trust, estate, government, or other
         entity, or a political  subdivision,  agency, or  instrumentality  of a
         government.

8.       Public Company.  The term "public company" means a company with a class
         of  securities  registered  pursuant  to section  12 of the  Securities
         Exchange Act of 1934 or subject to the requirements of section 15(d) of
         that Act or any company  registered as an investment  company under the
         Investment Company Act of 1940.
                                       
                                   16

<PAGE>



9.       Arrangement.  Any  plan,*  contract,  authorization  or  understanding,
         whether or not set forth in a formal document.

10.      Immediate  Family.  Any  relationship  by blood,  marriage or adoption,
         including the person's spouse, parents, children, brothers and sisters,
         mothers and fathers-in-law,  sons and daughters-in-law and brothers and
         sisters-in law, but not more remote than first cousin.

                                     17
<PAGE>

                                   APPENDIX B

                              PLAN OF DISTRIBUTION

         The MedTox  Shareholders may from time to time effect the sale of their
Shares in one or more  transactions in the public market, at prices and at terms
then  prevailing or at prices related to the  then-current  market price,  or in
negotiated  transactions  or  otherwise.  The Shares may be sold pursuant to the
Registration  Statement,  another  registration  statement  or  pursuant  to  an
exemption  from  registration,  including  Rule 144.  If all or a portion of the
Shares are sold in such transactions,  they may be sold by means of: (a) a block
trade in which the broker or dealer so engaged  will  attempt to sell the Shares
as agent but may  position  and  resell a portion of the block as  principal  to
facilitate the  transactions;  (b) purchases by a broker as principal and resale
by such broker for its account  pursuant to the Prospectus that is a part of the
Registration  Statement;  (c) an exchange  distribution  in accordance  with the
rules of such exchange;  (d) ordinary brokerage transactions and transactions in
which the broker  solicits  purchasers;  or (e) a  combination  of the foregoing
methods.  In  effecting  sales,   brokers  or  dealers  engaged  by  the  MedTox
Shareholders  may  arrange  for other  brokers or dealers  to  participate.  The
brokers or dealers engaged by the MedTox  Shareholders will receive  commissions
or discounts from the MedTox  Shareholders in amounts to be negotiated  prior to
the sale.  Such  brokers  or  dealers  and any other  participating  brokers  or
dealers, as well as the MedTox Shareholders,  may be deemed to be "underwriters"
within the meaning of the  Securities Act in connection  with such sales.  There
are currently no plans, arrangements or understandings between any of the MedTox
Shareholders  and any broker or dealer regarding the sale of stock by the MedTox
Shareholders.



                           18
<PAGE>







                              ASSIGNMENT AGREEMENT


         THIS ASSIGNMENT AGREEMENT ("Assignment") is made and entered into as of
the  10th  day of  January,  1996,  by and  between  EDITEK,  INC.,  a  Delaware
corporation  ("Purchaser"),  MEDTOX LABORATORIES,  INC., a Minnesota corporation
("Seller"), and PSYCHIATRIC DIAGNOSTIC LABORATORIES OF AMERICA, INC., a Delaware
corporation ("Assignee").

         WHEREAS,  Seller  and  Purchaser  are  parties  to that  certain  Asset
Purchase  Agreement  dated  as of July  1,  1995,  and  that  certain  Amendment
Agreement  dated as of January 2, 1996,  pursuant to which  Purchaser  agreed to
purchase  and Seller  agreed to sell  substantially  all of the assets of Seller
(collectively, the "Purchase Agreement"); and

         WHEREAS,  Purchaser desires to assign to Assignee,  Assignee has agreed
to assume and Seller desires to consent to the assignment of, Purchaser's rights
under the Purchase  Agreement  under the terms and  conditions set forth herein;
and

         WHEREAS,  Assignee  is an  Affiliate  of  Purchaser  (as  such  term is
contemplated in the Purchase Agreement) of Purchaser; and

         WHEREAS, the assignment effected hereby is permitted under Section 13.3
of the Purchase Agreement.

         NOW, THEREFORE,  in consideration of the foregoing premises,  and other
good and  valuable  consideration,  the receipt and adequacy of which are hereby
acknowledged, the parties hereto agree as follows:

         1.  Assignment.  Purchaser  hereby  assigns and  transfers to Assignee,
Purchaser's  rights to purchase  assets  pursuant  to the terms of the  Purchase
Agreement.

         2.  Acceptance of Assignment.  Assignee hereby accepts the rights being
assigned hereby and assumes all responsibilities and obligations of Purchaser as
set forth in the Purchase  Agreement.  Assignee  hereby  covenants and agrees to
perform all terms and conditions contained in the Purchase Agreement.

         3.  Non-Release  of  Purchaser.  In accordance  with the  provisions of
Section 13.3 of the Purchase Agreement,  Purchaser agrees that the assignment to
Assignee of its rights under the Purchase Agreement shall not operate to release
Purchaser  from any  liability  to Seller  under  the  Purchase  Agreement,  and
Purchaser  shall remain  obligated to perform all terms and conditions and shall
remain  liable for all  indemnification  obligations  contained  in the Purchase
Agreement required to be performed by Purchaser.



<PAGE>



         4. Seller's Consent. Seller hereby consents to the foregoing assignment
on the terms and  conditions  set forth  herein,  and in  connection  therewith,
agrees to treat  Assignee  for all  purposes  as  Purchaser  under the  Purchase
Agreement  and to take  whatever  action may be necessary  to transfer  Seller's
assets to  Assignee,  including  without  limitation,  executing  or causing the
execution of deeds,  assignments,  consents and other  similar  documents in the
name of Assignee.

         5. Additional  Party. By execution of this  Assignment,  Assignee shall
become a party to the  Purchase  Agreement  and shall  hereafter be bound by the
terms and conditions thereof.

         6.  Warranties  of  Purchaser.  Purchaser  warrants and  represents  to
Assignee as follows: (a) the Purchase Agreement is in full force and effect; (b)
neither  the  Purchase  Agreement  nor  any  of  the  obligations,   duties  and
responsibilities  of the  Purchaser  or Seller  thereunder  have  been  amended,
modified  or altered in any manner  other  than as  reflected  in the  Amendment
Agreement;  and (c) there  exists no  circumstance,  condition or act of default
which would entitle or permit  Seller to terminate the Purchase  Agreement or to
abridge any rights of Purchaser thereunder or exercise any remedies for default.

         7. Binding Effect. This Assignment shall be binding upon successors and
assigns of the parties.  The parties  shall execute and deliver such further and
additional  instruments,  agreements and other  documents as may be necessary to
evidence or carry out the provisions of this Assignment.

         8.  Counterparts.  This  Assignment  may be  executed  in  two or  more
counterparts,  each of  which  shall  be  deemed  an  original  but all of which
together shall constitute one and the same instrument.

         9. Governing Law; Interpretation. The execution and performance of this
Assignment  shall be governed by the substantive laws of the State of Minnesota,
without  giving effect to the provisions  thereof  relating to conflicts of law.
Unless otherwise defined herein, capitalized terms shall have the meanings given
to them under the Purchase Agreement.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


<PAGE>


         IN WITNESS  WHEREOF,  the parties hereto have executed this  Assignment
effective as of the day and year first above written.

                               PURCHASER:

                              EDITEK, INC.


ATTEST:                                 By: _______________________________
                                        Title: ____________________________
[SEAL]


- ----------------------
  Secretary

                                 SELLER:

                                        MEDTOX LABORATORIES, INC.


ATTEST:                                 By: _______________________________
                                        Title: ____________________________
[SEAL]


- ----------------------
  Secretary

                                ASSIGNEE:

                                        PSYCHIATRIC DIAGNOSTIC LABORATORIES OF
                                          AMERICA, INC.


ATTEST:                                 By: _______________________________
                                        Title: ____________________________
[SEAL]


- ---------------------
  Secretary






<PAGE>





                           LOAN AND SECURITY AGREEMENT


         This LOAN AND SECURITY  AGREEMENT is dated as of January ___, 1996, and
entered into by and between EDITEK,  INC., a Delaware  corporation,  PSYCHIATRIC
DIAGNOSTIC   LABORATORIES  OF  AMERICA,   INC.,  a  Delaware  corporation,   and
DIAGNOSTIX, INC., a Delaware corporation (collectively, "Borrowers"), with their
principal  place of business at 1238 Anthony Road,  Burlington,  North  Carolina
27215,  and HELLER  FINANCIAL,  INC., a Delaware  corporation  ("Lender"),  with
offices at 500 West Monroe Street,  Chicago,  Illinois  60661.  All  capitalized
terms used herein are defined in Section 1 of this Agreement.

         WHEREAS,  Borrowers  desire  that  Lender  extend a credit  facility to
provide  working  capital  financing  and to  provide  funds for  other  general
corporate purposes; and

         WHEREAS,  Borrowers desire to secure their  obligations  under the Loan
Documents by granting to Lender a security  interest in and lien upon certain of
Borrowers' property;

         NOW,  THEREFORE,  in  consideration of the premises and the agreements,
provisions  and  covenants  herein  contained,  Borrowers  and  Lender  agree as
follows:



                                  1 DEFINITIONS

     1.1   Certain Defined Terms. The following terms used in this Agreement 
shall have the following meanings:

         "Accounts"  means,  all  "accounts"  (as defined in the UCC),  accounts
receivable,  contract rights and general  intangibles  relating thereto,  notes,
drafts and other forms of obligations  owed to or owned by a Borrower arising or
resulting from the sale of goods or the rendering of services.

         "Affiliate"  means any Person  (other  than  Lender):  (a)  directly or
indirectly controlling, controlled by, or under common control with, a Borrower;
(b)  directly or  indirectly  owning or holding five percent (5%) or more of any
equity interest in a Borrower;  or (c) five percent (5%) or more of whose voting
stock or other  equity  interest is directly  or  indirectly  owned or held by a
Borrower. For purposes of this definition, "control" (including with correlative
meanings,  the terms  "controlling",  "controlled  by" and "under common control
with") means the  possession  directly or  indirectly  of the power to direct or
cause the direction of the management and policies of a Person,  whether through
the ownership of voting securities or by contract or otherwise.

         "Agreement"  means  this  Loan  and  Security  Agreement  as it  may be
amended, supplemented or otherwise modified from time to time.

<PAGE>

         "Asset  Disposition"  means the  disposition,  whether by sale,  lease,
transfer, loss, damage, destruction, condemnation or otherwise, of any or all of
the  assets  of a  Borrower  or any of its  Subsidiaries  other  than  sales  of
Inventory in the ordinary course of business.

         "Availability" means, at any time of determination thereof, the Maximum
Revolving Loan Amount,  less the outstanding  principal balance of the Revolving
Loan.

         "Base  Rate" means a variable  rate of interest  per annum equal to the
higher of (a) the rate of interest  from time to time  published by the Board of
Governors of the Federal Reserve System as the "Bank Prime Loan" rate in Federal
Reserve  Statistical Release H.15(519) entitled "Selected Interest Rates" or any
successor  publication of the Federal  Reserve  System  reporting the Bank Prime
Loan rate or its  equivalent,  or (b) the  Federal  Funds  Effective  Rate.  The
statistical  release  generally  sets  forth a Bank  Prime  Loan  rate  for each
Business Day. In the event the Board of Governors of the Federal  Reserve System
ceases to publish a Bank Prime Loan rate or its equivalent, the term "Base Rate"
shall mean a variable  rate of  interest  per annum  equal to the highest of the
"prime rate",  "reference  rate",  "base rate",  or other similar rate announced
from time to time by any of Bankers Trust  Company,  The Chase  Manhattan  Bank,
National   Association  or  Chemical  Bank,  or  their   successors   (with  the
understanding  that any such  rate may  merely be a  reference  rate and may not
necessarily  represent the lowest or best rate actually  charged to any customer
by any such bank).

         "Blocked  Accounts" has the meaning assigned to that term in subsection
5.6.

         "Borrowers"  has the meaning  assigned to that term in the  preamble to
this Agreement.

         "Borrowing  Base" has the meaning  assigned to that term in  subsection
2.1(B).

         "Borrowing  Base  Certificate"   means  a  certificate  and  assignment
schedule duly executed by an officer of the  applicable  Borrower  appropriately
completed and in substantially the form of Exhibit A.

         "Business  Day" means any day  excluding  Saturday,  Sunday and any day
which is a legal holiday under the laws of the States of Minnesota,  New Jersey,
Illinois,  Pennsylvania  or  North  Carolina  or  is  a  day  on  which  banking
institutions located in any such state are closed.

         "Capital Expenditures" means all expenditures (including deposits) for,
or contracts for expenditures  (excluding  contracts for  expenditures  under or
with respect to Capital  Leases,  but  including  cash down  payments for assets
acquired under Capital Leases) with respect to any fixed assets or improvements,
or for  replacements,  substitutions or additions  thereto,  which have a useful
life of more than one year, including the direct or indirect acquisition of such
assets  by  way of  increased  product  or  service  charges,  offset  items  or
otherwise.

                                       2
<PAGE>
         "Capital Lease" means any lease of any property (whether real, personal
or mixed) that,  in conformity  with GAAP,  should be accounted for as a capital
lease.

         "Cash  Equivalents"  means: (a) marketable direct obligations issued or
unconditionally  guarantied  by the United  States  Government  or issued by any
agency thereof and backed by the full faith and credit of the United States,  in
each case maturing  within six (6) months from the date of acquisition  thereof;
(b)  commercial  paper maturing no more than six (6) months from the date issued
and, at the time of acquisition, having a rating of at least A-1 from Standard &
Poor's Corporation or at least P-1 from Moody's Investors Service, Inc.; and (c)
certificates of deposit or bankers'  acceptances  maturing within six (6) months
from the date of issuance  thereof  issued by, or overnight  reverse  repurchase
agreements  from,  any commercial  bank  organized  under the laws of the United
States of  America or any state  thereof  or the  District  of  Columbia  having
combined  capital and surplus of not less than  $250,000,000  and not subject to
setoff rights in favor of such bank.

         "Closing  Certificate"  means a certificate  duly executed by the chief
executive  officer or chief financial  officer of Borrowers in a form reasonably
acceptable to Lender

         "Closing Date" means January ___, 1996.

         "Collateral" has the meaning assigned to that term in subsection 2.7.

         "Collecting  Banks" has the meaning assigned to that term in subsection
5.6.

         "Commitment"  or  "Commitments"  means the commitment or commitments of
Lender to make Loans as set forth in subsections 2.l(A) and 2.1(B).

         "Compliance Certificate" means a certificate duly executed by the chief
executive  officer  or  chief  financial  officer  of  Borrowers   appropriately
completed and in substantially the form of Exhibit B.

         "Default"  means a condition  or event that,  after  notice or lapse of
time or both,  would  constitute an Event of Default if that  condition or event
were not cured or removed within any applicable grace or cure period.

         "Default Rate" has the meaning assigned to that term in subsection 2.2.

                                        3
<PAGE>
         "diAGnostix" means diAGnostix,  Inc., a Delaware  corporation,  and its
successors and permitted assigns.

         "EBITDA" means, for any period,  without duplication,  the total of the
following for  Borrowers and their  respective  Subsidiaries  on a  consolidated
basis, each calculated for such period:  (1) net income determined in accordance
with GAAP;  plus, to the extent included in the  calculation of net income,  (2)
the sum of (a)  income  and  franchise  taxes  paid  or  accrued;  (b)  Interest
Expenses,  net of interest income,  paid or accrued;  (c) interest paid in kind;
(d)  amortization  and  depreciation;  (e)  other  non-cash  charges  (excluding
accruals  for cash  expenses  made in the ordinary  course of business)  and (f)
Registration  Payments  paid or  accrued;  less,  to the extent  included in the
calculation  of net  income,  (3) the sum of (a) the income of any Person  other
than  wholly-owned  Subsidiaries  of  Borrowers  in which a Borrower or a wholly
owned  Subsidiary of a Borrower has an ownership  interest unless such income is
received by a Borrower or such wholly-owned  Subsidiary in a cash  distribution;
(b) gains or losses  from  sales or other  dispositions  of assets  (other  than
Inventory  in  the  normal  course  of  business);   and  (c)  extraordinary  or
non-recurring  gains,  but  not net of  extraordinary  or  non-recurring  "cash"
losses.

         "Editek" means EDITEK, Inc., a Delaware corporation, and its successors
and permitted assigns.

         "Eligible Accounts" has the meaning assigned to that term in subsection
2.1(B).

         "Eligible   Inventory"  has  the  meaning  assigned  to  that  term  in
subsection 2.1(B).

         "Employee  Benefit  Plan" means any  employee  benefit  plan within the
meaning of Section 3(3) of ERISA which (a) is  maintained  for  employees of any
Loan Party or any ERISA  Affiliate  or (b) has at any time within the  preceding
six (6) years been maintained for the employees of any Loan Party or any current
or former ERISA Affiliate.

         "Environmental  Claims"  means  claims,  liabilities,   investigations,
litigation,   administrative  proceedings,   judgments  or  orders  relating  to
Hazardous Materials.

         "Environmental  Laws"  means any  present or future  federal,  state or
local law, rule,  regulation or order relating to pollution,  waste, disposal or
the  protection  of human health or safety,  plant life or animal life,  natural
resources or the environment.

         "Equipment"  means all "equipment" (as defined in the UCC),  including,
without limitation, all machinery,  motor vehicles,  trucks, trailers,  vessels,
aircraft  and  rolling  stock  and  all  parts  thereof  and all  additions  and
accessions thereto and replacements therefor.

         "ERISA" means the Employee  Retirement  Income Security Act of 1974, as
amended  from  time to  time,  and any  successor  statute  and  all  rules  and
regulations promulgated thereunder.

                                       4
<PAGE>
         "ERISA  Affiliate",  as applied to any Loan Party, means any Person who
is a member of a group which is under common  control  with any Loan Party,  who
together with any Loan Party is treated as a single  employer within the meaning
of Section 414(b) and (c) of the IRC.

         "Event of  Default"  means each of the  events set forth in  subsection
8.1.
         "Excess Cash Flow" means, for any period,  the greater of (A) zero (0);
or (B) without  duplication,  the total of the following for Borrowers and their
respective  Subsidiaries  on a  consolidated  basis,  each  calculated  for such
period:  (1) EBITDA;  plus (2) tax refunds actually  received;  less (3) Capital
Expenditures  (to the extent actually made in cash and/or due to be made in cash
within such period but in no event more than the amount  permitted by subsection
6.5 hereof);  less (4) income and franchise taxes paid or accrued  excluding any
provision for deferred taxes included in the  determination of net income;  less
(5) decreases in deferred income taxes resulting from payments of deferred taxes
accrued in prior periods;  less (6) Interest Expenses paid or accrued;  less (7)
scheduled  amortization  of  Indebtedness  actually  paid  and/or due to be paid
within  such period and  permitted  under  subsection  7.5;  less (8)  voluntary
prepayments of the Term Loans.

         "Federal Funds Effective Rate" means, for any day, the weighted average
of the rates on overnight Federal funds transactions with members of the Federal
Reserve  System  arranged  by  Federal  funds  brokers,   as  published  on  the
immediately  following  Business Day by the Federal Reserve Bank of New York or,
if  such  rate is not  published  for  any  Business  Day,  the  average  of the
quotations  for the day of the  requested  Loan  received  by Lender  from three
Federal funds brokers of recognized standing selected by Lender.

         "Fiscal  Year" means each twelve month period ending on the last day of
December in each year.

         "Fixed Charge  Coverage"  means,  for any period,  Operating  Cash Flow
divided by Fixed Charges.

         "Fixed  Charges"  means,  for any period,  and each calculated for such
period (without duplication), (a) Interest Expenses paid or accrued by Borrowers
and their respective Subsidiaries; plus (b) scheduled payments of principal with
respect to all Indebtedness of Borrowers and their respective Subsidiaries; plus
(c) any  provision  for (to the  extent  it is  greater  than  zero)  income  or
franchise  taxes  included in the  determination  of net income,  excluding  any
provision for deferred taxes;  plus (d) Restricted  Junior Payments made in cash
to the extent  permitted under subsection  7.5(b);  plus (e) payment of deferred
taxes accrued in any prior period.

         "Funding Date" means the date of each funding of a Loan.

                                             5
<PAGE>
         "GAAP" means generally accepted accounting  principles set forth in the
opinions and  pronouncements of the Accounting  Principles Board of the American
Institute of Certified Public  Accountants and statements and  pronouncements of
the  Financial   Accounting   Standards   Board  that  are   applicable  to  the
circumstances as of the date of determination.

         "Hazardous Material" means all or any of the following:  (a) substances
that are  defined  or listed  in,  or  otherwise  classified  pursuant  to,  any
Environmental  Laws  or  regulations  as  "hazardous   substances",   "hazardous
materials",  "hazardous  wastes",  "toxic  substances" or any other  formulation
intended  to  define,  list or  classify  substances  by reason  of  deleterious
properties  such  as  ignitability,  corrosivity,  reactivity,  carcinogenicity,
reproductive toxicity or "EP toxicity";  (b) oil, petroleum or petroleum derived
substances,  natural  gas,  natural gas liquids or  synthetic  gas and  drilling
fluids,  produced  waters  and other  wastes  associated  with the  exploration,
development or production of crude oil, natural gas or geothermal resources; (c)
any flammable  substances or explosives or any  radioactive  materials;  and (d)
asbestos  in  any  form  or  electrical  equipment  which  contains  any  oil or
dielectric fluid  containing  levels of  polychlorinated  biphenyls in excess of
fifty parts per million.

         "Indebtedness",  as applied to any Person,  means without  duplication:
(a) all indebtedness  for borrowed money; (b) obligations  under leases which in
accordance  with GAAP constitute  Capital  Leases;  (c) notes payable and drafts
accepted   representing   extensions  of  credit  whether  or  not  representing
obligations for borrowed  money;  (d) any obligation owed for all or any part of
the deferred purchase price of property or services if the purchase price is due
more than six months from the date the obligation is incurred or is evidenced by
a note or similar written  instrument;  and (e) all indebtedness  secured by any
Lien on any property or asset owned or held by that Person regardless of whether
the  indebtedness  secured  thereby shall have been assumed by that Person or is
nonrecourse to the credit of that Person.

         "Intangible   Assets"  means  all  intangible  assets   (determined  in
conformity with GAAP) including, without limitation, goodwill, trademarks, trade
names,  licenses,  organizational  costs,  deferred  amounts,  covenants  not to
compete, unearned income and restricted funds.

         "Intellectual Property" means all present and future designs,  patents,
patent  rights  and  applications  therefor,  trademarks  and  registrations  or
applications therefor, trade names, inventions,  copyrights and all applications
and registrations therefor, software or computer programs, license rights, trade
secrets, methods, processes, know-how, drawings,  specifications,  descriptions,
and  all  memoranda,  notes  and  records  with  respect  to  any  research  and
development,  whether now owned or hereafter  acquired,  all goodwill associated
with any of the  foregoing,  and  proceeds of all of the  foregoing,  including,
without limitation, proceeds of insurance policies thereon.

         "Interest Coverage" means, for any period,  Operating Cash Flow divided
by Interest Expenses.

                                       6

<PAGE>

         "Interest  Expenses" means,  without  duplication,  for any period, the
following,  for Borrowers and their respective  Subsidiaries each calculated for
such  period:  interest  expenses  deducted in the determination  of net income
(excluding  (i)  the  amortization  of  fees  and costs  with  respect  to  the
transactions  contemplated  hereunder  on  the Closing  Date  which  have  been
capitalized as transaction costs; and (ii) interest paid in kind).

         "Interest  Rate" has the meaning  assigned  to that term in  subsection
2.2(A).
         "Inventory"  means all  "inventory"  (as defined in the UCC) including,
without  limitation,  finished goods,  raw materials,  work in process and other
materials and supplies used or consumed in a Person's business,  and goods which
are returned or repossessed.

         "IRC" means the Internal  Revenue Code of 1986, as amended from time to
time,  and any  successor  statute  and all  rules and  regulations  promulgated
thereunder.

         "Lender" means Heller Financial,  Inc. together with its successors and
permitted assigns pursuant to
subsection 9.1.

         "Lender's Account" means ABA No.  0710-0001-3,  Account No. 52-98695 at
First National Bank of Chicago,  One First National  Plaza,  Chicago,  IL 60670,
Reference: Heller Business Credit for the benefit of Editek.

         "Liabilities" shall have the meaning given that term in accordance with
GAAP and shall include Indebtedness.

         "Lien" means any lien, mortgage,  pledge, security interest,  charge or
encumbrance  of any kind,  whether  voluntary  or  involuntary,  (including  any
conditional  sale or other title  retention  agreement,  any lease in the nature
thereof, and any agreement to give any security interest).

         "Loan" or  "Loans"  means an advance  or  advances  under the Term Loan
Commitment or the Revolving Loan Commitment.

         "Loan  Documents"  means this  Agreement,  the Term  Notes,  the Pledge
Agreements and all other instruments, documents and agreements executed by or on
behalf  of a  Borrower  and  delivered  concurrently  herewith  or at  any  time
hereafter to or for Lender in connection  with the Loans and other  transactions
contemplated  by this  Agreement,  all as  amended,  restated,  supplemented  or
modified from time to time.

         "Loan Party"  means,  collectively,  Borrowers,  Borrowers'  respective
Subsidiaries  and any other  Person  (other than  Lender)  which is or becomes a
party to any Loan Document.

                                      7
<PAGE>

         "Loan  Year"  means  each  period of  twelve  (12)  consecutive  months
commencing on the Closing Date and on each anniversary thereof.

         "Material  Adverse Effect" means a material adverse effect upon (a) the
business, operations,  prospects,  properties, assets or condition (financial or
otherwise) of any Loan Party on an  individual  basis or taken as a whole or (b)
the ability of any Loan Party to perform its obligations under any Loan Document
to which it is a party or Lender to enforce or collect any of the Obligations.

         "Maximum  Revolving Loan Amount" has the meaning  assigned to that term
in subsection 2.1(B).

         "MedTox" means MedTox Laboratories,  Inc., a Minnesota corporation, and
its successors and permitted assigns.

         "MedTox  Acquisition"  means the acquisition by PDLA of the business of
MedTox occurring on or about the Closing Date.

         "MedTox  Acquisition  Agreement"  means  that  certain  Asset  Purchase
Agreement dated effective July 1, 1995, between Editek and MedTox, as amended by
that certain Amendment Agreement dated as of January 2, 1996, between Editek and
MedTox.

         "MedTox Acquisition  Documents" means the MedTox Acquisition  Agreement
and all other  documents,  agreements and  instruments  executed or delivered in
connection with the MedTox Acquisition.

         "Net Worth"  means,  as of any date,  the sum of the capital  stock and
additional paid-in capital plus retained earnings (or minus accumulated deficit)
calculated in conformity with GAAP.

         "Obligations"  means all  obligations,  liabilities and indebtedness of
every  nature of each Loan Party from time to time owed to Lender under the Loan
Documents  including the principal amount of all debts,  claims and indebtedness
(whether  incurred  before or after the  Termination  Date),  accrued and unpaid
interest and all fees, costs and expenses, whether primary,  secondary,  direct,
contingent,  fixed  or  otherwise,  heretofore,  now  and/or  from  time to time
hereafter owing, due or payable.

         "Operating  Cash Flow"  means,  for any period,  (a)  EBITDA;  less (b)
Capital Expenditures; less (c) Registration Payments paid or accrued.

         "PDLA" means Psychiatric  Diagnostic  Laboratories of America,  Inc., a
Delaware corporation, and its successors and permitted assigns.

                                        8
<PAGE>

         "Permitted  Encumbrances" means the following types of Liens: (a) Liens
(other  than  Liens  relating  to  Environmental  Claims  or ERISA)  for  taxes,
assessments or other governmental charges not yet due and payable; (b) statutory
Liens of landlords,  carriers,  warehousemen,  mechanics,  materialmen and other
similar  liens  imposed by law,  which are  incurred in the  ordinary  course of
business  for sums not more than thirty (30) days  delinquent;  (c) Liens (other
than any Lien imposed by ERISA) incurred or deposits made in the ordinary course
of business in connection with workers' compensation, unemployment insurance and
other types of social security, statutory obligations,  surety and appeal bonds,
bids,   leases,   government   contracts,   trade  contracts,   performance  and
return-of-money  bonds and other similar  obligations  (exclusive of obligations
for the payment of borrowed money); (d) easements, rights-of-way,  restrictions,
and other  similar  charges or  encumbrances  not  interfering  in any  material
respect  with the  ordinary  conduct of the business of any Loan Party or any of
its Subsidiaries;  (e) Liens for purchase money  obligations,  provided that (i)
the purchase of the asset subject to any such Lien is permitted under subsection
6.5,  (ii)  the  Indebtedness  secured  by any  such  Lien  is  permitted  under
subsection  7.1, and (iii) such Lien encumbers only the asset so purchased;  (f)
Liens in favor of Lender, and (g) Liens set forth on Schedule 1.1(A).

         "Person"  means and includes  natural  persons,  corporations,  limited
partnerships,  general  partnerships,  limited liability companies,  joint stock
companies,  joint  ventures,  associations,   companies,  trusts,  banks,  trust
companies,  land trusts, business trusts or other organizations,  whether or not
legal entities, and governments and agencies and political subdivisions thereof.

         "Pledge  Agreements"  means the stock pledge  agreements to be executed
and  delivered by each of Editek and  Princeton in favor of Lender,  in form and
substance reasonably satisfactory to Lender.

         "PPSA" means the Personal Property  Security Act (Ontario),  as amended
from time to time.

         "Preferred  Stock" means the Series A  Convertible  Preferred  Stock of
Editek, $1.00 par value per share.

         "Princeton" means Princeton Diagnostic Laboratories of America, Inc., a
Delaware corporation, and its successors and permitted assigns.

         "Pro Forma" means the unaudited  consolidated and consolidating balance
sheet of  Borrowers  and their  respective  Subsidiaries  as of the Closing Date
after  giving  effect  to the  MedTox  Acquisition  and the  other  transactions
contemplated  by this  Agreement.  The Pro Forma is annexed  hereto as  Schedule
1.1(B).

                                            9
<PAGE>

         "Projections"    means   Borrowers'    forecasted    consolidated   and
consolidating: (a) balance sheets; (b) profit and loss statements; (c) cash flow
statements;  and (d)  capitalization  statements,  all prepared on a division by
division and  Subsidiary  by  Subsidiary  basis and  otherwise  consistent  with
Borrowers' historical financial statements, together with appropriate supporting
details and a statement of underlying assumptions.

         "Registration Payment" means a cash payment made or required to be made
by a Borrower to a holder of Preferred Stock as a result of Editek's  failure to
register  the common stock into which such  Preferred  Stock is  convertible  or
converted,  as provided in Section 2(d) of the Registration Rights Agreements or
any successor or substitute provision.

         "Registration  Rights  Agreements"  means  those  certain  Registration
Rights  Agreements  dated on or about the  Closing  Date,  executed by Editek in
favor of the holders of the Preferred Stock.

         "Restricted   Junior  Payment"   means:   (a)  any  dividend  or  other
distribution, direct or indirect, on account of any shares of any class of stock
of a Borrower or any of its Subsidiaries now or hereafter outstanding,  except a
stock dividend;  (b) any payment or prepayment of principal of, premium, if any,
or interest on, or any redemption, conversion, exchange, retirement, defeasance,
sinking fund or similar payment, purchase or other acquisition for value, direct
or indirect,  of any Subordinated  Debt or any shares of any class of stock of a
Borrower  or any of its  Subsidiaries  now or  hereafter  outstanding;  (c)  any
payment made to retire, or to obtain the surrender of, any outstanding warrants,
options or other rights to acquire shares of any class of stock of a Borrower or
any of its  Subsidiaries  now or  hereafter  outstanding;  (d) any  payment by a
Borrower or any of its  Subsidiaries  of any management  fees or similar fees to
any Affiliate,  whether pursuant to a management agreement or otherwise; (e) any
Registration Payment; and (f) any payment of the Tax Liability.

         "Revolving  Loan"  means  all  advances  made  by  Lender  pursuant  to
subsection  2.1(B)  and  any  amounts  added  to the  principal  balance  of the
Revolving Loan pursuant to this Agreement.

         "Revolving Loan Commitment"  means the commitment of Lender to make the
Revolving Loan in the aggregate not to exceed at anytime $7,000,000.

         "Scheduled  Installment"  has the  meaning  assigned  to  that  term in
subsection 2.1(A).

         "Subsidiary"  means,  with  respect  to any  Person,  any  corporation,
association or other  business  entity of which more than fifty percent (50%) of
the  total  voting  power  of  shares  of  stock  (or  equivalent  ownership  or
controlling  interest)  entitled  (without  regard  to  the  occurrence  of  any
contingency) to vote in the election of directors,  managers or trustees thereof
is at the time owned

                                           10
<PAGE>


or controlled,  directly or  indirectly,  by that Person or one or more of the
other subsidiaries of that Person or a combination thereof.

         "Tangible Net Worth" means an amount equal to: (a) Net Worth;  less (b)
Intangible Assets;  less (c) prepaid expenses;  less (d) all obligations owed to
such Person or any of its Subsidiaries by any Affiliate of such Person or any of
its  Subsidiaries;  and  less  (e) all  loans by such  Person  to its  officers,
stockholders or employees;  provided,  however,  that in computing  Tangible Net
Worth hereunder, up to $2,000,000 in book value of patents, trademarks and trade
names shall be deemed not to be Intangible Assets.

         "Tax  Liability"  has the  meaning  assigned to such term in the MedTox
Acquisition Agreement.

         "Term Loans" means, collectively, Term Loan A and Term Loan B.

         "Term Loan A" means the advance made pursuant to subsection 2.1(A)(1).

         "Term Loan B" means the advance made pursuant to subsection 2.1(A)(2).

         "Term Loan Commitment"  means the commitment of Lender to make the Term
Loans as set forth in this Agreement.

         "Term Note" or "Term Notes" means each  promissory note of Borrowers in
a form reasonably acceptable to Lender, issued pursuant to subsection 2.1(E).

         "Termination  Date" means the date this  Agreement is terminated as set
forth in subsection 2.5.

         "Total Loan Commitment"  means the aggregate  commitment of Lender with
respect to the Revolving Loan Commitment and the Term Loan Commitment.

         "UCC" means the Uniform Commercial Code as in effect on the date hereof
in the  State of  Illinois,  as  amended  from time to time,  and any  successor
statute.

         "Working   Capital"  means:  (a)  current  assets;   less  (b)  current
liabilities;  and less (c) the amount of any obligations  owed to such Person or
any  of  its  Subsidiaries  by  any  Affiliate  of  such  Person  or  any of its
Subsidiaries.

                                              11
<PAGE>

             1.2  Accounting   Terms.  For  purposes  of  this  Agreement,   all
accounting terms not otherwise  defined herein shall have the meanings  assigned
to  such  terms  in  conformity  with  GAAP.   Financial  statements  and  other
information  furnished to Lender pursuant to subsection 5.1 shall be prepared in
accordance  with  GAAP  (as in  effect  at the  time of such  preparation)  on a
consistent basis. In the event any "Accounting Changes" (as defined below) shall
occur and such changes affect  financial  covenants,  standards or terms in this
Agreement,  then Borrowers and Lender agree to enter into  negotiations in order
to amend such  provisions  of this  Agreement  so as to  equitably  reflect such
Accounting  Changes with the desired result that the criteria for evaluating the
financial condition of Borrowers shall be the same after such Accounting Changes
as if such Accounting  Changes had not been made, and until such time as such an
amendment  shall have been executed and  delivered by Borrowers and Lender,  (A)
all  financial  covenants,  standards  and  terms  in this  Agreement  shall  be
calculated and/or construed as if such Accounting Changes had not been made, and
(B) Borrowers  shall prepare  footnotes to each  Compliance  Certificate and the
financial   statements   required  to  be  delivered  hereunder  that  show  the
differences  between the  financial  statements  delivered  (which  reflect such
Accounting Changes) and the basis for calculating  financial covenant compliance
(without reflecting such Accounting  Changes).  "Accounting  Changes" means: (a)
changes in accounting  principles required by GAAP and implemented by Borrowers;
(b) changes in accounting principles  recommended by Borrowers' certified public
accountants;  and (c) changes in carrying  value of  Borrowers'  or any of their
Subsidiaries'  assets,  liabilities  or equity  accounts  resulting from (i) the
application  of purchase  accounting  principles  (A.P.B.  16 and/or 17 and EITF
88-16  and FASB 109) to the  MedTox  Acquisition  or (ii) any other  adjustments
that, in each case, were applicable to, but not included in, the Pro Forma.  All
such adjustments resulting from expenditures made subsequent to the Closing Date
(including,  but not limited to, capitalization of costs and expenses or payment
of pre-Closing Date liabilities)  shall be treated as expenses in the period the
expenditures  are made and deducted as part of the calculation of EBITDA in such
period.

         1.3     Other  Definitional  Provisions.   References  to  "Sections",
"subsections",  "Exhibits" and  "Schedules"  shall be to Sections,  subsections,
Exhibits  and  Schedules,  respectively,  of  this  Agreement  unless  otherwise
specifically  provided.  Any of the terms defined in subsection 1.1 may,  unless
the context otherwise requires,  be used in the singular or the plural depending
on the  reference.  In this  Agreement,  words  importing any gender include the
other genders;  the words "including,"  "includes" and "include" shall be deemed
to be followed by the words "without  limitation";  references to agreements and
other contractual  instruments shall be deemed to include subsequent amendments,
assignments,  and  other  modifications  thereto,  but only to the  extent  such
amendments,  assignments and other modifications are not prohibited by the terms
of this  Agreement or any other Loan  Document;  references  to Persons  include
their  respective   permitted   successors  and  assigns  or,  in  the  case  of
governmental  Persons,  Persons  succeeding  to the  relevant  functions of such
Persons;  and all references to statutes and related  regulations  shall include
any amendments of same and any successor statutes and regulations.

                                    12

<PAGE>
                             2 LOANS AND COLLATERAL

            2.1 Loans.
                  (A)(1)  Term Loan A.  Subject to the terms and  conditions  of
this  Agreement  and in reliance  upon the  representations  and  warranties  of
Borrowers  herein set forth,  Lender  agrees to lend to Borrowers on the Closing
Date Term Loan A,  which is in the  amount of  $2,000,000.  Term Loan A shall be
funded in one drawing.  Amounts  borrowed  under this  subsection  2.1(A)(1) and
repaid may not be reborrowed.  Borrowers  shall make  principal  payments in the
amounts of the applicable Scheduled  Installments of Term Loan A (or such lesser
principal  amount as shall then be  outstanding) on the dates and in the amounts
set forth below.

         "Scheduled  Installment  of Term Loan A means,  for each date set forth
below, the amount set forth opposite such date.

                  Date                               Scheduled Installment
                  ----                               ---------------------
         August 1, 1997                                      $111,111.11
         September 1, 1997                                    111,111.11
         October 1, 1997                                      111,111.11
         November 1, 1997                                     111,111.11
         December 1, 1997                                     111,111.11
         January 1, 1998                                      111,111.11
         February 1, 1998                                     111,111.11
         March 1, 1998                                        111,111.11
         April 1, 1998                                        111,111.11
         May 1, 1998                                          111,111.11
         June 1, 1998                                         111,111.11
         July 1, 1998                                         111,111.11
         August 1, 1998                                       111,111.11
         September 1, 1998                                    111,111.11
         October 1, 1998                                      111,111.11
         November 1, 1998                                     111,111.11
         December 1, 1998                                     111,111.11
         January 1, 1999                                      111,111.13

         If at any time prior to the  commencement of Scheduled  Installments of
Term Loan A set forth above, Term Loan B is fully repaid,  then on the first day
of each month,  commencing on the first day of the month following  repayment of
Term Loan B and continuing through July 1, 1997,  Borrowers shall make principal
prepayments of Term Loan A in the amount of $111,111.11  each, which prepayments
shall be applied to the Scheduled  Installments  of Term Loan A in inverse order
of maturity.
                                      13
<PAGE>

                  (A)(2)  Term  Loan B Term  Loan B.  Subject  to the  terms and
conditions  of this  Agreement  and in  reliance  upon the  representations  and
warranties of Borrowers herein set forth,  Lender agrees to lend to Borrowers on
the Closing Date Term Loan B, which is in the amount of $2,000,000.  Term Loan B
shall be funded in one drawing. Amounts borrowed under this subsection 2.1(A)(2)
and repaid may not be reborrowed. Borrowers shall make principal payments in the
amount of the  applicable  Scheduled  Installment of Term Loan B (or such lesser
principal  amount as shall then be  outstanding) on the dates and in the amounts
set forth below

         "Scheduled  Installment of Term Loan B" means,  for each date set forth
below, the amount set forth opposite such date.

                  Date                           Scheduled Installment
                  ----                           ---------------------
         February 1, 1996                                $111,111.11
         March 1, 1996                                    111,111.11
         April 1, 1996                                    111,111.11
         May 1, 1996                                      111,111.11
         June 1, 1996                                     111,111.11
         July 1, 1996                                     111,111.11
         August 1, 1996                                   111,111.11
         September 1, 1996                                111,111.11
         October 1, 1996                                  111,111.11
         November 1, 1996                                 111,111.11
         December 1, 1996                                 111,111.11
         January 1, 1997                                  111,111.11
         February 1, 1997                                 111,111.11
         March 1, 1997                                    111,111.11
         April 1, 1997                                    111,111.11
         May 1, 1997                                      111,111.11
         June 1, 1997                                     111,111.11
         July 1, 1997                                     111,111.13

         (B)  Revolving  Loan.  Subject  to the  terms  and  conditions  of this
Agreement and in reliance upon the  representations  and warranties of Borrowers
herein  set  forth,  Lender  agrees  to lend to  Borrowers  from time to time an
aggregate  amount not to exceed at any time  $7,000,000.  Amounts borrowed under
this  subsection  2.1(B) may be repaid and  reborrowed  at any time prior to the
earlier of (i) the  termination  of the Revolving  Loan  Commitment  pursuant to
subsection 8.3 or (ii) the Termination  Date. Lender shall have no obligation to
make  advances  under this  subsection  2.1(B) to a  Borrower  to the extent the
requested advance would cause the balance of the Revolving Loan of such Borrower
then  outstanding  (after  giving  effect to any  immediate  application  of the
proceeds  thereof) to exceed the Maximum  Revolving Loan Amount of such Borrower
or to the extent any requested  advance would cause the balance of the Revolving
Loan of all  Borrowers  then

                                         14
<PAGE>

outstanding  (after giving effect to any immediate application of the proceeds
thereof) to exceed the Revolving  Loan Commitment; provided that Lender may,
in its sole discretion, elect from time to time to make Loans in excess of the
Maximum Revolving Loan Amount of a Borrower or the Revolving Loan Commitment.
Borrowers shall maintain records of the Revolving Loan advanced to or for the
benefit of each Borrower and the amount of all repayments made by each Borrower
of such advances from proceeds of Accounts or otherwise. To the extent that the
outstanding balance of the Revolving  Loan owing by a Borrower  exceeds such
Borrower's  Borrowing Base at any time,  such excess shall be deemed to
constitute an intercompany  loan to such Borrower from another  Borrower whose
outstanding  balance of the Revolving Loan is less than its Borrower's
Borrowing Base, which intercompany loans shall be subordinate in right of
payment to the  Obligations  and shall be subject to the limitations of
subsection 7.1(b).

                  (1) "Maximum  Revolving  Loan Amount"  means,  with respect to
each Borrower, as of any date of determination,  the lesser of (a) the Revolving
Loan Commitment and (b) the Borrowing Base of such Borrower.

                  (2) "Borrowing Base" means, with respect to a Borrower,  as of
any date of determination, an amount equal to the sum of (a) eighty-five percent
(85%) of such  Borrower's  Eligible  Accounts  plus (b) the  lesser  of (i) such
Borrower's  Inventory Sublimit,  and (ii) fifty percent (50%) of such Borrower's
Eligible Inventory,  less in each case such reserves as Lender in its reasonable
discretion elects to establish.

                  (3) "Inventory  Sublimit" means,  with respect to Editek,  the
amount of  $800,000,  with  respect  to PDLA,  the amount of  $500,000  and with
respect to diAGnostix, the amount of $200,000.

          (C)   Eligible Collateral.

         "Eligible  Accounts" means, with respect to a Borrower,  as at any date
of determination, the aggregate of all Accounts of such Borrower that Lender, in
its reasonable  judgment,  deems to be eligible for borrowing purposes.  Without
limiting the generality of the foregoing, unless otherwise agreed by Lender, the
following Accounts are not Eligible Accounts:

                  (1) Accounts  which, at the date of issuance of the respective
invoice  therefor,  were  payable  more than  sixty  (60) days after the date of
issuance of such invoice;

                  (2) Accounts which remain unpaid for more than sixty (60) days
after the due date  specified  in the  original  invoice or for more than ninety
(90) days after invoice date if no due date was specified;

                  (3)  Accounts  which are  otherwise  eligible  with respect to
which the account debtor is owed a credit by a Borrower,  but only to the extent
of such credit;
                                      15
<PAGE>
                  (4)  Accounts  due from a customer  whose  principal  place of
business is located  outside the United States of America unless such Account is
backed by a letter of credit,  in form and substance  acceptable to Lender,  and
issued or  confirmed  by a bank that is  organized  under the laws of the United
States of America or a State  thereof,  that is acceptable  to Lender,  provided
that  such  letter  of  credit  has  been  delivered  to  Lender  as  additional
collateral,  or the applicable  Borrower is the beneficiary of credit  insurance
with  respect to such account in such amounts and against such risks as shall be
acceptable to Lender;

                  (5)  Accounts  due from a customer  which  Lender has notified
Borrowers does not have a satisfactory credit standing;

                  (6) Accounts  with respect to which the customer is the United
States of America, any state or any municipality,  or any department,  agency or
instrumentality  thereof,  unless the  applicable  Borrower has, with respect to
such  Accounts,  complied  with the Federal  Assignment of Claims Act (31 U.S.C.
Section  3727) or any  applicable  statute  or  municipal  ordinance  of similar
purpose and effect;

                  (7)  Accounts  with  respect  to  which  the  customer  is  an
Affiliate of a Borrower or a director,  officer, agent,  stockholder or employee
of a Borrower or any of its Affiliates;

                  (8)  Accounts  due from a  customer  if more than  twenty-five
percent (25%) of the  aggregate  amount of Accounts of such customer have at the
time remained unpaid for more than sixty (60) days after due date or ninety (90)
days after the invoice date if no due date was specified;

                  (9)  Accounts  with  respect to which there is any  unresolved
dispute with the respective customer (but only to the extent of such dispute);

                  (10) Accounts  evidenced by an "instrument" or "chattel paper"
(as defined in the UCC) not in the possession of Lender;

                  (11)  Accounts  with  respect to which  Lender does not have a
valid, first priority and fully perfected security interest;

                  (12)  Accounts  subject to any Lien  except  those in favor of
Lender;
                  (13)  Accounts  with  respect  to which  the  customer  is the
subject of any bankruptcy or other insolvency proceeding;

                                           16
<PAGE>

                  (14)  Accounts  due from a  customer  to the  extent  that all
Accounts of such  customer  owing to all  Borrowers  exceed in the  aggregate an
amount equal to twenty percent (20%) of the aggregate of all otherwise  Eligible
Accounts of all Borrowers at said date;

                  (15) Accounts with respect to which the customer's  obligation
to pay is conditional  or subject to a repurchase  obligation or right to return
or with respect to which the goods or services  giving rise to such Account have
not been  delivered (or performed,  as applicable)  and accepted by such account
debtor, including progress billings, bill and hold sales, guarantied sales, sale
or return transactions, sales on approval or consignment sales;

                  (16) Accounts with respect to which the customer is located in
Indiana, New Jersey,  Minnesota,  or any other state denying creditors access to
its courts in the  absence of a Notice of  Business  Activities  Report or other
similar filing, unless the applicable Borrower has either qualified as a foreign
corporation  authorized to transact business in such state or has filed a Notice
of Business Activities Report or similar filing with the applicable state agency
for the then current year;

                  (17) Accounts with respect to which the customer is a creditor
of a Borrower, provided, however, that any such Account shall only be ineligible
as to that  portion  of such  Account  which is less than or equal to the amount
owed by such Borrower to such Person.

         "Eligible Inventory" means, with respect to a Borrower,  as at any date
of  determination,  the  value  (determined  at the lower of cost or market on a
first-in,  first-out  basis) of all  Inventory  that is readily  marketable  raw
materials,  supplies in unopened  containers  or finished  goods  consisting  of
pre-packaged  test  kits,  in each case owned by and in the  possession  of such
Borrower  and located in the United  States of America and that  Lender,  in its
reasonable credit judgment, deems to be eligible for borrowing purposes. Without
limiting the generality of the foregoing, unless otherwise agreed by Lender, the
following is not Eligible Inventory: (a) work-in-process;  (b) sample collection
kits;  (c) finished goods which do not meet the  specifications  of the purchase
order for such goods; (d) Inventory which Lender determines, is unacceptable for
borrowing  purposes due to age,  quality,  type,  category and/or quantity;  (e)
Inventory with respect to which Lender does not have a valid, first priority and
fully  perfected  security  interest;  (f) Inventory with respect to which there
exists any Lien in favor of any Person other than Lender; (g) Inventory produced
in violation of the Fair Labor  Standards Act and subject to the so-called  "hot
goods"  provisions  contained in Title 29 U.S.C.  215 (a)(i);  and (h) Inventory
located at any location other than those set forth on Schedule 4.7.

                                   17
<PAGE>

         (D) Borrowing  Mechanics.  On any day when a Borrower desires to borrow
under this subsection 2.1, Editek, acting as agent for such Borrower, shall give
Lender telephonic notice of the proposed borrowing by 11:00 a.m. (Chicago time).
Lender shall not incur any liability to Borrowers for acting upon any telephonic
notice  Lender  believes  in good faith to have been given by a duly  authorized
officer or other  person  authorized  to borrow on behalf of a  Borrower  or for
otherwise  acting in good faith under this  subsection  2.1(D).  Lender will not
make any  advance  pursuant  to any  telephonic  notice  unless  Lender has also
received the most recent  Borrowing Base  Certificates  and all other  documents
required  under  subsection  5.1(F).  Each advance made to a Borrower  under the
Revolving  Loan shall be deposited  by wire  transfer in  immediately  available
funds in such account of Editek, as agent for each Borrower,  as Editek may from
time to time  designate  to Lender in  writing,  and Editek  shall  forward  the
appropriate amount of proceeds of each such advance to or for the benefit of the
appropriate Borrower. Unless payment is otherwise timely made by a Borrower, the
becoming  due of any amount  required to be paid under this  Agreement or any of
the other Loan Documents as principal, accrued interest and fees shall be deemed
irrevocably  to be a request by such  Borrower  for a Revolving  Loan on the due
date of, and in the amount required to pay, such principal, accrued interest and
fees,  and the proceeds of each such  Revolving  Loan if made by Lender shall be
disbursed  by  Lender  by way of  direct  payment  of the  relevant  obligation.
Anything herein to the contrary notwithstanding, Lender may elect at any time to
disburse directly to each Borrower advances of the Revolving Loan that are based
upon the Borrowing Base of such Borrower.

         (E) Term Notes.  Borrowers  shall  execute and deliver to Lender a Term
Note to evidence each of the Term Loans,  such Term Notes to be in the principal
amount  of the  respective  Term  Loan  Commitment  and with  other  appropriate
insertions. In the event of an assignment under subsection 9.1, Borrowers shall,
upon surrender of the assigning  Lender's Notes,  issue new Notes to reflect the
new Commitments of the assigning Lender and its assignee.

         (F) Evidence of Revolving Loan Obligations.  The advances  constituting
the Revolving  Loan shall be evidenced by this Agreement and notations made from
time to time by Lender in its books and  records,  including  computer  records.
Lender's  books  and  records  shall  constitute  presumptive  evidence,  absent
manifest error, of the accuracy of the information contained therein. Failure by
the Lender to make any such notation or record shall not affect the  obligations
of Borrowers to Lender with respect to the Revolving Loans.

         2.2  Interest  Interest

         (A) Rate of Interest.  The Loans and all other  Obligations  shall bear
interest from the date such Loans are made or such other Obligations  become due
to the date  paid at a rate per  annum  equal  to (i) one and  one-half  percent
(1.50%) plus the Base Rate with respect to the Revolving  Loan, (ii) two percent
(2.00%)  plus the Base  Rate  with  respect  to Term  Loan A and  (iii)  two and
one-half  percent  (2.50%)  plus the Base Rate with  respect to Term Loan B (the
"Interest

                                 18
<PAGE>

Rate"). After the occurrence and during the continuance of an Event of Default,
the Loans and all other  Obligations shall, at Lender's option,  bear interest
at a rate per annum  equal to three percent  (3.0%) plus the  Interest Rate
(the "Default Rate").

         (B) Computation and Payment of Interest.  Interest on the Loans and all
other  Obligations shall be computed on the daily principal balance on the basis
of a 360 day year for the actual  number of days  elapsed  in the period  during
which it  accrues  and shall be  payable  monthly in arrears on the first day of
each month.  Any publicly  announced  change in the Base Rate shall result in an
adjustment to the Interest  Rate on the day such change takes  effect.  Whenever
interest  payable  hereunder is  calculated  on the basis of a year of 360 days,
each rate of interest  determined  pursuant to such calculation  expressed as an
annual rate for the purpose of the Interest Act (Canada) is  equivalent  to such
rate as so  determined  multiplied by the number of days in the calendar year in
which the same is to be ascertained and divided by 360.

         (C)  Interest  Laws.  Notwithstanding  any  provision  to the  contrary
contained in this Agreement or any other Loan Document,  Borrowers  shall not be
required to pay, and Lender  shall not be  permitted  to collect,  any amount of
interest in excess of the maximum  amount of interest  permitted by law ("Excess
Interest").  If any Excess  Interest is provided for or determined by a court of
competent  jurisdiction  to have been  provided for in this  Agreement or in any
other Loan Document,  then in such event:  (1) the provisions of this subsection
shall  govern and  control;  (2) neither  Borrowers  nor any Loan Party shall be
obligated to pay any Excess  Interest;  (3) any Excess  Interest that Lender may
have received  hereunder shall be, at Lender's  option,  (a) applied as a credit
against the  outstanding  principal  balance of the  Obligations  or accrued and
unpaid  interest  (not to exceed  the  maximum  amount  permitted  by law),  (b)
refunded to the payor thereof, or (c) any combination of the foregoing;  (4) the
interest  rate(s)  provided  for herein  shall be  automatically  reduced to the
maximum lawful rate allowed from time to time under applicable law (the "Maximum
Rate"),  and this Agreement and the other Loan Documents shall be deemed to have
been and shall be,  reformed  and modified to reflect  such  reduction;  and (5)
neither  Borrowers nor any Loan Party shall have any action  against  Lender for
any damages  arising out of the payment or  collection  of any Excess  Interest.
Notwithstanding  the  foregoing,  if for  any  period  of time  interest  on any
Obligations  is calculated at the Maximum Rate rather than the  applicable  rate
under this Agreement,  and thereafter such applicable rate becomes less than the
Maximum Rate, the rate of interest payable on such  Obligations  shall remain at
the Maximum Rate until Lender shall have  received the amount of interest  which
Lender would have received  during such period on such  Obligations had the rate
of interest not been limited to the Maximum Rate during such period.

       2.3  Fees. 


         (A) Closing  Fee.  Borrowers  shall pay to Lender on the Closing Date a
closing fee in the amount of $165,000.

                                      19
<PAGE>

         (B) Unused Line Fee.  Borrowers  shall pay to Lender a fee in an amount
equal to the Revolving Loan Commitment less the sum of the average daily balance
of the Revolving  Loan during the preceding  month  multiplied by  three-eighths
percent  (0.375) per annum,  such fee to be calculated on the basis of a 360
day year for the actual number of days elapsed and to be payable  monthly in
arrears on the first day of the first month following the Closing Date and the
first day of each month thereafter.

         (C) Prepayment Fees. If Borrowers voluntarily prepay the Obligations in
full  (other  than  voluntary  prepayments  of the  Revolving  Loan which do not
terminate the Revolving  Loan  Commitment,  including  payments of the Revolving
Loan from the Blocked Accounts),  or, in the case of any voluntary prepayment of
any Term Loan, in part, prior to the Termination Date,  Borrowers at the time of
prepayment shall pay to Lender,  as compensation for the costs of being prepared
to make funds available to Borrowers under this Agreement, and not as a penalty,
an amount determined by multiplying the percentage set forth below by (1) in the
case of a  prepayment  in full of the  Obligations,  the sum of the  outstanding
principal  balance  of the Term  Loans at the date of such  prepayment  plus the
amount of the Revolving Loan  Commitment,  or (2) in the case of a prepayment of
the Term Loans only, in whole or in part, the amount of such  prepayment:  three
percent  (3.00%)  upon a  prepayment  during the first Loan  Year;  two  percent
(2.00%) upon a prepayment  during the second Loan Year; and one percent  (1.00%)
upon a prepayment during the third Loan Year.  Borrower shall not be required to
pay  prepayment  fees  in  connection  with  any  mandatory  prepayments  of the
Obligations  pursuant to  subsection  2.4(B) or the last  sentence of subsection
2.1(A)(1).

         (D) Collateral Monitoring Fee. On the Closing Date and on the first day
of each calendar quarter thereafter,  Borrowers shall pay Lender a nonrefundable
collateral monitoring fee of $5,000; provided, however, that if as a result of a
Borrower's merging with another Borrower,  the number of Borrowers  decreases to
two or fewer,  then such  collateral  monitoring  fee shall reduce to $2,500 per
quarter  commencing  on the first day of the  calendar  quarter  following  such
merger.

         (E) Audit  Fees.  Borrowers  agree to pay  Lender an audit fee for each
inspection equal to $650 per auditor per day or any portion  thereof,  excluding
all full  days  spent  by  Lender  traveling  to or from  Borrowers'  locations,
together with  out-of-pocket  expenses,  or the  reasonable  fees,  expenses and
out-of-pocket  costs paid to third party  auditors.  Audit fees shall not exceed
$20,000 per year, plus out-of-pocket expenses, except during the existence of an
Event of Default.

         (F) Other Fees and Expenses. Borrowers shall pay to Lender, for its own
account,  all charges for returned items and all other bank charges  incurred by
Lender,  as well as  Lender's  standard  wire  transfer  charges  for each  wire
transfer made under this Agreement.

                                      20
<PAGE>

     2.4  Payments and Prepayments.

         (A)  Manner and Time of  Payment.  In its sole  discretion,  Lender may
charge interest and other amounts  payable  hereunder to the Revolving Loan, all
as set forth on Lender's  books and records.  If Lender elects to bill Borrowers
for any amount due hereunder,  such amount shall be immediately  due and payable
with interest  thereon as provided  herein.  All payments made by Borrowers with
respect to the Obligations shall be made without deduction,  defense,  setoff or
counterclaim.  All payments to Lender hereunder shall, unless otherwise directed
by Lender,  be made in accordance  with  subsection  5.6.  Proceeds  remitted to
Lender's  Account shall be credited to the  Obligations on the day such proceeds
were received, provided, however, for the purpose of calculating interest on the
Obligations,  such funds  shall be deemed  received  on the first  Business  Day
thereafter.  Proceeds  remitted to Lender's  Account by wire  transfer  shall be
credited to the Obligations on the Business Day received; provided, however, for
the  purpose of  calculating  interest  on the  Obligations  such funds shall be
deemed received the first Business Day thereafter.

           (B) Mandatory Prepayments.

                  (1) Overadvance. At any time that the principal balance of the
Revolving Loan exceeds the Maximum Revolving Loan Amount,  Borrowers shall, upon
demand by Lender,  immediately  repay the Revolving Loan to the extent necessary
to reduce the  principal  balance to an amount that is equal to or less than the
Maximum Revolving Loan Amount.

                  (2) Proceeds of Asset Dispositions. For so long as any portion
of either Term Loan remains outstanding,  immediately upon receipt by a Borrower
or any of its  Subsidiaries  of proceeds of any Asset  Disposition  (in one or a
series  of  related  transactions),  which  proceeds  exceed  $10,000  (it being
understood that if the proceeds  exceed $10,000,  the entire amount and not just
the  portion  above  $10,000  shall be  subject to this  subsection  2.4(B)(2)),
Borrowers  shall prepay the Term Loans in an amount equal to such  proceeds.  If
Borrowers  reasonably  expect  the  proceeds  of  any  Asset  Disposition  to be
reinvested  within 180 days to repair or replace  such assets with like  assets,
Borrowers  shall  deliver the proceeds to Lender to be applied to the  Revolving
Loan,  and  Borrowers  may, so long as no Default or Event of Default shall have
occurred  and be  continuing,  reborrow  such  proceeds  only for such repair or
replacement.  If  Borrowers  fail to  reinvest  such  proceeds  within 180 days,
Borrowers  hereby  authorize  Lender to make a Revolving  Loan to repay the Term
Loans as required hereby. All such prepayments shall be applied first in payment
of Scheduled  Installments  of Term Loan B in the inverse  order of maturity and
second in payment of Scheduled  Installments of Term Loan A in the inverse order
of maturity.

                                   21
<PAGE>

                  (3)  Prepayments  from  Excess  Cash Flow.  For so long as any
portion of either Term Loan remains  outstanding,  within ninety (90) days after
the end of each Fiscal Year,  Borrowers shall prepay the Term Loans in an amount
equal to fifty  percent  (50%) of Excess  Cash Flow for such prior  Fiscal  Year
calculated on the basis of the audited financial statements for such Fiscal Year
delivered to Lender pursuant to subsection  5.1(C).  All such  prepayments  from
Excess Cash Flow shall first be applied in payment of Scheduled  Installments of
Term Loan B until  repaid in full and then in  repayment  of Term Loan A each in
inverse  order of maturity.  Concurrently  with the making of any such  payment,
Borrowers  shall deliver to Lender a certificate of Borrowers'  chief  executive
officer or chief financial  officer  demonstrating its calculation of the amount
required to be paid.

         (C)  Voluntary  Prepayments  and  Repayments.  Except  as  provided  in
subsection 2.4(B) and except for partial prepayments from the proceeds of equity
securities  issued  by  Borrowers  on or  after  the  Closing  Date,  Borrowers'
Obligations  may only be prepaid in full and not in part.  Borrowers may, at any
time upon not less than three Business Days' prior notice to Lender,  prepay the
Term Loans or terminate the Revolving Loan Commitment;  provided,  however,  the
Revolving  Loan  Commitment  may not be terminated  by Borrowers  until the Term
Loans are paid in full.

         (D)  Payments  on  Business  Days.  Whenever  any  payment  to be  made
hereunder  shall be stated to be due on a day that is not a  Business  Day,  the
payment may be made on the next  succeeding  Business Day and such  extension of
time shall be included in the  computation of the amount of interest or fees due
hereunder.

           2.5    Term of this  Agreement.  This  Agreement  shall be  effective
until December 31, 1998 (the "Termination  Date"). The Commitments shall (unless
earlier terminated) terminate upon the earlier of (i) the occurrence of an event
specified in subsection 8.3 or (ii) the Termination  Date.  Upon  termination in
accordance with subsection 8.3 or on the Termination Date, all Obligations shall
become immediately due and payable without notice or demand. Notwithstanding any
termination,  until all Obligations  have been fully paid and satisfied,  Lender
shall be entitled to retain security interests in and liens upon all Collateral,
and even after payment of all Obligations  hereunder,  Borrowers'  obligation to
indemnify Lender in accordance with the terms hereof shall continue.

           2.6    Statements. Lender shall render a monthly statement of account
to Borrowers within twenty (20) days after the end of each month. Such statement
of account shall  constitute an account  stated  unless  Borrowers  make written
objection thereto within thirty (30) days from the date such statement is mailed
to Borrowers.  Borrowers  promise to pay all of the  Obligations as such amounts
become due or are declared due pursuant to the terms of this Agreement.

                                          22
<PAGE>

           2.7    Grant  of  Security  Interest.   To  secure  the  payment  and
performance   of  the   Obligations,   including   all   renewals,   extensions,
restructurings and refinancings of any or all of the Obligations,  each Borrower
hereby grants to Lender a continuing security interest, lien and mortgage in and
to all right, title and interest of such Borrower in the following  property  of
such  Borrower,  whether now owned or existing or hereafter  acquired or arising
and  regardless  of where  located  (all being  collectively  referred to as the
"Collateral"):  (A) Accounts,  and all guaranties and security therefor, and all
goods and rights represented thereby or arising therefrom including the right of
stoppage  in transit,  replevin  and  reclamation;  (B)  Inventory;  (C) general
intangibles  (as defined in the UCC);  (D)  documents (as defined in the UCC) or
other receipts covering,  evidencing or representing  goods; (E) instruments (as
defined in the UCC);  (F) chattel paper (as defined in the UCC);  (G) Equipment;
(H) Intellectual  Property; (I) all deposit accounts of such Borrower maintained
with any bank or  financial  institution;  (J) all cash  and  other  monies  and
property of such  Borrower in the  possession  or under the control of Lender or
any participant;  (K) all books, records,  ledger cards, files,  correspondence,
computer programs, tapes, disks and related data processing software that at any
time evidence or contain  information  relating to any of the property described
above or are  otherwise  necessary  or  helpful  in the  collection  thereof  or
realization  thereon;  and (L) proceeds of all or any of the property  described
above,  including,  without  limitation,  the proceeds of any insurance policies
covering any of the above described property.

             2.8  Capital  Adequacy and Other  Adjustments.  In the event Lender
shall  have  determined  that the  adoption  after  the date  hereof of any law,
treaty,  governmental (or  quasi-governmental)  rule,  regulation,  guideline or
order regarding capital adequacy,  reserve  requirements or similar requirements
or compliance by Lender or any corporation  controlling  Lender with any request
or  directive  regarding  capital  adequacy,  reserve  requirements  or  similar
requirements  (whether or not having the force of law and whether or not failure
to comply  therewith  would be unlawful)  from any central bank or  governmental
agency or body having  jurisdiction  does or shall have the effect of increasing
the amount of  capital,  reserves or other funds  required to be  maintained  by
Lender or any corporation  controlling  Lender and thereby  reducing the rate of
return  on  Lender's  or such  corporation's  capital  as a  consequence  of its
obligations  hereunder,  then  Borrowers  shall from time to time within fifteen
(15) days after  notice and demand from Lender  (together  with the  certificate
referred to in the next sentence) pay to Lender additional amounts sufficient to
compensate  such Lender for such  reduction.  A certificate  as to the amount of
such cost and showing the basis of the  computation  of such cost  submitted  by
Lender to Borrowers  shall,  absent  manifest  error,  be final,  conclusive and
binding for all purposes.

         2.9      Taxes.

         (A)  No  Deductions.  Any  and  all  payments  or  reimbursements  made
hereunder  or under the Term Notes  shall be made free and clear of and  without
deduction  for  any and all  taxes,  levies,  imposts,  deductions,  charges  or
withholdings,  and all liabilities with respect thereto; excluding, however, the
following:  taxes imposed on the net income of Lender by the jurisdiction  under
the  laws of which  Lender  is  organized  or doing  business  or any  political
subdivision  thereof

                                        23

<PAGE>

and  taxes imposed on its net income by the  jurisdiction of Lender's applicable
lending office or any political  subdivision  thereof (all such  taxes,  levies,
imposts,  deductions,  charges  or  withholdings  and  all  liabilities   with
respect  thereto  excluding  such  taxes  imposed  on  net  income,  herein "Tax
Liabilities").  If  Borrowers  shall  be  required by law to deduct any such Tax
Liabilities from or in respect of any sum payable  hereunder to Lender, then the
sum payable  hereunder  shall be increased as may be necessary so that, after
making all required deductions, Lender receives an amount equal to the sum it
would have received had no such deductions been made.

         (B) Changes in Tax Laws.  In the event that,  subsequent to the Closing
Date, (i) any changes in any existing law, regulation, treaty or directive or in
the interpretation or application thereof, (ii) any new law, regulation,  treaty
or directive  enacted or any  interpretation  or application  thereof,  or (iii)
compliance  by Lender with any request or  directive  (whether or not having the
force of law) from any governmental authority, agency or instrumentality:

                  (1)  does or  shall  subject  Lender  to any  tax of any  kind
whatsoever with respect to this Agreement, the other Loan Documents or any Loans
made  hereunder,  or  change  the basis of  taxation  of  payments  to Lender of
principal,  fees, interest or any other amount payable hereunder (except for net
income taxes,  or franchise  taxes imposed in lieu of net income taxes,  imposed
generally by federal, state or local taxing authorities with respect to interest
or commitment  or other fees payable  hereunder or changes in the rate of tax on
the overall net income of Lender); or

                  (2) does or shall  impose on Lender  any  other  condition  or
increased  cost in  connection  with the  transactions  contemplated  hereby  or
participations herein; and the result of any of the foregoing is to increase the
cost to Lender of making or continuing any Loan  hereunder,  as the case may be,
or to reduce any amount receivable hereunder,  then, in any such case, Borrowers
shall promptly pay to Lender,  upon its demand, any additional amounts necessary
to compensate Lender, on an after-tax basis, for such additional cost or reduced
amount receivable, as determined by Lender with respect to this Agreement or the
other Loan Documents. If Lender becomes entitled to claim any additional amounts
pursuant to this subsection,  it shall promptly notify Borrowers of the event by
reason  of  which  Lender  has  become  so  entitled.  A  certificate  as to any
additional  amounts  payable  pursuant to the  foregoing  sentence  submitted by
Lender to Borrowers  shall,  absent  manifest  error,  be final,  conclusive and
binding for all purposes.


                     3      CONDITIONS TO LOANS

      3.1 Conditions to Loans. The obligations of Lender to make Loans on the
Closing Date and on each Funding Date are subject to  satisfaction of all of the
conditions set forth below.

                                          24
<PAGE>

         (A)  Closing  Deliveries.  Lender  shall  have  received,  in form  and
substance  satisfactory  to Lender,  all documents,  instruments and information
identified on Schedule  3.1(A) and all other  agreements,  notes,  certificates,
orders,  authorizations,  financing  statements,  mortgages and other  documents
which Lender may at any time reasonably request.

         (B)  Security  Interests.   Lender  shall  have  received  satisfactory
evidence that all security  interests  and liens  granted to Lender  pursuant to
this  Agreement  or the  other  Loan  Documents  have been  duly  perfected  and
constitute  first  priority liens on the  Collateral,  subject only to Permitted
Encumbrances.

         (C) Closing Date Availability.  After giving effect to the consummation
of the transactions  contemplated  hereunder on the Closing Date and the payment
by  Borrowers  of all costs,  fees and expenses  relating  thereto,  the Maximum
Revolving Loan Amount on the Closing Date shall exceed the principal  balance of
the Revolving Loans by at least $1,500,000.

         (D) Representations and Warranties.  The representations and warranties
contained  herein and in the Loan Documents shall be true,  correct and complete
in all  material  respects on and as of that  Funding Date to the same extent as
though made on and as of that date,  except for any  representation  or warranty
limited by its terms to a specific  date and taking into account any  amendments
to the Schedules or Exhibits as a result of any disclosures made by Borrowers to
Lender after the Closing Date and approved by Lender.

         (E) Fees.  With  respect  to Loans to be made or issued on the  Closing
Date,  Borrowers  shall pay the fees payable on the Closing Date  referred to in
subsection 2.3 out of the proceeds of the Loan.

         (F) No Default. No event shall have occurred and be continuing or would
result from the consummation of the requested borrowing that would constitute an
Event of Default or a Default.

         (G) Performance of Agreements.  Each Loan Party shall have performed in
all material respects all agreements and satisfied all conditions which any Loan
Document provides shall be performed by it on or before that Funding Date.

         (H) No  Prohibition.  No  order,  judgment  or  decree  of  any  court,
arbitrator or governmental  authority shall purport to enjoin or restrain Lender
from making any Loans.

         (I) No  Litigation.  There shall not be pending or, to the knowledge of
Borrowers,  threatened,  any action,  charge,  claim, demand, suit,  proceeding,
petition, governmental investigation or arbitration by, against or affecting any
Loan Party or any of its  Subsidiaries  or any property of any Loan Party or any
of its  Subsidiaries  that has not been  disclosed by Borrowers in writing,  and
there shall have  occurred no  development  in any such action,  charge,  claim,
demand,

                                       25
<PAGE>

suit, proceeding,  petition,  governmental  investigation or arbitration that,
in the opinion of Lender,  would reasonably be expected to have a Material
Adverse Effect.

         (J) Issuance of Preferred Stock. Editek shall have issued the Preferred
Stock for an aggregate  gross purchase price of not less than  $16,000,000,  and
Editek shall have received the net cash proceeds from such issuance in an amount
not less than $15,040,000.

         (K)  MedTox  Acquisition.   The  MedTox  Acquisition  shall  have  been
consummated  on  substantially  the terms set  forth in the  MedTox  Acquisition
Documents. In connection with the MedTox Acquisition, MedTox shall have accepted
shares of Editek's  common stock in payment for not less than  $5,000,000 of the
purchase price for such acquisition.


               4 BORROWERS' REPRESENTATIONS AND WARRANTIES

       To  induce  Lender  to enter  into this  Agreement  and to make  Loans,
Borrowers represent and warrant to Lender that the following  statements are and
will be true, correct and complete:

       4.1   Organization, Powers, Capitalization.

         (A) Organization and Powers.  Each of the Loan Parties is a corporation
duly  organized,  validly  existing and in good  standing  under the laws of its
jurisdiction of  incorporation  and qualified to do business in all states where
such qualification is required except where failure to be so qualified could not
be  reasonably  expected  to have a Material  Adverse  Effect.  Each of the Loan
Parties has all requisite  corporate  power and authority to own and operate its
properties,  to  carry on its  business  as now  conducted  and  proposed  to be
conducted and to enter into each Loan Document.

         (B)  Capitalization.  The authorized  capital stock of each of the Loan
Parties is as set forth on Schedule 4.1(B). All issued and outstanding shares of
capital  stock  of each of the Loan  Parties  are duly  authorized  and  validly
issued, fully paid, nonassessable,  free and clear of all Liens other than those
in favor of Lender and such shares were issued in compliance with all applicable
state and federal laws concerning the issuance of securities.  The capital stock
of each of the Loan Parties is owned by the  stockholders and in the amounts set
forth on  Schedule  4.1(B).  No shares of the  capital  stock of any Loan Party,
other than those  described  above,  are issued and  outstanding.  Except as set
forth on Schedule 4.1(B),  there are no preemptive or other outstanding  rights,
options, warrants, conversion rights or similar agreements or understandings for
the purchase or acquisition  from any Loan Party, of any shares of capital stock
or other securities of any such entity.

                                    26
<PAGE>

           4.2   Authorization of Borrowing, No Conflict. Each Borrower has the
corporate  power and authority to incur the  Obligations  and to grant  security
interests in the  Collateral.  On the Closing Date, the execution,  delivery and
performance of the Loan Documents by each Loan Party signatory thereto will have
been duly  authorized by all necessary  corporate and  shareholder  action.  The
execution,  delivery and performance by each Loan Party of each Loan Document to
which it is a party and the  consummation  of the  transactions  contemplated by
this Agreement and the other Loan Documents by each Loan Party do not contravene
and will not be in contravention of any applicable law, the corporate charter or
bylaws of any Loan  Party or any  agreement  or order by which any Loan Party or
any Loan  Party's  property  is bound.  This  Agreement  is,  and the other Loan
Documents,  including the Term Notes,  when executed and delivered  will be, the
legally  valid  and  binding   obligations  of  the   applicable   Loan  Parties
respectively,  each  enforceable  against the Loan Parties,  as  applicable,  in
accordance with their respective terms.

            4.3  Financial  Condition.   All  financial  statements  concerning
Borrowers and their respective Subsidiaries which have been or will hereafter be
furnished by Borrowers and their  respective  Subsidiaries to Lender pursuant to
this  Agreement  have  been  or  will  be  prepared  in  accordance   with  GAAP
consistently  applied  throughout  the  periods  involved  (except as  disclosed
therein)  and  do  or  will  present  fairly  the  financial  condition  of  the
corporations  covered  thereby as at the dates  thereof and the results of their
operations  for the periods then ended.  The Pro Forma was prepared by Borrowers
based on the unaudited  balance sheets of Borrowers dated December 31, 1995. The
Projections  delivered  and to be  delivered  have been and will be  prepared by
Borrowers in light of the past operations of the business of Borrowers and their
respective  Subsidiaries,  and such Projections represent and will represent the
good faith estimate of Borrowers and their senior management concerning the most
probable course of its business as of the date such Projections are prepared and
delivered.

            4.4  Indebtedness  and  Liabilities.  As of the  Closing  Date,  no
Borrower  nor  any of its  Subsidiaries  has  (a)  any  Indebtedness  except  as
reflected on the Pro Forma;  or (b) any  Liabilities  other than as reflected on
the Pro Forma or as incurred in the ordinary  course of business  following  the
date of the Pro Forma.

            4.5  Account Warranties.  Borrowers represent, warrant and covenant
as to each Account that,  at the time of its  creation,  the Account is a valid,
bona fide account, representing an undisputed indebtedness incurred by the named
account debtor for goods actually sold and delivered or for services  completely
rendered; there are no setoffs, offsets or counterclaims,  genuine or otherwise,
against the Account;  the Account does not represent a sale to an Affiliate or a
consignment,  sale or return or a bill and hold transaction; no agreement exists
permitting  any  deduction or discount  (other than the  discount  stated on the
invoice);  a Borrower  is the lawful  owner of the  Account and has the right to
assign the same to Lender; the Account is free of all security interests,  liens
and encumbrances other than those in favor of Lender, and the Account is due and
payable in accordance with its terms.

                                      27
<PAGE>

             4.6  Names. Schedule  4.6  sets  forth  all  names,  trade  names,
fictitious names and business names under which each Borrower currently conducts
business or has at any time during the past five years conducted business.

             4.7  Locations; FEIN. Schedule 4.7 sets forth the location of each
Borrower's  principal place of business,  the location of each Borrower's  books
and  records,  the  location  of all  other  offices  of each  Borrower  and all
Collateral locations, and such locations are Borrowers' sole locations for their
business and the Collateral.  Each Borrower's  federal  employer  identification
number is set forth on the signature page hereof.

             4.8  Title to Properties;  Liens.  Each  Borrower  and each of its
Subsidiaries  has  good,  sufficient  and  legal  title,  subject  to  Permitted
Encumbrances,  to all its respective material properties and assets.  Except for
Permitted  Encumbrances,  all such  properties  and assets are free and clear of
Liens.  To the best  knowledge  of  Borrowers  after due  inquiry,  there are no
actual,  threatened  or  alleged  defaults  with  respect  to any leases of real
property under which any Borrower or any of its Subsidiaries is lessee or lessor
which would have a Material Adverse Effect.

             4.9  Litigation; Adverse  Facts. There are no judgments outstanding
against any Loan Party or affecting  any property of any Loan Party nor is there
any action,  charge,  claim, demand, suit,  proceeding,  petition,  governmental
investigation  or arbitration now pending or, to the best knowledge of Borrowers
after  due  inquiry,  threatened  against  or  affecting  any Loan  Party or any
property of any Loan Party which could  reasonably  be expected to result in any
Material Adverse Effect. No Loan Party has received any opinion or memorandum or
legal  advice  from  legal  counsel  to the  effect  that it is  exposed  to any
liability which could  reasonably be expected to result in any Material  Adverse
Effect.

             4.10 Payment of Taxes. All material tax returns and reports of each
Borrower and each of its  Subsidiaries  required to be filed by any of them have
been  timely  filed,  and all taxes,  assessments,  fees and other  governmental
charges upon such Persons and upon their respective  properties,  assets, income
and franchises which are shown on such returns as due and payable have been paid
when due and payable.  As of the Closing Date,  none of the United States income
tax returns of each Borrower or any of its  Subsidiaries are under audit. No tax
liens have been filed and no claims  (except as  otherwise  permitted by Section
5.9) are being  asserted with respect to any such taxes.  The charges,  accruals
and  reserves  on the books of each  Borrower  and each of its  Subsidiaries  in
respect of any taxes or other governmental charges are in accordance with GAAP.

             4.11 Performance of  Agreements.  None of the Loan Parties and none
of their respective Subsidiaries is in default in the performance, observance or
fulfillment of any of the obligations,  covenants or conditions contained in any
contractual  obligation of any such Person,  and no condition  exists that, with
the  giving  of notice or the  lapse of time or both,  would  constitute  such a
default.

                                       28
<PAGE>

             4.12 Employee   Benefit   Plans.   Each   Borrower,   each  of  its
Subsidiaries and each ERISA Affiliate is in compliance in all material  respects
with all applicable  provisions of ERISA,  the IRC and all other applicable laws
and the  regulations  and  interpretations  thereof with respect to all Employee
Benefit Plans. No material  liability has been incurred by any Borrower,  any of
its  Subsidiaries  or any ERISA  Affiliate  which  remains  unsatisfied  for any
funding  obligation,  taxes or penalties  with  respect to any Employee  Benefit
Plan.

             4.13 Intellectual   Property.   Each   Borrower  and  each  of  its
Subsidiaries  owns,  is licensed to use or  otherwise  has the right to use, all
Intellectual  Property  used in or necessary  for the conduct of its business as
currently  conducted,  and all  such  Intellectual  Property  is  identified  on
Schedule 4.13.


             4.14  Broker's  Fees.  Except as set  forth on  Schedule  4.14,  no
broker's or finder's  fee or  commission  will be payable with respect to any of
the transactions contemplated hereby.

             4.15  Environmental  Compliance.  Each  Loan  Party has been and is
currently  in  compliance  with all  applicable  Environmental  Laws,  including
obtaining   and   maintaining   in  effect  all   permits,   licenses  or  other
authorizations  required by applicable  Environmental Laws. There are no claims,
liabilities,  investigations,  litigation,  administrative proceedings,  whether
pending  or  threatened,  or  judgments  or  orders  relating  to any  Hazardous
Materials  asserted or threatened against any Loan Party or relating to any real
property currently or formerly owned, leased or operated by any Loan Party.

             4.16 Solvency. As of and from and after the date of this Agreement,
each Borrower:  (a) owns and will own assets the fair salable value of which are
(i)  greater  than the total  amount of its  liabilities  (including  contingent
liabilities)  and (ii)  greater than the amount that will be required to pay the
probable  liabilities  of such Borrower as they mature;  (b) has capital that is
not unreasonably small in relation to its business as presently conducted or any
contemplated  or  undertaken  transaction;  and (c) does not intend to incur and
does not believe  that it will incur debts  beyond its ability to pay such debts
as they become due.  There is no material  fact known to a Borrower  that has or
could have a  Material  Adverse  Effect  and that has not been  fully  disclosed
herein or in such other  documents,  certificates  and  statements  furnished to
Lender for use in connection with the transactions contemplated hereby.

             4.17 Disclosure. No representation or warranty of Borrowers, any of
their  respective  Subsidiaries  or any  other  Loan  Party  contained  in  this
Agreement,  the financial  statements,  the other Loan  Documents,  or any other
document,  certificate or written statement  furnished to Lender by or on behalf
of any such Person for use in connection  with the Loan  Documents  contains any
untrue  statement of a material  fact or omitted,  omits or will omit to state a
material  fact  necessary in order to make the  statements  contained  herein or
therein  not  misleading  in light of the  circumstances  in which the same were
made. The  Projections  and pro forma  financial information

                                   29

<PAGE>

contained in such materials are based upon good faith estimates and assumptions
believed by such Persons to be reasonable  at the time made,  it being
recognized by Lender that such  projections  as to  future  events  are not to
be viewed as facts and that actual results during the period or periods covered
by any such  projections may differ from the projected results.  There is no
material fact known to Borrowers that  has had or will  have a  Material Adverse
Effect  and  that has not been disclosed  herein  or in  such  other documents,
certificates  and  statements furnished to Lender for use inconnection with the
transactions  contemplated hereby.

             4.18  Insurance.   Each  Borrower  and  each  of  its  Subsidiaries
maintains adequate insurance policies for public liability,  property damage for
its business and properties,  product liability,  and business interruption,  no
notice of cancellation  has been received with respect to such policies and each
Borrower  and each of its  Subsidiaries  is in  compliance  with all  conditions
contained in such policies.

             4.19 Compliance with Laws. No Borrower nor any of its  Subsidiaries
is in  violation  of  any  law,  ordinance,  rule,  regulation,  order,  policy,
guideline  or other  requirement  of any domestic or foreign  government  or any
instrumentality or agency thereof,  having  jurisdiction over the conduct of its
business or the ownership of its properties,  including, without limitation, any
violation  relating to any use, release,  storage,  transport or disposal of any
Hazardous  Material,  which  violation  would  subject a Borrower  or any of its
Subsidiaries,  or any of their respective officers to criminal liability or have
a Material Adverse Effect and no such violation has been alleged.

             4.20 Bank  Accounts.  Schedule 4.20 sets forth the account  numbers
and locations of all bank accounts of each Borrower and its Subsidiaries.

             4.21 Subsidiaries. Borrowers have no Subsidiaries other than as set
forth on Schedule 4.21.

             4.22 Employee Matters. Except as set forth on Schedule 4.22, (a) no
Loan Party nor any of such Loan Party's  employees is subject to any  collective
bargaining  agreement,  (b) no petition for  certification  or union election is
pending  with  respect  to the  employees  of any  Loan  Party  and no  union or
collective  bargaining unit has sought such  certification  or recognition  with
respect  to the  employees  of any Loan  Party  and (c)  there  are no  strikes,
slowdowns,  work stoppages or controversies pending or, to the best knowledge of
Borrowers  after  due  inquiry,  threatened  between  any  Loan  Party  and  its
respective  employees,  other than employee  grievances  arising in the ordinary
course  of  business  which  could  reasonably  be  expected  to  have,   either
individually or in the aggregate, a Material Adverse Effect. Except as set forth
on Schedule  4.22,  no  Borrower  nor any of its  Subsidiaries  is subject to an
employment contract.

             4.23 Governmental Regulation. None of the Loan Parties is, or after
giving  effect to any loan  will be,  subject  to  regulation  under the  Public
Utility  Holding  Company Act of 1935,  the

                                       30

<PAGE>

Federal Power Act or the  Investment Company Act of 1940 or to any federal or
state  statute or  regulation  limiting its ability to incur indebtedness for
borrowed money.

         Borrowers  may,  at any  time  and from  time to time  and  subject  to
subsection 5.13, amend any one or more of the Schedules referred in this Section
4 and any  representation or warranty  contained herein which refers to any such
Schedule  shall  from and  after  the date of any such  amendment  refer to such
Schedule as so amended, provided,  however, that in no event may Borrowers amend
any such Schedule if such amendment would reflect or evidence a Default or Event
of Default.

                         5  AFFIRMATIVE COVENANTS

         Borrowers  covenant and agree that,  so long as any of the  Commitments
hereunder  shall be in effect  and  until  payment  in full of all  Obligations,
unless Lender shall  otherwise give its prior written  consent,  Borrowers shall
perform,  and shall cause each of its Subsidiaries to perform,  all covenants in
this Section 5 applicable to such Person.

         5.1 Financial  Statements and Other  Reports.  Borrowers will maintain,
and  cause  each of their  respective  Subsidiaries  to  maintain,  a system  of
accounting  established  and  administered  in  accordance  with sound  business
practices to permit preparation of financial statements in conformity with GAAP.
Borrowers  will deliver to Lender the  financial  statements  and other  reports
described below.

                  (A) Monthly Financials.  As soon as available and in any event
within thirty (30) days after the end of each month,  Borrowers will deliver (1)
the  consolidated  and  consolidating  balance  sheet  of  Borrowers  and  their
respective Subsidiaries as at the end of such month and the related consolidated
and consolidating  statements of income,  stockholders' equity and cash flow for
such month and for the period from the beginning of the then current Fiscal Year
to the end of such month, and (2) a schedule of the outstanding Indebtedness for
borrowed  money of Borrowers  and their  respective  Subsidiaries  describing in
reasonable  detail each such debt issue or loan  outstanding  and the  principal
amount and amount of accrued and unpaid  interest with respect to each such debt
issue or loan.

                  (B)  Quarterly  Financials.  As soon as  available  and in any
event  within  forty-five  (45) days  after the end of each  quarter of a Fiscal
Year, Borrowers will deliver the consolidated and consolidating balance sheet of
Borrowers and their respective Subsidiaries as at the end of such period and the
related  consolidated  and  consolidating  statements  of income,  stockholders'
equity and cash flow for such  quarter of a Fiscal  Year and for the period from
the  beginning of the then  current  Fiscal Year to the end of such quarter of a
Fiscal Year and such financial  statements shall have been reviewed by a firm of
independent certified public accountants selected by Borrowers and acceptable to
Lender.

                                       31

<PAGE>

                  (C) Year-End Financials. As soon as available and in any event
within  ninety  (90) days  after the end of each  Fiscal  Year,  Borrowers  will
deliver:  (1) the  consolidated  balance sheet of Borrowers and their respective
Subsidiaries as at the end of such year and the related consolidated  statements
of  income,  stockholders'  equity  and cash flow for such  Fiscal  Year;  (2) a
schedule of the  outstanding  Indebtedness  of  Borrowers  and their  respective
Subsidiaries  describing  in  reasonable  detail  each such  debt  issue or loan
outstanding  and the principal  amount and amount of accrued and unpaid interest
with  respect to each such debt issue or loan;  (3) a report with respect to the
financial  statements from a firm of independent  certified  public  accountants
selected  by  Borrowers  and  acceptable  to  Lender,   which  report  shall  be
unqualified  as to going  concern  and  scope of audit of  Borrowers  and  their
respective  Subsidiaries  and shall state that (a) such  consolidated  financial
statements  present fairly the consolidated  financial position of Borrowers and
their respective Subsidiaries as at the dates indicated and the results of their
operations  and cash flow for the  periods  indicated  in  conformity  with GAAP
applied on a basis  consistent  with prior years and (b) that the examination by
such accountants in connection with such consolidated  financial  statements has
been made in accordance  with generally  accepted  auditing  standards;  and (4)
copies  of  the  consolidating  financial  statements  of  Borrowers  and  their
respective Subsidiaries, including (a) consolidating balance sheets of Borrowers
and their  respective  Subsidiaries  as at the end of such Fiscal  Year  showing
intercompany  eliminations and (b) related consolidating  statements of earnings
of   Borrowers   and  their   respective   Subsidiaries   showing   intercompany
eliminations.

                  (D) Accountants' Certification and Reports. Together with each
delivery of consolidated  financial statements of Borrowers and their respective
Subsidiaries pursuant to subsection 5.1(C), Borrowers will deliver (1) a written
statement by its independent  certified public  accountants (a) stating that the
examination  has included a review of the terms of this Agreement as same relate
to  accounting  matters  and  (b)  stating  whether,   in  connection  with  the
examination,  any  condition or event that  constitutes a Default or an Event of
Default has come to their  attention  and, if such a condition or event has come
to their  attention,  specifying the nature and period of existence  thereof and
(2) a letter  addressed  to  Lender  from  such  accountants  stating  that such
accountants  have been informed  that a primary  intent of Borrowers was to have
the professional  services such  accountants  provided to Borrowers in preparing
their audit report and the letter referred to in this subsection  5.1(D) benefit
or influence  Lender,  and  identifying  Lenders as a party that  Borrowers have
indicated intends to rely on such professional services provided to Borrowers by
such accountants.  Promptly upon receipt thereof,  Borrowers will deliver copies
of  all  significant  reports  submitted  to  Borrowers  by  independent  public
accountants  in  connection  with each annual,  interim or special  audit of the
financial  statements  of  Borrowers  made by such  accountants,  including  the
comment letter  submitted by such  accountants to management in connection  with
their annual audit.

                  (E) Compliance Certificate. Together with the delivery of each
set of  financial  statements  referenced  in subparts  (A), (B) and (C) of this
subsection  5.1,  Borrowers  will  deliver to

                                          32
<PAGE>

Lender a  Compliance  Certificate, together  with  copies of the  calculations
and work-up  employed to  determine Borrowers' compliance or noncompliance
with the financial covenants set forth in Section 6.

                  (F) Borrowing Base  Certificates,  Registers and Journals.  On
the Closing Date and within five (5) Business  Days after both the fifteenth and
the last day of each  month and from time to time upon the  request  of  Lender,
each Borrower shall deliver to Lender: (1) a Borrowing Base Certificate  updated
since the date of the prior Borrowing Base  Certificate,  together with a report
of the outstanding  balance of the Revolving Loan owing by such Borrower and the
amount  of all  intercompany  advances  owing  by and to such  Borrower;  (2) an
invoice  register or sales journal  describing  all sales of such Borrower since
the date of the prior invoice  register,  in form and substance  satisfactory to
Lender, and, if Lender so requests, copies of invoices evidencing such sales and
proofs of delivery relating thereto;  (3) a cash receipts journal describing all
cash  receipts  of such  Borrower  since  the date of the  prior  cash  receipts
journal; (4) an aged trial balance of all its then existing Accounts; and (5) an
aged trial balance of all its then existing accounts payable; and (6) a detailed
inventory  listing and cover summary  report.  All such reports shall be in form
and substance  satisfactory to Lender.  Notwithstanding the foregoing,  upon the
later  of July 1,  1996,  and the  first  day of the  month  following  Lender's
completion of an acceptable  field  examination of each Borrower's  reporting of
its Accounts and  Inventory,  provided that no Default or Event of Default shall
have  occurred  and be  continuing  and  provided  that  Borrowers  continuously
maintain thereafter aggregate Availability of not less than $750,000,  Borrowers
shall be required to deliver to Lender the reports set forth in this  subsection
5.1(F) only once each month,  within  five (5)  Business  Days after last day of
each month.

                  (G)  Management   Report.   Together  with  each  delivery  of
financial statements of Borrowers and their respective  Subsidiaries pursuant to
subdivisions  (A), (B) and (C) of this subsection 5.1,  Borrowers will deliver a
management  report:  (1) describing  the  operations and financial  condition of
Borrowers  and their  respective  Subsidiaries  for the month then ended and the
portion of the  current  Fiscal  Year then  elapsed (or for the Fiscal Year then
ended in the case of year-end financials); (2) setting forth in comparative form
the corresponding  figures for the corresponding  periods of the previous Fiscal
Year and the  corresponding  figures  from the most recent  Projections  for the
current Fiscal Year delivered to Lender  pursuant to 5.1(O);  and (3) discussing
the reasons  for any  significant  variations.  The  information  above shall be
presented in such detail as Lender and Borrowers shall mutually agree within two
(2) months  after the Closing Date (or in the absence of an  agreement,  in such
detail as Lender shall  reasonably  request based upon similar reports  received
from its other  asset-based  lending  borrowers)  and shall be  certified by the
chief financial officer of Borrowers to the effect that such information  fairly
presents the results of  operations  and  financial  condition of Borrowers  and
their respective Subsidiaries as at the dates and for the periods indicated.

                  (H) Appraisals. From time to time, upon the request of Lender,
Borrowers will obtain and deliver to Lender,  at Borrowers'  expense,  appraisal
reports  in form and  substance  and

                                        33
<PAGE>

from  appraisers  satisfactory  to  Lender, stating the then  current fair
market and orderly  liquidation  values of all or any portion of the Collateral;
provided, however, so long as no Event of Default is  continuing,  Lender  shall
not  request an  appraisal  as to any  particular category  of  Collateral  to
be  performed  more  than once  every  Loan Year at Borrowers' expense.

            (I)  Government  Notices.  Borrowers  will  deliver  to Lender
promptly after receipt copies of all notices, requests, subpoenas,  inquiries or
other writings  received from any  governmental  agency  concerning any Employee
Benefit Plan, the violation or alleged violation of any Environmental  Laws, the
storage,  use or disposal of any  Hazardous  Material,  the violation or alleged
violation of the Fair Labor  Standards Act or Borrowers'  payment or non-payment
of any taxes including any tax audit.

                  (J) Events of  Default,  etc.  Promptly  upon any officer of a
Borrower  obtaining  knowledge  of any of the  following  events or  conditions,
Borrowers  shall deliver a certificate  of Borrowers'  chief  executive  officer
specifying  the nature and period of  existence  of such  condition or event and
what action  Borrowers  have taken,  are taking and propose to take with respect
thereto:  (1) any  condition  or event that  constitutes  an Event of Default or
Default; (2) any notice of default that any Person has given to Borrowers or any
of their  respective  Subsidiaries  or any other  action taken with respect to a
claimed default; or (3) any Material Adverse Effect.

                  (K)  Trade  Names.  Borrowers  and  each of  their  respective
Subsidiaries  will give Lender at least thirty (30) days advance  written notice
of any change of name or of any new trade name or fictitious business name. Each
Borrower's  use of any  trade  name  or  fictitious  business  name  will  be in
compliance with all laws regarding the use of such names.

                  (L) Locations. Borrowers will give Lender at least thirty (30)
days advance  written  notice of any change in a Borrower's  principal  place of
business  or any  change  in  the  location  of its  books  and  records  or the
Collateral or of any new location for its books and records or the Collateral.

                  (M) Bank Accounts. Borrowers will give Lender prompt notice of
any new bank accounts a Borrower or any of its Subsidiaries intends to establish
prior to its their opening same.

                  (N) Litigation. Promptly upon any officer of a Borrower or its
subsidiaries  obtaining  knowledge of (1) the  institution of any action,  suit,
proceeding,  governmental  investigation or arbitration against or affecting any
Loan  Party or any  property  of any Loan  Party  not  previously  disclosed  by
Borrowers  to  Lender  or (2) any  material  development  in any  action,  suit,
proceeding,  governmental  investigation  or  arbitration  at any  time  pending
against or  affecting  any Loan Party or any property of any Loan Party which is
reasonably  likely to have a Material  Adverse  Effect,  Borrowers will promptly
give  notice  thereof to Lender and  provide  such other  information  as may be
reasonably  available to them to enable  Lender and its counsel to evaluate such
matter.

                                              34
<PAGE>

                  (O)  Projections.  As soon as  available  and in any  event no
later  than the last day of  Borrowers'  Fiscal  Year,  Borrowers  will  deliver
consolidated  and  consolidating  Projections of Borrowers and their  respective
Subsidiaries  through the Termination  Date, which Projections shall be month by
month for the forthcoming Fiscal Year and shall be year by year thereafter.

                  (P) Preferred Stock and Indebtedness Notices.  Borrowers shall
promptly  deliver  copies of all notices given or received by a Borrower and any
of its  Subsidiaries  with respect to  noncompliance  with any term or condition
related to the Preferred  Stock or any  Indebtedness,  and shall promptly notify
Lender of any potential or actual event of default with respect to the Preferred
Stock or any Indebtedness.

                  (Q) Other Information.  With reasonable promptness,  Borrowers
will deliver such other information and data with respect to any Loan Party, any
Subsidiary of any Loan Party or the Collateral as Lender may reasonably  request
from time to time.

                  (R) Opening  Balance  Sheet.  As soon as available  and in any
event within ninety (90) days after the Closing Date,  Borrowers will deliver an
audited consolidated and consolidating balance sheet as of the effective date of
the  MedTox  Acquisition  prepared  by a firm of  independent  certified  public
accountants reasonably acceptable to Lender.

         5.2 Access to Accountants.  Borrowers  authorize  Lender to discuss the
financial  condition and financial  statements of Borrowers and their respective
Subsidiaries  with Borrowers'  independent  public  accountants  upon reasonable
notice to Borrowers of its intention to do so, and authorizes  such  accountants
to respond to all of Lender's inquiries.

         5.3  Inspection.  Borrowers  shall  permit  Lender  and any  authorized
representatives  designated by Lender to visit and inspect any of the properties
of  Borrowers  or  any  of  its  Subsidiaries,  including  their  financial  and
accounting  records,  and to make  copies and take  extracts  therefrom,  and to
discuss their affairs, finances and business with their officers and independent
public accountants, at such reasonable times during normal business hours and as
often as may be reasonably requested.  Borrowers acknowledge that Lender intends
to make such inspections on at least a quarterly basis.

         5.4 Collateral  Records.  Borrowers  shall keep full and accurate books
and records  relating to the Collateral and shall mark such books and records to
indicate Lender's security interests in the Collateral.

         5.5 Account  Covenants;  Verification.  Borrowers  shall,  at their own
expense:  (a) cause all invoices  evidencing  Accounts and all copies thereof to
bear a notice that such  invoices are payable to the  lockboxes  established  in
accordance  with  subsection  5.6 and (b) use its best efforts to assure  prompt
payment of all amounts due or to become due under the  Accounts.  No  discounts,

                                          35
<PAGE>

credits or  allowances  will be  issued,  granted  or  allowed  with  respect to
Accounts by  Borrowers  to  customers  and no returns  will be accepted  without
Lender's prior written consent;  provided,  that until Lender notifies Borrowers
to the  contrary,  Borrowers may presume  consent.  Borrowers  will  immediately
notify  Lender in the event that a customer  alleges  any  dispute or claim with
respect to an Account or of any other  circumstances known to Borrowers that may
impair the  validity  or  collectibility  of an Account.  Lender  shall have the
right,  at any time or times  hereafter,  to verify the validity,  amount or any
other matter relating to an Account, by mail,  telephone or in person. After the
occurrence of a Default or an Event of Default, Borrowers shall not, without the
prior consent of Lender,  adjust,  settle or compromise the amount or payment of
any Account,  or release  wholly or partly any customer or obligor  thereof,  or
allow any credit or discount thereon.

         5.6 Collection of Accounts and Payments.  Each Borrower shall establish
lockboxes  and  blocked  accounts  (collectively,  "Blocked  Accounts")  in such
Borrower's name with such banks ("Collecting Banks") as are acceptable to Lender
(subject to irrevocable  instructions  acceptable to Lender as  hereinafter  set
forth) to which all account  debtors of such Borrower  shall  directly remit all
payments on Accounts and in which such  Borrower  will  immediately  deposit all
payments  made  for  Inventory  or  other  payments   constituting  proceeds  of
Collateral in the identical form in which such payment was made, whether by cash
or  check.  The  Collecting  Banks  shall  acknowledge  and  agree,  in a manner
satisfactory to Lender,  that all payments made to the Blocked  Accounts are the
sole and exclusive  property of Lender,  and that the  Collecting  Banks have no
right of setoff against the Blocked Accounts and that all such payments received
will be promptly  transferred to Lender's  Account.  Borrowers hereby agree that
all payments  received by Lender,  whether by cash,  check, wire transfer or any
other instrument,  made to such Blocked Accounts or otherwise received by Lender
and whether on the Accounts or as proceeds of other Collateral or otherwise will
be the sole and exclusive  property of Lender.  The  applicable  Borrower  shall
irrevocably  instruct each Collecting Bank to promptly  transfer all payments or
deposits to the Blocked Accounts into Lender's Account.  Each Borrower,  and any
of its Affiliates,  employees,  agents or other Persons acting for or in concert
with a Borrower,  shall, acting as trustee for Lender,  receive, as the sole and
exclusive property of Lender,  any monies,  checks,  notes,  drafts or any other
payments  relating to and/or proceeds of Accounts or other Collateral which come
into the  possession  or under the control of a Borrower or any of a  Borrower's
Affiliates,  employees,  agents or other Persons acting for or in concert with a
Borrower, and immediately upon receipt thereof,  Borrowers or such Persons shall
remit  the  same or cause  the same to be  remitted,  in  kind,  to the  Blocked
Accounts or to Lender at its address set forth in subsection 9.6 below.

         5.7 Endorsement.  Each Borrower hereby  constitutes and appoints Lender
and all Persons  designated by Lender for that purpose as such  Borrower's  true
and lawful  attorney-in-fact,  with power to endorse such Borrower's name to any
of the items of payment or proceeds  described in  subsection  5.6 above and all
proceeds of  Collateral  that come into Lender's  possession  or under  Lender's
control. Both the appointment of Lender as each Borrower's attorney and Lender's
rights and powers are coupled with an interest and are irrevocable until payment
in full and complete performance of all of the Obligations.

                                           36
<PAGE>

         5.8 Corporate Existence. Each Borrower will, and will cause each of its
Subsidiaries  to, at all times  preserve  and keep in full  force and effect its
corporate  existence  and all rights and  franchises  material to its  business.
Borrowers  will  promptly  notify  Lender of any change in a  Borrower's  or its
Subsidiaries' ownership or corporate structure.

         5.9  Payment  of Taxes.  Borrowers  will,  and will cause each of their
respective  Subsidiaries to, pay all taxes,  assessments and other  governmental
charges  imposed upon it or any of its  properties  or assets or with respect to
any of its franchises,  business,  income or property before any penalty accrues
thereon  provided  that no such  tax  need be paid if a  Borrower  or one of its
Subsidiaries  is  contesting  same  in good  faith  by  appropriate  proceedings
promptly  instituted  and  diligently  conducted  and if such  Borrower  or such
Subsidiary  has  established  appropriate  reserves  as  shall  be  required  in
conformity with GAAP.

         5.10 Maintenance of Properties;  Insurance. Each Borrower will maintain
or cause to be  maintained  in good  repair,  working  order and  condition  all
material  properties used in the business of such Borrower and its  Subsidiaries
and  will  make or  cause  to be made  all  appropriate  repairs,  renewals  and
replacements  thereof.  Borrowers will maintain or cause to be maintained,  with
financially sound and reputable  insurers,  public liability and property damage
insurance  with respect to their  respective  businesses  and properties and the
businesses  and  properties  of their  respective  Subsidiaries  against loss or
damage of the  kinds  customarily  carried  or  maintained  by  corporations  of
established  reputation  engaged in similar businesses and in amounts acceptable
to  Lender.  Borrowers  shall  cause  Lender  to be named  as loss  payee on all
insurance  policies  relating to any Collateral and as additional  insured under
all liability  policies,  in each case pursuant to appropriate  endorsements  in
form and  substance  satisfactory  to Lender  and shall  collaterally  assign to
Lender as security for the payment of the Obligations all business  interruption
insurance of  Borrowers.  Borrowers  shall apply any proceeds  received from any
policies of insurance relating to any Collateral to the Obligations as set forth
in subsection 2.4(B).

         5.11  Compliance  with Laws. Each Borrower will, and will cause each of
its Subsidiaries to, comply with the requirements of all applicable laws, rules,
regulations and orders of any governmental  authority as now in effect and which
may be imposed in the future in all  jurisdictions in which each Borrower or any
of its  Subsidiaries  is now doing business or may hereafter be doing  business,
other  than those laws the  noncompliance  with which  would not have a Material
Adverse Effect.

         5.12 Further  Assurances.  Each Borrower shall, and shall cause each of
its  Subsidiaries to, from time to time,  execute such guaranties,  financing or
continuation  statements,  documents,  security  agreements,  reports  and other
documents or deliver to Lender such instruments,  certificates of title or other
documents as Lender at any time may reasonably  request to evidence,  perfect or
otherwise implement the guaranties and security for repayment of the Obligations
provided for in the Loan Documents.  At Lender's request,  Borrowers shall cause
any Subsidiaries of Borrowers

                                    37
<PAGE>

promptly to guaranty the Obligations and to grant to Lender  security  interests
in the real,  personal and mixed property of such Subsidiary to secure the
Obligations.

            5.13 Collateral  Locations.  Borrowers  will keep the Collateral at
the locations specified on Schedule 4.7. With respect to any new location (which
in any event shall be within the  continental  United  States),  Borrowers  will
execute  such  documents  and take such  actions as Lender  deems  necessary  to
perfect and protect the security interests of the Lender in the Collateral prior
to the transfer or removal of any Collateral to such new location.

           5.14  Bailees. If any Collateral is at any time in the possession or
control of any warehouseman, bailee or any of a Borrower's agents or processors,
such  Borrower  shall,  upon the request of Lender,  notify  such  warehouseman,
bailee,  agent or processor of the security interests in favor of Lender created
hereby and shall  instruct such Person to hold all such  Collateral for Lender's
account subject to Lender's instructions.

         5.15   Use of Proceeds and Margin  Security.  Borrowers shall use the
proceeds  of  all  Loans  for  proper  business  purposes  consistent  with  all
applicable laws, statutes, rules and regulations.  No portion of the proceeds of
any Loan shall be used by a Borrower or any of its  Subsidiaries for the purpose
of  purchasing or carrying of margin stock within the meaning of Regulation G or
Regulation U, or in any manner that might cause the borrowing or the application
of such proceeds to violate Regulation T or Regulation X or any other regulation
of the Board of  Governors  of the  Federal  Reserve  System,  or to violate the
Exchange Act.


                              6  FINANCIAL COVENANTS

      Borrowers  covenant  and agree  that so long as any of the  Commitments
remain in effect and until payment in full of all  Obligations,  Borrowers shall
comply with and shall cause each of their respective Subsidiaries to comply with
all covenants in this Section 6.

      6.1  Tangible Net Worth.  Borrowers  shall  maintain a consolidated
Tangible  Net Worth of at least the  amounts  set forth below at the end of each
quarter of a Fiscal Year set forth below.

                  Fiscal Quarter                               Amount

                  March 31, 1996                             $  500,000
                  June 30, 1996                               1,000,000
                  September 30, 1996                          1,500,000
                  December 31, 1996                           2,000,000
                  March 31, 1997                              2,500,000
                  June 30, 1997                               2,500,000
                  September 30, 1997                          2,700,000

                                                  38
<PAGE>

                  December 31, 1997                           3,000,000
                  March 31, 1998                              3,500,000
                  June 30, 1998                               4,000,000
                  September 30, 1998                           4,750,000
                  December 31, 1998 and as of the
                  end of each       of each fiscal quarter
                  thereafter                                   5,250,000


      6.2  Minimum  EBITDA.  Borrowers  shall  at all  times  maintain  a
consolidated EBITDA less Registration Payments paid or accrued of at least the
amount set forth below for the applicable period set forth below.

                                             Editek &
          Period                             diAGnostix     PDLA   Consolidated

Two (2) Months ending February 29,         $  100,000  $    50,000 $  150,000
Three (3) months ending March 31, 1996        100,000      100,000     200,000
Four (4) months ending April 30, 1996         100,000      400,000     500,000
Five (5) months ending May 31, 1996           100,000      800,000     900,000
Six (6) months ending June 30, 1996           200,000    1,000,000   1,200,000
Seven (7) months ending July 31, 1996         200,000    1,400,000   1,600,000
Eight (8) months ending August 31, 1996       200,000    1,800,000   2,000,000
Nine (9) months ending September 30, 1996     200,000    2,100,000   2,300,000
Ten (10) months ending October 31, 1996       300,000    2,400,000   2,700,000
Eleven (11) months ending November 30, 1996   300,000    2,800,000   3,100,000
Twelve (12) month ending December 31, 1996    300,000    3,100,000   3,400,000
Twelve (12) month ending March 31, 1997       350,000    3,100,000   3,450,000
Twelve (12) month ending June 30, 1997        350,000    3,150,000   3,500,000
Twelve (12) month ending September 30, 1997   400,000    3,150,000   3,550,000
Twelve (12) month ending December 31, 1997    400,000    3,200,000   3,600,000
Twelve (12) month ending March 31, 1998       400,000    3,250,000   3,650,000
Twelve (12) month ending June 30, 1998        500,000    3,200,000   3,700,000
Twelve (12) month ending September 30, 1998   500,000    3,250,000   3,750,000
Twelve (12) month ending December 31, 1998
and for the twelve (12) months ending at the
end of each fiscal quarter thereafter         500,000    3,300,000    3,800,000

      6.3  Ratio of Indebtedness to Tangible Net Worth.  The ratio of (a)
Borrowers' consolidated Indebtedness to (b) Borrowers' consolidated Tangible Net
Worth,  shall be no  greater  than the ratio set forth  below at the end of each
quarter of a Fiscal Year set forth below.

                                      39

<PAGE>

           Fiscal Quarter                                             Ratio

           March 31, 1996                                                7.5:1
           June 30, 1996                                                 7.5:1
           September 30, 1996                                            7.5:1
           December 31, 1996                                             7.5:1
           March 31, 1997                                                4.5:1
           June 30, 1997                                                 4.5:1
           September 30, 1997                                            4.5:1
           December 31, 1997                                             4.5:1
           March 31, 1998                                                3.0:1
           June 30, 1998                                                 3.0:1
           September 30, 1998                                            3.0:1
           December 31, 1998 and as of the
           end of each       of each fiscal quarter
           thereafter                                                    3.0:1

       6.4   Capital  Expenditure  Limits.  The  aggregate  amount  of  all
Capital Expenditures of Borrowers and their respective  Subsidiaries  (excluding
trade-ins and excluding Capital Expenditures in respect of replacement assets to
the extent funded with casualty insurance  proceeds) will not exceed $950,000 in
any Fiscal Year. In the event that a Borrower or any of its Subsidiaries  enters
into a  Capital  Lease or other  contract  with  respect  to fixed  assets,  for
purposes of calculating  Capital  Expenditures  under this subsection  only, the
amount of the Capital Lease or contract initially capitalized on such Borrower's
or  Subsidiary's  balance  sheet  prepared  in  accordance  with  GAAP  shall be
considered  expended in full on the date that such Borrower or Subsidiary enters
into such Capital Lease or contract.

       6.5   Fixed  Charge  Coverage.  Borrowers  shall  not  permit  their
consolidated  Fixed  Charge  Coverage  for any period set forth below to be less
than the amount set forth below for such period.

                        Period                                        Amount

         Three (3) Months ending March 31, 1996                        0.8
         Six (6) months ending June 30, 1996                           1.0
         Nine (9) months ending September 30, 1996                     1.3
         Twelve (12) month ending December 31, 1996                    1.3

                                       40

<PAGE>

         Twelve (12) month ending March 31, 1997                       1.3
         Twelve (12) month ending June 30, 1997                        1.4
         Twelve (12) month ending September 30, 1997                   1.4
         Twelve (12) month ending December 31, 1997                    1.4
         Twelve (12) month ending March 31, 1998                       1.4
         Twelve (12) month ending June 30, 1998                        1.4
         Twelve (12) month ending September 30, 1998                   1.4
         Twelve (12) month ending December 31, 1998
         and for the twelve (12) months ending at the
         end of each fiscal quarter thereafter                          1.4

          6.6    Interest   Coverage.   Borrowers   shall  not   permit   their
consolidated  Interest  Coverage  for any period set forth below to be less than
the amount set forth below for such period.

                       Period                                        Amount

         Three (3) Months ending March 31, 1996                        3.0
         Six (6) months ending June 30, 1996                           3.4
         Nine (9) months ending September 30, 1996                     4.6
         Twelve (12) month ending December 31, 1996                    5.6
         Twelve (12) month ending March 31, 1997                       6.0
         Twelve (12) month ending June 30, 1997                        6.0
         Twelve (12) month ending September 30, 1997                   6.0
         Twelve (12) month ending December 31, 1997                    6.0
         Twelve (12) month ending March 31, 1998                       6.0
         Twelve (12) month ending June 30, 1998                        6.0
         Twelve (12) month ending September 30, 1998                   6.0
         Twelve (12) month ending December 31, 1998
         and for the twelve (12) months ending at the
         end of each fiscal quarter thereafter                         6.0


                          7   NEGATIVE COVENANTS

         Borrowers  covenant  and agree  that so long as any of the  Commitments
remain in effect and until payment in full of all Obligations,  unless Borrowers
have received the prior written consent of Lender,  Borrowers shall not and will
not permit any of their respective Subsidiaries to:

          7.1    Indebtedness and Liabilities.  Directly or indirectly  create,
incur,  assume,  guaranty,  or otherwise become or remain directly or indirectly
liable, on a fixed or contingent basis, with respect to any Indebtedness except:
(a) the  Obligations;  (b)  intercompany  Indebtedness,  not to exceed  $250,000
outstanding at any time in the aggregate,  among  Borrowers;  provided that such

                                          41
<PAGE>


Indebtedness  is  subordinated  in  right of  payment  to the  Obligations;  (c)
Indebtedness  (excluding capital leases) not to exceed $100,000 in the aggregate
at any time outstanding  secured by purchase money Liens; (d) Indebtedness under
Capital Leases not to exceed $250,000  outstanding at any time in the aggregate;
and (e)  Indebtedness  existing on the Closing Date and  identified  on Schedule
7.1.  Except for  Indebtedness  described  permitted in the preceding  sentence,
Borrowers will not, and will not permit any of their respective Subsidiaries to,
incur any  Liabilities  except for trade  payables  and normal  accruals  in the
ordinary  course  of  business  not yet due and  payable  or with  respect  to a
Borrower or any of its  Subsidiaries  is  contesting in good faith the amount or
validity  thereof by  appropriate  proceedings  and then only to the extent that
such Borrower or Subsidiary  has  established  adequate  reserves  therefor,  if
appropriate under GAAP.

           7.2   Guaranties. Except for endorsements of instruments or items of
payment for collection in the ordinary course of business, guaranty, endorse, or
otherwise in any way become or be responsible  for any  obligations of any other
Person, whether directly or indirectly by agreement to purchase the indebtedness
of any other Person or through the purchase of goods,  supplies or services,  or
maintenance of working  capital or other balance sheet  covenants or conditions,
or by way of  stock  purchase,  capital  contribution,  advance  or loan for the
purpose of paying or discharging  any  indebtedness  or obligation of such other
Person or otherwise.

         7.3  Transfers, Liens and Related Matters.

         (A) Transfers.  Sell,  assign (by operation of law or  otherwise)  or
otherwise dispose of, or grant any option with respect to any of the  Collateral
or the assets of such Person,  except that Borrowers and their  respective
Subsidiaries  may (i) sell inventory in the ordinary course of business;  and
(ii) make Asset  Dispositions if all of the following  conditions are met:
(1) the market value of assets sold or  otherwise  disposed  of in any  single
transaction  or  series  of  related transactions  does not exceed  $25,000 and
the aggregate  market value of assets sold or otherwise  disposed of in any
Fiscal Year does not exceed  $50,000;  (2) the  consideration  received is at
least equal to the fair market value of such assets; (3) the sole consideration
received is cash;  (4) the net proceeds of such Asset Disposition are applied as
required by subsection  2.4(B);  (5) after giving effect to the sale or other
disposition of the assets included within the Asset  Disposition  and the
repayment  of the  Obligations  with  the  proceeds thereof, Borrowers are in
compliance on a pro forma basis with the covenants set forth in  Section  6
recomputed  for the most  recently  ended  month for which information  is
available  and  is in  compliance  with  all  other  terms  and conditions
contained in this Agreement;  and (6) no Default or Event of Default shall
then exist or result from such sale or other disposition.

     (B) Liens.  Except  for  Permitted  Encumbrances,  directly  or  indirectly
create,  incur, assume or permit to exist any Lien on or with  respect to any
of the  Collateral or the assets of such Person or any proceeds, income or
profits therefrom.

                                  42
<PAGE>

     (C) No Negative Pledges.  Enter into or assume any agreement (other than
the Loan Documents) prohibiting the creation or assumption of any Lien upon its
properties or assets, whether now owned or hereafter acquired.

      (D) No Restrictions on Subsidiary  Distributions  to Borrowers.  Except as
provided  herein, directly or  indirectly  create or otherwise  cause or suffer
to exist or become effective any  consensual  encumbrance or restriction of any
kind on the ability of any such  Subsidiary to: (1) pay dividends or make any
other  distribution on any of such Subsidiary's  capital stock owned by a
Borrower or any Subsidiary of a Borrower; (2) subject to subordination
provisions,  pay any indebtedness owed to a Borrower or any other Subsidiary;
(3) make loans or advances to a Borrower or any other  Subsidiary;  or (4)
transfer  any of its  property or assets to a Borrower or any other
Subsidiary.

      7.4  Investments and Loans.  Make or permit to exist investments in
or loans to any other Person,  except:  (a) Cash Equivalents;  and (b) loans and
advances  to  employees  for  moving,  entertainment,  travel and other  similar
expenses in the ordinary course of business in an aggregate  outstanding  amount
not in excess of $50,000 at any time.


     7.5  Restricted  Junior Payments.  Directly or indirectly  declare,  order,
pay, make or set apart any sum for any Restricted Junior Payment, except that:

                  (a)  Subsidiaries  of  Borrowers  may make  Restricted  Junior
         Payments with respect to their common stock to the extent  necessary to
         permit  Borrowers to pay the  Obligations,  to make  Restricted  Junior
         Payments  permitted  under clause (b) below and to permit  Borrowers to
         pay expenses incurred in the ordinary course of business; and

                  (b) Editek may make dividend  payments on the Preferred  Stock
         and may make Registration Payments,  provided that all of the following
         limitations  shall be applicable to dividend  payments and Registration
         Payments:

                           (i)      no Default or Event of Default may be
                  existence at the time of such payment or
                  may be created by any such payment;

                           (ii)     no such payment may be made prior to
                  February 1, 1997;

                           (iii)    no such payment may be made prior to the
                  repayment in full of all principal of and interest on Term
                  Loan B;

                           (iv)     no such  payment may be made in any Fiscal
                  Year prior to the delivery to Lender of Borrowers' audited
                  financial statements for the previous Fiscal Year;

                                       43
<PAGE>

                           (v) the  aggregate  amount of dividend  payments  and
                  Registration Payments in a Fiscal Year shall not exceed of the
                  lesser of (A) nine percent  (9%) of the amount of  outstanding
                  Preferred  Stock and (B) one-third of  Borrowers'  Excess Cash
                  Flow  for  the  previous   Fiscal  Year,  as  determined  from
                  Borrower's audited financial  statements  delivered to Lender;
                  and

                            (vi)  after  giving  effect  to  any  such  payment,
                  Availability shall not be less than $500,000.

      7.6 Restriction  on  Fundamental   Changes.  (a)  Enter  into  any
transaction  of merger or  consolidation,  except that a Borrower may merge with
another  Borrower and PDLA may merge with Princeton;  (b) liquidate,  wind-up or
dissolve itself (or suffer any liquidation or  dissolution);  (c) convey,  sell,
lease,  sublease,  transfer or  otherwise  dispose of, in one  transaction  or a
series of  transactions,  all or any substantial part of its business or assets,
or the capital stock of any of its Subsidiaries,  whether now owned or hereafter
acquired;  or (d) except  for the MedTox  Acquisition,  acquire by  purchase  or
otherwise all or any substantial  part of the business or assets of, or stock or
other evidence of beneficial ownership of, any Person.

       7.7  Changes Relating to Preferred Stock. Change or amend the terms
of the Preferred  Stock if the effect of such  amendment is to: (a) increase the
dividend rate thereon;  (b) change the  redemption  provisions  thereof;  or (c)
change or amend any other  term if such  change or  amendment  would  materially
increase the obligations of the obligor or confer additional  material rights on
the holder of such Preferred  Stock in a manner adverse to any Borrower,  any of
its Subsidiaries, or Lender.

     7.8 Transactions  with Affiliates.  Directly or indirectly,  enter
into or  permit  to exist  any  transaction  (including  the  purchase,  sale or
exchange of property or the rendering of any service) with any Affiliate or with
any officer,  director or employee of any Loan Party, except for transactions in
the ordinary course of and pursuant to the reasonable requirements of Borrowers'
business and upon fair and reasonable  terms which are fully disclosed to Lender
and  which are no less  favorable  to  Borrowers  than  they  would  obtain in a
comparable arm's length transaction with an unaffiliated Person.

      7.9  Environmental   Liabilities.   (a)  Violate   any   applicable
Environmental Law; (b) dispose of any Hazardous  Materials (except in accordance
with applicable  law) into or onto or from, any real property  owned,  leased or
operated  by any Loan  Party;  or (c) permit any Lien  imposed  pursuant  to any
Environmental Law to be imposed or to remain on any real property owned,  leased
or operated by any Loan Party.

                                     44

<PAGE>

      7.10  Conduct of Business.  From and after the Closing Date,  engage
in any  business  other than  businesses  of the type engaged in by Borrowers or
such Subsidiary on the Closing Date.

     7.11  Compliance with ERISA. Establish any new Employee Benefit Plan
or amend any  existing  Employee  Benefit  Plan if the  liability  or  increased
liability  resulting  from such  establishment  or  amendment  is  material.  No
Borrower  nor any of its  Subsidiaries  shall fail to  establish,  maintain  and
operate each Employee  Benefit Plan in compliance in all material  respects with
the  provisions  of  ERISA,  the IRC  and  all  other  applicable  laws  and the
regulations and interpretations thereof.

      7.12  Tax  Consolidations.  File or consent to the filing of any
consolidated  income tax return  with any Person other than a Borrower or any of
its Subsidiaries.

     7.13  Subsidiaries.  Establish, create or acquire any new Subsidiaries.

     7.14  Fiscal Year.  Change its Fiscal Year.

     7.15  Press Release; Public Offering Materials. Disclose the name of
Lender in any press  release  or in any  prospectus,  proxy  statement  or other
materials  filed with any  governmental  entity relating to a public offering of
the capital stock of any Loan Party except as may be required by law.

     7.16 Bank  Accounts.  Establish any new bank  accounts,  or amend or
terminate any Blocked  Account or lockbox agreement.


                       8   DEFAULT, RIGHTS AND REMEDIES

     8.1 Event of Default.  "Event of Default"  shall mean the  occurrence or
existence of any one or more of the following:

          (A) Payment.  Failure  to make  payment of any of the  Obligations
when due and in the case of interest, such failure shall not be cured within
five (5) days of the applicable due date; or

          (B) Default in Other  Agreements.  (1) Failure of a Borrower or any of
its  Subsidiaries  to pay when due any  principal  or  interest  on any
Indebtedness  (other  than  the Obligations)  or (2)  breach  or  default  of
a  Borrower  or  any  of its  Subsidiaries with  respect  to  any  Indebtedness
(other  than  the Obligations);  if  such  failure to pay, breach or default
entitles  the  holder  to  cause  such  Indebtedness  having an  individual
principal  amount in excess of  $25,000  or having

                                    45
<PAGE>

an  aggregate principal amount in excess of $50,000 to become or be declared due
prior to its stated maturity; or

           (C) Breach of Certain  Provisions.  Failure of  Borrowers to perform
or comply with any term or condition contained in subsections 5.1 (A), (B), (C)
and (R),  5.3, 5.5 or 5.6 or contained in Section 6 or Section 7; or

          (D) Breach of Warranty. Any representation, warranty, certification or
other statement made by any Loan Party in any Loan Document or in any statement
or  certificate at any time given by such Person in writing pursuant or in
connection  with any Loan Document is false in any material respect on the date
made; or

         (E) Other  Defaults  Under Loan  Documents.  A Borrower or any other
Loan Party  defaults in the  performance  of or compliance  with any term 
contained in this Agreement or the other Loan  Documents  and such default is
not remedied or waived within ten (10) days after  receipt by Borrowers of
notice  from  Lender of such  default (other than occurrences described in
other provisions of this subsection 8.1 for which a  different  grace  or cure
period  is  specified  or  which  constitute immediate Events of Default); or

        (F) Change  in  Control.  Editek  ceases  to  beneficially  own  and
control,  directly  or indirectly,  one hundred  percent  (100%) of the issued
and  outstanding  shares of each class of capital  stock of PDLA and diAGnostix;
or

        (G) Involuntary Bankruptcy;  Appointment of Receiver,  etc. (1) A court
enters a decree or order for relief  with  respect to a Borrower or any of its
Subsidiaries  in an involuntary  case  under  the  Bankruptcy  Code  or any
applicable  bankruptcy, insolvency  or other  similar law now or  hereafter  in
effect,  which decree or order is not stayed or other similar  relief is not
granted under any applicable federal or state law; or (2) the continuance of any
of the following events for sixty (60) days unless dismissed, bonded or
discharged: (a) an involuntary case is commenced against a Borrower or any of
its Subsidiaries, under any applicable bankruptcy, insolvency or other similar
law now or hereafter in effect; or (b) adecree  or order  of a court  for the
appointment  of a  receiver,  liquidator, sequestrator,  trustee,  custodian or
other officer having similar powers over a Borrower or any of its Subsidiaries,
or over all or a substantial part of their respective  property, is entered; or
(c) an interim receiver,  trustee or other custodian  is  appointed  without
the  consent  of a  Borrower  or  any  of its Subsidiaries,  for all or a
substantial part of the property of such Borrower or Subsidiary; or

         (H) Voluntary  Bankruptcy;  Appointment  of  Receiver,  etc.  (1) An
order  for  relief  is entered with respect to a Borrower or any of its
Subsidiaries,  or a Borrower or any of its Subsidiaries  commences a voluntary
case under the Bankruptcy Code or any applicable  bankruptcy,  insolvency or
other similar law now or hereafter in effect,  or consents to the entry of an
order for relief in an involuntary  case or to the conversion of an involuntary
case to a voluntary case under any such law or  consents  to the  appointment
of or taking  possession  by a  receiver, trustee or other

                               46
<PAGE>

custodian for all or a substantial part of its property; or (2) a Borrower or
any of its Subsidiaries makes  any assignment for  the benefit of creditors; or
(3)  the  board  of  directors  of a  Borrower  or  any  of  its Subsidiaries
adopts any resolution or otherwise authorizes action to approve any of the
actions referred to in this subsection 8.1(H); or

         (I)  Liens.  Any lien,  levy or  assessment is filed or recorded with
respect to or otherwise imposed upon all or any part of the Collateral or the as
sets of a Borrower or any of its Subsidiaries by the United States or any
department or instrumentality thereof or by any state, county, municipality or
other governmental agency (other than Permitted Encumbrances) unless such lien,
levy or assessment is stayed, vacated, paid or discharged within ten (10) days
or Borrowers contest the validity thereof in good faith by appropriate
proceedings and establish appropriate reserves on their books in respect
thereof; or

         (J) Judgment and Attachments. Any money judgment, writ or warrant of
attachment,  or similar process involving (1) an amount in any individual case
in excess of $25,000 or (2) an amount in the  aggregate  at any time in excess
of $50,000 (in either  case not  adequately  covered  by  insurance  as to which
the  insurance company has acknowledged coverage) is entered or filed against a
Borrower or any of its Subsidiaries or any of their respective assets and
remains  undischarged, unvacated, unbonded or unstayed for a period of thirty
(30) days or in any event later than five (5) days prior to the date of any
proposed sale thereunder; or

         (K)  Dissolution.  Any  order,  judgment  or decree is entered  against
a Borrower  or any of its  Subsidiaries  decreeing the  dissolution  or split up
of a Borrower or that Subsidiary  and such order  remains  undischarged  or
unstayed  for a period in excess of twenty (20) days; or

         (L) Solvency.  A Borrower  ceases to be solvent (as  represented by
Borrowers in subsection 4.17) or admits in writing its present or prospective
inability to pay its debts as they become due; or

         (M) Injunction.  A Borrower or any of its  Subsidiaries  is enjoined,
restrained  or in any way  prevented  by the order of any court or any
administrative  or  regulatory agency from conducting all or any material part
of its business and such order continues for more than thirty (30) days; or

         (N) Invalidity of Loan  Documents.  Any of the Loan  Documents for any
reason,  other than a partial or full release in accordance  with the terms
thereof,  ceases to be in full  force and  effect or is  declared  to be null
and void,  or any Loan Party denies that it has any further liability under any
Loan Documents to which it is party, or gives notice to such effect; or

         (O)  Failure  of  Security.  Lender  does not have or ceases  to have a
valid  and  perfected first  priority  security  interest  in the  Collateral
(subject  to  Permitted Encumbrances),  in each case, for any reason other than
the failure of Lender to take any action within its control; or

                                    47

<PAGE>

         (P) Damage,  Strike,  Casualty.  Any material  damage to, or loss,
theft or destruction of, any Collateral,  whether or not insured, or any strike,
lockout, labor dispute, embargo,  condemnation,  act of God or public  enemy,
or other  casualty  which causes,   for  more  than  fifteen  (15)  consecutive
days,  the  cessation  or substantial  curtailment  of revenue  producing
activities at any facility of a Borrower  or any of its  Subsidiaries  if any
such event or  circumstance  could reasonably be expected to have a Material
Adverse Effect; or

            (Q) Licenses and Permits.  The loss,  suspension or revocation of,
or failure to renew,  any license or permit now held or  hereafter  acquired
by a Borrower  or any of its Subsidiaries,  if such loss,  suspension,
revocation  or failure to renew could have a Material Adverse Effect; or

            (R)  Forfeiture.  There is filed  against a Borrower  any civil
or criminal  action,  suit or proceeding under any federal or state
racketeering  statute (including,  without limitation,  the Racketeer
Influenced  and Corrupt  Organization  Act of 1970), which action,  suit or
proceeding (1) is not dismissed within one hundred twenty (120)  days;
and (2) could  result in the  confiscation  or  forfeiture  of any
material portion of the Collateral; or

      8.2  Suspension of Commitments.  Upon the occurrence of any Default
or Event of Default,  notwithstanding any grace period or right to cure, Lender,
without notice or demand,  may immediately cease making additional Loans and the
Commitments shall be suspended;  provided that, in the case of a Default, if the
subject  condition  or event is waived or cured within any  applicable  grace or
cure period, the Commitments shall be reinstated.

      8.3  Acceleration.  Upon the  occurrence  of any  Event of  Default
described in the foregoing  subsections  8.1(G) or 8.1(H), all Obligations shall
automatically become immediately due and payable,  without presentment,  demand,
protest or other  requirements  of any kind,  all of which are hereby  expressly
waived by Borrowers,  and the Commitments  shall thereupon  terminate.  Upon the
occurrence and during the continuance of any other Event of Default, Lender may,
by written notice to Borrowers, declare all or any portion of the Obligations to
be, and the same shall  forthwith  become,  immediately  due and payable and the
Commitments shall thereupon terminate.

       8.4 Remedies.  If any Event of Default  shall have occurred and be
continuing,  in  addition  to and not in  limitation  of any rights or  remedies
available  to Lender at law or in equity,  Lender may exercise in respect of the
Collateral,  in addition to all other rights and remedies provided for herein or
otherwise  available  to it, all the rights and  remedies of a secured  party on
default  under  the  UCC  (whether  or not  the  UCC  applies  to  the  affected
Collateral)  and may also (a) notify any or all obligors on the Accounts to make
all payments directly to Lender;  (b) require Borrowers to, and Borrowers hereby
agree that they will,  at their  expense and upon  request of Lender  forthwith,
assemble  all or part of the  Collateral  as  directed  by  Lender  and  make it
available to Lender at a place to be  designated  by Lender which is  reasonably
convenient  to both parties;  (c) withdraw all cash in the Blocked  Accounts and
apply such  monies in  payment of the  Obligations  in

                                     48
<PAGE>

the  manner  provided  in subsection  8.7; (d) without notice or demand or legal
process,  enter upon any premises of a Borrower and take  possession of the
Collateral;  and (e) without notice except as specified below, sell the
Collateral or any part thereof in one or more parcels at public or private sale,
at any of the  Lender's  offices or elsewhere,  at such time or times, for cash,
on credit or for future  delivery, and at such  price or  prices  and upon  such
other terms as Lender  may deem commercially  reasonable.  Borrowers agree that,
to the extent  notice of sale shall be required by law, at least ten (10) days
notice to Borrowers of the time and place of any public sale or the time after
which any private  sale is to be made shall constitute reasonable notification.
At any sale of the Collateral, if permitted by law,  Lender may bid (which bid
may be, in whole or in part, in the form of cancellation of indebtedness)  for
the purchase of the Collateral or any portion thereof for the account of Lender.
Lender shall not be obligated to make any sale of Collateral regardless of
notice of sale having been given. Borrowers shall remain liable for any
deficiency. Lender may adjourn any public or private sale from time to time by
announcement at the time and place fixed therefor, and such sale may, without
further notice, be made at the time and place to which it was so adjourned.  To
the extent permitted by law, Borrowers hereby specifically waive all rights of
redemption, stay or appraisal which it has or may have under any law now
existing  or  hereafter  enacted.  Lender  shall not be required to proceed
against any Collateral but may proceed against Borrowers directly.

     8.5 Appointment   of   Attorney-in-Fact.   Each  Borrower   hereby
constitutes and appoints Lender as such  Borrower's  attorney-in-fact  with full
authority  in the  place  and  stead  of such  Borrower  and in the name of such
Borrower, Lender or otherwise, from time to time in Lender's discretion while an
Event of Default is continuing to take any action and to execute any  instrument
that Lender may deem  necessary or advisable to accomplish  the purposes of this
Agreement,  including: (a) to ask, demand, collect, sue for, recover,  compound,
receive and give acquittance and receipts for moneys due and to become due under
or in respect of any of the Collateral;  (b) to adjust, settle or compromise the
amount or payment of any  Account,  or release  wholly or partly any customer or
obligor  thereunder  or allow any credit or  discount  thereon;  (c) to receive,
endorse,  and collect  any drafts or other  instruments,  documents  and chattel
paper, in connection  with clause (a) above;  (d) to file any claims or take any
action or institute any proceedings  that Lender may deem necessary or desirable
for the  collection of any of the  Collateral or otherwise to enforce the rights
of Lender with respect to any of the Collateral; and (e) to sign and endorse any
invoices,  freight  or express  bills,  bills of  lading,  storage or  warehouse
receipts, assignments, verifications and notices in connection with Accounts and
other documents  relating to the  Collateral.  The appointment of Lender as each
Borrower's  attorney and Lender's rights and powers are coupled with an interest
and are irrevocable until payment in full and complete performance of all of the
Obligations.

                                 49
<PAGE>

     8.6  Limitation  on Duty of  Lender  with  Respect  to  Collateral.
Beyond the safe custody  thereof,  Lender shall have no duty with respect to any
Collateral in its  possession or control (or in the possession or control of any
agent or bailee) or with respect to any income  thereon or the  preservation  of
rights  against prior  parties or any other rights  pertaining  thereto.  Lender
shall  be  deemed  to  have  exercised   reasonable  care  in  the  custody  and
preservation  of the  Collateral in its possession if the Collateral is accorded
treatment  substantially  equal to that which Lender  accords its own  property.
Lender shall not be liable or  responsible  for any loss or damage to any of the
Collateral,  or for any diminution in the value thereof, by reason of the act or
omission of any warehouseman,  carrier,  forwarding  agency,  consignee or other
agent or bailee selected by Lender in good faith.

      8.7  Application  of Proceeds.  Upon the  occurrence and during the
continuance of an Event of Default, (a) Borrowers irrevocably waive the right to
direct the  application of any and all payments at any time or times  thereafter
received  by  Lender  from or on  behalf  of  Borrowers,  and  Borrowers  hereby
irrevocably agree that Lender shall have the continuing exclusive right to apply
and to reapply  any and all  payments  received  at any time or times  after the
occurrence  and  during  the  continuance  of an Event of  Default  against  the
Obligations  in such  manner as Lender may deem  advisable  notwithstanding  any
previous  entry by Lender upon any books and records and (b) the proceeds of any
sale of, or other  realization  upon, all or any part of the Collateral shall be
applied:  first, to all fees, costs and expenses incurred by Lender with respect
to this Agreement,  the other Loan Documents or the Collateral;  second,  to all
fees due and owing to Lender;  third,  to accrued  and  unpaid  interest  on the
Obligations;  fourth, to the principal  amounts of the Obligations  outstanding;
and fifth,  to any other  indebtedness  or  obligations of any Borrower owing to
Lender. Lender shall account to Borrowers for any surplus and Borrowers shall be
liable for any deficiency.

   8.8 License  of  Intellectual   Property.   Each  Borrower  hereby
assigns,  transfers and conveys to Lender, effective during the existence of any
Event of  Default  hereunder,  the  non-exclusive  right and  license to use all
Intellectual  Property owned or used by such Borrower together with any goodwill
associated therewith, all to the extent necessary to enable Lender to realize on
the  Collateral  and any  successor  or  assign  to enjoy  the  benefits  of the
Collateral. This right and license shall inure to the benefit of all successors,
assigns and transferees of Lender and its successors,  assigns and  transferees,
whether  by  voluntary  conveyance,  operation  of  law,  assignment,  transfer,
foreclosure, deed in lieu of foreclosure or otherwise. Such right and license is
granted free of charge, without requirement that any monetary payment whatsoever
be made to Borrowers by Lender.

    8.9  Canadian Remedies. If any Event of Default shall have occurred
and be  continuing,  in addition to and not in limitation of any other rights or
remedies  provided  for herein or any rights or remedies  available to Lender or
otherwise  available to it at law or in equity,  Lender shall have the following
rights, powers and remedies,  subject to compliance with the PPSA, in respect of
any of the Collateral to which the PPSA is applicable:

                                         50
<PAGE>

                  (A) to  appoint  any  Person  to be an  agent  or any
         Person to be a receiver, manager or receiver and manager (herein called
         the  "Receiver")  of such  Collateral  and to remove  any  Receiver  so
         appointed  and to appoint  another if the Lender so  desires,  it being
         agreed that any Receiver  appointed  pursuant to the provisions of this
         Agreement will have all of the powers of the Lender  hereunder,  and in
         addition, will have the power to carry on the business of any Borrower;

                  (B) to make payments to parties having prior charges or
         encumbrances on properties on which any Borrower may hold charges or
         encumbrances;

                  (C) to take  possession  of all or any  part  of such
         Collateral  with  power  to exclude the Borrowers, their agents and
         servants therefrom;

                  (D) to preserve, protect and maintain such Collateral
         and make such replacements  thereof and additions thereto as the Lender
         may deem advisable;

                  (E) to enjoy and  exercise  all powers  necessary  or
         incidental to the  performance  of all  functions  provided for in this
         Agreement,  including,  without  limitation,  the power to  purchase on
         credit,  the power to borrow in any  Borrower's  name or in the name of
         the Receiver, the power to borrow on all or any part of such Collateral
         in priority to this  Agreement or otherwise for such purposes as may be
         approved by the Lender to be evidenced by a Receiver's certificate, and
         to advance its own money to the  Borrowers at such rates of interest as
         it may deem  reasonable,  provided  that the  Receiver may borrow money
         only with the prior consent of the Lender;

                 (F) to sell,  lease or  dispose of all or any part of
         such Collateral whether by public or private sale or lease or otherwise
         in such manner and on such terms as to the Lender may seem commercially
         reasonable,  including, without limitation, terms that provide time for
         payment or credit, provided that:

                                 (1) the Lender or the  Receiver  will not be
                  required to sell, lease or dispose of such Collateral, but may
                  peaceably and quietly take,  hold,  use,  occupy,  possess and
                  enjoy  such   Collateral,   without   molestation,   eviction,
                  hindrance or  interruption by any Borrower or any other person
                  or persons whomsoever;

                                  (2)      the  Lender or the  Receiver  may
                  convey,  transfer  and  assign to a purchaser or purchasers
                  the title to any of such Collateral so sold; and

                                  (3) the  Borrowers  will be  entitled  to be
                  credited with the actual  proceeds of any such sale,  lease or
                  other  disposition only when such proceeds are received by the
                  Lender or the Receiver in cash;

                                       51

<PAGE>

                           (G) to seize, collect,  demand, enforce,  recover and
         receive all or any part of the Accounts,  and to notify account debtors
         of the  Borrowers to pay such  Accounts to the Lender or the  Receiver,
         and to give valid and binding  receipts and discharges  therefor and in
         respect thereof, and to compromise all or any part of the Accounts that
         may seem bad or  doubtful  to the Lender or the  Receiver,  and to give
         time for payment thereof, with or without security;

                           (H) to enjoy and exercise all of the rights and 
         remedies of a secured  party under the PPSA;

                           (I) to dispose of all or any part of such  Collateral
         in the  condition  in  which it was on the  date  possession  of it was
         taken,  or after any  commercially  reasonable  repair,  processing  or
         preparation for disposition;

                           (J) if such  Collateral is perishable,  or the Lender
         or the Receiver  believes on  reasonable  grounds that any part of such
         Collateral will decline speedily in value, such Collateral is of a type
         customarily sold on a recognized  market,  the cost of care and storage
         of such Collateral is  disproportionately  large relative to its value,
         or the  Receiver  disposes  of such  Collateral  in the  course  of the
         Borrowers' business,  then the Lender or Receiver may sell or otherwise
         dispose  of any  part of such  Collateral  without  giving  any  notice
         whatsoever;

                           (K) to commence,  continue or defend  proceedings  in
         any court of  competent  jurisdiction  in the name of the  Lender,  the
         Receiver  or any  Borrower  for the  purpose of  exercising  any of the
         rights,  powers and remedies set out in this subsection 8.09, including
         the  institution  of  proceedings  for the  appointment  of a receiver,
         manager or receiver and manager of such Collateral; and

                           (L) at the sole option of the Lender, elect to retain
         all or any part of such Collateral in satisfaction of the Obligations.

      8.10  Waivers,  Non-Exclusive  Remedies.  No  failure on the part of
Lender to  exercise,  and no delay in  exercising  and no course of dealing with
respect to, any right under this  Agreement  or the other Loan  Documents  shall
operate as a waiver thereof;  nor shall any single or partial exercise by Lender
of any right under this Agreement or any other Loan Document  preclude any other
or further  exercise  thereof or the exercise of any other right.  The rights in
this Agreement and the other Loan Documents are cumulative and are not exclusive
of any other remedies provided by law.

      8.11 Judgment. 

                                       52
<PAGE>

                        (A) If for the purposes of obtaining judgment in any
court it is necessary to convert a sum due hereunder or under any instrument
delivered  hereunder in any currency (the "Original Currency") into another
currency (the "Other Currency"), the parties hereto agree, to the fullest
extent  permitted by law, that the rate of  exchange  used  shall be that at
which in  accordance  with  normal  banking procedures  the Lender  could
purchase  the  Original  Currency  with the Other Currency on the Business
Day preceding that on which the payment is made.

                         (B) The obligation of any Borrower with respect to any
sum due from it to the Lender  hereunder  or  under  such  instrument  shall,
notwithstanding any judgment in any Other  Currency,  be discharged  only  to
the extent that on the Business Day following receipt by the Lender of any sum
adjudged to be so due in the Other Currency, the Lender may, in accordance with
normal  banking  procedures,  purchase  the Original  Currency  with the Other
Currency.  If the amount of the Original Currency so purchased is less than the
sum  originally  due to the Lender in the Original  Currency,  such Borrower
agrees to indemnify the Lender  against such loss,  and if the amount of the
Original  Currency so purchased  exceeds the sum originally  due to the Lender
in the  Original  Currency,  the Lender  agrees to remit  to  the  Borrowers
such  excess.  This  indemnity  shall  constitute  an obligation separate and
independent from the other obligations contained in this Agreement,  shall give
rise to a separate and independent cause of action, shall apply irrespective of
any indulgence granted by the Lender from time to time and shall  continue in
full force and effect  notwithstanding  any judgment or order for a liquidated
sum in  respect  of any  amount  due  hereunder  or under any judgment or order.

                        9      MISCELLANEOUS

    9.1  Assignments and  Participations.  Lender may assign its rights
and delegate its  obligations  under this  Agreement and further may assign,  or
sell  participations  in, all or any part of the Loans,  the  Commitments or any
other interest  herein to an Affiliate or to another  Person.  In the case of an
assignment authorized under this subsection 9.1, the assignee shall have, to the
extent of such assignment, the same rights, benefits and obligations as it would
if it were a Lender  hereunder.  Lender  shall be  relieved  of its  obligations
hereunder with respect to the Commitments or assigned portion thereof. Borrowers
hereby  acknowledge  and agree  that any  assignment  will give rise to a direct
obligation  of  Borrowers  to the  assignee  and  that  the  assignee  shall  be
considered  to be a  "Lender".  Lender may furnish  any  information  concerning
Borrowers and their respective  Subsidiaries in its possession from time to time
to   assignees   and   participants   (including   prospective   assignees   and
participants).

       9.2  Set Off. In addition  to any rights now or  hereafter  granted
under  applicable law and not by way of limitation of any such rights,  upon the
occurrence of any Event of Default,  Lender, each assignee of Lender's interest,
and each participant is hereby  authorized by Borrowers at any time or from time
to time,  without  notice to Borrowers or to any other  Person,  any such notice
being hereby  expressly  waived,  to set off and to appropriate and to apply any
and all balances  held

                                            53
<PAGE>

by it at any of its offices for the account of a Borrower or any of its
Subsidiaries  (regardless of whether such balances are then due to a Borrower
or its Subsidiaries) and any other property at any time held or owing by that
Lender or assignee to or for the credit or for the account of a Borrower
against and on account of any of the  Obligations  then  outstanding;  provided,
that no participant  shall exercise such right without the prior written consent
of Lender.

      Borrowers  hereby agree,  to the fullest extent  permitted by law, that
any  Lender,  assignee  or  participant  may  exercise  its right of setoff with
respect to amounts in excess of its pro rata share of the  Obligations  (or,  in
the case of a participant,  in excess of its pro rata participation  interest in
the Obligations) and that such Lender, assignee or participant,  as the case may
be,  shall be deemed to have  purchased  for cash in the amount of such  excess,
participations in each other Lender's or holder's share of the Obligations.

        9.3  Expenses and Attorneys' Fees.  Whether or not the transactions
contemplated  hereby shall be  consummated,  Borrowers agree to promptly pay all
reasonable  fees,  costs and expenses  incurred by Lender in connection with any
matters  contemplated  by or  arising  out of this  Agreement  or the other Loan
Documents  including the  following,  and all such  reasonable  fees,  costs and
expenses shall be part of the Obligations,  payable on demand and secured by the
Collateral:  (a)  reasonable  fees,  costs and  expenses  (including  reasonable
attorneys'  fees,  allocated  costs of internal  counsel and reasonable  fees of
environmental  consultants,  accountants  and other  professionals  retained  by
Lender)  incurred in  connection  with the  examination,  review,  due diligence
investigation, documentation and closing of the financing arrangements evidenced
by the Loan  Documents;  (b)  reasonable  fees,  costs and  expenses  (including
reasonable  attorneys' fees,  allocated costs of internal counsel and reasonable
fees of environmental consultants,  accountants and other professionals retained
by Lender)  incurred in connection  with the review,  negotiation,  preparation,
documentation,  execution and  administration of the Loan Documents,  the Loans,
and any amendments,  waivers,  consents,  forbearances  and other  modifications
relating  thereto  or  any  subordination  or  intercreditor   agreements;   (c)
reasonable  fees,  costs and  expenses  incurred  in  creating,  perfecting  and
maintaining  perfection of Liens in favor of Lender;  (d) reasonable fees, costs
and expenses incurred in connection with forwarding to Borrowers the proceeds of
Loans including Lender's standard wire transfer fee; (e) reasonable fees, costs,
expenses and bank charges,  including bank charges for returned checks, incurred
by Lender in establishing,  maintaining and handling lock box accounts,  blocked
accounts or other  accounts for  collection of the  Collateral;  (f)  reasonable
fees, costs,  expenses (including reasonable attorneys' fees and allocated costs
of internal  counsel) and costs of  settlement  incurred in  collecting  upon or
enforcing  rights  against the  Collateral  or incurred in any action to enforce
this  Agreement or the other Loan  Documents or to collect any payments due from
Borrowers  or any other  Loan  Party  under  this  Agreement  or any other  Loan
Document or incurred in connection with any refinancing or  restructuring of the
credit  arrangements  provided under this Agreement,  whether in the nature of a
"workout" or in connection  with any  insolvency or  bankruptcy  proceedings  or
otherwise.
 
                                           54
<PAGE>

      9.4 Indemnity.  In addition to the payment of expenses pursuant to
subsection 9.3,  whether or not the  transactions  contemplated  hereby shall be
consummated,  Borrowers  agree  to  indemnify,  pay  and  hold  Lender,  and the
officers, directors,  employees, agents, consultants,  auditors, persons engaged
by Lender to evaluate or monitor the  Collateral,  affiliates  and  attorneys of
Lender and such holders  (collectively  called the "Indemnitees")  harmless from
and against any and all liabilities,  obligations,  losses, damages,  penalties,
actions, judgments, suits, claims, costs, expenses and disbursements of any kind
or nature whatsoever (including the reasonable fees and disbursements of counsel
for such  Indemnitees in connection with any  investigative,  administrative  or
judicial  proceeding  commenced or  threatened,  whether or not such  Indemnitee
shall be  designated a party  thereto)  that may be imposed on,  incurred by, or
asserted  against that  Indemnitee,  in any manner relating to or arising out of
this Agreement or the other Loan Documents, the consummation of the transactions
contemplated  by this  Agreement,  the  statements  contained in the  commitment
letters,  if any,  delivered  by Lender,  Lender's  agreement  to make the Loans
hereunder,  the use or intended  use of the  proceeds of any of the Loans or the
exercise of any right or remedy hereunder or under the other Loan Documents (the
"Indemnified Liabilities");  provided that Borrowers shall have no obligation to
an Indemnitee hereunder with respect to Indemnified Liabilities arising from the
gross  negligence or willful  misconduct  of that  Indemnitee as determined by a
court of competent jurisdiction.

       9.5   Amendments   and   Waivers.   No   amendment,    modification,
termination  or waiver of any  provision of this  Agreement or of the other Loan
Documents,  or  consent  to any  departure  by  Borrowers  therefrom,  shall  be
effective  unless  the  same  shall be in  writing  and  signed  by  Lender  and
Borrowers.  Each  amendment,  modification,   termination  or  waiver  shall  be
effective only in the specific  instance and for the specific  purpose for which
it was given.

       9.6  Notices.  Unless otherwise  specifically  provided herein, all
notices shall be in writing addressed to the respective party as set forth below
and may be personally served, telecopied or sent by overnight courier service or
United  States mail and shall be deemed to have been given:  (a) if delivered in
person,  when  delivered;   (b)  if  delivered  by  telecopy,  on  the  date  of
transmission if transmitted on a Business Day before 4:00 p.m.  Chicago time or,
if not, on the next  succeeding  Business  Day;  (c) if  delivered  by overnight
courier, two (2) days after delivery to such courier properly addressed;  or (d)
if by U.S.  Mail,  four (4) Business Days after  depositing in the United States
mail, with postage prepaid and properly addressed.


   If to Borrowers:                            Editek, Inc.
                                               1238 Anthony Road
                                               Burlington, North Carolina  27215
                                               Attention: President
                                               Telecopy No.: (910) 229-4471

                                    55

<PAGE>

    With a copy to:                        Petree Stockton, L.L.P.
                                           4101 Lake Boone Trail, Suite 400
                                           Raleigh, North Carolina  27607-6519
                                           Attention: James F. Verdonik
                                           Telecopy No.: (919) 420-1800


     If to Lender:                          HELLER FINANCIAL, INC.
                                            Attn:  HBC Portfolio Manager
                                            500 West Monroe Street
                                            Chicago, Illinois 60661
                                            Telecopy No.: (312) 441-6969

     With a copy to:                         HELLER FINANCIAL, INC.
                                             Attn:  Legal Department
                                             500 West Monroe Street
                                             Chicago, Illinois 60661
                                             Telecopy No. (312) 441-7367

or to such other address as the party addressed shall have previously designated
by written notice to the serving party, given in accordance with this subsection
9.6.

      9.7  Survival of Warranties and Certain Agreements. All agreements,
representations  and  warranties  made herein shall  survive the  execution  and
delivery   of  this   Agreement   and  the   making  of  the  Loans   hereunder.
Notwithstanding  anything in this  Agreement or implied by law to the  contrary,
the agreements of Borrowers set forth in  subsections  9.3 and 9.4 shall survive
the payment of the Loans and the termination of this Agreement.

      9.8  Indulgence  Not  Waiver.  No  failure  or delay on the part of
Lender in the exercise of any power, right or privilege shall impair such power,
right or privilege or be construed to be a waiver of any default or acquiescence
therein,  nor shall any single or partial  exercise of any such power,  right or
privilege  preclude  other or further  exercise  thereof or of any other  right,
power or privilege.

     9.9  Marshaling;  Payments Set Aside. Lender shall not be under any
obligation  to marshal  any assets in favor of any Loan Party or any other party
or against or in payment of any or all of the  Obligations.  To the extent  that
any Loan Party  makes a payment or  payments  to Lender or Lender  enforces  its
security  interests  or  exercise  its  rights of  setoff,  and such  payment or
payments or the proceeds of such  enforcement  or setoff or any part thereof are
subsequently invalidated,  declared to be fraudulent or preferential,  set aside
and/or required to be repaid to a trustee, receiver or any other party under any
bankruptcy law, state or federal law, common law or equitable cause, then to the
extent of such recovery,  the Obligations or part thereof originally intended to
be satisfied,  and all Liens, rights and remedies therefor, shall be revived and
continued

                                   56
<PAGE>

in full force and effect as if such payment had not been made or such
enforcement or setoff had not occurred.

      9.10  Entire  Agreement.  This  Agreement,  the Term Notes,  and the
other Loan Documents referred to herein embody the final, entire agreement among
the parties  hereto and  supersede  any and all prior  commitments,  agreements,
representations,  and  understandings,  whether written or oral, relating to the
subject  matter  hereof and may not be  contradicted  or varied by  evidence  of
prior,  contemporaneous,  or subsequent  oral  agreements or  discussions of the
parties hereto. There are no oral agreements among the parties hereto.

      9.11 Independence  of Covenants.  All covenants  hereunder shall be
given  independent  effect so that if a  particular  action or  condition is not
permitted  by any of such  covenants,  the fact that it would be permitted by an
exception to, or be otherwise  within the limitations of, another covenant shall
not avoid the  occurrence  of a Default or an Event of Default if such action is
taken or condition exists.

      9.12 Severability.  The invalidity,  illegality or unenforceability
in any  jurisdiction  of any provision in or obligation  under this Agreement or
the other Loan  Documents  shall not affect or impair the validity,  legality or
enforceability of the remaining  provisions or obligations under this Agreement,
or the other Loan  Documents  or of such  provision or  obligation  in any other
jurisdiction.

       9.13  Headings.  Section and  subsection  headings in this Agreement
are included herein for convenience of reference only and shall not constitute a
part of this Agreement for any other purpose or be given any substantive effect.

       9.14  APPLICABLE LAW. THIS AGREEMENT SHALL BE GOVERNED BY, AND SHALL
BE CONSTRUED AND ENFORCED IN ACCORDANCE  WITH, THE INTERNAL LAWS OF THE STATE OF
ILLINOIS, WITHOUT REGARD TO CONFLICTS OF LAWS PRINCIPLES.

      9.15  Successors and Assigns.  This Agreement  shall be binding upon
and inure to the benefit of the parties hereto and their  respective  successors
and assigns  except that  Borrowers  may not assign their rights or  obligations
hereunder without the prior written consent of Lender.
 
     9.16   No Fiduciary Relationship; Limitation of Liabilities. 

                           (A)       No provision in this  Agreement or in any
of the other Loan  Documents  and no course of dealing  between the parties
shall be deemed to create any  fiduciary duty by Lender to Borrowers.

                                     57
<PAGE>
                           (B)       Neither Lender, nor any affiliate, officer,
director,  shareholder, employee, attorney, or agent of Lender  shall have any
liability  with  respect  to, and Borrowers  hereby  waive,  release,  and
agree not to sue any of them upon,  any claim for any special,  indirect,
incidental, or consequential damages suffered or incurred  by  Borrowers  in
connection  with,  arising out of, or in any way related to, this  Agreement
or   any   of the   other   Loan  Documents,  or   any   of   the
transactions  contemplated by this Agreement or any of the other Loan Documents.
Borrowers hereby waive,  release, and agree not to sue Lender or any of Lender's
affiliates,  officers, directors,  employees,  attorneys, or agents for punitive
damages in respect of any claim in  connection  with,  arising out of, or in any
way related to, this Agreement or any of the other Loan Documents, or any of the
transactions   contemplated  by  this  Agreement  or  any  of  the  transactions
contemplated hereby.

      9.17  CONSENT TO JURISDICTION.  EACH BORROWER HEREBY CONSENTS TO THE
JURISDICTION  OF ANY STATE OR FEDERAL COURT  LOCATED  WITHIN THE COUNTY OF COOK,
STATE OF ILLINOIS AND IRREVOCABLY AGREES THAT, SUBJECT TO LENDER'S ELECTION, ALL
ACTIONS OR PROCEEDINGS  ARISING OUT OF OR RELATING TO THIS  AGREEMENT,  THE TERM
NOTES OR THE OTHER  LOAN  DOCUMENTS  SHALL BE  LITIGATED  IN SUCH  COURTS.  EACH
BORROWER ACCEPTS FOR ITSELF AND IN CONNECTION WITH ITS PROPERTIES, GENERALLY AND
UNCONDITIONALLY,  THE  NON-EXCLUSIVE  JURISDICTION  OF THE AFORESAID  COURTS AND
WAIVES ANY DEFENSE OF FORUM NON CONVENIENS,  AND IRREVOCABLY  AGREES TO BE BOUND
BY ANY JUDGMENT  RENDERED  THEREBY IN CONNECTION WITH THIS  AGREEMENT,  THE TERM
NOTES, THE OTHER LOAN DOCUMENTS OR THE OBLIGATIONS.

       9.18   WAIVER OF JURY TRIAL.  EACH  BORROWER AND LENDER  HEREBY WAIVE
THEIR  RESPECTIVE  RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION  BASED
UPON OR  ARISING  OUT OF THIS  AGREEMENT,  THE  TERM  NOTES  OR THE  OTHER  LOAN
DOCUMENTS.  BORROWERS  AND  LENDER  ACKNOWLEDGE  THAT THIS  WAIVER IS A MATERIAL
INDUCEMENT TO ENTER INTO A BUSINESS  RELATIONSHIP,  THAT EACH HAS ALREADY RELIED
ON THE WAIVER IN ENTERING INTO THIS AGREEMENT, THE TERM NOTES AND THE OTHER LOAN
DOCUMENTS  AND THAT EACH WILL  CONTINUE  TO RELY ON THE WAIVER IN THEIR  RELATED
FUTURE  DEALINGS.  BORROWERS AND LENDER FURTHER  WARRANT AND REPRESENT THAT EACH
HAS REVIEWED  THIS WAIVER WITH ITS LEGAL  COUNSEL,  AND THAT EACH  KNOWINGLY AND
VOLUNTARILY  WAIVES  ITS JURY TRIAL  RIGHTS  FOLLOWING  CONSULTATION  WITH LEGAL
COUNSEL.

       9.19   Construction.  Each Borrower and Lender each  acknowledge that
it has had the benefit of legal  counsel of its own choice and has been afforded
an  opportunity  to review this  Agreement and the other Loan Documents with its
legal  counsel and that this  Agreement  and the other Loan  Documents  shall be
construed as if jointly drafted by Borrowers and Lender.

                                  58
<PAGE>
          9.20  Counterparts;    Effectiveness.   This   Agreement   and   any
amendments,  waivers,  consents, or supplements may be executed in any number of
counterparts and by different parties hereto in separate  counterparts,  each of
which when so executed and  delivered  shall be deemed an  original,  but all of
which  counterparts  together shall  constitute but one and the same instrument.
This Agreement shall become effective upon the execution of a counterpart hereof
by each of the parties hereto.

          9.21  No Duty. All  attorneys,  accountants,  appraisers,  and other
professional  Persons and consultants retained by Lender shall have the right to
act  exclusively in the interest of Lender and shall have no duty of disclosure,
duty of loyalty, duty of care, or other duty or obligation of any type or nature
whatsoever  to  Borrowers  or any of any  Borrower's  shareholders  or any other
Person.

          9.22  Confidentiality.  Lender shall hold all nonpublic  information
identified  as such by  Borrowers in  accordance  with such  Person's  customary
procedures  for  handling  confidential   information  of  this  nature  and  in
accordance  with safe and  sound  business  practices  and in any event may make
disclosure   reasonably  required  by  a  bona  fide  offeree  or  assignee  (or
participation),  or as required or  requested by any  Governmental  Authority or
representative  thereof,  or pursuant to legal process,  or to its  accountants,
lawyers and other  advisors,  and shall require any such offeree or assignee (or
participant)   to  agree  (and  require  any  of  its  offerees,   assignees  or
participants  to agree) to comply  with this  Section  9.22.  In no event  shall
Lender be obligated or required to return any materials  furnished by Borrowers;
provided,  however,  each Offeree shall be required to agree that if it does not
become a assignee (or participant) it shall return all materials furnished to it
by Borrowers in connection herewith.





                      [Signatures appear on following page]


                                     59

<PAGE>



         Loan and Security Agreement - Signature Page
                                 

         Witness the due  execution  hereof by the  respective  duly  authorized
officers of the undersigned as of the date first written above.


                                                 HELLER FINANCIAL, INC.


                                                  By:

                                                  Title:
                                                 
                                                  EDITEK, INC.

                                                  By:

                                                  Title:

                                                  FEIN:


                                                  PSYCHIATRIC DIAGNOSTIC
                                                  LABORATORIES OF AMERICA, INC.

                                                   By:

                                                   Title:

                                                   FEIN:


                                                   DIAGNOSTIX, INC.

                                                   By:

                                                   Title:

                                                   FEIN:


                                         60
<PAGE>



                           LOAN AND SECURITY AGREEMENT

                          DATED AS OF JANUARY ___, 1996

                                     between

                                  EDITEK, INC.
              PSYCHIATRIC DIAGNOSTIC LABORATORIES OF AMERICA, INC.
                                DIAGNOSTIX, INC.

                                  as Borrowers

                                       and

                             HELLER FINANCIAL, INC.

                                    as Lender


                                        61
<PAGE>



                                TABLE OF CONTENTS


         SECTION 1  DEFINITIONS

         1.1      Certain Defined Terms......................................  1
         1.2      Accounting Terms........................................... 11
         1.3      Other Definitional Provisions.............................. 12

         SECTION 2  LOANS AND COLLATERAL

         2.1      Loans...................................................... 12
                  (A)(1)   Term Loan A....................................... 12
                  (A)(2)   Term Loan B....................................... 13
                  (B)      Revolving Loan...................     ............ 14
                  (C)      Eligible Collateral...................   ......... 15
                  (D)      Borrowing Mechanics............................... 17
                  (E)      Term Notes........................................ 18
                  (F)      Evidence of Revolving Loan Obligations............ 18
         2.2      Interest................................................... 18
                  (A)      Rate of Interest......................... ........ 18
                  (B)      Computation and Payment of Interest............... 18
                  (C)      Interest Laws..................................... 18
         2.3      Fees....................................................... 19
                  (A)      Closing Fee....................................... 19
                  (B)      Unused Line Fee................................... 19
                  (C)      Prepayment Fees..................................  19
                  (D)      Collateral Monitoring Fee......................... 20
                  (E)      Audit Fees........................................ 20
                  (F)      Other Fees and Expenses........................... 20
         2.4      Payments and Prepayments................................... 20
                  (A)      Manner and Time of Payment........................ 20
                  (B)      Mandatory Prepayments............................. 21
                           (1)      Overadvance.............................. 21
                           (2)      Proceeds of Asset Dispositions........... 21
                           (3)      Prepayments from Excess Cash Flow........ 21
                  (C)      Voluntary Prepayments and Repayments.............  21
                  (D)      Payments on Business Days......................... 22
         2.5      Term of this Agreement..................................... 22
         2.6      Statements................................................. 22
         2.7      Grant of Security Interest................................. 22
         2.8      Capital Adequacy and Other Adjustments..................... 23

                                                 i
<PAGE>

                  (A)      No Deductions..................................... 23
                  (B)      Changes in Tax Laws............................... 23

         SECTION 3  CONDITIONS TO LOANS

         3.1      Conditions to Loans........................................ 24
                  (A)      Closing Deliveries................................ 24
                  (B)      Security Interests................................ 24
                  (C)      Closing Date Availability......................... 24
                  (D)      Representations and Warranties.................... 24
                  (E)      Fees.............................................. 25
                  (F)      No Default........................................ 25
                  (G)      Performance of Agreements......................... 25
                  (H)      No Prohibition.................................... 25
                  (I)      No Litigation..................................... 25
                  (J)      Issuance of Preferred Stock....................... 25
                  (K)      MedTox Acquisition................................ 25

         SECTION 4  BORROWERS' REPRESENTATIONS AND WARRANTIES

         4.1      Organization, Powers, Capitalization....................... 26
                  (A)      Organization and Powers........................... 26
                  (B)      Capitalization.................................... 26
         4.2      Authorization of Borrowing, No Conflict................ ... 26
         4.3      Financial Condition........................................ 27
         4.4      Indebtedness and Liabilities............................... 27
         4.5      Account Warranties......................................... 27
         4.6      Names...................................................... 27
         4.7      Locations; FEIN............................................ 27
         4.8      Title to Properties; Liens................................. 27
         4.9      Litigation; Adverse Facts.................................. 28
         4.10     Payment of Taxes........................................... 28
         4.11     Performance of Agreements.................................. 28
         4.12     Employee Benefit Plans..................................... 28
         4.13     Intellectual Property...................................... 28
         4.14     Broker's Fees.............................................. 29
         4.15     Environmental Compliance................................... 29
         4.16     Solvency................................................... 29
         4.17     Disclosure................................................. 29
         4.18     Insurance.................................................. 29
         4.19     Compliance with Laws....................................... 30
         4.20     Bank Accounts.............................................. 30

                                                       ii
<PAGE>

         4.21     Subsidiaries............................................... 30
         4.22     Employee Matters........................................  . 30
         4.23     Governmental Regulation.....................................30

                                                        iii
<PAGE>
         SECTION 5  AFFIRMATIVE COVENANTS

         5.1      Financial Statements and Other Reports..................... 31
                  (A)      Monthly Financials................................ 31
                  (B)      Quarterly Financials.............................. 31
                  (C)      Year-End Financials............................... 31
                  (D)      Accountants' Certification and Reports............ 32
                  (E)      Compliance Certificate............................ 32
                  (F)      Borrowing Base Certificates, Registers and
                           Journals.......................................... 32
                  (G)      Management Report........................... ..... 33
                  (H)      Appraisals........................................ 33
                  (I)      Government Notices................................ 33
                  (J)      Events of Default, etc............................ 34
                  (K)      Trade Names....................................... 34
                  (L)      Locations......................................... 34
                  (M)      Bank Accounts..................................... 34
                  (N)      Litigation........................................ 34
                  (O)      Projections....................................... 34
                  (P)      Preferred Stock and Indebtedness Notice........... 34
                  (Q)      Other Information................................. 35
                  (R)      Opening Balance Sheet............................. 35
         5.2      Access to Accountants...................................... 35
         5.3      Inspection................................................. 35
         5.4      Collateral Records......................................... 35
         5.5      Account Covenants; Verification............................ 35
         5.6      Collection of Accounts and Payments........................ 36
         5.7      Endorsement................................................ 36
         5.8      Corporate Existence........................................ 36
         5.9      Payment of Taxes........................................... 36
         5.10     Maintenance of Properties; Insurance....................... 37
         5.11     Compliance with Laws....................................... 37
         5.12     Further Assurances......................................... 37
         5.13     Collateral Locations....................................... 37
         5.14     Bailees.................................................... 38
         5.15     Use of Proceeds and Margin Security........................ 38

         SECTION 6  FINANCIAL COVENANTS

         6.1      Tangible Net Worth......................................... 38
         6.2      Minimum EBITDA............................................. 39
         6.3      Ratio of Indebtedness to Tangible Net Worth................ 39
         6.4      Capital Expenditure Limits................................. 40

                                            iv
<PAGE>

         6.5      Fixed Charge Coverage...................................... 40
         6.6      Interest Coverage.......................................... 40

         SECTION 7  NEGATIVE COVENANTS

         7.1      Indebtedness and Liabilities............................... 41
         7.2      Guaranties................................................. 42
         7.3      Transfers, Liens and Related Matters....................... 42
                  (A)      Transfers......................................... 42
                  (B)      Liens............................................. 42
                  (C)      No Negative Pledges............................... 42
                  (D)      No Restrictions on Subsidiary Distributions to 
                           Borrowers......................................... 42
         7.4      Investments and Loans...................................... 43
         7.5      Restricted Junior Payments................................. 43
         7.6      Restriction on Fundamental Changes......................... 43
         7.7      Changes Relating to Preferred Stock........................ 44
         7.8      Transactions with Affiliates............................... 44
         7.9      Environmental Liabilities.................................. 44
         7.10     Conduct of Business........................................ 44
         7.11     Compliance with ERISA...................................... 44
         7.12     Tax Consolidations......................................... 44
         7.13     Subsidiaries............................................... 44
         7.14     Fiscal Year................................................ 44
         7.15     Press Release; Public Offering Materials................... 45
         7.16     Bank Accounts.............................................. 45

         SECTION 8  DEFAULT, RIGHTS AND REMEDIES

         8.1      Event of Default........................................... 45
                  (A)      Payment........................................... 45
                  (B)      Default in Other Agreements....................... 45
                  (C)      Breach of Certain Provisions...................... 45
                  (D)      Breach of Warranty................................ 45
                  (E)      Other Defaults Under Loan Documents............... 45
                  (F)      Change in Control................................. 46
                  (G)      Involuntary Bankruptcy; Appointment of 
                           Receiver, etc..................................... 46
                  (H)      Voluntary Bankruptcy; Appointment of 
                           Receiver, etc..................................... 46
                  (I)      Liens............................................. 46
                  (J)      Judgment and Attachments.......................... 46
                  (K)      Dissolution....................................... 47
                  (L)      Solvency.......................................... 47
                  (M)      Injunction........................................ 47

                                        v
<PAGE>

                  (N)      Invalidity of Loan Documents...................... 47
                  (O)      Failure of Security............................... 47
                  (P)      Damage, Strike, Casualty.......................... 47
                  (Q)      Licenses and Permits.............................. 47
                  (R)      Forfeiture........................................ 47
         8.2      Suspension of Commitments.................................. 48
         8.3      Acceleration............................................... 48
         8.4      Remedies................................................... 48
         8.5      Appointment of Attorney-in-Fact............................ 49
         8.6      Limitation on Duty of Lender with Respect to Collateral.... 49
         8.7      Application of Proceeds.................................... 49
         8.8      License of Intellectual Property........................... 50
         8.9      Canadian Remedies.......................................... 50
         8.10     Waivers, Non-Exclusive Remedies............................ 52
         8.11     Judgment................................................... 52

         SECTION 9  MISCELLANEOUS

         9.1      Assignments and Participations..............................53
         9.2      Set Off.................................................... 53
         9.3      Expenses and Attorneys' Fees............................... 53
         9.4      Indemnity.................................................. 54
         9.5      Amendments and Waivers..................................... 55
         9.6      Notices.................................................... 55
         9.7      Survival of Warranties and Certain Agreements.............. 56
         9.8      Indulgence Not Waiver...................................... 56
         9.9      Marshaling; Payments Set Aside............................. 56
         9.10     Entire Agreement........................................... 56
         9.11     Independence of Covenants.................................. 56
         9.12     Severability............................................... 56
         9.13     Headings................................................... 57
         9.14     APPLICABLE LAW............................................. 57
         9.15     Successors and Assigns..................................... 57
         9.16     No Fiduciary Relationship; Limitation of Liabilities....... 57
         9.17     CONSENT TO JURISDICTION.................................... 57
         9.18     WAIVER OF JURY TRIAL....................................... 58
         9.19     Construction............................................... 58
         9.20     Counterparts; Effectiveness................................ 58
         9.21     No Duty.................................................... 58
         9.22     Confidentiality............................................ 58

                                           vi

<PAGE>


                                    EXHIBITS

A                 Borrowing Base Certificate
B                 Compliance Certificate


                                    SCHEDULES

1.1(A)   Other Liens
1.1(B)   Pro Forma
3.1(A)   List of Closing Documents
4.1(B)   Capitalization of Loan Parties
4.6               Trade Names (Present and Past Five Years)
4.7               Location of Principal Place of Business, Books
                  and Records and Collateral
4.13              Intellectual Property
4.14              Brokers Fees
4.20              Bank Accounts
4.21              Subsidiaries
4.22              Employee Matters
7.1               Existing Indebtedness

                                               vii




<PAGE>

                                    EXHIBIT B

                        [FORM OF COMPLIANCE CERTIFICATE]

                                              _________________, 19___

Heller Business Credit
500 West Monroe Street
Chicago, Illinois  60661

         Re:      Compliance Certificate for EDITEK and Subsidiaries

Ladies and Gentlemen:

         This certificate is given in accordance with subsection  5.1(E) of that
certain Loan and Security Agreement dated as of January ___, 1996 by and between
EDITEK,  Inc.,  Psychiatric   Diagnostic   Laboratories  of  America,  Inc.  and
DiAgnostix,  Inc.  ("Borrowers") and Heller Financial,  Inc. (as the same may be
amended,  supplemented  or  otherwise  modified  from  time to time,  the  "Loan
Agreement").  Capitalized  terms used herein without  definition  shall have the
meanings assigned to such terms in the Loan Agreement. I hereby certify that:

         (a)      I am the [Chief Executive Officer] [Chief  Financial  Officer]
                  of Editek;

         (b)      The enclosed  consolidated and  consolidating  balance sheets,
                  income  statements  and cash flow  statements of Borrowers and
                  their respective  Subsidiaries fairly present the consolidated
                  and consolidating  financial  condition of Borrowers and their
                  respective Subsidiaries as of the dates indicated,  and I have
                  reviewed such statements in preparing this certificate;

         (c)      I have reviewed the terms of the Loan Agreement and have made,
                  or  caused  to be made  under  my  supervision,  a  review  in
                  reasonable detail of the transactions and financial  condition
                  of  Borrowers  during  the  accounting  period  covered by the
                  enclosed financial statements;

         (d)      The  examination  in paragraph (c) did not disclose and I have
                  no knowledge of the  existence of any  condition or event that
                  constitutes a Default or an Event of Default as of the date of
                  this certificate except as set forth below.

                  Described below (or in a separate  attachment  hereto) are the
                  exceptions,  if any, to paragraph (d), listing in detail,  the
                  nature  of   the   condition  or  event,   the  period  during
 
                  which it has existed and the  action  which   Borrowers   have
                  taken,  are taking or propose to  take  with  respect  to each
                  such  condition or event:

                  _____________________________________________________________
                  _____________________________________________________________
                  _____________________________________________________________

<PAGE>

         (e)      Except as disclosed in paragraph  (d) above,  Borrowers are in
                  compliance with the financial covenants contained in Section 6
                  of the Loan Agreement,  as detailed in the worksheet  attached
                  as Schedule I.

         The foregoing  certifications  and the financial  statements  delivered
with this Certificate in support hereof are made and delivered this _____ day of
_____________, 19___.

                                                     Name:
                                                     Title:


<PAGE>

                                   SCHEDULE I

                          COVENANT COMPLIANCE WORKSHEET

Based upon financial statements dated: _________________________, 19___


1.     TANGIBLE NET WORTH (ss.6.1)

       (A)    Net Worth                                                 $

less   (B)   Intangible Assets (including patents,                      $
             trademarks and trade names)

plus   (C)   Patents, Trademarks and Trade Names                        $
             (up to $2,000,000)

less   (D)   prepaid expenses                                           $

less   (E)   Affiliate obligations                                      $

less   (F)   loans to officers, stockholders

                   or employees                                         $

TANGIBLE NET WORTH (A - B - C - D - E)                                  $

Required TANGIBLE NET WORTH                                             $

                           COMPLIANCE

                         YES          NO

2.      EBITDA (ss.6.2) - Editek and diAGnostix

       (A)    net income                                                $

plus   (B)   to the extent included in the calculation of net           $
             income, income and franchise taxes paid or accrued

plus   (C)   to the extent included in the calculation of net           $
             income, Interest Expense, net of interest
             income, paid or accrued


<PAGE>


plus   (D)   to the extent included in the calculation of net           $
             income, amortization and depreciation

plus   (E)   to the extent included in the calculation of net           $
             income, other non-cash charges (excluding
             accruals for cash expenses made in the ordinary
             course of business)

less   (F)   to the extent included in the calculation of net           $
             income, the income of any Person in which
             a Borrower has an ownership interest unless such
             income is received by a Borrower in a cash distribution

less   (G)   to the extent included in the calculation of net           $
             income, gains or losses from sales or other dispositions
             of assets, other than gains or losses from sales
             or other dispositions of Inventories in the normal
             course of business

less   (H)   to the extent included in the calculation of net           $
             income, other extraordinary or non-recurring
             gains, but not net of extraordinary or
             non-recurring "cash" losses

EBITDA (A + B + C + D + E - F - G - H)                                  $

less   Registration Payments                                            $

=      EBITDA - Registration Payments                                   $

Required EBITDA - Registration Payments                                 $


                                COMPLIANCE

                             YES          NO

3.      EBITDA (ss.6.2) - PDLA

       (A)    net income                                                $

plus   (B)   to the extent included in the calculation of net           $

<PAGE>

             income, income and franchise taxes paid or accrued

plus   (C)   to the extent included in the calculation of net           $
             income, Interest Expense, net of interest
             income, paid or accrued

plus   (D)   to the extent included in the calculation of net           $
             income, amortization and depreciation

plus   (E)   to the extent included in the calculation of net           $
             income, other non-cash charges (excluding
             accruals for cash expenses made in the ordinary
             course of business)

less   (F)   to the extent included in the calculation of net           $
             income, the income of any Person in which
             a Borrower has an ownership interest unless such
             income is received by a Borrower in a cash distribution

less   (G)   to the extent included in the calculation of net           $
             income, gains or losses from sales or other dispositions
             of assets, other than gains or losses from sales
             or other dispositions of Inventories in the normal
             course of business

less   (H)   to the extent included in the calculation of net           $
             income, other extraordinary or non-recurring
             gains, but not net of extraordinary or
             non-recurring "cash" losses

EBITDA (A + B + C + D + E - F - G - H)                                  $

less   Registration Payments                                            $

=      EBITDA - Registration Payments                                   $

Required EBITDA - Registration Payments                                 $


                                 COMPLIANCE

                               YES          NO

<PAGE>


4.      EBITDA (ss.6.2) - Consolidated

       (A)    net income                                                $

plus   (B)   to the extent included in the calculation of net           $
             income, income and franchise taxes paid or accrued

plus   (C)   to the extent included in the calculation of net           $
             income, Interest Expense, net of interest
             income, paid or accrued

plus   (D)   to the extent included in the calculation of net           $
             income, amortization and depreciation

plus   (E)   to the extent included in the calculation of net           $
             income, other non-cash charges (excluding
             accruals for cash expenses made in the ordinary
             course of business)

less   (F)   to the extent included in the calculation of net           $      
             income, the income of any Person in which
             a Borrower has an ownership interest unless such
             income is received by a Borrower in a cash distribution

less   (G)   to the extent included in the calculation of net           $
             income, gains or losses from sales or other dispositions
             of assets, other than gains or losses from sales
             or other dispositions of Inventories in the normal
             course of business

less   (H)   to the extent included in the calculation of net           $
             income, other extraordinary or non-recurring
             gains, but not net of extraordinary or
             non-recurring "cash" losses

EBITDA (A + B + C + D + E - F - G - H)                                  $

less   Registration Payments                                            $

=      EBITDA - Registration Payments                                   $

Required EBITDA - Registration Payments                                 $

<PAGE>

                                COMPLIANCE

                              YES          NO

     5.    RATIO OF INDEBTEDNESS TO TANGIBLE NET WORTH (ss.6.3)

             (A) Indebtedness                                           $

             (B) Tangible Net Worth                                     $

INDEBTEDNESS TO TANGIBLE NET WORTH (A / B :1)

Required INDEBTEDNESS TO TANGIBLE NET WORTH

                           COMPLIANCE

                         YES          NO

     6.    CAPITAL EXPENDITURES (ss.6.5)

     Capital   Expenditures   (excluding   trade-ins   and   excluding   Capital
     Expenditures  in respect of  replacement  assets to the extent  funded with
     casualty insurance proceeds)

     for Fiscal Year ended _______________, 19___                       $


CAPITAL EXPENDITURE Limit:                                              $

                          COMPLIANCE

                       YES          NO

5.     FIXED CHARGE COVERAGE (ss.6.6)


       (A)    Sum of:

             (i)    EBITDA for Period                                   $

<PAGE>

       less  (ii)  Capital Expenditures                                 $

       less  (iii) Registration Payments                                $       

       =   Operating Cash Flow                                          $

       (B)    Fixed Charges for Period                                  $

FIXED CHARGE COVERAGE (A / B)

Required FIXED CHARGE COVERAGE

                         COMPLIANCE

                       YES          NO

5.     INTEREST COVERAGE (ss.6.7)

       (C)    Sum of:

             (i)    EBITDA for Period                                   $

       less  (ii)  Capital Expenditures                                 $

       less  (iii) Registration Payments                                $

       =   Operating Cash Flow                                          $

       (D)    Interest Expenses for Period                              $

INTEREST COVERAGE (A / B)

Required INTEREST COVERAGE

                              COMPLIANCE

                           YES          NO



                                         Schedule 1.1(A)

                                         Permitted Liens


Debtor              Secured Party                 Jurisdiction       Collateral
MedTox              Hewlett-Packard               Minnesota          See item 1
MedTox              Hewlett-Packard               Minnesota          See item 2
MedTox              Hewlett-Packard               Minnesota          See item 3
MedTox              Hewlett-Packard               Minnesota          See item 6
MedTox              SYVA Co.                      Minnesota          See item 7
MedTox              SYVA Co.                      Minnesota          See item 8
MedTox              Hewlett-Packard               Minnesota          See item 9
Psychiatric         First Wisconsin National      New Jersey         See item 12
Diagnostic          Bank of Milwaukee
Laboratories        First Wisconsin National      New Jersey         See item 13
Princeton           Bank of Milwaukee
Diagnostic
Laboratories
Editek              Graybar Financial Services    Alamance           See item 14
                                                  County      
Psychiatric         SYVA Co.                      New Jersey         See item 20
Diagnostic Lab
Psychiatric         SYVA Co.                      New Jersey         See item 21
Diagnostic Lab
Editek              Graybar Financial Services    North Carolina     See item 26


<PAGE>

                                         Schedule 1.1(B)

                                            Pro Forma


               Attached is a copy of the unaudited consolidated balance sheet
               of Borrowers after giving effect to the MedTox Acquisition.


<PAGE>


                                         Schedule 3.1(A)

                                    List of Closing Documents


<PAGE>
                                         Schedule 4.1(B)


I.     Capitalization of Borrowers and Affiliates


A.     Editek, Inc.

       The authorized capital stock of Editek, Inc. consists of
       31,000,000 shares of which 30,000,000 are designated common
       stock, $0.15 par value and 1,000,000 are designated preferred
       stock, $1.00 par value.  As of the Closing, 10,440,083 shares of
       common stock and 240 shares of preferred stock are outstanding.


B.     diAGnostix, Inc.

       The authorized capital stock of diAGnostix, Inc. consists of
       7,500,000 shares of common stock, $0.01 par value, of which 1,000
       shares are issued and outstanding and are owned by Editek, Inc.


C.     Princeton Diagnostic Laboratories of America, Inc.

       The authorized capital stock of Princeton Diagnostic Laboratories
       of America, Inc. consists of 7,500,000 shares of common stock,
       $0.01 par value, of which 500 shares are issued and outstanding
       and are owned by Editek, Inc.


D.     Psychiatric Diagnostic Laboratories of America, Inc.

       The authorized capital stock of Psychiatric Diagnostic
       Laboratories of America, Inc. consists of 256,000 shares of which
       250,000 shares are designated common stock, $0.004 par value and
       6,000 shares are designated preferred stock, no par value.  As of
       the closing, 500 shares of common stock are issued and
       outstanding and are owned by Princeton Diagnostic Laboratories of
       America, Inc.  No shares of preferred stock are outstanding.


E.     National Consortium For A Drug-Free Workplace, Inc.

       The authorized capital stock of National Consortium For A
       Drug-Free Workplace, Inc. consists of 100 shares of common stock,
       $0.01 par value, of which 50 shares are issued and outstanding
       and are owned by Princeton Diagnostics Laboratories of America,
       Inc.

<PAGE>
II.    Outstanding Conversion Rights, Options, Warrants for Purchase of
       Capital Stock of Borrowers and Affiliates

A.     EDITEK, Inc.

       Outstanding options to purchase an aggregate of 449,406 shares of
       Common Stock pursuant to awards under the EDITEK, Inc. 1983
       Incentive Stock Option Plan.

       Outstanding options to purchase an aggregate of 47,864 shares of
       Common Stock pursuant to awards under the EDITEK, Inc. Amended
       and Restated Stock Option Plan for Non-Employee Directors.

       Outstanding option to purchase 7,760 shares of Common Stock
       pursuant to Stock Option Agreement dated January 14, 1993 between
       EDITEK, Inc. and Mark D. Dibner.

       Outstanding subscriptions to purchase an aggregate of 5,446
       shares of Common Stock pursuant to awards under the EDITEK, Inc.
       Qualified Employee Stock Purchase Plan.

       Outstanding options to purchase an aggregate of 33,333 shares of
       Common Stock pursuant to nonqualified stock option agreements
       between EDITEK, Inc. and James D. Skinner.

       Outstanding options to purchase an aggregate of 721,289 shares of
       Common Stock pursuant to awards under the EDITEK, Inc. Amended
       and Restated Equity Compensation Plan.

       Stock Purchase Warrants to purchase an aggregate of 473,229
       shares of Common Stock.

B.     diAGnostix, Inc.

       None.

C.     Princeton Diagnostic Laboratories of America, Inc.

       None.

D.     Psychiatric Diagnostic Laboratories of America, Inc.

       None.

E.     National Consortium For A Drug-Free Workplace, Inc.

       None.

<PAGE>
                                          Schedule 4.6


                            Trade Names (Present and Past Five Years)


                                              NONE

<PAGE>

                                          Schedule 4.7

                         Location of Principal Place of Business, Books
                                   and Records and Collateral


A.     Editek, Inc.

       Corporate headquarters, research and development, operations and
       administrative functions are located in the NOVA building at 1238
       Anthony Road, Burlington, North Carolina 27215.

       Editek also leases laboratory space and land for its Granite Hall
       Laboratory Animal Facility in Warrenton, North Carolina.  The
       address for the facility is Route 1, Box 110-S, Warrenton, North
       Carolina 27589.

B.     Princeton Diagnostic Laboratories of America, Inc.

       Corporate headquarters are located at the NOVA building at 1238
       Anthony Road, Burlington, North Carolina 27215.

C.     Psychiatric Diagnostic Laboratories of America, Inc.

       Laboratory testing facility including administrative functions
       are located at 100 Corporate Court, South Plainfield, New Jersey
       07080.

       The leases assumed by Psychiatric Diagnostic Laboratories of
       America, Inc., pursuant to the MedTox acquisition are as follows:

       Location                                         Description

       402 West County Road D                     Primary laboratory location
       St. Paul, Minnesota  55112                 and administrative
                                                  offices

       8600 West Catalpa Avenue                   Facility empty
       Chicago, Illinois  60656

       109 West Dudleytown Road                   Service center, local client
       Bloomfield, Connecticut  06002             service and courier service

       6160 Variel Avenue                         Subleased premises to
       Woodland Hills, California  91367          TOXWORX Laboratories

<PAGE>
                                          Schedule 4.7
                                           (continued)



D.     diAGnostix, Inc.

       Warehouse and administrative functions located at 5730 Coopers
       Avenue, Unit #27, Mississauga, Ontario Canada L4Z 2E9.


E.     National Consortium For A Drug-Free Workplace, Inc.

       Administrative facilities located at 100 Corporate Court, South
       Plainfield, New Jersey 07080.

<PAGE>


                                          Schedule 4.13

                                      Intellectual Property


A.     The following patents are owned by Editek.  The other Borrowers
do not own any patents.

                                                  Patent
Jurisdiction    Patent Name                       Number      Issue Date

U.S.          Rapid Radioimmunoassay              4,399,229    08/16/83
              Product and Method of Making
              and Using Same
U.S.          Rotary Fluid Manipulator            4,938,927    07/03/90
U.S.          Rotary Fluid Manipulator            5,141,875    08/25/92
U.S.          Test Kit For Determining The        4,900,663    02/13/90
              Presence of Organic Materials
              and Method of Utilizing Same
U.S.          Test Kit For Determining The        5,240,844    08/31/93
              Presence of Organic Materials
              and Method of Utilizing Same
U.S.          Suspension Liquid Separator         4,696,797    09/29/87
U.S.          Multi-Layered Test Card For         5,202,268    04/13/93
              The Determination of Substances
              In Liquids
U.S.          Devise For Analysis For             5,435,970    07/25/95
              Constituents In Biological Fluids
U.S.          Animal Cage and Method              4,593,650    06/10/86
U.S.          Method For Preserving Plated        4,709,819    12/01/87
              Media and Products
Australia     Test Kit - Original                   594,942    09/13/85
Australia     Test Kit - Bi-Directional Flow        608,956    03/14/88
              Continuation
Australia     Suspension Liquid Separator           586,849    04/15/85
Belgium       Test Kit - Original                   904,484    03/25/86

<PAGE>


                                                   Patent
Jurisdiction     Patent Name                       Number      Issue Date
Belgium          Test Kit - Bi-Directional Flow    0 333 286   03/13/89
                 Continuation
Belgium          Suspension Liquid Separator       Pending     Pending
Canada           Test Kit - Original               1,258,626   08/22/89
Canada           Test Kit - Bi-Directional Flow    Pending     Pending
                 Continuation
Canada           Suspension Liquid Separator       1,271,709   07/17/90
Canada           Multi-Layered Test Card           Pending     Pending
France           Test Kit - Original               2,587,488   04/03/86
France           Test Kit - Bi-Directional Flow    0 333 286   03/13/89
                 Continuation
France           Suspension Liquid Separator       904,484     03/25/86
France           Multi-Layered Test Card           Pending     Pending
Germany          Test Kit - Original               3,606,124   02/26/86
Germany          Test Kit - Bi-Directional Flow    689 19 103  03/13/89
                 Continuation
Germany          Suspension Liquid Separator       Pending     Pending
Germany          Multi-Layered Test Card           Pending     Pending
G. Britain       Test Kit - Original               2,180,645   12/28/89
G. Britain       Test Kit - Bi-Directional Flow    0 333 286   03/13/89
                 Continuation
G. Britain       Suspension Liquid Separator       2,181,662   06/21/89
G. Britain       Multi-Layered Test Card           Pending     Pending
Holland          Test Kit - Original               Pending     Pending
Holland          Test Kit - Bi-Directional Flow    0 333 286   03/13/89
                 Continuation
Holland          Suspension Liquid Separator       Pending     Pending
Holland          Multi-Layered Test Card           Pending     Pending
Italy            Test Kit - Original               1,190,191   02/16/88

<PAGE>
                                                   Patent
Jurisdiction       Patent Name                     Number      Issue Date
Italy            Test Kit - Bi-Directional Flow    0 333 286   03/13/89
                 Continuation
Italy            Suspension Liquid Separator       1,190,204   02/16/88
Italy            Multi-Layered Test Card           Pending     Pending
Japan            Test Kit - Original               Pending     Pending
Japan            Test Kit - Bi-Directional Flow    Pending     Pending
                 Continuation
Japan            Suspension Liquid Separator       1916522     03/23/95
Japan            Multi-Layered Test Card           Pending     Pending
Sweden           Test Kit - Original               86,004,546  04/08/93
Sweden           Test Kit - Bi-Directional Flow    0 333 286   03/13/89
                 Continuation
Sweden           Suspension Liquid Separator       86,000,197  04/15/85
Sweden           Multi-Layered Test Card           Pending     Pending
Switzerland      Test Kit - Original               671,467     02/27/86
Switzerland      Test Kit - Bi-Directional Flow    0 333 286   03/13/89
                 Continuation
Switzerland      Suspension Liquid Separator       671,343     02/15/86
Luxembourg       Multi-Layered Test Card           Pending     Pending


<PAGE>

                                          Schedule 4.13
                                           (continued)



B.     The following trademarks are owned by Editek:


Trade Mark             Registration Number            Registration Date
EDITEK                     1,879,044                       02/14/95
BIOMAN                       363,506                       11/10/89
LOGO                       1,374,423                       12/10/85
QUIK-CARD                  1,387,168                       03/25/86
EZ-SCREEN                  1,412,788                       10/14/86
DAIRISCREEN                1,629,710                       01/01/91
DAIRYSCREEN                1,629,709                       01/01/91
VERDICT                    1,771,281                       05/18/93
PREDICT                    1,877,141                       01/31/95
RECON                      1,847,306                       07/26/94
EZ-QUANT                   1,917,508                       09/12/95

B.     The following trademarks are owned by Princeton.

Trade Mark             Registration Number            Registration Date
PDLA                       1,477,191                       02/16/88

C.     The following trademarks are owned by PDLA.  The other Borrowers
       do not own any trademarks.

Trade Mark             Registration Number            Registration Date
MEDTOX                     1,542,034                      05/30/89

<PAGE>
                                          Schedule 4.14

                                          Broker's Fees


Pursuant to the issuance of the Convertible Preferred Stock, Shoreline
Pacific, The Institutional Division of Financial West Group, will be
paid 6% of the gross proceeds in cash and will be issued warrants to
purchase shares of common stock of Editek, Inc., having a fair market
value and aggregate exercise price equal to 8% of the gross proceeds.

Interstate Johnson Lane will be paid a commission of $122,000 at the closing.



<PAGE>

                                          Schedule 4.20

                                          Bank Accounts



Psychiatric Diagnostic Laboratories of America, Inc.

First Fidelity - New Jersey

Account Number:  508-006533-1 (operating account)
Account Number:  508-005627-1 (payroll account)
Account Number:  3000397418 (blocked account)

Norwest - M.N.

Account Number:  3973656691 (operating account)
Account Number:  3973656552 (payroll account)
Account Number:  3973656616 (blocked account)


Editek, Inc.

First Union National Bank of N.C.

Account Number:       2000000009889 (payroll account)
Account Number:       2000000009892 (operating account)
Account Number:       2000000706674 (money market account)
Account Number:       2000000706645 (flexible benefits account)
Account Number:       2000000034825 (401(k) account)
Account Number:       2000000734905 (blocked account)


diAGnostix, Inc.

The Toronto-Dominion Bank

Account Number:       0566 7302749 (operating account)
Account Number:       0566 0314541 (payroll account)



Princeton Diagnostic Laboratories of America, Inc. and National
Consortium For A Drug- Free Workplace, Inc. do not have any bank
accounts.

<PAGE>
                                          Schedule 4.21

                                          Subsidiaries



Editek, Inc. owns all of the issued and outstanding stock of: (i)
Princeton Diagnostic Laboratories of America, Inc., a Delaware
corporation; and (ii) diAGnostix, Inc., a Delaware corporation.

Princeton Diagnostic Laboratories of America, Inc., in turn, owns all of
the issued and outstanding stock of: (i) Psychiatric Diagnostic
Laboratories of America, Inc., a Delaware corporation; and (ii) National
Consortium For A Drug-Free Workplace, Inc., a Delaware corporation.
National Consortium For A Drug-Free Workplace, Inc. has no assets.

<PAGE>
                                          Schedule 4.22

                                        Employee Matters

A.     Employment and Other Contracts

       1.      Editek, Inc.

               a.     Employment Agreement with James Skinner, dated on
                      or about January 25, 1996;

               b.     Employment Agreement with Peter Heath, dated on or
                      about January 25, 1996;

               c.     Employment Agreement with Michael Terretti, dated
                      on or about January 25, 1996; and

               d.     Severance Agreement with James S. Arrington, dated
                      on or about January 25, 1996.


       2.      Princeton Diagnostic Laboratories of America, Inc.

               NONE


       3.      Psychiatric Diagnostic Laboratories of America, Inc.

               a.     Letter dated February 15, 1995 regarding the
                      employment of Dr. Lawrence J. Felice;

               b.     Employment Agreement with Harry G. McCoy, dated on
                      or about January 25, 1996;

               c.     Employment Agreement with D. Gary Hemphill, dated
                      on or about January 25, 1996;

               d.     Employment Agreement with Jennifer S. Collins,
                      dated on or about January 25, 1996;

               e.     Employment Agreement with Jacquelyn L. Heytens,
                      dated January 25, 1996;

               f.     Employment Agreement with Susan E. Puskas, dated
                      on or about January 25, 1996;

               g.     Employment Agreement with Barbara S. Mayer, dated
                      on or about January 25, 1996; and
 <PAGE>

                                          Schedule 4.22
                                           (continued)

               h.     Employment Agreement with Gregory A. Lowery, dated
                      on or about January 25, 1996.


       4.      diAGnostix, Inc.

               NONE


       5.      National Consortium For A Drug-Free Workplace, Inc.

               NONE
<PAGE>

                                          Schedule 7.1

                                      Existing Indebtedness

<TABLE>
<CAPTION>

<S>                                                     <C>
Editek, Inc.

North Carolina Biotechnology                              $ 62,834.75
Center (NCBC) Promissory Note
due August 15, 1996

Novamann International, Final                               14,497.85
payment due for purchase of
Bioman Products, Inc.

Dr. Samuel C. Powell, 90 Day                               100,000.00
Note due March 17, 1996
(Unsecured loan made by Dr.
Powell to provide operating funds
prior to recently completed private
placement)

First Union National Bank of NC,                            15,700.00    (est)
Promissory Note secured by
1996 Ford Pickup Truck, Serial #
1FTEF15Y3TLA11649
                                                          $193,032.60



Psychiatric Diagnostic Laboratories of America, Inc.

Norwest Loan #031597                                      $407,853.27 (to be paid at 1/29/96 closing)
Norwest Loan #033095                                       437,463.95 (to be paid at 1/29/96 closing)
Norwest Equipment Loans                                    368,906.20 (to be paid at 1/29/96 closing)

                                                        $1,214,223.42
                                                           __________

                                                        $1,407,256.02

<PAGE>

                                          Schedule 7.1
                                           (continued)



Princeton Diagnostic Laboratories of America, Inc.

NONE

diAGnostix, Inc.

NONE

National Consortium For A Drug Free Work Place, Inc.

NONE







</TABLE>

<PAGE>
                                   TERM NOTE A

$2,000,000                                                     January ___, 1996


         FOR VALUE RECEIVED, undersigned,  EDITEK, INC., a Delaware corporation,
PSYCHIATRIC  DIAGNOSTIC  LABORATORIES OF AMERICA,  INC., a Delaware corporation,
and DIAGNOSTIX, a Delaware corporation (collectively,  the "Borrowers"),  hereby
unconditionally  jointly  and  severally  promise  to pay to the order of HELLER
FINANCIAL,  INC., a Delaware corporation (the "Lender"),  at the Lender's office
located at 500 West Monroe Street,  Chicago,  Illinois  60661,  or at such other
place as the holder of this Note may from time to time designate in writing,  in
lawful money of the United States of America and in immediately available funds,
the principal sum of TWO MILLION DOLLARS  ($2,000,000),  payable in installments
on the dates and in the  amounts  set forth in that  certain  Loan and  Security
Agreement of even date herewith, between the Borrowers and the Lender (the "Loan
Agreement"; capitalized terms used herein and not otherwise specifically defined
herein shall have the meanings assigned to them in the Loan Agreement).

         This Note is a Term Note referred to in  subsection  2.1(E) of the Loan
Agreement and is issued to evidence the Term Loan A made to the Borrowers by the
Lender pursuant to the provisions of the Loan  Agreement,  to which reference is
hereby made for a statement of the terms,  conditions and covenants  under which
the loan  evidenced  hereby  was made and is to be  repaid,  including,  but not
limited to, those  related to the mandatory  prepayment of the principal  hereof
and the acceleration of the indebtedness  represented hereby upon the occurrence
of an Event of Default or upon the  termination  of the  financing of which this
Note is part  pursuant to the Loan  Agreement.  Payment of this Note is secured,
inter alia, by the Collateral.

         The  Borrowers  jointly and  severally  promise to pay  interest on the
outstanding  unpaid  principal  amount  hereof  at the rate and on the dates set
forth in the Loan  Agreement.  Interest shall be computed on the daily principal
balance on the basis of a 360-day year for the actual  number of days elapsed in
the period during which it accrues.

         In no contingency or event whatsoever shall interest charged hereunder,
however such interest may be characterized or computed,  exceed the highest rate
permissible  under any law which a court of competent  jurisdiction  shall, in a
final  determination,  deem  applicable  hereto.  In the event that such a court
determines  that the Lender has  received  interest  hereunder  in excess of the
highest rate applicable  hereto,  the provisions of the Loan Agreement  relating
thereto shall control.

         The Borrowers  hereby waive  demand,  presentment,  protest,  notice of
demand,  dishonor,  presentment,  protest,  nonpayment  and all other notices in
connection with this Note.

<PAGE>

         If this Note is collected by or through an  attorney-at-law,  all costs
of collection,  including  reasonable  attorneys'  fees, shall be payable by the
undersigned.



         THIS NOTE HAS BEEN  DELIVERED  AT AND SHALL BE DEEMED TO HAVE BEEN MADE
AT CHICAGO, ILLINOIS, AND SHALL BE INTERPRETED AND THE RIGHTS AND LIABILITIES OF
THE PARTIES HERETO  DETERMINED IN ACCORDANCE  WITH THE INTERNAL LAWS (AS OPPOSED
TO CONFLICTS OF LAW PROVISIONS) AND DECISIONS OF THE STATE OF ILLINOIS. Whenever
possible each  provision of this Note shall be  interpreted in such manner as to
be effective and valid under  applicable  law, but if any provision of this Note
shall be prohibited by or invalid under  applicable law, such provision shall be
ineffective  to  the  extent  of  such   prohibition   or  invalidity,   without
invalidating the remainder of such provision or the remaining provisions of this
Note.  Whenever in this Note  reference is made to the Lender or the  Borrowers,
such reference shall be deemed to include,  as applicable,  a reference to their
respective  successors and assigns. The provisions of this Note shall be binding
upon  and  shall  inure to the  benefit  of such  successors  and  assigns.  The
Borrowers' successors and assigns shall include, without limitation, a receiver,
trustee or debtor in possession of or for the Borrowers.

                      [Signatures appear on following page]


<PAGE>


         WITNESS  the  hand and seal of the  undersigned,  as of the date  first
above written.

                                               EDITEK, INC.

                                               By:

                                               Title:

                                               Attest:

                                               Title:

                                                     [CORPORATE SEAL]

                                               PSYCHIATRIC DIAGNOSTIC 
                                               LABORATORIES OF AMERICA, INC.

                                               By:

                                               Title:

                                               Attest:

                                               Title:

                                                     [CORPORATE SEAL]

                                               DIAGNOSTIX, INC.

                                               By:

                                               Title:

                                               Attest:

                                               Title:

                                                     [CORPORATE SEAL]


<PAGE>
                                   TERM NOTE B

$2,000,000                                                     January ___, 1996


         FOR VALUE RECEIVED, undersigned,  EDITEK, INC., a Delaware corporation,
PSYCHIATRIC  DIAGNOSTIC  LABORATORIES OF AMERICA,  INC., a Delaware corporation,
and DIAGNOSTIX, a Delaware corporation (collectively,  the "Borrowers"),  hereby
unconditionally  jointly  and  severally  promise  to pay to the order of HELLER
FINANCIAL,  INC., a Delaware corporation (the "Lender"),  at the Lender's office
located at 500 West Monroe Street,  Chicago,  Illinois  60661,  or at such other
place as the holder of this Note may from time to time designate in writing,  in
lawful money of the United States of America and in immediately available funds,
the principal sum of TWO MILLION DOLLARS  ($2,000,000),  payable in installments
on the dates and in the  amounts  set forth in that  certain  Loan and  Security
Agreement of even date herewith, between the Borrowers and the Lender (the "Loan
Agreement"; capitalized terms used herein and not otherwise specifically defined
herein shall have the meanings assigned to them in the Loan Agreement).

         This Note is a Term Note referred to in  subsection  2.1(E) of the Loan
Agreement and is issued to evidence the Term Loan B made to the Borrowers by the
Lender pursuant to the provisions of the Loan  Agreement,  to which reference is
hereby made for a statement of the terms,  conditions and covenants  under which
the loan  evidenced  hereby  was made and is to be  repaid,  including,  but not
limited to, those  related to the mandatory  prepayment of the principal  hereof
and the acceleration of the indebtedness  represented hereby upon the occurrence
of an Event of Default or upon the  termination  of the  financing of which this
Note is part  pursuant to the Loan  Agreement.  Payment of this Note is secured,
inter alia, by the Collateral.

         The  Borrowers  jointly and  severally  promise to pay  interest on the
outstanding  unpaid  principal  amount  hereof  at the rate and on the dates set
forth in the Loan  Agreement.  Interest shall be computed on the daily principal
balance on the basis of a 360-day year for the actual  number of days elapsed in
the period during which it accrues.

         In no contingency or event whatsoever shall interest charged hereunder,
however such interest may be characterized or computed,  exceed the highest rate
permissible  under any law which a court of competent  jurisdiction  shall, in a
final  determination,  deem  applicable  hereto.  In the event that such a court
determines  that the Lender has  received  interest  hereunder  in excess of the
highest rate applicable  hereto,  the provisions of the Loan Agreement  relating
thereto shall control.

         The Borrowers  hereby waive  demand,  presentment,  protest,  notice of
demand,  dishonor,  presentment,  protest,  nonpayment  and all other notices in
connection with this Note.

<PAGE>

         If this Note is collected by or through an  attorney-at-law,  all costs
of collection,  including  reasonable  attorneys'  fees, shall be payable by the
undersigned.

         THIS NOTE HAS BEEN  DELIVERED  AT AND SHALL BE DEEMED TO HAVE BEEN MADE
AT CHICAGO, ILLINOIS, AND SHALL BE INTERPRETED AND THE RIGHTS AND LIABILITIES OF
THE PARTIES HERETO  DETERMINED IN ACCORDANCE  WITH THE INTERNAL LAWS (AS OPPOSED
TO CONFLICTS OF LAW PROVISIONS) AND DECISIONS OF THE STATE OF ILLINOIS. Whenever
possible each  provision of this Note shall be  interpreted in such manner as to
be effective and valid under  applicable  law, but if any provision of this Note
shall be prohibited by or invalid under  applicable law, such provision shall be
ineffective  to  the  extent  of  such   prohibition   or  invalidity,   without
invalidating the remainder of such provision or the remaining provisions of this
Note.  Whenever in this Note  reference is made to the Lender or the  Borrowers,
such reference shall be deemed to include,  as applicable,  a reference to their
respective  successors and assigns. The provisions of this Note shall be binding
upon  and  shall  inure to the  benefit  of such  successors  and  assigns.  The
Borrowers' successors and assigns shall include, without limitation, a receiver,
trustee or debtor in possession of or for the Borrowers.

                      [Signatures appear on following page]


<PAGE>

         WITNESS  the  hand and seal of the  undersigned,  as of the date  first
above written.

                                                  EDITEK, INC. 

                                                  By:

                                                  Title:

                                                  Attest:

                                                  Title:

                                                        [CORPORATE SEAL]

                                                  PSYCHIATRIC DIAGNOSTIC 
                                                  LABORATORIES OF AMERICA, INC.

                                                  By:

                                                  Title:

                                                  Attest:

                                                  Title:

                                                        [CORPORATE SEAL]

                                                  DIAGNOSTIX, INC.

                                                  By:

                                                  Title:

                                                  Attest:

                                                  Title:

                                                        [CORPORATE SEAL]



                             ASSIGNMENT FOR SECURITY
                                    (Patents)


STATE OF GEORGIA           )
                           )  ss.:
COUNTY OF FULTON           )


                  WHEREAS,   EDITEK,   INC.,   a   Delaware   corporation   (the
"Assignor"),  holds  Letters  Patent of the United States and  applications  for
Letters Patent of the United States as set forth on Exhibit A (collectively, the
"Patents"), and

                  WHEREAS,  the Assignor is the sole owner of the entire  right,
title  and  interest  in and to the  Patents  and the  inventions  which are the
subject matter thereof, and

                  WHEREAS,  Assignor  has  entered  into that  certain  Loan and
Security  Agreement,  dated of even date (as amended,  supplemented  or restated
from time to time,  the "Loan  Agreement"),  between  Assignor,  certain  of its
affiliates and HELLER FINANCIAL,  INC., a Delaware corporation  ("Lender"),  and
Lender  has, on the date  hereof,  made  certain  loans to or for the benefit of
Assignor and may make additional loans to or for the benefit of Assignor, and

                  WHEREAS,  pursuant  to the Loan  Agreement  and as a condition
precedent to the extension of the financial accommodations to or for the benefit
of the Assignor under the Loan  Agreement,  the Assignor has agreed to assign to
Lender  and to  grant  to  Lender  a  continuing  security  interest  in,  and a
continuing  lien on, all of the Assignor's  right,  title and interest in and to
the following (collectively the "Patent Collateral"),

                  (a)  the Patents, together with any reissue, continuation,
         continuation-in-part  or extension of any thereof, along  with all 
         rights,  benefits and privileges derived therefrom,

                  (b)  the inventions which are the subject matter thereof, and

                  (c)  all proceeds thereof, including, but not limited to, any
         claims and demands  arising  out of any  infringement  of the  Patents,
         including  the right to settle  disputes  concerning  such  claims  and
         demands.

                  NOW,  THEREFORE,  in order to induce Lender to consummate  the
financial accommodations to the Assignor provided for in the Loan Agreement, and
for other good and valuable consideration,  receipt and sufficiency of which are
hereby  acknowledged,  the  Assignor  does hereby  assign to Lender and grant to
Lender a continuing  security  interest in and a continuing

<PAGE>

lien on, the entire right,  title and  interest  of Assignor  in and to the
Patent  Collateral.  The Patent  Collateral shall serve as collateral  security
to Lender for the payment and  performance  of the  Obligations  (as  such  term
is  defined  in the  Loan Agreement)  and  shall  constitute  a part of the
Collateral  (as such  term is defined  in the Loan  Agreement),  and shall be
subject to all of the terms and conditions of the Loan Agreement, which is
incorporated herein by reference.

                  Unless and until said lien and security interest is foreclosed
upon, Assignor (i) shall be deemed and is hereby licensed to remain in exclusive
and undisturbed  possession of the Patents,  (ii) shall  exclusively  retain all
rights to make, use, and sell the inventions claimed in the Patents,  to license
others under the Patents,  but only in a manner consistent with the preservation
of their current  substance,  validity,  registration and the security  interest
granted herein, and (iii) may bring suit for the infringement of the Patents and
to  retain  the  proceeds  of the  foregoing.  Lender  need not be  joined  as a
plaintiff in any such infringement suit; provided,  that should it be necessary,
in Lender's sole judgment,  that Lender be joined as an  indispensable  party or
true party in interest  in any such  infringement  suit,  Lender  shall,  at its
option, either

                  (1) appoint  Assignor  its attorney in fact for the purpose of
         prosecuting  such  infringement  suit  on the  express  condition  that
         Assignor  indemnify and hold Lender harmless for any liability incurred
         by Lender as a result of such appointment, or

                  (2) participate actively in the prosecution of such suit.

                  Assignor  further  agrees  (i)  that  while  a  secured  party
hereunder,  Lender  shall have no  obligation  or  responsibility  to protect or
defend the Patent  Collateral  and  Assignor  shall at its own expense  protect,
defend  and  maintain  the  same  to the  extent  reasonably  advisable  for its
business,  (ii) to use its best efforts to detect any  infringers  of the Patent
Collateral, to forthwith advise Lender in writing of infringements detected, and
protect,  defend and maintain the Patent Collateral  against any  infringements,
(iii) that if Assignor fails to comply with the foregoing  clauses (i) and (ii),
Lender  may do so in  Assignor's  name or in  Lender's  name  but at  Assignor's
expense,  and  Assignor  hereby  agrees to  reimburse  Lender for all  expenses,
including  reasonable   attorneys'  fees,  incurred  by  Lender  in  protecting,
defending and maintaining the Patent  Collateral owned by Assignor,  and (iv) to
use the Patents only in its businesses as they are presently conducted.

                  The  security  interest  in  the  Patent  Collateral   granted
hereunder  shall  remain  in full  force  and  effect  until  the  later  of the
termination  of the Loan Agreement and the payment and  satisfaction  in full of
the Obligations. At any time thereafter, Lender shall, if requested by Assignor,
execute  and  deliver  to  Assignor,   or  to  a  third  party  upon  Assignor's
instructions,  for filing with the United States Patent and Trademark Office and
in each  office  in which  any  financing  statement  relative  to the  security
interest  granted hereby may have been filed,  (i)  documentation  in accordance
with the rules and regulations of said office, (ii) termination statements under
the  Uniform  Commercial  Code and  (iii)  any  other  documentation  reasonably
requested by Assignor,  all as may be necessary to release Lender's  interest in
the Patent Collateral, and all at the cost and expense of Assignor.

                                     -2-

<PAGE>

                  IN WITNESS WHEREOF, the Assignor has caused this Assignment to
be duly executed by its authorized officer or agent as of January ___, 1996.


                                                 EDITEK, INC.



                                                 By:

                                                 Title:

                                                 Attest:

                                                 Title:


                                                           [CORPORATE SEAL]



STATE OF GEORGIA  )
                  )  ss.:
COUNTY OF FULTON  )


                  On this ___ day of January,  1996,  before me personally  came
___________________  and  _____________________,  to me known,  who, being by me
duly   sworn,   did   depose   and  say  that   they  are,   respectively,   the
____________________and  _____________________  of EDITEK, INC., the corporation
described herein and which executed the foregoing instrument; that they know the
seal of said  corporation;  that the seal  affixed  to said  instrument  is such
corporate  seal;  that it was so affixed by order of the Board of  Directors  of
said corporation and that they signed thereto by like order.

                                               Sworn  to  and subscribed  before
                                               me this ___ day of January, 1996.


                                               Notary Public

                                                        [NOTARIAL SEAL]

                                               My Commission Expires:

                                       -3-

<PAGE>

                                    EXHIBIT A

<TABLE>
<CAPTION>

                                                                     Patent
                      Patent Name                                    Number                     Issue Date
<S>                                                                 <C>                          <C>
Rapid Radioimmunoassay Product and Method of Making and             4,399,229                    08/16/83
Using Same

Rotary Fluid Manipulator                                            4,938,927                    07/03/90

Rotary Fluid Manipulator                                            5,141,875                    08/25/92

Test Kit for Determining the Presence of Organic                    4,900,663                    02/13/90
Materials and Method of Utilizing Same

Test Kit for Determining the Presence of Organic                    5,240,844                    08/13/93
Materials and Method of Utilizing Same

Suspension Liquid Separator                                         4,696,797                    09/29/87

Multi-Layered Test Card for the Determination of                    5,202,268                    04/13/93
Substances in Liquids

Device for Analysis for Constituents in Biological Fluids           5,435,970                    07/25/90

Animal Cage and Method                                              4,593,650                    06/10/86
Method for Preserving Plated Media and Products                     4,709,819                    12/01/87

</TABLE>

                                 -4-

<PAGE>



<PAGE>
                             ASSIGNMENT FOR SECURITY

                                  (TRADEMARKS)

STATE OF GEORGIA  )

                  )  SS.:

COUNTY OF FULTON  )

                  WHEREAS,   EDITEK,   INC.,   a   Delaware   corporation   (the
"Assignor"), has adopted, used and is using marks which are either registered or
applied for in the United  States  Patent and  Trademark  Office as set forth on
Exhibit A (the "Trademarks"), and

                  WHEREAS,  the Assignor is the sole owner of the entire  right,
title  and  interest  in and to the  Trademarks  which  are  registered  and the
goodwill of the business  symbolized  by the  Trademarks  and the  registrations
thereof, and

                  WHEREAS,  Assignor  has  entered  into that  certain  Loan and
Security  Agreement,  dated of even date (as amended,  supplemented  or restated
from time to time,  the "Loan  Agreement"),  between  Assignor,  certain  of its
affiliates and HELLER FINANCIAL,  INC., a Delaware corporation  ("Lender"),  and
Lender  has, on the date  hereof,  made  certain  loans to or for the benefit of
Assignor and may make additional loans to or for the benefit of Assignor, and

                  WHEREAS,  pursuant  to the Loan  Agreement  and as a condition
precedent to the extension of the financial accommodations to or for the benefit
of the Assignor under the Loan  Agreement,  the Assignor has agreed to assign to
Lender  and to  grant  to  Lender  a  continuing  security  interest  in,  and a
continuing  lien on, all of the Assignor's  right,  title and interest in and to
the following (collectively the "Trademark Collateral"),

                  (a)  the Trademarks, together with all  rights,  benefits  and

         privileges  derived  therefrom,  and the goodwill   of   the   business
         symbolized  by the  Trademarks   and  the  registrations  thereof,  and

                  (b)  all proceeds thereof, including, but not limited to, any

         claims and demands  arising out of any  infringement of the Trademarks,
         including  the right to settle  disputes  concerning  such  claims  and
         demands.

                  NOW,  THEREFORE,  in order to induce Lender to consummate  the
financial accommodations to the Assignor provided for in the Loan Agreement, and
for other good and valuable consideration,  receipt and sufficiency of which are
hereby  acknowledged,  the  Assignor  does hereby  assign to Lender and grant to
Lender a continuing  security  interest in and a continuing  lien on, the entire
right,  title and interest of Assignor in and to the Trademark  Collateral.  

<PAGE>

The Trademark  Collateral  shall  serve as  collateral  security  to Lender  
for the payment and  performance of the  Obligations (as such term is defined 
in the Loan Agreement)and  shall constitute a part of the Collateral (as such 
term is defined in  the  Loan  Agreement), and  shall  be  subject to all of 
the terms and  conditions  of  the  Loan Agreement,  which is incorporated 
herein by reference.

                  Unless and until said lien and security interest is foreclosed
upon,  Assignor  (i) shall be deemed to  remain  in  exclusive  and  undisturbed
possession  of the  Trademarks,  (ii)  shall  exclusively  retain  all rights to
license others under the  Trademarks,  but only in a manner  consistent with the
preservation of their current substance, validity, registration and the security
interest  granted herein,  and (iii) may bring suit for the  infringement of the
Trademarks  and to retain the  proceeds  of the  foregoing.  Lender  need not be
joined as a plaintiff in any such infringement suit; provided, that should it be
necessary,  in Lender's sole judgment, that Lender be joined as an indispensable
party or true party in interest in any such infringement  suit, Lender shall, at
its option, either

                  (1) appoint  Assignor  its attorney in fact for the purpose of
         prosecuting  such  infringement  suit  on the  express  condition  that
         Assignor  indemnify and hold Lender harmless for any liability incurred
         by Lender as a result of such appointment, or

                  (2) participate actively in the prosecution of such suit.

                  Assignor  further  agrees  (i)  that  while  a  secured  party
hereunder,  Lender  shall have no  obligation  or  responsibility  to protect or
defend the Trademark  Collateral and Assignor shall at its own expense  protect,
defend  and  maintain  the  same  to the  extent  reasonably  advisable  for its
business, (ii) to use its best efforts to detect any infringers of the Trademark
Collateral, to forthwith advise Lender in writing of infringements detected, and
protect, defend and maintain the Trademark Collateral against any infringements,
(iii) that if Assignor fails to comply with the foregoing  clauses (i) and (ii),
Lender  may do so in  Assignor's  name or in  Lender's  name  but at  Assignor's
expense,  and  Assignor  hereby  agrees to  reimburse  Lender for all  expenses,
including  reasonable   attorneys'  fees,  incurred  by  Lender  in  protecting,
defending and maintaining the Trademark  Collateral owned by Assignor,  and (iv)
to use the Trademarks only in its businesses as they are presently conducted.

                  The  security  interest in the  Trademark  Collateral  granted
hereunder  shall  remain  in full  force  and  effect  until  the  later  of the
termination  of the Loan Agreement and the payment and  satisfaction  in full of
the Obligations.  At any time thereafter Lender shall, if requested by Assignor,
execute  and  deliver  to  Assignor,   or  to  a  third  party  upon  Assignor's
instructions,  for filing with the United States Patent and Trademark Office and
in each  office  in which  any  financing  statement  relative  to the  security
interest  granted hereby may have been filed,  (i)  documentation  in accordance
with the rules and regulations of said office, (ii) termination statements under
the  Uniform  Commercial  Code and  (iii)  any  other  documentation  reasonably
requested by Assignor,  all as may be necessary to release Lender's  interest in
the Trademark Collateral, and all at the cost and expense of Assignor.

                                           -2-


<PAGE>

                  IN WITNESS WHEREOF, the Assignor has caused this Assignment to
be duly executed by its authorized officer or agent as of January ___, 1996.

<PAGE>

                                                  EDITEK, INC.      

                                                  By:

                                                  Title:

                                                  Attest:

                                                  Title:

                                                         [CORPORATE SEAL]


STATE OF GEORGIA  )

                  )  ss.:

COUNTY OF FULTON  )

                  On this ___ day of January,  1996,  before me personally  came
___________________  and  _____________________,  to me known,  who, being by me
duly   sworn,   did   depose   and  say  that   they  are,   respectively,   the
____________________and  _____________________  of EDITEK, INC., the corporation
described herein and which executed the foregoing instrument; that they know the
seal of said  corporation;  that the seal  affixed  to said  instrument  is such
corporate  seal;  that it was so affixed by order of the Board of  Directors  of
said corporation and that they signed thereto by like order.

                                               Sworn to and subscribed before me
                                               this ___ day of January, 1996.

                                               Notary Public

                                                     [NOTARIAL SEAL]

                                    -3-
<PAGE>

                                               My Commission Expires:


                                      -4-

<PAGE>

                                    EXHIBIT A


       TRADEMARK          REGISTRATION NUMBER     REGISTRATION DATE

EDITEK                          1,879,044              02/14/95

BIOMAN                            363,506              11/10/89

LOGO                            1,374,423              12/10/85

QUIK-CARD                       1,387,168              03/25/86

EZ-SCREEN                       1,412,788              10/14/86

DAIRISCREEN                     1,629,710              01/01/91

DAIRYSCREEN                     1,629,709              01/01/91

VERDICT                         1,771,281              05/18/93

PREDICT                         1,877,141              01/31/95

RECON                           1,847,306              07/26/94

EZ-QUANT                        1,917,508              09/12/95


<PAGE>


<PAGE>
                             ASSIGNMENT FOR SECURITY

                                  (TRADEMARKS)

STATE OF GEORGIA  )

                  )  SS.:

COUNTY OF FULTON  )

                  WHEREAS, PRINCETON DIAGNOSTIC LABORATORIES OF AMERICA, INC., a
Delaware  corporation  (the  "Assignor"),  has adopted,  used and is using marks
which are either  registered  or applied  for in the  United  States  Patent and
Trademark Office as set forth on Exhibit A (the "Trademarks"), and

                  WHEREAS,  the Assignor is the sole owner of the entire  right,
title  and  interest  in and to the  Trademarks  which  are  registered  and the
goodwill of the business  symbolized  by the  Trademarks  and the  registrations
thereof, and

                  WHEREAS, Assignor has entered into that certain Guaranty dated
of even date (as  amended,  supplemented  or  restated  from  time to time,  the
"Guaranty")  in  favor  of  HELLER  FINANCIAL,   INC.,  a  Delaware  corporation
("Lender"), and

                  WHEREAS,  as a condition  precedent  to the  extension  of the
financial  accommodations  to or for the  benefit of certain  affiliates  of the
Assignor  pursuant  to the Loan  Agreement  (as  defined in the  Guaranty),  the
Assignor  has  agreed to assign  to Lender  and to grant to Lender a  continuing
security  interest in, and a continuing  lien on, all of the  Assignor's  right,
title  and  interest  in and  to  the  following  (collectively  the  "Trademark
Collateral"),

                  (a) the  Trademarks,  together  with all rights,  benefits and
         privileges  derived  therefrom,   and  the  goodwill  of  the  business
         symbolized by the Trademarks and the registrations thereof, and

                  (b) all proceeds thereof,  including,  but not limited to, any
         claims and demands  arising out of any  infringement of the Trademarks,
         including  the right to settle  disputes  concerning  such  claims  and
         demands.

                  NOW,  THEREFORE,  in order to induce Lender to consummate  the
financial  accommodations  to certain  affiliates of the Assignor as provided in
the Loan Agreement,  and for other good and valuable consideration,  receipt and
sufficiency of which are hereby acknowledged, the Assignor does hereby assign to
Lender and grant to Lender a  continuing  security  interest in and a continuing
lien on,  the  entire  right,  title  and  interest  of  Assignor  in and to the
Trademark  Collateral.  The  Trademark  Collateral  shall  serve  as  collateral
security to Lender for the payment 

<PAGE>

and  performance  of the  obligations  of the Assignor  under  the  Guaranty  
and  for  the  payment  and  performance  of the Obligations (as such term is 
defined in the Loan Agreement) and shall constitute a part of the  Collateral 
(as such term is defined in the Loan  Agreement),  and shall be subject to all 
of the terms and conditions of the Loan Agreement, which is incorporated 
herein by reference.

                  Unless and until said lien and security interest is foreclosed
upon,  Assignor  (i) shall be deemed to  remain  in  exclusive  and  undisturbed
possession  of the  Trademarks,  (ii)  shall  exclusively  retain  all rights to
license others under the  Trademarks,  but only in a manner  consistent with the
preservation of their current substance, validity, registration and the security
interest  granted herein,  and (iii) may bring suit for the  infringement of the
Trademarks  and to retain the  proceeds  of the  foregoing.  Lender  need not be
joined as a plaintiff in any such infringement suit; provided, that should it be
necessary,  in Lender's sole judgment, that Lender be joined as an indispensable
party or true party in interest in any such infringement  suit, Lender shall, at
its option, either

                  (1) appoint  Assignor  its attorney in fact for the purpose of
         prosecuting  such  infringement  suit  on the  express  condition  that
         Assignor  indemnify and hold Lender harmless for any liability incurred
         by Lender as a result of such appointment, or

                  (2) participate actively in the prosecution of such suit.

                  Assignor  further  agrees  (i)  that  while  a  secured  party
hereunder,  Lender  shall have no  obligation  or  responsibility  to protect or
defend the Trademark  Collateral and Assignor shall at its own expense  protect,
defend  and  maintain  the  same  to the  extent  reasonably  advisable  for its
business, (ii) to use its best efforts to detect any infringers of the Trademark
Collateral, to forthwith advise Lender in writing of infringements detected, and
protect, defend and maintain the Trademark Collateral against any infringements,
(iii) that if Assignor fails to comply with the foregoing  clauses (i) and (ii),
Lender  may do so in  Assignor's  name or in  Lender's  name  but at  Assignor's
expense,  and  Assignor  hereby  agrees to  reimburse  Lender for all  expenses,
including  reasonable   attorneys'  fees,  incurred  by  Lender  in  protecting,
defending and maintaining the Trademark  Collateral owned by Assignor,  and (iv)
to use the Trademarks only in its businesses as they are presently conducted.

                  The  security  interest in the  Trademark  Collateral  granted
hereunder  shall  remain  in full  force  and  effect  until  the  later  of the
termination  of the Loan Agreement and the payment and  satisfaction  in full of
the Obligations  and the obligations of the Assignor under the Guaranty.  At any
time thereafter  Lender shall, if requested by Assignor,  execute and deliver to
Assignor, or to a third party upon Assignor's instructions,  for filing with the
United  States  Patent  and  Trademark  Office  and in each  office in which any
financing  statement  relative to the security  interest granted hereby may have
been filed,  (i)  documentation  in accordance with the rules and regulations of
said office,  (ii) termination  statements under the Uniform Commercial Code and
(iii) any other documentation  reasonably  requested by Assignor,  all as may be
necessary to release Lender's interest in the Trademark  Collateral,  and all at
the cost and expense of Assignor.

                                  -2-

<PAGE>

                  IN WITNESS WHEREOF, the Assignor has caused this Assignment to
be duly executed by its authorized officer or agent as of January ___, 1996.

                                                  PRINCETON DIAGNOSTIC 
                                                  LABORATORIES OF AMERICA, INC.

                                                  By:

                                                  Title:

                                                  Attest:

                                                  Title:

                                                       [CORPORATE SEAL]



STATE OF GEORGIA  )

                  )  ss.:

COUNTY OF FULTON  )

                  On this ___ day of January,  1996,  before me personally  came
___________________  and  _____________________,  to me known,  who, being by me
duly   sworn,   did   depose   and  say  that   they  are,   respectively,   the
____________________and    _____________________    of   PRINCETON    DIAGNOSTIC
LABORATORIES  OF  AMERICA,  INC.,  the  corporation  described  herein and which
executed the foregoing instrument;  that they know the seal of said corporation;
that the seal affixed to said  instrument is such corporate seal; that it was so
affixed by order of the Board of  Directors  of said  corporation  and that they
signed thereto by like order.

                                               Sworn to and subscribed before me
                                               me this ___ day of January, 1996.

                                               Notary Public

                           -3-

<PAGE>

                                                       [NOTARIAL SEAL]

                                               My Commission Expires:

                           -4-

<PAGE>


                                    EXHIBIT A

     TRADEMARK        REGISTRATION NUMBER       REGISTRATION DATE

PDLA                       1,477,191                 02/16/88



                            AMENDMENT NO. 2 TO LEASE
                        DATED AS OF MARCH 5, 1992 BETWEEN
           MEDTOX LABORATORY, INC., A MINNESOTA CORPORATION ("TENANT")
                                       AND
                   PHOENIX HOME LIFE MUTUAL INSURANCE COMPANY,
                (FORMERLY PHOENIX MUTUAL LIFE INSURANCE COMPANY)
                       A NEW YORK CORPORATION ("LANDLORD")

         THIS AGREEMENT IS MADE AND ENTERED INTO this 27th day of June. 1994, by
and between Phoenix Home Life Mutual Insurance  Company  ("Landlord") and Medtox
Laboratories,  Inc.,  a  Minnesota  Corporation  ("Tenant")  for the  purpose of
amending that certain  Lease  Agreement  ("the Lease")  entered into between the
Landlord and Tenant on March 5, 1992,  covering the premises  presently occupied
by Tenant at 402 West County Road D, New Brighton, Minnesota.

         WHEREAS,  Landlord  and Tenant  amended said Lease  (Amendment  No. 1 -
March 12,  1993),  expanding  the  premises  by 9,989  square feet to a total of
37,630 square feet.

         WHEREAS,  Landlord  and Tenant  hereby  agree  that the lease  shall be
further amended as follows:

1. Article 1: Description of Premises. The Leased Premises shall remain at Suite
402,  County Road D and 35W, New  Brighton,  Minnesota,  but the square  footage
shall be  increased  by 3,387 square feet by adding Suite 382 (shown on attached
Exhibit) for a total amended  square footage of 41,017 square feet. The Premises
now includes Suites 108, 410, 412, 414 and 382 as shown on the attached Exhibit.

2. Article 2: Term and Base Rent.  Effective  October 1, 1994,  Tenant agrees to
pay a Base Rent during the  remainder of the term of the Lease on the  following
rent schedule:
                             Months       Monthly Base Rent

                       10/1/94 - 3/31/97     $27,501.43

3.  Additional  Rent.  Effective  October 1, 1994, the Additional  Rent shall be
calculated on 41,017 square feet.

     4. Tenant Improvement Allowance. None; Tenant accepts Premises in "As Is"
condition.

7. Except as expressly  provided  herein above,  the Lease remains in full force
and effect and has not been otherwise amended.

TENANT:                                   LANDLORD:
Medtox Laboratories, Inc.                 Phoenix Home Life Mutual Insurance Co.

By: /s/ James S. Arrington                 By: /s/ Donald P. Maurus
Its: Chairman & CEO                       Its: Managing Director

<PAGE>


                                     EXHIBIT
                                 INTERSTATE 35W

(New Brighton Business Plaza Floor Plan appears here)

<PAGE>



                            AMENDMENT NO. 1 TO LEASE
                        DATED AS OF MARCH 5, 1992 BETWEEN
            MEDTOX LABORATORY INC., A MINNESOTA CORPORATION ("TENANT")
                                       AND
                   PHOENIX HOME LIFE MUTUAL INSURANCE COMPANY,
                (FORMERLY PHOENIX MUTUAL LIFE INSURANCE COMPANY)
                       A NEW YORK CORPORATION ("LANDLORD")

         THIS  AGREEMENT  IS MADE AND ENTERED INTO this 12th day of March , 1993
 by and between Phoenix Home Life Mutual Insurance Company  ("Landlord") and the
Medtox Laboratories  Inc., a Minnesota Corporation ("Tenant) for the purpose  of
amending  that  certain Lease  Agreement  ("the Lease") entered into between the
Landlord and Tenant on March 5, 1992 covering the premises presently occupied by
Tenant at 402 West County Road D, New Brighton, Minnesota.

The Landlord and Tenant hereby agree that the lease shall be amended as follows:

1. Article 1: Description of Premises. The Leased Premises shall remain at Suite
402,  County Road D and 35W, New  Brighton,  Minnesota,  but the square  footage
shall be increased  by 9,989  square feet  (Suites 108,  410, 412 and 414) for a
total  amended  square  footage of 37,630  square feet.  The Leased  Premises as
changed and  amended  are  depicted on the  building  plans  attached  hereto as
Exhibit A-2 and said A-2 shall  replace  Exhibit Al  originally  attached to the
Lease.

2. Article 2: Term and Base Rent.  The Tenant agrees to pay Base Rent during the
remainder  of  the  term  of  the  Lease  on  the   following   rent   schedule:

Months                               Monthly
4/1/93 to 7/31/93                    $18,749.81
8/1/93 to 2/28/94                    $25,525.68
3/1/94 to 3/31/94                         $0.00
4/1/94 to 3/31/97                    $25,525.68

3. Additional Rent. Effective April 1, 1993, the Additional Rent shall be 
calculated on 37,630 square feet.

4. Tenant Improvement Allowance. Tenant shall be given a Tenant Improvement 
Allowance not to exceed the sum of $86,673.00 (9,989 sf. x $8.68 p.s.f) which 
shall be paid to Tenant upon completion of the following conditions.


b. Medtox will provide Landlord a list of all contractors,  subcontractors.  and
vendors  performing  work on the project.  Such list shall include  contractor's
name. address, phone number,  description of work performed. and name of contact
person.

c. Medtox will provide a copy of approved building permit.

d. Medtox will provide a certificate of occupancy from the City upon  completion
of work.

e.  Medtox  will  provide   final  lien  waivers   from  all   contractors   and
subcontractors  indicating final contract amount and full release of lien rights
contingent upon final payment



<PAGE>



5. Tenant/Contractor  Construction  Amendment. In conjunction with approval from
Landlord for the Tenant to directly perform construction  activities,  and prior
to the commencement of any construction,  Tenant agrees to provide the following
information:

a.  Contractor's  Certificate  of  Insurance  shall be forwarded to Landlord for
approval.  Insurance  limits and  certificate  shall be on forms  acceptable  to
Landlord.

b. A project construction schedule shall be provided to Landlord.

Tenant also agrees to perform work to the standards set forth below:

a. All roof penetrations  shall be installed per details provided or approved by
Landlord.

b. All roof penetrations  shall be inspected by representative of Landlord,  and
any cost associated with said inspection shall be paid for by the Landlord.

c.  All  remaining  paint,  wallcovering,  carpet,  etc.  shall  be  removed  at
completion of construction  unless Tenant  specifically  requests material to be
saved and stored within Tenant's Leased Premises.


Upon completion of she project, the following  information shall be submitted to
Landlord:

a. Copies of all project change orders approved by Tenant.

b.  Copies  of  project   punchlist   indicating  all  items  are  complete  and
satisfactory to Tenant

c. As-built drawings documenting any changes made during the project.

d. Operation and maintenance  manuals  including  warranties for all appropriate
equipment

e. Air balancing report from mechanical contractor certifying all diffusers have
been properly adjusted and all equipment has been inspected.

 6. Security Deposit. Tenant agrees to provide Landlord with a current financial
statement  on or before  four (4) months  after hue end of their  fiscal year as
defined as December 31. If after  reviewing said financial  statement.  Tenant's
net worth is less than  $1,500,000,  Tenant  agrees upon  Landlord's  request to
provide Landlord with one month's base rent totaling  $25,525.68 to be held as a
security deposit.

7. Except as expressly  provided  herein above.  the Lease remains in full force
and effect and has not been otherwise amended.

This Lease Amendment is contingent upon a mutually  executed  Amendment  between
Phoenix  Home  Life  Mutual  Insurance  Company  (Landlord)  and The  Pacesetter
Corporation  (Tenant)  providing for  Pacesetter to vacate Suite 108 in Building
"A."

LANDLORD:                                 TENANT:

Phoenix Home Life Mutual Insurance Co.    Medtox Laboratories Inc.

By:  /s/ Donald P. Maurus                 By: Kingsley R. Labrosse
Its: Managing Director                    Its: President
     North Central Region
By:            
Its:


<PAGE>

                            EXHIBIT A-2

(Amended New Brighton Business Plaza Floor Plan appears here)

<PAGE>




                            STANDARD LEASE AGREEMENT
                            FOR OFFICE/SERVICE SPACE

This lease, made this ________ day of ____________, 19___ by and between Phoenix
Mutual Life insurance Company, a Connecticut  corporation,  (hereinafter  called
the "Landlord"), and MEDTOX Laboratories, Inc. (hereinafter called "Tenant").

                                   WITNESSETH

ARTICLE 1 - DESCRIPTION OF PREMISES

         Landlord, in consideration of the rents and covenants herein contained,
hereby leases the following to wit:  27,641 square feet of space in Suite 402 of
an office and Warehouse  building  ("The  Building")  located at County Road D &
35W, New  Brighton,  MN  Minnesota  as outlined in red on Exhibit  "A-1" to this
Lease  Agreement  said  space  hereinafter  called  the  "Premises",  having the
approximate  areas:  _______  square feet of office  space _____  square feet of
warehouse,  storage or service  space.  Appurtenant  to the Premises  shall be a
non-exclusive  license for access to and use of the common areas of New Brighton
Business  Center  including  without  limitation  the parking lots and driveways
thereon (together hereinafter "the Parking Area").

ARTICLE 2 - TERM AND BASE RENT

         TO HAVE AND TO HOLD the Premises  together with all appurtenant  rights
and  privileges,  unto Tenant for a term of 60 months,  commencing on the day of
April  1,  1992,  and  terminating  ________  on  the  31  day  of  March,  1997
(hereinafter called the "Term"),  Tenant to pay during the Term a monthly minium
rent ("Minimum Rent") of _________________________  Dollars ($18,749.81) payable
in advance on the first day of each  calendar  month or any extension or renewal
thereof; provided, that said commencement and termination dates are specifically
subject to the  provisions of Article 4 hereof.  In the event of any  fractional
calendar  month.  Tenant shall pay for each day in such  partial  month a rental
equal to 1/30 of said  base  rent.  The  monthly  base  rent  together  with any
additional  rent payable  hereunder,  shall be paid in advance without demand on
the first of each month during the Lease Term to Landlord's  Agent at its office
at United Properties  Brokerager and Management Company, NW 9044, P.O. Box 1450,
Minneapolis,  MN 55485,  or at such other  address as tenant shall be advised to
use by Landlord.

ARTICLE 3 - USE OF PREMISES

         The  Premises  shall be used by Tenant for  office/tech/laboratory/whse
and for no other purpose,  subject to all regulations  imposed by local state or
other  governmental  agencies and subject to rules and regulations  which may be
promulgated by Landlord.

ARTICLE 4 - CONSTRUCTION AND POSSESSION

         If  construction  of the  Premises  is not  complete  at  the  time  of
execution  of this Lease,  Landlord  agrees to  complete  such  construction  in
accordance  with  Exhibit  A-2,  which shall be attached  hereto and made a part
hereof. If Landlord for any reason cannot deliver  possession of the Premises to
Tenant at the  commencement of the term hereof.  Landlord shall not be liable to
Tenant for any loss or damage resulting  therefrom nor shall such failure affect
the  validity of this lease or the  obligations  of Tenant  hereunder  and shall
automatically  extend  the  term of  this  Lease  by the  number  of  days  that
possession is so delayed  (unless Tenant chooses to accept  possession  prior to
completion,  in which  case the term shall  commence  from the date of
possession  and full rental shall be payable from the date of  possession).  The
premises  shall be considered to be ready to be delivered to the Tenant when the
Premises are substantially  completed and generally  suitable for occupancy.  In
the event that the Tenant has  undertaken  to complete  some of the finishing in
the Premises,  unavailability of materials order independently by the Tenant for
installation  in the Premises or any other  inability  on the  Tenant's  part to
complete  that work  shall not be  considered  a reason  for the Tenant to delay
possession  and hence delay and/or avoid  payment of rent.  If Landlord  permits
Tenant to occupy the Premises prior to the commencement date of the term hereof,
such  occupancy  shall be subject to all of the  previsions  of this Lease,  but
early possession shall not advance the expiration date set forth herein.

ARTICLE 5 - ADDITIONAL RENT

         A. Tenant shall pay to Landlord as Additional  Rent throughout the term
its pro rata share of real estate taxes and operating expenses.

         (1.) Real Estate: Taxes Tenant shall pay its pro rata share of the Real
Estate  Taxes.  The term "Real Estate  Taxes"  herein shall mean all real estate
taxes,  all  assessments,  and any taxes in lien  thereof or any tax that may be
levied  assessed  or imposed  which may become due or payable  against or by the
Building  or the  parcel of land  upon  which it is  constructed.  All costs and
expenses incurred by Landlord during  negotiations for or contests of the amount
of Real  Estate  Taxes  shall be include  within the term "Real  Estate  Taxes".
Tenant  shall  pay to  Landlord,  in each  year  during  the Term of this  Lease
Agreement and any extension or renewal thereof,  Tenant's proportionate share of
all Real Estate  Taxes paid by Landlord  in that year.  Any tax year  commencing
during any lease year shall be deemed to  correspond  to such lease year. In the
event the taxing  authorities  include in the Real Estate Taxes the value of any
of machinery, equipment, fixtures, inventory or other personal property or asset
of Tenant,  then Tenant  shall pay all the taxes  attributable  to such items in
addition to its addition to its proportionate  share of said aforementioned Real
Estate Taxes.

         (2.) Common Area Operating Expense: Tenant shall pay its pro rate share
of the annual aggregate  Common Area Operating  Expenses  ("Operating  Expense")
incurred by Landlord in the operation,  maintenance  and repair of the Building,
the  Parking  Area and the  parcel of land on which  they are  locate.  The term
"Operating  Expense"  herein  shall  include but not be limited to  maintenance,
operator,  repair,  replacement  and care of all heating,  lighting and plumbing
fixture  in or  severing  common  areas and of all  equipment,  systems,  roofs,
exterior glass, landscaped areas, signs, Building exteriors (non-structural) and
parking  lots,  all  payments  by  Landlord  for snow  removal,  refuse  removal
insurance  premiums,  management  fees,  wages and fringe  benefits of personnel
employed for the aforesaid work and proportionate  costs of equipment  purchases
and used for such purposes;  and the cost (amortized over such reasonable period
as Landlord shall determine) of any capital improvements made to the building by
Landlord after commencement of the Term which result in a reduction of Operating
Expenses or which are required under any governmental law or regulation that was
not applicable to the Building at the time it was constructed.  Tenant shall pay
for all water, gas heat, light, power, and other utilities and services supplied
to the Premises,  together with any taxes thereon.  If any such services are not
separately  metered to Tenant then Tenant  shall pay a pro ratable  share of all
charges  jointly  metered with other portions of the Building such ratable share
to be calculated as the ratio of the tenant's  gross  rentable area to the total
gross renewable area of the Building.

         B. In the event the Term shall  begin or expire at any time  during the
calendar year.  Tenant shall be responsible for his pro rata share of Additional
Rent under subdivisions 1 and 2 of paragraph A for such partial year.

<PAGE>


         C.  Prior to  commencement  of this  Lease  Agreement  and prior to the
commencement of each calendar year thereafter  commencing during the Term or any
renewal or extension thereof.  Landlord may estimate for the following  calendar
year, or portion,  thereof  remaining.  Tenant's  share of Real Estate Taxes and
Operating  Expenses and the ___ Rent payable by Tenant during such calendar year
to cover those charges or a current  basis.  Such estimates will be in wrong and
will be delivered or mailed to Tenant at the Premises.  The  Additional  Rent so
estimated shall be payable by Tenant an equal monthly installments,  an advance,
on the first day of each month during such calendar year. In the event that each
estimate is delivered  to Tenant after the fist day of January of such  calendar
year, the estimated Additional Rent for that year shall be payable as Additional
Rent in equal monthly  installments,  in advance, on the first day of each month
over the balance of such calendar year,  with the number of  installments  being
equal to the number of full  calendar  months  remaining in such  calendar  year
after delivery of the estimate.

         D. For  purposes of this  Article  Tenant's  "pro rata share"  shall be
determined as the ratio of the local rentable square feet in the Premises to the
total rentable square feet in the Building.

         E. Upon completion of each calendar year during the Term or any renewal
or extension  thereof.  Landlord shall  determined the actual amount of the Real
Estate Taxes and Operating  Expenses payable by Tenant in such calendar year and
deliver a written  certification of the amounts thereof to Tenant. If Tenant has
underpaid its proportionate share of Real Estate Taxes or Operating Expenses for
such calendar  year,  Tenant shall pay the balance  thereof within ten (10) days
after the receipt of such statement.  If Tenant has overpaid the same,  Landlord
shall  either (i) refused such  excess,  or (ii) credit such excess  against the
next  monthly  installment  of  Additional  Rent  payable by Tenant.  A pro rata
adjustment  shall be made for a fractional  calendar year  occurring  during the
Term of this Lease Agreement or any renewal or extension  thereof based upon the
number of days of the Term of the Lease  Agreement  during said calendar year as
compared to three hundred  sixty-five (365) days and all additional sums payable
by Tenant or credit due Tenant as a result of the  provisions  of this Article 5
shall be adjusted accordingly.

         F. Landlord reserves,  and Tenant hereby assigns to Landlord,  the sole
and exclusive right to contest, protest, petition for review, or otherwise seek
a reduction in the Real Estate Taxes.

ARTICLE 6 - TENANTS RESPONSIBILITY, CARE OF PREMISES AND UTILITIES

         A. In addition to section 2 above,  Tenant shall be responsible for the
maintenance of the Premises, including but not limited to maintenance, repair or
replacement of entrance doors, overhead garage doors, truck dock doors, heating,
plumbing,  electrical,  mechanical and air conditioning fixtures, and equipment
used by Tenant.

         B. Maintenance of heating, mechanical and air conditioning fixtures and
equipment   shall   specifically   include  the  reasonable  cost  of  quarterly
inspections  and  repairs  preformed  by  Landlord's  own  engineers  and  by an
independent mechanical contractor who shall be contracted for by Landlord said 
cost to be included in Operating Expenses under Article 5 of this Lease 
Agreement.

         C. Tenant shall pay for and provide for trash removal  unless  Landlord
chooses to use a single trash removal  company for the property and allocate the
prorata share of the cost to the Tenant.  Tenant shall use the dumpster provided
by Landlord or trash removal company and shall not leave or store any materials 
or trash on the grounds, in the Parking Areas or in any common areas. If 
Landlord makes a trash room or area available to the Tenant in the building. 
Tenant shall dispose of its trash in said room or area if so requested by 
Landlord.

         D. Tenant shall be  responsible  for prompt and adequate removal of 
snow, ice and other hazardous conditions accumulating or occurring on all 
sidewalk and walkways between the Premises and the Parking Areas and/or 
street.*

         E. Tenant  further agrees (a) to keep the Premises in as good condition
and  repair  as it was in at the  time  that  Tenant  took  possession  of  same
reasonable  wear and tear and  damage  from  fire and other  casualty  for which
insurance is normally procured excepted; (b) to keep the Premises in a clean and
sanitary  condition;  (c) not to commit any  nuisance or waste on the  Premises,
throw foreign substances in plumbing  facilities,  or waste any of the utilities
furnished by Landlord; (d) not to obstruct entries, halls, stairways, 
lavatories, or other common areas not use the same for  anything  other than 
their intended purposes; (e) and (f) that the use of the Premises, Parking 
Areas and the common areas  shall be  subject  to such  reasonable  Rules and  
Regulations  as may be procumlgated  by  Landlord  for  the  comfort  and  
convenience  of the  owners, occupants, and visitors of the Building.

         F. If Tenant  shall fail to keep and preserve the Premises in the state
of condition  required by the provisions of this Lease Agreement,  Landlord may,
at its  option,  put or cause the same to be put in the  condition  and state of
repair agreed upon, and in such case, Tenant shall pay the cost thereof.

         G.  Tenant  shall pay when due all  charges  for sewer usage or rental,
garbage  disposal,  refuse removal, water,  electricity, gas, fuel oil, L.P. Gas
telephone  and/or  other  utility  services or energy  source  furnished  to the
Premises during the Term or any renewal or extension thereof.

      * Landlord shall remove snow one inch or greater from sidewalk.

ARTICLE 7 - LANDLORD'S RESPONSIBILITIES AND QUIET ENJOYMENT

         Landlord  shall at its own expense keep in good order,  safe  condition
and repair the structural  parts of the Building  including the outer walls roof
foundation,   and  interior  support  columns,   except  that  Tenant  shall  be
responsible  for the  cost of the  repairs  that  are  caused  by the  fault or
negligence of Tenant its employees,  or invites.  Landlord  warrants that it has
full right to  execute  and to perform  this  Lease  Agreement  and to grant the
estate ___ and that Tenant,  upon payment of the rents and other amounts due and
the  performance  of all the terms,  conditions,  covenants  and  agreements  on
Tenant's  part to be observed  and  performed  under this Lease  Agreement,  may
peaceably  and quietly  enjoy the  Premises  for the uses  permitted  hereunder,
subject, nevertheless, to the terms and conditions of this Lease Agreement.

ARTICLE 8 - ESTOPPEL CERTIFICATES

         A. Each party  hereto  agrees  that at any time,  and from time to time
during the Term (but not more often than twice in each  calendar  year),  within
ten (10)  days  after  request  by the  other  party  hereto,  it will  execute,
acknowledge  and  deliver to such other  party or to any  prospective  purchase,
assignee or mortgage designated by such other party, an estoppel certificate in
a form acceptable to Landlord.

ARTICLE 9 - NON PERMITTED USE

         Tenant  agrees not to commit or permit any act to be  performed  on the
Premises or any  omission to occur which will be in  violation  of any  statute,
regulation,  or ordinance of any  governmental  body or which will  increase the
insurance  rates on the Building or which will be in violation of any  insurance
policy  carried on the  Premises by  Landlord.  Tenant  shall not disturb  other
occupants of the Building by making any undue or unseemly noise and shall not do
or permit to be done in or about the Premises  anything  which will be dangerous
to life or limb. Tenant warrants and represents it shall not nor shall it permit
the storage,  production,  use or disposal of hazardous wastes or substances (as
defined  under  Federal  or State law) in or around the  Premises  Building  or
Parking Areas.  Tenant's  indemnification in the next Article shall be deemed to
include any breach of this representation and warranty. There shall be no sale 
of food or beverages by mobile facility or otherwise on the Premises without the
written consent of Landlord.  Tenant further agrees not to use or permit the use
by its employees or visitors of the Parking  Areas for the overnight  storage of
vehicles.

<PAGE>

ARTICLE 10 - INSURANCE AND INDEMNITY

         A.  Tenant shall  maintain in full  force and effect  during the Term a
policy of public  liability  insurance under which Landlord is named  additional
insured. The maximum  limits of liability of such insurance shall be $1,000,000.
This  limit shall apply  per  ___. Said insurance also provides  for contractual
liability  coverage  by  endorsement.  Tenant  further  covenants  and agrees to
indemnify and hold Landlord and Landlord's manager of the Building harmless from
any claim, loss or damage,  including  reasonable  attorney's fees, suffered by
Landlord. Landlord's  manager or  Landlord's  other tenants caused by any act or
omission of Tenant.  Tenant's  employees or anyone claiming through or by Tenant
in, at or around the Premises or the  Building.  If Tenant shall not comply with
its  covenants  made in this  Article 10,  Landlord  may,  at its option,  cause
insurance as aforesaid to be issued,  and in such event Tenant agrees to pay the
premium for such insurance promptly upon Landlord's demand.

         B. Landlord shall carry and cause to be in full force and effect a fire
and extended  coverage  insurance policy on the Building but not contents owned,
leased to or otherwise in possession of Tenant. The cost of such insurance shall
be as an Operating Expense as defined in Article 5 of this Lease Agreement.

         C.  Landlord  and Tenant  each  waives  any  and all rights of recovery
against   the  other  or  against   the   officers,   employees,   agents,   and
representatives  of the other,  for loss of or damage to such waivering party or
property or the property of others under its control,  where such loss or damage
is insured against under any insurance  policy in force at the time of such loss
or damage.

ARTICLE 11 - NON-LIABILITY OF LANDLORD AND LANDLORD'S AGENTS

         In the absence of fraud, no person, firm, or corperation, or the heirs,
legal representatives,  successors and assigns, respectively, thereof, executing
this lease on Landlord's behalf as agent, trustee or in any other representative
capacity  shall ever be deemed or held  individually  liable  hereunder  for any
reason or cause whatsoever. Landlord's liability under this lease shall not 
extend to any of Landlord's  assets or property  other than the Building,  
but shall be limited to Landlord's interest in the Building and the underlying 
real estate.

ARTICLE 12 - FIRE REPAIR

         In the event of  damage to the  Building  or the  Premises by fire, the
elements,  or other  casualty,  Landlord at its option may terminate this  Lease
Agreement or repair the damage. If the damage renders the Premises  untenantable
in whole or in such part that it is  impracticable  to conduct  business therein
the rent shall  wholly abate until the damage has been  repaired.  If the damage
renders the Premises untenantable in part but Tenant continues to occupy them in
part the rent shall be reduced in the proportion that the unoccupied  portion of
the Premises bears to the entire Premises until the damage has been repaired.

ARTICLE 13 - CONDEMNATION LOSS

         Should all the  Premises  be taken in  condemnation  proceedings  or by
exercise  of any right of eminent   domain,   then  this  Lease  Agreement shall
automatically terminate as of the case the condemning authority or the authority
exercising  its right of eminent  domain takes  possession of the  Premises.  If
there is a partial  taking but Tenant  continues  to occupy the Premises in part
the rent shall be  reduced in the  proportion  that the  unoccupied  part of the
Premises bears to the entire Premises.  If as a result of a partial taking,  the
Premises are no longer usable for the purpose(s)  specified in Article 3 of this
Lease  Agreement.  Tenant may terminate this Lease  Agreement as of the date the
condemning authority or the authority exercises its right  of eminent domain and
takes  possession of the Premises by giving  written notice thereof to Landlord.
If there is a partial taking of the Building or other Parking Area. Landlord may
terminate  this  Lease  Agreement  as of the  date  specified  in the  foregoing
sentence by giving written notice thereof to Tenant. All damages awarded for any
such taking shall belong to and be the property of Landlord irrespective of this
basis upon which they are awarded  provided,  however,  that  nothing  contained
herein  shall  prevent  Tenant  from making a separate  claim to the  condemning
authority for its moving expenses, trade fixtures and Tenant's loss of business.
For purposes of this Article a taking by eminent domain shall include Landlord's
giving of a deed under threat of condemnation.

ARTICLE 14 - ASSIGNMENT AND SUBLETTING

         A. Tenant  agrees not to assign, sublet, license   mortgage or encumber
this Lease Agreement the Premises or any part thereof,  whether by voluntary act
operation of law, or otherwise,  without the specific  prior written  consent of
Landlord in each instance.  If Tenant is a corporation or partnership,  transfer
of a  controlling  interest of Tenant shall be  considered an assignment of this
Lease  Agreement for purposes of this  Article.  Consent by Landlord in one such
instance  shall not be a waiver of Landlord in one such instance  shall not be a
waiver of  Landlord's  rights under this Article as to requiring consent for any
subsequent instance.  In the event Tenant desires to sublet a part or all of the
Premises,  or assign this Lease  Agreement.  Tenant shall give written notice to
Landlord  at  lease  thirty  (30)  days  prior  to the  proposed  subletting  or
assignment,  which  notice  shall state the name of the  proposed  subtenant  or
assignee,  the terms of any  sublease  or  assignment  documents  and  copies of
financial  reports  or other  relevant  financial  information  of the  proposed
subtenant  or  assignee.  At  Landlord's  option,  any and all  payments  by the
proposed  assignee or sublessee with respect to the assignment or sublease shall
be paid directly to Landlord.  In any event,  no subletting or assignment  shall
release  Tenant  of its  obligation  to pay the rent and to  perform  all  other
obligations  to be  performed  by Tenant  hereunder  for the Term of this  Lease
Agreement. The acceptance of rent by Landlord from any other person shall not be
deemed to be a waiver by Landlord of any provision hereof. At Landlord's option,
Landlord may terminate the Lease Agreement in lien of giving it's consent to any
proposed assignment of this Lease Agreement or subletting of the Premises (which
termination  may contingent  upon the execution of a new lease with the proposed
assignee or subtenant).

         B. Landlord's  right to assign this Lease Agreement is and shall remain
unqualified  upon  any sale or  transfer  of the  Building  and,  providing  the
purchaser  succeeds  to the  interest of  Landlord  under this Lease  Agreement.
Landlord shall  thereupon be entirely  freed of all  obligations of the Landlord
hereunder  and shall not be subject to any liability  resulting  from any act or
omission or event occurring after such conveyance.

ARTICLE 15 - MECHANICS LIENS

         In the event any mechanic's lien shall at any time be filed against the
Premises  or any part of the  Building  by reason  of work  labor,  services  or
materials  performed or  furnished  to Tenant or to anyone  holding the Premises
through or under Tenant.  Tenant shall forthwith cause the same to be discharged
of record.  If Tenant shall fail to cause such lien  forthwith to be  discharged
within five (5) days after being  notified of the filing thereof ___ in addition
to any other  right or  remedy  for  Landlord.  Landlord  may,  but shall not be
obligated  to  discharge  the same by paying the amount  claimed to be due or by
bonding and the amount so paid by Landlord and all costs and expenses, including
reasonable  attorney's  fees  incurred by Landlord in procuring the discharge of
such lien, shall be due and payable in full by Tenant to Landlord on demand.

<PAGE>


ARTICLE 16 - SURRENDER

         On the last day of the Term or upon  the  sooner  termination  thereof,
Tenant  shall  peaceably  surrender  the Premises in good  condition  and repair
consistent  with  Tenant's duty to make repairs as provided in Article 6 hereof.
On or before the last day of the Term or the sooner termination thereof,  Tenant
shall at its expense  remove all of its  equipment and other  personal  property
from the Premises,  repairing any damage  caused  thereby,  and any property not
removed shall be deemed abandoned. At the election of Landlord, all alterations,
additions and fixtures,  other than Tenant's equipment,  which have been made or
installed  by either Landlord  or  Tenant  upon the  Premises  shall  remain  as
Landlord's  property and shall be surrendered with the Premises as part thereof,
or  Landlord  may  require  removal  or the same at the end of the  Term.  It is
specifically  agreed that any and all  telephonic,  coaxial,  or other computer,
wordprocessing,  facsimile,  or electronic wiring installed by the Tenant within
the  Premises  (hereafter  "Wiring")  shall  be  removed  at  Tenant's  cost  at
expiration of the Term,  unless Landlord has  specifically  requested in writing
that said Wiring shall remain,  whereupon said Wiring shall be surrendered  with
the Premises as Landlord's property.  If the Premises are not surrendered at the
end of the Term or sooner termination  thereof.  Tenant shall indemnify Landlord
against loss or liability  resulting from delay by Tenant in so surrendering the
Premises,  including without  limitation claims made by a succeeding tenant as a
result of such delay.  Tenant shall promptly surrender all keys for the Premises
to Landlord at the place then fixed for payment of rent.

ARTICLE 17 - HOLDING OVER

         In the event Tenant  remains in  possession  of the Premises  after the
expiration of this Lease Agreement, whether by lapse of time or termination, and
without  the  execution  of a new  Lease  Agreement,  it shall be  deemed  to be
occupying said Premises as a tenant at sufferance. Tenant  shall pay during that
time a  monthly  rental  at the  rate of  150%  of the  Minimum  Rent  plus  all
Additional Rent payable hereunder, subject to all the conditions, provisions and
obligations  of this Lease  Agreement  insofar as the same can be  applicable to
said tenancy.

ARTICLE 18 - DEFAULT OF TENANT

         If any one or more of the following  occurs:  (1) a rent payment or any
other payment due from Tenant to Landlord shall be and remain unpaid in whole or
in part for more than  fifteen  (15) days  after  same is due and  payable;  (2)
Tenant  shall  violate  or default  on any of the other  covenants,  agreements,
stipulations or conditions herein or in any other agreement between Landlord and
Tenant  relating to the Premises and such  violation or defaults  shall continue
for a period of thirty  (30) days after  written  notice  from  Landlord of such
violation or default;  (3) if Tenant or any  guarantor  of this Lease  Agreement
shall  commence or have commenced  against  Tenant or any guarantor  proceedings
under a bankruptcy, receivership,  insolvency or similar types of action; or (4)
Landlord may, without process, re-enter immediately into the Leased Premises and
remove all persons and property  therefrom and at its option,  cancel this Lease
as to all  future  rights  of  Tenant,   and  regain,  repossess,  and enjoy the
Premises, and Tenant hereby  expressly waives the right of any notice in writing
of intention to re-entry and also the right of  restoration to possession of the
Leased Premises after re-entry or after judgment for possession thereof,  Tenant
shall be responsible for, in addition to the rentals and other sums agreed to be
paid  hereunder,  the cost of any necessary  maintenance,  repair,  restoration,
relenting   (including  related  cost  of  removal  or  modification  of  tenant
improvements) or cure as well as reasonable  attorney's fees incurred or awarded
in any suit or action  instituted by Landlord to enforce the  provisions of this
Lease  Agreement,  regain  possession  of the Premises or the  collection of the
rentals due Landlord hereunder. Tenant shall also be liable to  Landlord for the
payment of a late charge in the amount of 10% of rental installment or other sum
due Landlord  hereunder if said  payment has not been  received  within ten (10)
days  from  the date  said  payment  becomes  due and  payable,  or  cleared  by
Landlord's  bank within six (6)  business  days after  deposit.  Each night  or
remedy of Landlord  provided for in this Lease Agreement shall be cumulative and
shall be in addition to every other right or remedy  provided  for in this Lease
Agreement  now or  hereafter  existing  at law or in  equity  or by  statute  or
otherwise.

ARTICLE 19 - DEFAULT OF LANDLORD

         Landlord  shall be deemed to be in default  under this Lease  Agreement
until the  Tenant  has  given Landlord written notice  specifying the nature  of
the default and  Landlord  does not cure such  default  within  thirty (30) days
after receipt of such notice or within such reasonable time thereafter as may be
necessary to cure such  default  where such default is of such a character as to
reasonably require more than thirty (30) days to cure.

ARTICLE 20 - ALTERATIONS

* See Addendum

ARTICLE 21 - SIGNAGE

         The only Tenant signage permitted on or in any part of the Premises and
visible from the exterior of the Premises shall be Landlord's  standard building
signage* approved and installed by Landlord at Tenant's  expense.  Tenant agrees
to maintain its signage in good repair,  and to hold Landlord  harmless from any
loss, cost, or damages resulting from the erection,  existence,  maintenance, or
removal of the signage.  Landlord may with reasonable  notice enter the Premises
at any time and, at the expense of Tenant,  remove  unauthorized  signs  without
liability  for  damages.  Landlord  may  maintain any signage at the Premises or
Building  and the cost of such  maintenance  shall be the  obligation  of Tenant
payable on demand. * See Addendum

ARTICLE 22 - ENTRY

         Tenant agrees to provide  Landlord with a list of people which Landlord
may contact in order to gain access to Tenant's space in case of an emergency.

<PAGE>

ARTICLE 23 - SUBORDINATION

         It is mutually  agreed that this Lease  Agreement shall be subordinated
to any and all mortgages, including any renewals, modifications, consolidations,
replacements and extensions  thereof now or hereafter imposed on the building by
Landlord.  Tenants  right to quick possession  of the  Premises  shall not be
disturbed  if Tenant is not in default and so long as Tenant  shall pay the rent
and observe and perform all of the  provisions of this Lease  Agreement,  unless
this Lease Agreement is otherwise terminated pursuant to its terms. In the event
Landlord's  mortgagee wishes to waive the  subordinator  right set forth in this
Article, then upon written notice to Tenant, this lease shall be deemed prior in
encumbrance to said mortgage. In confirmation of such subordination or priority,
Tenant,  upon request,  shall promptly  execute and deliver any  instrument,  as
required by Landlord's mortgagee.

ARTICLE 24 - GENERAL

         This Lease Agreement does not create the  relationship of principal and
agent  or of  partnership  or of joint  venture  or of any  association  between
Landlord and Tenant,  the sole  relationship  between  Landlord and Tenant being
that of  landlord  and  tenant.  The  submission  of this  Lease  Agreement  for
examination  does not constitute a reservation  of, or option for, the Premises,
and this Lease Agreement shall become effective only upon execution and delivery
thereof by  Landlord  and Tenant.  No waiver of any default of Tenant  hereunder
shall be implied  from any omission by Landlord to take any action on account of
such default if such  default  persists or is  repeated,  and no express  waiver
shall affect any default other than the default  specified in the express waiver
and that only for the time and to the extent  therein  stated.  The covenants of
Tenant to pay the Minimum Rent and the Additional  Rent are each  independent of
any other covenant,  condition,  provision or agreement  contained in this Lease
Agreement.  The  marginal  or topical  headings of the  several  paragraphs  and
clauses  are for  convenience  only and do not  define,  limit or  construe  the
contents of such paragraphs or clauses. All preliminary  negotiations are merged
into and incorporated in this Lease Agreement.  This Lease Agreement can only be
modified or amended by an agreement in writing signed by the parties hereto. All
provisions  hereof  shall be binding upon the heirs,  successors  and assigns of
each party hereto.  Any notice required to be served in writing  hereunder shall
be delivered  personally or sent by registered  mail to Tenant at the address of
the Premises and to Landlord at the address then fixed for payment of rent.  The
place at which  Tenant  is to pay all rent  shall be  designated  in a  separate
writing from Landlord. This Lease Agreement shall be construed under the laws of
the State of Minnesota.  If Tenant is a corporation,  each individual  executing
this Lease Agreement on behalf of said corporation  represents and warrants that
he is duly  authorized to execute and deliver this Lease  Agreement on behalf of
said  corporation in accordance  with the Bylaws of said  corporation,  and that
this Lease  Agreement is binding upon said  corporation  in accordance  with its
terms. No receipt or acceptance by Landlord from Tenant of less than the monthly
rent  herein  stipulated  shall be deemed to be other than a partial  payment on
account for any due and unpaid  stipulated  rent no  endorsement or statement of
any check or any letter or other writing  accompany any check or payment of rent
to Landlord  shall be deemed an accord and  satisfaction,  and the  Landlord may
accept and  negotiate  such check or payment  without  prejudice  to  Landlord's
rights to: (i) recover the remaining  balance of such unpaid rent or (ii) pursue
any other remedy  provided in this Lease  Agreement.  Neither party shall record
this Lease Agreement or any memorandum thereof and any such recordation shall be
a breach  of this  Lease  Agreement,  void and  without  effect.  Time is of the
essence  with  respect  to the  due  performance  of the  terms,  covenants  and
conditions herein contained.

ARTICLE 25 - SECURITY DEPOSIT

ARTICLE 26 - SUBSTITUTION

ARTICLE 27 - EXCULPATION

         Tenant agrees to look solely to Landlord's interest in the Building for
the recovery of any judgment  from  Landlord,  it being agreed that Landlord and
Landlord's  partners,  whether general or limited (if Landlord is a partnership)
or its directors, officers or shareholders (if Landlord is a corporation), shall
never be personally liable for any such judgment.

         IN WITNESS WHEREOF, the Landlord and Tenant have caused this instrument
to be executed in duplicate  the day and year first above  written.  Individuals
signing on behalf of a principal's  warrant that they have the authority to bind
said principal.


<TABLE>
<CAPTION>

<S>                                          <C>
TENANT: MEDTOX Laboratories, Inc.            LANDLORD: PHOENIX MUTUAL LIFE INSURANCE COMPANY

By /s/ Kingsley R. Labrosse                  By /s/ Donald P. Maurus
       Kingsley R. Labrosse                         Managing Director
                                                    North Central Region

By                                           By

ITS                                          ITS

DATE                                         DATE   3-5-95

</TABLE>

<PAGE>

EXHIBIT A-1

(West Brighton Building Plaza Floor Plan Appears Here)



<PAGE>



                                    ADDENDUM

Article 2 - Term and Base Rent

Free minimum  rent:  Medtox,  Inc.  will not be required to pay minimum rent the
first six (6) months and the  Twenty-fourth  (24th) month of the lease term, but
shall be responsible for an other expenses pursuant to this lease.

Article 14 - Assignment and Subletting

Landlord will not unreasonably withhold consent

Article 20 - Alterations

Medtox Laboratories,  Inc. shall be given a Tenant improvement  allowance not to
exceed the sum of $171,752.40 which shall be paid to Medtox  Laboratories,  Inc.
upon the completion of the following conditions:

1. Medtox Laboratories, Inc. shall receive formal written acceptance from United
Properties  approving all  construction  to be done.  Said approval shall not be
unreasonably withheld or delayed.

2. List of all contractors,  subcontractors,  and vendors performing work on the
project.   list  shall  include   contractor's  name,  address,   phone  number,
description of work performed, and name of contact person.

3. Copy of approved building permit.

4. Certificate of occupancy from the City.

5. Final lien waivers from all contractors and  subcontractors  indicating final
contract amount and full release of lien rights contingent upon final payment.

Tenant/Contractor Construction Amendment

In conjunction  with approval from United  Properties for the tenant to directly
perform  construction  activities,   tenant  agrees  to  provide  the  following
information and perform to the standards as set forth below.

1. Contractor's Certificate of Insurance shall be forwarded to United Properties
for approval.  Insurance limits and certificate  shall be on forms acceptable to
United Properties.

2. Provide project construction schedule to United Properties.

<PAGE>


3. All roof penetrations  shall be installed per details provided or approved by
United Properties.

4.  All roof  penetrations  shall  be  inspected  by  representative  of  United
Properties

Upon completion of the project, the following  information shall be submitted to
United Properties.

5. Copies of all project change orders approved by tenant

6. Copy of project punchlist  indicating all items are complete and satisfactory
to tenant

7. As-built drawings documenting any charges made during the project

8. Submission of operation and maintenance  manuals including  warranties for an
appropriate equipment.

9. Air balancing report from mechanical contractor certifying all diffusers have
been properly adjusted and all equipment has been inspected.

10.  All  remaining  paint,  wallcovering,  carpet,  etc.  shall be  removed  at
completion of project unless tenant  specifically  requests material to be saved
and stored within tenant's leased premises.

Option To Expand

Medtox  shall have the one time right to expand into the  adjacent  3,239 square
feet  (Suite  #410) on  October  1, 1992 or upon  availability  of the  Premises
whichever is sooner.  Landlord  shall give Tenant a 30 day prior written  notice
(Notice) of the  availability of such space.  Upon receipt of such Notice Tenant
shall have fifteen  days to notify  Landlord in writing  (Tenant  Notice) of its
intent  to take the  Expansion  Space.  If Tenant  elects to take the  Expansion
Space,  it shall be on the same terms and  conditions  as their  existing  lease
except  that  Tenant  shall have a Tenant  Improvement  Allowance  of $10.00 per
square  foot and there  shall be six (6) months of free Base Rent  Landlord  and
Tenant shall then execute a Lease Amendment memorializing this Agreement.

Picnic Area

The Landlord agrees to create at Landlord's  expense a picnic area to be located
near Medtox's main entrance.


                                     2

<PAGE>


 Design Change

The landlord agrees to work with Medtox in achieving the following:

1. Increase tenant identity through signage alterations.

2. Create a greater  ease of entry into  Medtox's  space via their  current main
entry.

Any changes made to the building shall be subject to city codes and restrictions
and  Landlord's   sole  approval.   The  cost  of  said  changes  shall  be  the
responsibility of the tenant.

Lease Contingency

This lease is contingent  upon a mutually  executed  lease  cancellation  letter
between Phoenix Mutual Life Insurance Company and CRA Inc.


                                   3

<PAGE>

                               LEASE CANCELLATION

A lease  dated  March 6,  1990 by and  between  Phoenix  Mutual  LIFE  Insurance
Company, as successors in interests to WRI, Inc., DBA Winfield Realty, as agents
for the owner (the prior  landlord)  and C.R.A for the  premises  located at New
Brighton Business Center, Building "A", 382 West County Road "D" (partial Bay 2,
Bay 3 and 4, partial Bay 5) is hereby canceled effective April 1 , 1992 with the
following conditions:

Whereas:  Phoenix  Mutual Life  Insurance  Company  desires to extend and expand
Medtox Laboratories in the property.

Whereas: CRA desires to relocate from the above premises.

Therefore:  It is the desire of Phoenix Mutual Life  Insurance  Company and CRA,
Inc. to cancel this lease effective April l, 1992.

This lease  cancellation  is contingent  upon a mutually  executed lease for the
above space between Medtox Laboratories,  Inc. and Phoenix Mutual Life Insurance
Company for a term of five years, beginning April 1 , 1992.


/s/ Donald P. Maurus                   /s/ Brian C. Boevers
Phoenix Mutual Life Insurance Company  CRA, Inc., a New York corporation

<PAGE>



                     LANDLORD'S WAIVER OF LIEN AND AGREEMENT

THIS LANDLORD'S WAIVER OF LIEN AND AGREEMENT  ("Agreement")was  made and entered
into on the 28 day of July , 1993 by and between  NORWEST BANK  MINNESOTA,  N.A.
with offices at 2329 Central  Avenue N.E.,  Minneapolis,  MN, 55418 (the "Bank')
and Phoenix  Home Life Mutual  Insurance  Company,  with offices at One American
Row, Hartford, CT 06115 (the "Landlord").

WHEREAS, MEDTOX Laboratories, Inc. (the 'Tenant") has a leasehold interest under
a certain  lease (the  "Lease")  dated  March 5, 1992,  covering  the  following
described real property  ("Leased  Premises") in the County of Ramsey,  State of
Minnesota to-wit:

         Suite 402
         New Brighton Business Center
         County Road D and 35W
         New Brighton, MN

WHEREAS,  Bank  proposes to extend  loans or credit from time to time to Tenant,
which loans or credit will be evidenced by notes or loan documents  which may be
extended or renewed from time to time (hereinafter  referred to as the "Loans"),
which  Loans may be secured by a security  interest  covering  certain  personal
property located or to be located on the Leased Premises described above; and,

WHEREAS,  Bank is  unwilling to make Loans to Tenant  unless and until  Landlord
executes this agreement with respect to the personal  property of Tenant located
in or on the Leased Premises.

NOW  THEREFORE,  in  order  to  induce  Bank to make  Loans  to  Tenant,  and in
consideration of Bank making said loans,  Landlord hereby certifies,  represents
and covenants to Bank as follows:

1. That the Tenant is presently in lawful  possession of the Leased  Premises by
virtue of the Lease.

2. That as of the date of this  Agreement  no default  exists under any terms of
the Lease or any other conditions relative to occupancy of the Leased Premises.

                            1                           
<PAGE>


3. That should the Tenant  default in any of the Loans so that the Bank proposes
to foreclose or otherwise realize upon collateral  securing any such Loan, or in
the event of termination of Tenant's  rights to occupy said Leased  Premises for
any reason, Bank shall have the following rights:

(a) The right to enter upon the Leased Premises,  with notification to Landlord,
for the  purposes of  enforcing  its lien upon the  personal  property of Tenant
located in or on the Leased  Premises,  including  the  foreclosure  and sale of
machinery,  equipment,  furniture, or other personal property, title to which is
in  Tenant  and not in Bank and for the  purpose  of  removing  from the  Leased
Premises such machinery,  equipment,  furniture,  or other personal  property of
Tenant; and,

(b) The right upon such entry to retain  possession of Leased  Premises for such
time as shall be  required  by Bank to effect a  complete  removal  or  complete
disposition  of the  personal  property  of the  Tenant,  but such  duration  of
possession shall in no event exceed a period of sixty (60) days from the date of
such  entry and for such  possession  Bank  shall be liable for and shall pay to
Landlord a rental of not more than the rental  provided  for in the Lease or the
rent last paid by Tenant  prior to the entry of Bank in the event said Lease has
been terminated.  Bank shall repair any damages caused by Bank's entry,  use, or
removal of said personal property.

 4. That none of the  personal  property  of the Tenant  situated on said Leased
Premises  constitutes  fixtures or any part of the real estate of the  Landlord.
The personal property has been placed on said Leased Premises with the agreement
and  understanding  that part or all of such property may at any time be removed
therefrom by the Tenant or his assigns,  and that any and all personal  property
hereafter placed on said Leased Premises by Tenant may be removed  therefrom and
shall not be considered affixed to or as a part of said real estate.

 5. That Landlord  shall give Bank written notice of any default under or breach
of the Lease which left uncured  would cause a  termination  of the Lease by the
Landlord.  Said notice shall be in writing and be forwarded to Bank by certified
mail addressed to Bank at its aforementioned address.

                                     2

<PAGE>

This Agreement shall be incorporated as part of the Lease by reference and shall
be binding on and inure to the benefit of the signatories hereto and their 
executors, administrators, heirs, successors, and assigns.


IN WITNESS WHEREOF, the undersigned have executed this Agreement this 28 day of
July, 1993.


                       (Landlord)  PHOENIX HOME LIFE MUTUAL INSURANCE 
                                   COMPANY
                                   By: /s/ Nadine F. Huff
                                   Its: Directors, Real Estate

                       (Bank)      NORWEST BANK MINNESOTA, N.A.
                                   By: Janet Stodola
                                   Its: Commercial Banking Officer

The undersigned hereby consents to the above agreement and agrees to be bound
thereby. Dated this         of                      ,                .


                       (Tenant)    MEDTOX Laboratories, Inc.
                                   By: John ? McC???
                                   Its: Executive Vice President

                                     3
<PAGE>


                               SUBLEASE AGREEMENT

This  Sublease  Agreement,  is made this l day of April,  1993,  by and  between
MEDTOX  Laboratories,  Inc.,  as  SUBLESSOR  and  Wooddale  Builders,  Inc.,  as
SUBLESSEE

WHEREAS,  SUBLESSOR  and SUBLESSEE  hereto now mutually  agree to lease space as
herein provided.

1.       SUBLESSEE  shall  sublease  approximately  6,499 square  feet,  for the
         purpose of  office/showroom in the demised premises located at 410 West
         County Road D, New Brighton, Minnesota.

 2.      Term: The term for the 6,499 square feet at 410 West County Road D
         shall commence April 1, 1993 and continue until May 31, 1993.
         SUBLESSEE specifically agrees to vacate premises no later than May 31,
         1993.

3.       Gross Rent:  SUBLESSEE  shall pay rent in the amount of Three  Thousand
         Three  Hundred  Eighty  Five and no/100  ($3,385.00)  Dollars per month
         gross  for the  term of this  Agreement.  However,  SUBLESSEE  shall be
         responsible for any utility cost  throughout  Sublease Term. Said gross
         rent shall be due on the first of every month.

4.       Master  Lease:  SUBLESSOR  is the Lessee of the premises by virtue of a
         lease hereinafter  referred to as the Master Lease dated March 5, 1992,
         wherein  Phoenix  Home Life  Mutual  Insurance  Company is the  LESSOR,
         hereinafter referred to as the Master Lessor. The SUBLEASE is and shall
         be at all times subject and subordinate to the Master Lease.  SUBLESSOR
         represents  to  SUBLESSEE  that the  Master  Lease is in full force and
         effect and that to the best of  SUBLESSOR's  knowledge  and belief,  no
         default exists on the part of any party to the Master Lease. The terms,
         conditions  and  respective  obligations  of SUBLESSOR and SUBLESSEE to
         each other under this Sublease  shall,  be the terms and  conditions of
         the Master Lease except for those  provisions of the Master Lease which
         are directly  contradicted by this Sublease in which event the terms of
         this Sublease document shall control over the Master Lease.  Therefore,
         for the  purposes of this  Sublease,  wherever in the Master  Lease the
         word  "Landlord"  is used it shall be  deemed  to mean,  the  SUBLESSOR
         herein and  wherever in the Master  Lease the word  "Tenant" is used it
         shall be deemed to mean the SUBLESSEE herein.

<PAGE>


 5.      SUBLESSEE shall not at any time during its temporary occupancy make any
         changes  or  alterations  to  the  demised   premises,   structural  or
         otherwise,  including changing of any locks, nor to any improvements or
         fixtures located in the demised premises,  nor shall it cause or suffer
         any mechanic's or other liens or claims therefore to be imposed against
         the demised premises.

6.       It is expressly agreed that SUBLESSOR shall have no  responsibility  or
         liability  for damage  caused to any  inventory  or  personal  property
         placed by  SUBLESSEE  in the  premises  regardless  of the cause of the
         damage,  and SUBLESSEE  agrees to carry,  at its own expense,  adequate
         inventory insurance and public liability insurance.  SUBLESSOR shall be
         named as an additional insured party. SUBLESSEE shall provide SUBLESSOR
         with  proof  of  insurance  prior  to  commencement  of this  Sublease.
         SUBLESSEE's insurance policy shall provide for at a minimum $100,000.00
         individual,  $300,000.00  liability,  and $50,000.00 property coverages
         and shall not be  canceled  without 15 days'  prior  written  notice to
         SUBLESSOR.

 7.      SUBLESSEE shall allow no improper or unlawful use of the demised
         premises.

 8.      In the event of damage or destruction of all or any part of the demised
         premises,  the  right  of  SUBLESSEE  to  occupancy  shall  immediately
         terminate  and any  obligation  of SUBLESSOR  arising  hereunder  shall
         cease.

 9.      SUBLESSEE  agrees that SUBLESSOR and its agents shall not be liable for
         any damage or injury to  SUBLESSEE,  its agents,  employees or invitees
         entering the  premises;  or the building of which the demised  premises
         forms a part; or to goods or chattels therein resulting from any defect
         in the  demised  premises or its  equipment  or  fixtures,  and further
         agrees to  indemnify  and save  SUBLESSOR  harmless  from all claims of
         every kind and nature  resulting  from its  temporary  occupancy of the
         demised premises.

10.      SUBLESSEE  agrees  to  accept  the  demised  premises  in  an  "as  is"
         condition.

11.      Utility cost  incurred  during the Sublease  Term shall be the sole and
         exclusive  responsibility of SUBLESSEE. in no event shall the SUBLESSOR
         be responsible for any utility costs.

12.      Attorney's  Fees: If any party named herein brings an action to enforce
         the terms hereof or to declare rights  hereunder,  the prevailing party
         in  such  action,  on  trial  and  appeal,  shall  be  entitled  to his
         reasonable  attorney's  fees to be paid by the losing party as fixed by
         the Court.


<PAGE>


SUBLESSEE:                           SUBLESSOR:

Wooddale Builders, Inc.              MEDTOX Laboratories, Inc.
By: /s/  ???????                     By:  /s/ ??????
Its: President                       Its: President
Date: 4/1/93                         Date: 4/9/93

Master LESSOR's Consent:
By: Nadine Huff
Its: Director, Real Estate
Date: 4/16/93              








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