CN BIOSCIENCES INC
8-K, 1998-01-12
MEDICINAL CHEMICALS & BOTANICAL PRODUCTS
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<PAGE>   1
                       Securities and Exchange Commission

                             Washington, D.C. 20549



                                    Form 8-K

                                 Current Report

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



       Date of Report (Date of earliest event reported) December 27, 1997

                              CN Biosciences, Inc.
             (Exact name of registrant as specified in its charter)

<TABLE>
<CAPTION>
<S>                                            <C>                                    <C>       
Delaware                                       000-21281                              33-0509785
(State or other                                (Commission                            (IRS Employer
jurisdiction of                                File Number)                           Identification No.)
incorporation)

10394 Pacific Center Court, San Diego, CA                                                92121
(Address of principal executive offices)                                              (Zip Code)
</TABLE>

       Registrant's Telephone Number, including area code: (619) 450-5500



                                       N/A
          (Former name or former address, if changed since last report)
<PAGE>   2
Item 2.  Acquisition or Disposition of Assets.

Effective as of December 27, 1997, CN Biosciences, Inc. (the "Registrant")
acquired all of the outstanding capital stock of Pel-Freez, Inc., an Arkansas
corporation ("Pel-Freez"), and all of the outstanding capital stock of
Pel-Freez's subsidiary Novagen, Inc., an Arkansas corporation ("Novagen"),
pursuant to a Stock Purchase Agreement, dated as of November 25, 1997, by and
among the Registrant, as Buyer, David W. Dubbell, Dennis Almond, Corrine
Fetherston, Lisa Johnson, Robert Mierendorf, Warren Kroeker, Barbara Morris,
Robert Novy and Tom Van Oosbree, as Sellers, and Pel-Freez for $10,500,000 cash.
On January 2, 1998, the Registrant paid the purchase price from cash on hand.
The purchase price was determined through arm's length negotiation between the
Registrant and the Sellers. Subsequent to the closing of the acquisition of
Pel-Freez and Novagen by the Registrant, Pel-Freez's Articles of Incorporation
were amended to change its name to Novagen Holdings, Inc.

Item 7.  Financial Statements and Exhibits.

(a)      Financial statements of business acquired.

         The required financial statements will be filed by amendment to this
Current Report on Form 8-K within the time period specified by Item 7(a)(4).

(b)      Pro forma financial information.

         The required pro-forma financial information will be filed by amendment
to this Current Report on Form 8-K within the time period specified by Item
7(a)(4).

(c)      Exhibits.

<TABLE>
<CAPTION>
Exhibit No.                     Description
- -----------                     -----------
<S>                             <C>
2(b)                            Stock Purchase Agreement, dated as of November 25, 1997, by
                                and among CN Biosciences, Inc., as Buyer, David W. Dubbell,
                                Dennis Almond, Corrine Fetherston, Lisa Johnson, Robert
                                Mierendorf, Warren Kroeker, Barbara Morris, Robert Novy and
                                Tom Van Oosbree, as Sellers, and Pel-Freez, Inc.*
</TABLE>

- -------------
*Portions of this exhibit have been omitted pursuant to a request for
confidential treatment.

                                      -2-
<PAGE>   3
                                    SIGNATURE

         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.

                                       CN Biosciences, Inc.

                                       By:  /s/ James G. Stewart
                                           ------------------------------------
                                            James G. Stewart
                                            Chief Financial Officer, Vice
                                            President-Administration and
                                            Secretary

Dated:  January 12, 1998

                                      -3-
<PAGE>   4
                                  EXHIBIT INDEX



<TABLE>
<CAPTION>
Exhibit No.                  Description
- -----------                  -----------
<S>                          <C>
2(b)                         Stock Purchase Agreement, dated as of November 25, 1997, by and
                             among CN Biosciences, Inc., as Buyer, David W. Dubbell, Dennis
                             Almond, Corrine Fetherston, Lisa Johnson, Robert Mierendorf, Warren
                             Kroeker, Barbara Morris, Robert Novy and Tom Van Oosbree, as Sellers,
                             and Pel-Freez, Inc.*
</TABLE>

- -------------
* Portions of this exhibit have been omitted pursuant to a request for
confidential treatment.

                                      -4-

<PAGE>   1
                                                                  EXECUTION COPY







                            STOCK PURCHASE AGREEMENT
                                  by and among
                              CN BIOSCIENCES, INC.,
                                    as Buyer,
              DAVID W. DUBBELL, DENNIS ALMOND, CORRINE FETHERSTON,
                LISA JOHNSON, ROBERT MIERENDORF, WARREN KROEKER,
                 BARBARA MORRIS, ROBERT NOVY and TOM VAN OOSBREE
                                   as Sellers,
                                       and
                                 PEL-FREEZ, INC.

                                   Dated as of
                                November 25, 1997


*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   2
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                              Page
                                                                                                              ----
<S>                                                                                                          <C>
                             ARTICLE I. DEFINITIONS


                          ARTICLE II. SALE AND PURCHASE

SECTION 2.1.  Agreement to Sell and to Purchase...................................................................11
SECTION 2.2.  Closing.............................................................................................11
SECTION 2.3.  Purchase Price; [**************]; Earn-Out Amount...................................................11
SECTION 2.4.  Preparation of Effective Date Financial Statements; Purchase Price Adjustment.......................13

           ARTICLE III. REPRESENTATIONS AND WARRANTIES OF THE SELLERS

SECTION 3.1.  Ownership; Title to the Shares......................................................................15
SECTION 3.2.  Authority...........................................................................................15
SECTION 3.3.  Corporate Organization..............................................................................15
SECTION 3.4.  Capitalization......................................................................................16
SECTION 3.5.  Subsidiaries........................................................................................16
SECTION 3.6.  No Conflict or Violation............................................................................16
SECTION 3.7.  Consents and Approvals..............................................................................17
SECTION 3.8.  Financial Statements................................................................................17
SECTION 3.9.  Liabilities for Borrowed Money; Absence of Undisclosed Liabilities; Guarantees......................18
SECTION 3.10.  Interests in Real Property.........................................................................18
SECTION 3.11.  Personal Property..................................................................................19
SECTION 3.12.  Intellectual Property; Intangible Assets...........................................................20
SECTION 3.13.  Compliance with Law................................................................................21
SECTION 3.14.  Licenses, Permits and Governmental Approvals.......................................................21
SECTION 3.15.  Environmental Matters..............................................................................22
SECTION 3.16.  Litigation.........................................................................................23
SECTION 3.17.  Contracts..........................................................................................24
SECTION 3.18.  Accounts Receivable................................................................................24
SECTION 3.19.  Inventories........................................................................................25
SECTION 3.20.  Catalogs, Brochures and Advertisements.............................................................25
SECTION 3.21.  Warranties.........................................................................................25
SECTION 3.22.  Customers and Suppliers............................................................................25
SECTION 3.23.  Products Liability.................................................................................26
SECTION 3.24.  Insurance..........................................................................................26
SECTION 3.25.  Transactions with Directors, Officers and Affiliates...............................................27
SECTION 3.26.  Propriety of Past Payments.........................................................................28
</TABLE>

                                      -i-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   3
<TABLE>
<CAPTION>
<S>                                                                                                              <C>
SECTION 3.27.  Employee Plans.....................................................................................28
SECTION 3.28.  Labor Matters......................................................................................28
SECTION 3.29.  Absence of Certain Changes or Events...............................................................29
SECTION 3.30.  Tax Matters........................................................................................32
SECTION 3.31.  Accuracy of Information............................................................................33

              ARTICLE IV. REPRESENTATIONS AND WARRANTIES OF DUBBELL

SECTION 4.1.  Corporate Organization..............................................................................33
SECTION 4.2.  Capitalization......................................................................................33
SECTION 4.3.  Subsidiaries........................................................................................34
SECTION 4.4.  Validity of Agreement...............................................................................34
SECTION 4.5.  No Conflict or Violation............................................................................34
SECTION 4.6.  Consents and Approvals..............................................................................34
SECTION 4.7.  Financial Statements................................................................................34
SECTION 4.8.  Tax Matters.........................................................................................35
SECTION 4.9.  Holding Company.....................................................................................36
SECTION 4.10.  Licenses, Permits and Governmental Approvals.......................................................37
SECTION 4.11.  Compliance with Law................................................................................37
SECTION 4.12.  Environmental Matters..............................................................................38
SECTION 4.13.  Litigation.........................................................................................39
SECTION 4.14.  Contracts..........................................................................................40
SECTION 4.15.  Intercompany Accounts..............................................................................40
SECTION 4.16.  Propriety of Past Payments.........................................................................40
SECTION 4.17.  Employee Plans.....................................................................................41
SECTION 4.18.  Absence of Certain Changes or Events...............................................................44
SECTION 4.19.  Parent's Liabilities...............................................................................46
SECTION 4.20.  Other Properties...................................................................................46
SECTION 4.21.  Accuracy of Information............................................................................46

             ARTICLE V. REPRESENTATIONS AND WARRANTIES OF THE BUYER

SECTION 5.1.  Corporate Organization..............................................................................47
SECTION 5.2.  Validity of Agreement...............................................................................47
SECTION 5.3.  No Conflict or Violation; No Defaults...............................................................47
SECTION 5.4.  Consents and Approvals..............................................................................47
SECTION 5.5.  Investment Representation...........................................................................47
SECTION 5.6.  Financial Capability................................................................................48

                              ARTICLE VI. COVENANTS

SECTION 6.1.  Redemption Transaction..............................................................................48
SECTION 6.2.  Continued Development of Novagen Brand Products.....................................................48
SECTION 6.3.  Non-Solicitation of Employees.......................................................................48
SECTION 6.4.  Access to Properties and Records....................................................................48
</TABLE>

                                      -ii-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   4
<TABLE>
<CAPTION>
<S>                                                                                                              <C>
SECTION 6.5.  Negotiations........................................................................................49
SECTION 6.6.  Consents and Approvals..............................................................................49
SECTION 6.7.  Commercially Reasonable Efforts.....................................................................49
SECTION 6.8.  Notice of Breach....................................................................................49
SECTION 6.9.  Confidential Information............................................................................50
SECTION 6.10.  Tax Covenants......................................................................................50
SECTION 6.11.  Release of Resigning Directors and Officers; Assumption of Obligations.............................51
SECTION 6.12.  Actions of Sellers.................................................................................52
SECTION 6.13.  Change of Name of the Parent.......................................................................52
SECTION 6.14.  Transfer of Corporate Books and Records............................................................52
SECTION 6.15.  Employee Relations and Benefits....................................................................53
SECTION 6.16.  Further Assurances.................................................................................55
SECTION 6.17.  Post-Closing Management of Promega Dispute.........................................................55
SECTION 6.18.  Intercompany Accounts..............................................................................56
SECTION 6.19.  Continuation of Company's Business.................................................................56
SECTION 6.20  Releases from Liability.............................................................................56
SECTION 6.21  Ancillary Agreements................................................................................57
SECTION 6.22 Closing Documentation................................................................................57
SECTION 6.23. Actions of Buyer....................................................................................57

               ARTICLE VII. CONDITIONS TO OBLIGATIONS OF THE BUYER

SECTION 7.1.  Representations and Warranties of the Sellers.......................................................57
SECTION 7.2.  Performance of the Sellers' Obligations.............................................................57
SECTION 7.3.  Redemption Transaction..............................................................................58
SECTION 7.4.  Receipt of Documents................................................................................58
SECTION 7.5.  Consents and Approvals..............................................................................58
SECTION 7.6.  No Violation of Orders..............................................................................59
SECTION 7.7.  No Material Adverse Change..........................................................................59
SECTION 7.8.  Discharge of Indebtedness; Release of Liens.........................................................59
SECTION 7.9.  Opinion of Counsel..................................................................................59
SECTION 7.10.  Legal Matters......................................................................................59

             ARTICLE VIII. CONDITIONS TO OBLIGATIONS OF THE SELLERS

SECTION 8.1.  Representations and Warranties of the Buyer.........................................................60
SECTION 8.2.  Performance of the Buyer's Obligations..............................................................60
SECTION 8.3.  Consents and Approvals..............................................................................60
SECTION 8.4.  No Violation of Orders..............................................................................60
SECTION 8.5.  Opinion of Counsel..................................................................................60
SECTION 8.6.  Legal Matters.......................................................................................60
</TABLE>

                                     -iii-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   5
<TABLE>
<CAPTION>
                           ARTICLE IX. INDEMNIFICATION
<S>                                                                                                              <C>
SECTION 9.1.  Indemnification by the Sellers and the Buyer........................................................61
SECTION 9.2.  Procedures..........................................................................................63
SECTION 9.3.  Procedures Relating to Tax Claims...................................................................65
SECTION 9.4.  Limitations on Indemnity............................................................................65
SECTION 9.5.  Set Off Against Earn-Out Payments...................................................................66
SECTION 9.6.  Purchase Price Adjustment...........................................................................66
SECTION 9.7.  Insurance...........................................................................................66
SECTION 9.8.  Exclusive Remedies..................................................................................66
SECTION 9.9.  Disclaimer..........................................................................................66

                     ARTICLE X. TERMINATION AND ABANDONMENT

SECTION 10.1.  Methods of Termination; Upset Date.................................................................67
SECTION 10.2.  Procedure Upon Termination.........................................................................68

                      ARTICLE XI. MISCELLANEOUS PROVISIONS

SECTION 11.1.  Representation of Sellers by Sellers' Agents.......................................................68
SECTION 11.2.  Nature and Survival of Representations, Etc........................................................69
SECTION 11.3.  Publicity..........................................................................................69
SECTION 11.4.  Successors and Assigns; No Third-Party Beneficiaries...............................................69
SECTION 11.5.  Brokers, Finders and Financial Advisors............................................................70
SECTION 11.6.  Fees and Expenses..................................................................................70
SECTION 11.7.  Notices............................................................................................70
SECTION 11.8  Release under Seller's Escrow Agreement.............................................................72
SECTION 11.9.  Entire Agreement...................................................................................73
SECTION 11.10.  Waivers and Amendments............................................................................73
SECTION 11.11.  Severability......................................................................................73
SECTION 11.12.  Titles and Headings...............................................................................73
SECTION 11.13.  Signatures and Counterparts.......................................................................73
SECTION 11.14.  Enforcement of the Agreement......................................................................74
SECTION 11.15.  Governing Law.....................................................................................74
SECTION 11.16.  Knowledge.........................................................................................74
</TABLE>

                                      -iv-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   6
Exhibits

<TABLE>
<CAPTION>
<S>                     <C>                                 
       Exhibit A-1      Shareholders of Novagen, Inc.
       Exhibit A-2      Shareholders of Novagen, Inc. as of the Closing Date
       Exhibit B        Form of Opinions of Counsel to the Parent, Dubbell and the Company Minority Shareholders
       Exhibit C        Form of Opinion of Buyer's Counsel
       Exhibit D        Form of Certificate of Non-Foreign Status
       Exhibit E        Sellers' Escrow Agreement
       Exhibit F        [************************]
       Exhibit G        Mierendorf Employment Agreement
       Exhibit H        rRTF Assignment and License Agreement
       Exhibit I        BEVSCO Agreement
       Exhibit J        CIMPRO Agreement
       Exhibit K        Terms of Agreements

Disclosure Schedule

      Company

      Section 3.3       Corporate Organization
      Section 3.6       Conflicts or Violations
      Section 3.7       Consents and Approvals
      Section 3.8       Financial Statements
      Section 3.9       Liabilities for Borrowed Money
      Section 3.10      Real Property Interests
      Section 3.11      Personal Property
      Section 3.12      Intellectual Property; Intangible Assets
      Section 3.13      Compliance with Laws
      Section 3.14      Licenses, Permits and Governmental Approval
      Section 3.15      Environmental Matters
      Section 3.16      Litigation
      Section 3.17      Contracts
      Section 3.18      Accounts Receivable
      Section 3.20      Catalogs, Brochures and Advertisements
      Section 3.21      Warranties
      Section 3.22      Customers and Suppliers
      Section 3.24      Insurance
      Section 3.25      Transactions with Directors, Officers and Affiliates
      Section 3.26      Past Payments
      Section 3.28      Labor Matters
      Section 3.29      Certain Changes or Events
      Section 3.30      Tax Matters
</TABLE>

                                      -v-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   7
      Parent
      ------

<TABLE>
<CAPTION>
<S>                    <C>                             
      Section 4.1       Corporate Organization
      Section 4.2       Options
      Section 4.3       Subsidiaries
      Section 4.5       Conflicts or Violations
      Section 4.6       Consents and Approvals
      Section 4.8       Taxes
      Section 4.9       Parent Lease
      Section 4.10      Licenses
      Section 4.11      Compliance with Laws
      Section 4.12      Environmental Matters
      Section 4.13      Litigation
      Section 4.14      Contracts
      Section 4.16      Past Payments
      Section 4.17      Employee Plans
      Section 4.18      Certain Changes or Events

      Other

      Section 6.15      Employee Relations and Benefits
</TABLE>

                                      -vi-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   8
                            STOCK PURCHASE AGREEMENT


         STOCK PURCHASE AGREEMENT (the "AGREEMENT"), dated as of November 25,
1997, by and among

         CN BIOSCIENCES, INC., a Delaware corporation (the "BUYER");

         DAVID W. DUBBELL ("DUBBELL");

         DENNIS ALMOND, CORRINE FETHERSTON, LISA JOHNSON, ROBERT MIERENDORF,
WARREN KROEKER, BARBARA MORRIS, ROBERT NOVY and TOM VAN OOSBREE (collectively,
the "COMPANY MINORITY SHAREHOLDERS" and, together with Dubbell, the "SELLERS");
and

         PEL-FREEZ, INC., an Arkansas corporation (the "PARENT").

                              W I T N E S S E T H:

         WHEREAS, Dubbell is the owner of all of the issued and outstanding
capital stock of the Parent;

         WHEREAS, immediately prior to the Closing (as defined herein), the
Parent shall (a) contribute the outstanding capital stock of Pel-Freez Rabbit
Meat, Inc., an Arkansas corporation ("PFRM"), to Tri-State Industrials, Inc., an
Arkansas corporation ("TRI-STATE") and (b) purchase from Dubbell 52,800 shares
of Common Stock, par value $.01 per share, of the Parent (the "PARENT COMMON
STOCK") in consideration for the transfer to him of all of the outstanding
capital stock of Tri-State (all of such redeemed shares of Parent Common Stock
are hereinafter referred to as the "REDEEMED SHARES" and such transfers of
capital stock and redemptions of the Redeemed Shares are hereinafter
collectively referred to as the "REDEMPTION TRANSACTION");

         WHEREAS, the Parent and the Company Minority Shareholders are the
respective owners of the shares of issued and outstanding capital stock of
Novagen, Inc., an Arkansas corporation (the "COMPANY"), listed after their names
on EXHIBIT A-1 hereto (such shares owned by the Company Minority Shareholders,
the "COMPANY MINORITY SHARES"), which shares constitute all of the issued and
outstanding capital stock of the Company;

         WHEREAS, the Buyer desires to purchase the Parent Common Stock other
than the Redeemed Shares (the "REMAINING PARENT SHARES") from Dubbell, and
Dubbell desires to sell the Remaining Parent Shares to the Buyer, in each case
upon the terms and subject to the conditions set forth in this Agreement;

         WHEREAS, the Buyer desires to purchase the Company Minority Shares from
the Company Minority Shareholders, and the Company Minority Shareholders desire
to sell the

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   9
Company Minority Shares to the Buyer, in each case upon the terms and subject to
the conditions set forth in this Agreement; and

         WHEREAS, as a result of the purchase by the Buyer of the Remaining
Parent Shares and the Company Minority Shares, each of the Parent and the
Company shall become wholly owned subsidiaries of the Buyer.

         NOW, THEREFORE, in consideration of the mutual terms, conditions and
other agreements set forth herein, the parties hereto hereby agree as follows:

                                   ARTICLE I.
                                   DEFINITIONS

         As used in this Agreement, the following terms have the respective
meanings set forth below or set forth in the Section hereof following such term:

         "ADJUSTMENT AMOUNT" shall have the meaning set forth in Section 2.3.

         "AFFILIATE" shall mean any Person that directly, or indirectly through
one or more intermediaries, controls or is controlled by, or is under common
control with such Person. As used in this definition, "control" (including the
terms "controlling," "controlled by" and "under common control with") means the
possession, direct or indirect, of the power to direct or cause the direction of
the management or policies of a Person, whether through the ownership of voting
securities, by contract or otherwise.

         "AGREEMENT" shall mean this Agreement, together with the Exhibits and
Disclosure Schedules referred to herein.

         "AGGRIEVED PARTY" shall have the meaning set forth in Section 9.2.

         "ANCILLARY DOCUMENT" shall have the meaning given thereto in Section
9.1.

         "BUSINESS DAY" shall mean a day other than a Saturday, Sunday or other
day on which banks in the State of New York are required or authorized to close.

         "BUYER" shall have the meaning set forth in the recitals to this
Agreement.

         "BUYER INDEMNIFIED PARTIES" shall mean the Buyer, any Affiliate of the
Buyer, and their respective officers, directors and employees.

         "BUYER'S PROPOSED PURCHASE PRICE ADJUSTMENT" shall have the meaning set
forth in Section 2.4(c).

                                      -2-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   10
         "C&L" shall have the meaning set forth in Section 2.4(b).

         "CELL LINES" shall mean all cell lines, sibling cell lines, strains,
cultures and other biological or biochemical source stocks used by the Company
in its business.

         "CERCLA" shall mean the Comprehensive Environmental Response,
Compensation and Liability Act, 42 U.S.C. Section 9601 et seq., as amended.

         "CERTIFICATION OF NOVAGEN BRAND NET SALES" shall mean, for each of the
years ending December 31, 1998, 1999 and 2000, a certificate, signed by an
officer of the Buyer, setting forth the dollar amount of Novagen Brand Net Sales
for the respective fiscal year and the dollar amount of any Earn-Out Amount
payable for such fiscal year.

         "CLAIM" shall have the meaning set forth in Section 9.2.

         "CLOSING" shall have the meaning set forth in Section 2.2.

         "CLOSING DATE" shall have the meaning set forth in Section 2.2.

         "COBRA" shall mean Section 4908B of the Code and Section 601 et seq. of
ERISA, and the proposed or final regulations thereunder.

         "CODE" shall mean the Internal Revenue Code of 1986, as amended.

         "COMPANY" shall have the meaning set forth in the recitals to this
Agreement.

         "COMPANY AUDITED FINANCIAL STATEMENTS" shall have the meaning set forth
in Section 3.8.

         "COMPANY COMMON STOCK" shall have the meaning set forth in Section 3.1.

         "COMPANY EFFECTIVE DATE STOCKHOLDERS EQUITY" shall have the meaning set
forth in Section 2.4(b).

         "COMPANY FINANCIAL STATEMENTS" shall have the meaning set forth in
Section 3.8.

         "COMPANY MINORITY SHARES" shall have the meaning set forth in the
recitals to this Agreement.

         "COMPANY MINORITY SHAREHOLDERS" shall have the meaning set forth in the
recitals to this Agreement.

                                      -3-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   11
         "COMPANY SEPTEMBER 27 STOCKHOLDERS EQUITY" shall have the meaning set
forth in Section 2.4(a).

         "COMPANY UNAUDITED INTERIM FINANCIAL STATEMENTS" shall have the meaning
set forth in Section 3.8.

         "CONFIDENTIAL INFORMATION" shall have the meaning set forth in Section
6.9.

         "CORPORATE RECORDS" shall have the meaning set forth in Section 6.14.

         "DB PLAN" shall have the meaning set forth in Section 6.15(g).

         "DISCLOSING PARTY"  shall have the meaning set forth in Section 6.9.

         "DISCLOSURE SCHEDULE" means, collectively, the respective schedules
provided by the Sellers in accordance with the terms of this Agreement.

         "DISPUTE NOTICE" shall have the meaning set forth in Section 2.4(c).

         "DUBBELL" shall have the meaning set forth in the recitals to this
Agreement.

         "DUBBELL'S AGENT" shall have the meaning set forth in Section 11.1.

         "E&Y" shall have the meaning set forth in Section 2.4(b).

         "EARN-OUT AMOUNT" shall mean, with respect to each of the fiscal years
ending December 31, 1998, 1999 and 2000, the dollar amount, if any, equal to the
product of (x) 0.20 and (y) the amount by which Novagen Brand Net Sales for such
year exceeds the Threshold Amount applicable to such year.

         "EARN-OUT PERIOD" shall mean the period commencing on January 1, 1998
and ending on December 31, 2000.

         "EFFECTIVE DATE" shall mean December 27, 1997.

         "EFFECTIVE DATE FINANCIAL STATEMENTS" shall have the meaning set forth
in Section 2.4(b).

         "EMPLOYMENT AND LABOR AGREEMENTS" shall have the meaning set forth in
Section 3.28.

         "ENVIRONMENTAL LAWS" shall have the meaning set forth in Section 3.15.

         "ENVIRONMENTAL PERMITS" shall have the meaning set forth in Section
3.15.

                                      -4-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   12
         "ERISA" shall mean the Employee Retirement Income Security Act of 1974,
as amended.

         "ERISA AFFILIATE" shall mean any trade or business (whether or not
incorporated) which is or has ever been treated as a single employer with the
Parent, the Company or any Subsidiary of the Parent, under Section 414(b), (c),
(m), or (o) of the Code, but only during the period in which such trade or
business was so treated.

         
         [*********************************************************************
**]

         "FINAL PURCHASE PRICE ADJUSTMENT" shall have the meaning set forth in
Section 2.4(c).

         "FURNITURE, FIXTURES AND EQUIPMENT" shall have the meaning set forth in
Section 3.11.

         "FURNITURE, FIXTURES AND EQUIPMENT LEASES" shall have the meaning set
forth in Section 3.11.

         "GAAP" shall mean United States generally accepted accounting
principles as in effect from time to time.

         "HAZARDOUS MATERIALS" shall have the meaning set forth in Section 3.15.

         "INDEMNIFYING PARTIES" shall have the meaning set forth in Section 9.2.

         "INITIAL PAYMENT" shall mean $10,500,000, which, in the aggregate,
shall be paid to the Sellers' Agents on the Closing Date on the terms and
subject to the conditions of this Agreement to be held and distributed by the
Sellers' Agents in accordance with the terms of the Sellers' Escrow Agreement.

         "INTANGIBLE ASSETS" shall mean all intangible personal property rights
(including Intellectual Property) owned or held by the Company and relating to
the operation of its business, including, without limitation, all goodwill of
the Company relating to its business, all know-how relating to the manufacture
or development of Novagen Brand Products by the Company at any time up to and
including the Closing Date, trade secrets, all software, software systems,
databases and all other information systems used in its business, the current
toll free "800" and "888" telephone numbers utilized by the Company in
connection with its business, DNA and RNA sequences, expression strains and
vectors, production formulations, manufacturing methods, laboratory methods, and
all rights on the part of the Company to proceeds of any insurance policies and
all claims on the part of the Company for recoupment, reimbursement and coverage
under any insurance policies, in each case arising in connection with the
operation of its business.

         "INTELLECTUAL PROPERTY" shall mean (i) trademarks and service marks
(registered or unregistered), trade dress, trade names and other names and
slogans embodying business or product goodwill or indications of origin, all
applications or registrations in any jurisdiction

                                      -5-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   13
pertaining to the foregoing and all goodwill associated therewith, including,
without limitation, the copyrights to all Product catalogs of the Company,
product guides, user instructions, technical notes and other supplements
published in connection with the Company's business, advertising copy used in
connection with the Company's business and art work related to the business;
(ii) patents, patentable inventions, discoveries, improvements, ideas, formula
methodology, processes, technology and computer programs, software and databases
(including source code, object code, development documentation, programming
tools, drawings, specifications and data) and all applications or registrations
in any jurisdiction pertaining to the foregoing, including all reissues,
continuations, divisions, continuations-in-part, renewals or extensions thereof;
(iii) trade secrets, know-how, including confidential and other non-public
information, and the right in any jurisdiction to limit the use or disclosure
thereof; and (iv) Internet Web sites, domain names and registrations or
applications for registrations thereof and those other items listed in Section
3.12 of the Disclosure Schedule.

         "IRCA" shall mean the Immigration Reform and Control Act of 1986 and
all rules and regulations adopted pursuant thereto or in connection therewith.

         "KUNZ AND OLANDER NOTES" shall mean, together, the Promissory Note
dated August 28, 1997 issued by the Parent in the name of Linda Kunz in the
principal amount of $59,072.00 and the Promissory Note dated October 28, 1997
issued by the Parent in the name of Charyl Olander in the principal amount of
$3,584.22.

         "LICENSE" shall have the meaning set forth in Section 3.14.

         "LOSS" shall have the meaning set forth in Section 9.1.

         "MATERIAL CONTRACT" shall have the meaning set forth in Section 3.17.

         "MIERENDORF" shall have the meaning set forth in Section 6.17.

         "MINORITY SHAREHOLDERS' AGENTS" shall have the meaning set forth in
Section 11.1.

         "MULTIEMPLOYER PLAN" has the meaning set forth in ERISA Section 3(37).

         "1998 SHORT PERIOD FEDERAL TAX RETURN" shall have the meaning set forth
in Section 6.10.

         "1997 FEDERAL TAX RETURNS" shall have the meaning set forth in Section
6.10.

         "NLRB" shall mean the National Labor Relations Board.

         "NOVAGEN BRAND NET SALES" shall mean, as to any given fiscal year, the
gross amount received by the Buyer and its Subsidiaries on a consolidated basis
from sales to any Person of 

                                      -6-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   14
Novagen Brand Products, including but not limited to sales to third party
manufacturers for use in products with another label or brand and intercompany
sales to Buyer or its Affiliates, after deducting, where applicable, the
following:

                  (a)      normal and customary trade discounts actually allowed
                           and taken;

                  (b)      returns and credits;

                  (c)      taxes (the legal incidence of which is on a purchase
                           and separately shown on a shipping invoice); and

                  (d)      transportation, insurance and postage charges (if
                           prepaid and invoiced as a separate item).

Sales to related parties shall be priced as if made on an arm's length basis to
an outside third party at the Company's or the Buyer's published sales price.

         "NOVAGEN BRAND PRODUCT" shall mean any Products having a Novagen Part
Number or Novagen Label, whether or not sold under the Novagen Label by the
Company, the Buyer or its Subsidiaries, including any Product currently sold by
the Company, together with any new Product which the Company may develop or
cause to be developed. Products sold by the Buyer and its Subsidiaries shall be
classified as "Novagen Brand Products" by reference to their having a Novagen
Part Number or Novagen Label without regard to the catalog or other type of
sales media in which they are listed.

         "NOVAGEN LABEL" shall mean the label attached to a Product which
identifies the Company.

         "NOVAGEN PART NUMBER" shall mean the number attributed by the Company
to a Product.

         "OCCURRENCE" shall have the meaning set forth in Section 3.23.

         "PARENT" shall have the meaning set forth in the recitals to this
Agreement.

         "PARENT AUDITED FINANCIAL STATEMENTS" shall have the meaning set forth
in Section 4.7.

         "PARENT COMMON STOCK" shall have the meaning set forth in the recitals
to this Agreement.

         "PARENT CONTRACT" shall have the meaning set forth in Section 4.14.

         "PARENT EMPLOYEE BENEFIT PLANS" has the meaning set forth in Section
4.17(a).

         "PARENT FINANCIAL STATEMENTS" shall have the meaning set forth in
Section 4.7.

                                      -7-
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   15
         "PARENT LEASE" shall mean the Lease Agreement dated June 3, 1983,
between the Parent and Teachers Insurance and Annuity Association of America, as
last amended by the Sixth Amendment to Lease, dated January 31, 1997 (as the
same may be amended, supplemented and modified from time to time).

         "PARENT LIABILITIES" shall mean all of the debts, obligations, or
liabilities, if any, of the Parent as of the Closing Date, of whatsoever kind,
whether contingent or otherwise, whether known or unknown.

         "PARENT PENSION PLAN" has the meaning set forth in Section 4.17(a).

         "PARENT SHARES" shall mean, as of the date of this Agreement, the
issued and outstanding shares of Parent Common Stock.

         "PBGC" shall mean the Pension Benefit Guaranty Corporation, or any
successor thereof.

         "PERSON" shall mean an individual, corporation, partnership, limited
liability company, joint-stock company, trust or unincorporated organization,
and a government or agency or political subdivision thereof.

         "PFRM" shall have the meaning set forth in the recitals to this
Agreement.

         "POLICIES" shall have the meaning set forth in Section 3.24.

         "PRE-CLOSING TAX PERIOD" shall mean any taxable period ending on or
before the Effective Date and the portion ending on and including the Effective
Date of any Straddle Period.

         "PRODUCT" shall mean any component, substance or material manufactured
by Novagen or any third party manufacturer under contract to Novagen, whether
sold separately or combined to form a kit with other articles.

         [*******************************************************************]

         "PROMEGA DISPUTE" shall mean the dispute involving patent infringement
and other matters in the case of Promega Corporation v. Novagen, Incorporated,
No 96-C-0164-C, in the United States District Court for the Western District of
Wisconsin, including all appeals therefrom and other actions relating to the
causes of action and underlying facts and patents involved in such case.


         [*********************************************************************
********************************************]

         "PROMEGA EUROPEAN APPLICATION MATTER" shall mean the actions by the
Company in opposition to patent EPO 566714B1 of Promega Corporation.

                                      -8-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   16
         "PROPERTY TAXES" shall have the meaning set forth in Section 6.10.

         "PURCHASE PRICE" shall mean the sum of (a) the Initial Payment and, (b)
any Earn-Out Amounts, including Adjustment Amounts, if any, (x) plus the Final
Purchase Price Adjustment if such amount is payable to the Sellers or (y) minus
the Final Purchase Price Adjustment if such amount is payable to the Buyer.

         "REAL PROPERTY LEASES" shall have the meaning set forth in Section
3.10.

         "RECEIVING PARTY" shall have the meaning set forth in Section 6.9.

         "REDEEMED SHARES" shall have the meaning set forth in the recitals to
this Agreement.

         "REDEMPTION TRANSACTION" shall have the meaning set forth in the
recitals to this Agreement.

         "REMAINING PARENT SHARES" shall have the meaning set forth in the
recitals to this Agreement.

         "RESET THRESHOLD TARGET FOR 1999" shall have the meaning set forth in
the definition of Threshold Amount.

         "RETENTION BONUS POOL" shall have the meaning set forth in Section
6.15(i).

         "SELLERS" shall have the meaning set forth in the recitals to this
Agreement.

         "SELLERS' AGENTS" shall have the meaning set forth in Section 11.1.

         "SELLERS' ESCROW AGREEMENT" shall mean the Sellers' Escrow Agreement in
the form attached hereto as Exhibit E.

         "SELLERS' PROPOSED PURCHASE PRICE ADJUSTMENT" shall have the meaning
set forth in Section 2.4(b).

         "SEVERANCE AGREEMENTS" shall mean the Employment Termination Agreement
dated June 23, 1997 between the Parent and Linda Kunz, including all exhibits
thereto, and the Employment Termination Agreement dated July 31, 1997 between
the Parent and Charyl Olander, including all exhibits thereto.

         "SHARES" shall mean the Remaining Parent Shares and the Company
Minority Shares.

                                      -9-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   17
         [*********************************************************************
*******************************************************************************
*******************************************************************************
*******************************************************************************
*******]

         "STRADDLE PERIOD" shall mean any taxable period of the Parent or the
Company that includes (but does not end on) the Effective Date.

         "STRADDLE TAX RETURN" shall mean any Tax Return required to be filed by
the Parent or the Company covering a taxable period commencing prior to the
Effective Date and ending after the Effective Date.

         "SUBSIDIARY" of any Person means any corporation, association,
partnership or other business entity of which a majority of the combined voting
power of all voting stock or other interests 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 or controlled, directly or indirectly,
through one or more intermediaries, or both, by such Person.

         "TAX" or "TAXES" shall mean any and all federal, state, local, foreign
and other taxes, levies, fees, imposts, duties and charges of whatever kind
(including any interest, penalties or additions to the tax imposed in connection
therewith or with respect thereto), whether or not imposed on the Parent or the
Company, including, without limitation, taxes imposed on, or measured by,
income, franchise, profits or gross receipts, and also ad valorem, value added,
sales, use, service, real or personal property, capital stock, license, payroll,
withholding, employment, social security, workers' compensation, unemployment
compensation, utility, severance, production, excise, stamp, occupation,
premium, windfall profits, transfer and gains taxes and customs duties.

         "TAX CLAIM" shall have the meaning set forth in Section 9.3.

         "TAX RETURNS" shall mean returns, reports, information statements and
other documentation (including any additional or supporting material) filed or
maintained, or required to be filed or maintained, in connection with the
calculation, determination, assessment or collection of any Tax and shall
include any amended returns required as a result of examination adjustments made
by the Internal Revenue Service or other Tax authority.

         "THRESHOLD AMOUNT" shall mean (a) $5,400,000 for the year ending
December 31, 1998, (b) $7,200,000 for the year ending December 31, 1999, and (c)
$9,700,000 for the year ending December 31, 2000; provided, however, that if
Novagen Brand Net Sales are less than $5,400,000 for the year ending December
31, 1998, then the amount set forth in (b) above shall be the product of Novagen
Brand Net Sales for the year ending December 31, 1998 multiplied by 1.34 (the
"RESET THRESHOLD TARGET FOR 1999") and the amount set forth in (c) above shall
be the product of the Reset Threshold Target for 1999 multiplied by 1.35.

                                      -10-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   18
         "TRI-STATE" shall have the meaning set forth in the recitals to this
Agreement.

         "VECTOR AGREEMENTS" shall mean the letter agreements, dated August 1,
1997, between the Parent and Vector Securities International, Inc.

         "WARN" means the Worker Adjustment and Retraining Notification Act and
any similar state or local "plant closing" law.

                                   ARTICLE II.
                                SALE AND PURCHASE

         SECTION 2.1. AGREEMENT TO SELL AND TO PURCHASE. On the Closing Date and
upon the terms and subject to the conditions set forth in this Agreement, (i)
Dubbell shall sell, assign, transfer, convey and deliver the Remaining Parent
Shares, free and clear of any liens, claims, charges, security interests or
other legal or equitable encumbrances, limitations or restrictions, to the
Buyer, and the Buyer shall purchase and accept the Remaining Parent Shares from
Dubbell, and (ii) the Company Minority Shareholders shall sell, assign,
transfer, convey and deliver the Company Minority Shares, free and clear of any
liens, claims, charges, security interests or other legal or equitable
encumbrances, limitations or restrictions, to the Buyer, and the Buyer shall
purchase and accept the Company Minority Shares from the Company Minority
Shareholders.

         SECTION 2.2. CLOSING. The closing of such purchases and sales (the
"CLOSING") shall take place at 10:00 A.M., on January 2, 1998 or such later date
that is the next Business Day after the Business Day on which each condition
described in Articles VII and VIII are satisfied or waived (the "CLOSING DATE"),
other than those conditions that can be satisfied only on the Closing Date, at
the offices of Willkie Farr & Gallagher, One Citicorp Center, 153 East 53rd
Street, New York, New York 10022, or at such other place as the Buyer and the
Sellers' Agents shall agree in writing. The Closing Date may be postponed to
such other time and date as the Buyer and the Sellers' Agents shall agree in
writing. At the Closing, (i) Dubbell shall deliver to the Buyer or its designees
stock certificates representing the Remaining Parent Shares, duly endorsed in
blank for transfer or accompanied by appropriate stock powers duly executed in
blank, with all taxes, direct or indirect, attributable to the transfer of the
Remaining Parent Shares paid or provided for and (ii) the Company Minority
Shareholders shall deliver to the Buyer or its designees stock certificates
representing the Company Minority Shares, duly endorsed in blank for transfer or
accompanied by appropriate stock powers duly executed in blank, with all taxes,
direct or indirect, attributable to the transfer of the Company Minority Shares
paid or provided for. In full consideration and exchange for the Remaining
Parent Shares and the Company Minority Shares, the Buyer shall thereupon pay to
the Sellers the Purchase Price in accordance with the provisions of Section 2.3
hereof.

         SECTION 2.3. PURCHASE PRICE; [**************]; EARN-OUT AMOUNT. The
Purchase Price for the Shares shall be paid as follows:

                                      -11-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   19
                  (a) On the Closing Date, the Buyer shall pay to the Sellers'
         Agents an amount equal to the Initial Payment,
         [************************************************] which payment shall
         be made by wire transfer in immediately available funds to the bank
         account specified by the Sellers' Agents in written instructions to the
         Buyer at least five (5) Business Days prior to the Closing Date and
         shall be held and distributed by the Sellers' Agents pursuant to the
         terms of the Sellers' Escrow Agreement.
         [*********************************************************************
         **********************************************************************
         ************************************************************]

                  (b) (i) On or prior to the March 31 following each of the
         years ending December 31, 1998, 1999 and 2000, the Buyer shall deliver
         to the Sellers' Agents a Certification of Novagen Brand Net Sales for
         the most recently completed fiscal year. If a Certification of Novagen
         Brand Net Sales indicates that an Earn-Out Amount is due to the
         Sellers, then simultaneously with the delivery of such Certification,
         the Buyer shall deliver to the Sellers' Agents a certified check in an
         amount equal to the aggregate Earn-Out Amount due to the Sellers, such
         amount to be held and distributed by the Sellers' Agents pursuant to
         the terms of the Sellers' Escrow Agreement.

                           (ii) During the Earn-Out Period, the Buyer shall keep
         complete and accurate records of Novagen Brand Net Sales in sufficient
         detail to enable the Sellers' Agents to verify payments owed to the
         Sellers under this Agreement in respect of any Earn-Out Amount. The
         Buyers shall permit Sellers' Agents to have reasonable access to such
         records annually, including the Buyer's detailed sales reports
         identifying sales by individual product, at the offices of the Buyer.
         If Dubbell's Agent notifies the Buyer that he has reasonable grounds to
         believe that the amount due in respect of an Earn-Out Amount is greater
         than the amount specified in the Certification of Novagen Brand Net
         Sales (which notice shall be delivered to the Buyer within sixty (60)
         days after the delivery of the applicable Certification of Novagen
         Brand Net Sales), the Buyer shall permit a certified public accountant
         appointed by the Sellers' Agents at Sellers' expense, to examine the
         Buyer's books, ledgers and records covering Novagen Brand Net Sales
         during regular business hours for the purpose of verifying, and only to
         the extent necessary to verify, whether any additional amount is due to
         each Seller (the "ADJUSTMENT AMOUNT"), but in no event shall such
         procedure be conducted more than once for each calendar year period.
         The accountant shall maintain all information received during such
         examination in strict confidence, and shall report to the Sellers'
         Agents only with respect to the accuracy of any Earn-Out Amount. In the
         event the records examined reveal that the Buyer has paid less than the
         amount due the Sellers in respect of the Earn-Out Amount in question,
         the Buyer shall pay the appropriate Adjustment Amount due to the
         Sellers based on such audit plus accrued interest on such additional
         amount at the base, prime, or similar interest rate in effect for the
         period covered by the audit as set by Citibank, N.A. and if the records
         examined reveal that the Buyer has paid less than ninety-five percent
         (95%) of the amount due the Sellers in respect of the Earn-Out Amount
         in question, the Buyer shall also pay the

                                      -12-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   20
         reasonable costs of the audit. In the event the records examined reveal
         that the Buyer has paid more than the amount due in respect of the
         Earn-Out Amount in question, the Sellers shall not be obligated to
         return any amounts to the Buyer. Payment of the amount due to the
         Sellers in respect of any Adjustment Amount shall be made by delivering
         a certified check payable to the order of the Sellers' Agents to be
         held and distributed by the Sellers' Agents pursuant to the terms of
         the Sellers' Escrow Agreement.

         SECTION 2.4. PREPARATION OF EFFECTIVE DATE FINANCIAL STATEMENTS;
PURCHASE PRICE ADJUSTMENT.

                  (a) (i) Prior to the execution of this Agreement, the Sellers
         have caused to be prepared and have delivered to the Buyer: the
         unaudited interim consolidated balance sheet of the Parent and its
         Subsidiaries as of September 27, 1997, and the unaudited interim
         balance sheet of the Company as of September 27, 1997, together with
         the related unaudited consolidated statements of income for the Parent
         and the Company for the period then ended and (ii) at the time of
         execution of this Agreement, the Sellers shall cause to be prepared and
         delivered to the Buyer a certificate signed by the Sellers' Agents
         certifying the amount of the stockholders' equity of the Company as of
         September 27, 1997 as reflected in such financial statements (the
         "COMPANY SEPTEMBER 27 STOCKHOLDERS EQUITY"). Such financial statements
         and the data reflected in such certificate shall have been derived from
         the Company Unaudited Interim Financial Statements, which financial
         statements are subject to any year-end adjustments which appropriately
         apply to such unaudited interim financial statements.

                  (b) Promptly after the Closing Date, the Sellers shall cause
         to be prepared the consolidated balance sheet of the Parent, together
         with a supplemental consolidating balance sheet of Parent and the
         Company, as of December 27, 1997, together with the respective related
         consolidated and supplemental consolidating statements of income,
         shareholders' equity and cash flows for the year then ended, which
         financial statements shall reflect the consummation of the Redemption
         Transaction (the "EFFECTIVE DATE FINANCIAL STATEMENTS"). The Effective
         Date Financial Statements shall be prepared in accordance with GAAP
         applied on a basis consistent with that used in, and in accordance with
         the same accounting principles applied in, the preparation of the
         Parent Audited Financial Statements and shall include all such
         information and schedules as are required by Regulation S-X of the
         Securities and Exchange Commission to permit their inclusion in the
         securities law filings of the Buyer. The Sellers shall cause Coopers &
         Lybrand L.L.P. ("C&L") to audit the Effective Date Financial Statements
         and shall cause C&L to issue, on or prior to February 28, 1998, an
         opinion containing no qualifications or exceptions with respect to the
         scope of its audit or otherwise, on the Effective Date Financial
         Statements that such accountants have audited the Effective Date
         Financial Statements in accordance with generally accepted auditing
         standards and that the Effective Date Financial Statements were
         prepared in accordance with GAAP. The Sellers shall cause the Effective
         Date Financial Statements together with the opinion of C&L referenced
         above to be 

                                      -13-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   21
         delivered to the Buyer on or prior to February 28, 1998. Ernst & Young,
         LLP ("E&Y") shall have access to C&L's work papers and personnel,
         subject to an officer of the Buyer and a partner of E&Y signing an
         appropriate hold harmless letter. Simultaneously with the delivery of
         the Effective Date Financial Statements, Sellers shall deliver to Buyer
         a certificate signed by the Sellers' Agents setting forth a schedule
         sufficient to permit an analysis of the stockholders' equity of the
         Company as of the Effective Date and certifying (i) such schedule has
         been properly derived from the Effective Date Financial Statements,
         (ii) the amount of the stockholders equity of the Company as of the
         Effective Date as reflected on such schedule (the "COMPANY EFFECTIVE
         DATE STOCKHOLDERS EQUITY") and (iii) a calculation of the difference
         between the Company September 27 Stockholders Equity and the Company
         Effective Date Stockholders Equity (the "SELLERS' PROPOSED PURCHASE
         PRICE ADJUSTMENT"). After the Closing, Buyer shall give Sellers and C&L
         such access to personnel and books and records as may be required for
         Sellers to fulfill their obligation under this Section 2.4(b).

                  (c) The Buyer shall have the right to dispute Sellers'
         Proposed Purchase Price Adjustment during a fifteen (15) day period
         following the delivery of the certificate described in Section 2.4(b)
         by delivering a dispute notice to the Sellers' Agents (a "DISPUTE
         NOTICE") setting forth in reasonable detail its disputes with the
         Sellers regarding the amount of the Company Effective Date Stockholders
         Equity or the calculation of the purchase price adjustment, and setting
         forth Buyer's proposed purchase price adjustment (the "BUYER'S PROPOSED
         PURCHASE PRICE ADJUSTMENT"). In the absence of the delivery of a
         Dispute Notice, or if the Buyer affirmatively notifies the Sellers'
         Agents that it agrees with Seller's Proposed Purchase Price Adjustment,
         the Sellers' Proposed Purchase Price Adjustment shall be deemed to be
         final and shall become the "FINAL PURCHASE PRICE ADJUSTMENT." If a
         Dispute Notice is delivered, the parties shall have a period of thirty
         (30) days after delivery of the Dispute Notice in which they shall
         seek, in good faith, together with their respective accountants to
         resolve the matters in dispute. If such matters are resolved by the
         parties, the Company Effective Date Stockholders Equity and the Final
         Payment Price Adjustment shall be as so agreed. If at the conclusion of
         such thirty (30) day period, the parties have been unable to resolve
         such dispute, the dispute shall be referred to a third firm of
         independent public accountants of recognized national standing that is
         not then engaged by either the Sellers or the Buyer to resolve such
         dispute. Such firm shall be instructed that it shall have authority to
         resolve the dispute only by selecting either the Sellers' Proposed
         Purchase Price Adjustment or the Buyer's Proposed Purchase Price
         Adjustment, whichever such firm considers as most closely reflecting
         the correct determination consistent with this Agreement. The purchase
         price adjustment selected by such third firm of accountants shall
         become the Final Purchase Price Adjustment, the amount of the Company
         Effective Date Stockholders Equity shall be adjusted accordingly and
         each shall be binding on all parties hereto. The parties shall
         cooperate fully with such third party accountants and provide such firm
         with access to personnel and work papers, with a view to permitting
         such firm to make its determination within 

                                      -14-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   22
         thirty (30) days after submission to it of the dispute. The fees of
         such firm shall be paid by the party whose proposed purchase price
         adjustment is not selected by such firm.

                  (d) Within five (5) days after the determination of the Final
         Purchase Price Adjustment as called for in the foregoing paragraphs:

                           (i) if the Company Effective Date Stockholders Equity
         exceeds the Company September 27 Stockholders Equity, the Buyer shall
         deliver a certified check in an amount equal to the Final Purchase
         Price Adjustment payable to the order of the Sellers' Agents to be held
         and distributed by the Sellers' Agents pursuant to the terms of the
         Sellers' Escrow Agreement; and

                           (ii) if the Company September 27 Stockholders Equity
         exceeds the Company Effective Date Stockholders Equity, the Sellers
         shall cause the Sellers' Agents to deliver a certified check to the
         Buyer, payable to the order of the Buyer, in an amount equal to the
         Final Purchase Price Adjustment.

                                  ARTICLE III.
                  REPRESENTATIONS AND WARRANTIES OF THE SELLERS

         Each of the Sellers hereby jointly and severally represents, warrants
and agrees (except with respect to Sections 3.1 and 3.2 to which each severally
represents, warrants and agrees) as follows:

         SECTION 3.1. OWNERSHIP; TITLE TO THE SHARES. Dubbell owns the Parent
Shares and will own at and as of the Closing the Remaining Parent Shares, in
each case free and clear of any lien, charge or encumbrance, and at and as of
the Closing there shall be no issued and outstanding shares of capital stock of
the Parent other than the Remaining Parent Shares. Each of the Company Minority
Shareholders and the Parent owns, free and clear of any lien, charge or
encumbrance, all of the shares of common stock, no par value, of the Company
(the "COMPANY COMMON STOCK") set forth after the name of such Minority
Shareholder and the Parent on EXHIBIT A-1 hereto and will own at and as of the
Closing Date, free and clear of any lien, charge or encumbrance, all of the
shares of Company Common Stock set forth after the name of such Minority
Shareholder and the Parent on EXHIBIT A-2 hereto.

         SECTION 3.2. AUTHORITY. This Agreement constitutes a valid and binding
obligation of each Seller (subject to normal equitable principles and subject to
bankruptcy, insolvency, fraudulent conveyance and similar laws affecting the
rights of creditors) and this Agreement and all transactions contemplated hereby
will not result in a violation of any of the terms and provisions of any
agreement to which such Seller is a party or by which such Seller is otherwise
bound.

         SECTION 3.3. CORPORATE ORGANIZATION. The Company is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Arkansas and

                                      -15-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   23
has all requisite corporate power and authority and all governmental licenses,
authorizations, permits, consents and approvals to own its properties and assets
and to conduct its businesses as now conducted. The Company is duly qualified to
do business as a foreign corporation and is in good standing in every
jurisdiction where the character of the properties owned or leased by it or the
nature of the business conducted by it makes such qualification necessary,
except in any jurisdiction where the failure to be so qualified would not have a
material adverse effect on the business, results of operations or the condition
(financial or otherwise) of the Company. Section 3.3 of the Disclosure Schedule
sets forth all of the jurisdictions in which the Company is qualified to do
business. The copies of the articles of incorporation and by-laws of the Company
included as part of Section 3.3 of the Disclosure Schedule constitute accurate
and complete copies of such organizational instruments and accurately reflect
all amendments thereto through the date hereof.

         SECTION 3.4. CAPITALIZATION. The authorized capital stock of the
Company consists of 5,000 shares of Company Common Stock, all of which are
issued and outstanding. As of the date hereof, such shares of Company Common
Stock are owned of record and beneficially by the Persons in the amounts set
forth opposite their names on EXHIBIT A-1 hereto, and at and as of to the
Closing Date, such shares of Company Common Stock will be owned of record and
beneficially by the Persons in the amounts set forth on EXHIBIT A-2 hereto. Such
shares of Company Common Stock represent all of the issued and outstanding
shares of capital stock of the Company. All shares of Company Common Stock have
been duly authorized and validly issued and are fully paid and nonassessable.
There are no outstanding options, warrants, agreements, conversion rights,
preemptive rights or other rights to subscribe for, purchase or otherwise
acquire any shares of Company Common Stock, and there are no outstanding
obligations of the Company to repurchase, redeem or otherwise acquire
outstanding shares of Company Common Stock.

         SECTION 3.5. SUBSIDIARIES. The Company does not own any shares of, or
control, directly or indirectly, or have any equity interest in, any Person.

         SECTION 3.6. NO CONFLICT OR VIOLATION.

                  (a) Except as set forth in Section 3.6 of the Disclosure
         Schedule, the execution, delivery and performance by the Sellers of
         this Agreement and the transactions contemplated hereby do not and will
         not: (i) violate or conflict with any provision of the articles of
         incorporation or by-laws of the Company; (ii) violate any provision of
         law, statute, judgment, order, writ, injunction, decree, award, rule,
         or regulation of any court, arbitrator, or other governmental or
         regulatory authority applicable to the Company; (iii) violate, result
         in a breach of, constitute (with due notice or lapse of time or both) a
         default or cause any obligation, penalty, premium, right of termination
         or acceleration to arise, accrue or occur under any material contract,
         lease, loan agreement, mortgage, security agreement, trust indenture or
         other agreement or instrument to which the Company is a party or by
         which the Company is bound or to which its properties or assets are
         subject; (iv) result in the creation or 

                                      -16-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   24
         imposition of any lien, charge or encumbrance of any kind whatsoever
         upon any of the properties or assets of the Company; or (v) result in
         the cancellation, modification, revocation or suspension of any
         License.

                  (b) Except as set forth in Section 3.6 of the Disclosure
         Schedule, to the best of each Seller's knowledge, neither the purchase
         of the Remaining Parent Shares and the Company Minority Shares by the
         Buyer nor the consummation of the transactions contemplated by this
         Agreement will result in any material adverse change in the business
         operations of the Company or in the loss of the benefits of any
         relationship with any customer or supplier.

         SECTION 3.7. CONSENTS AND APPROVALS. Section 3.7 of the Disclosure
Schedule sets forth a true and complete list of each consent, waiver,
authorization or approval of any governmental or regulatory authority, domestic
or foreign, or any other Person, and each declaration to or filing or
registration with any such governmental or regulatory authority, that is
required of or to be made by the Company in connection with the execution,
delivery and performance of this Agreement.

         SECTION 3.8.  FINANCIAL STATEMENTS.

                  (a) Section 3.8 of the Disclosure Schedule includes copies of
         (x) the audited balance sheet of the Company as of December 28, 1996,
         together with the related statements of income, shareholders' equity
         and cash flows for the year then ended and the notes thereto (the
         "COMPANY AUDITED FINANCIAL STATEMENTS") and (y) the unaudited interim
         balance sheet of the Company as of September 27, 1997, together with
         the related unaudited statement of income for the nine-month period
         then ended (the "COMPANY UNAUDITED INTERIM FINANCIAL STATEMENTS" and,
         together with the Company Audited Financial Statements, the "COMPANY
         FINANCIAL STATEMENTS"). The Company Financial Statements, including the
         notes thereto: (i) were prepared in accordance with GAAP applied on a
         consistent basis throughout the periods covered thereby; (ii) present
         fairly the financial position, results of operations and cash flows of
         the Company as of such dates and for the periods then ended (subject,
         in the case of the Company Unaudited Interim Financial Statements, to
         normal year-end audit adjustments consistent with prior periods and to
         possible damages related to the Promega Dispute); and (iii) are
         complete in all material respects, correct and in accordance with the
         books of account and records of the Company.

                  (b) Except as set forth in Section 3.8 of the Disclosure
         Schedule, the Company has no commitments to make any capital
         expenditures or to invest, advance or loan any monies to any Persons in
         excess of $10,000.

                                      -17-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   25
         SECTION 3.9. LIABILITIES FOR BORROWED MONEY; ABSENCE OF UNDISCLOSED
LIABILITIES; GUARANTEES.

                  (a) Section 3.9 of the Disclosure Schedule sets forth as of
         the date hereof a true and complete list of all indebtedness for
         borrowed money due from the Company to any Person.

                  (b) The Company has no indebtedness or liability, direct or
         indirect, absolute or, to the knowledge of any Seller, contingent,
         which is required by GAAP to be shown or provided for on the balance
         sheet of the Company included in the Company Unaudited Interim
         Financial Statements other than as shown on such balance sheet and
         other than liabilities incurred or accrued in the ordinary course of
         business (including liens for current Taxes and assessments not in
         default) since September 27, 1997 and there is no existing condition,
         situation or set of circumstances which could reasonably be expected to
         result in such a liability except for the Promega Dispute. Except as
         disclosed in Section 3.9 of the Disclosure Schedule or as shown in such
         balance sheet or in the notes to the Company Unaudited Interim
         Financial Statements, the Company is not, directly or indirectly,
         liable upon or with respect to (by discount, repurchase agreements or
         otherwise), or obligated in any other way to provide funds in respect
         of, or to guarantee or assume, any debt, obligation or dividend of any
         person, except endorsements in the ordinary course of business in
         connection with the deposit of items for collection.

         SECTION 3.10.  INTERESTS IN REAL PROPERTY.

                  (a) The Company does not own and has never owned any real
         property. Section 3.10 of the Disclosure Schedule sets forth a true and
         complete list of all real properties leased by the Company. Except as
         disclosed in Section 3.10 of the Disclosure Schedule, the Company has
         good and transferable leaseholds in all real property shown in Section
         3.10 of the Disclosure Schedule as leased by it (all such leases being
         referred to herein as "REAL PROPERTY LEASES"). To any Seller's
         knowledge each of the Real Property Leases is valid and enforceable. To
         any Seller's knowledge there does not exist under any Real Property
         Lease any default by the Company or any landlord or any event which
         with notice or lapse of time or both would constitute a default by
         either the Company or the landlord. Except as disclosed in Section 3.10
         of the Disclosure Schedule, none of the Company's interests in real
         property leased by the Company is subject to any liens (other than a
         lien of current property Taxes and assessments not in default, if any),
         mortgages or encumbrances; and none of such real properties is subject
         to any easement, right of way, license, grant, building or use
         restriction, exception, reservation, limitation or other impediment
         which materially and adversely affects the value thereof to the Company
         or which interferes with or impairs the present and continued use
         thereof in the usual and normal conduct of the business of the Company.
         Sellers have no reason to believe, nor have they attempted to determine
         whether improvements on all real property leased or

                                      -18-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   26
         used by the Company and the operations therein conducted fail to
         conform in all material respects to all applicable health, fire,
         environmental, safety, zoning and building laws, ordinances and
         administrative regulations, except for nonconforming uses or violations
         which do not and will not expose any person or property to injury or
         damage, adversely affect any insurance coverage, give rise to strict
         liability, penalties or fines, jeopardize any Licenses or Environmental
         Permits, or interfere materially in any respect with the present use,
         operation or maintenance thereof by the Company as now used, operated
         or maintained, or which do not and will not materially and adversely
         affect the value thereof. All buildings, structures, improvements and
         fixtures owned, leased or used by the Company in the conduct of its
         business are in good operating condition and repair.

                  (b) There are no outstanding requirements or recommendations
         by any insurance company which has issued a policy covering any real
         property leased or used by the Company, or by any board of fire
         underwriters or other body exercising similar functions, requiring or
         recommending any repairs or work to be done on any such property.

                  (c) None of the Company's leased real properties is subject to
         any sublease, license or other agreement granting to any person any
         right to the use, occupancy or enjoyment of such property or any
         portion thereof.

         SECTION 3.11. PERSONAL PROPERTY. Section 3.11 of the Disclosure
Schedule sets forth a complete and correct list and brief description of each
item of equipment, furniture, fixtures and other tangible personal property (the
"FURNITURE, FIXTURES AND EQUIPMENT") individually having an original purchase
cost or aggregate lease cost exceeding $5,000 owned or leased by the Company,
including vehicles, if any. Except as set forth in Section 3.11 of the
Disclosure Schedule, the Company owns outright and has good title, free and
clear of all title defects and objections, security interests, liens, charges
and encumbrances of any nature whatsoever (other than the lien of current
property Taxes and assessments not in default, if any) to the Furniture,
Fixtures and Equipment owned by it and to all the machinery, equipment,
furniture and fixtures reflected on the balance sheet included in the Company
Unaudited Interim Financial Statements and all such property acquired since the
date thereof, except for any of such property which has been sold or disposed of
in the ordinary course of business. None of the title defects, objections,
security interests, liens, charges or encumbrances (if any) listed in Section
3.11 of the Disclosure Schedule materially and adversely affects the value of
any of the items of personal property to which it relates or interferes with its
use in the conduct of business of the Company. Except as set forth in Section
3.11 of the Disclosure Schedule, the Company holds good and transferable
leaseholds under valid and enforceable leases in all of the Furniture, Fixtures
and Equipment leased by it, and none of such Furniture, Fixtures and Equipment
leased by the Company is subject to any sublease, license or other agreement
granting to any person any right to use such property (all such leases,
subleases, licenses and other agreements are collectively referred to herein as
"FURNITURE, FIXTURES AND EQUIPMENT LEASES"). To the knowledge of any Seller, all

                                      -19-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   27
Furniture, Fixtures and Equipment Leases are valid and enforceable. The Company
is not in breach of or default (and no event has occurred which, with due notice
or lapse of time or both, may constitute such a lapse or default) of any
provision of any of the Furniture, Fixtures and Equipment Leases. The Furniture,
Fixtures and Equipment and other personal property now owned, leased or used by
the Company is sufficient and adequate to carry on its business as presently
conducted and all items thereof are in good operating condition and repair. The
Company does not hold any personal property of any other person, firm or
corporation pursuant to any consignment or similar arrangement.

         SECTION 3.12.  INTELLECTUAL PROPERTY; INTANGIBLE ASSETS.

                  (a) Section 3.12 of the Disclosure Schedule sets forth a
         complete and correct listing of the Intellectual Property. Except as
         described in Section 3.12 of the Disclosure Schedule, all Intellectual
         Property listed therein is owned by the Company, free and clear of all
         liens, security interests and encumbrances of any nature whatsoever and
         is not known to be the subject of any challenge. The Intellectual
         Property is valid, subsisting, unexpired, in proper form and, to the
         knowledge of any Seller, enforceable and all renewal fees and other
         maintenance fees which have fallen due on or prior to the date of this
         Agreement have been paid. The grants, registrations and applications
         for the Intellectual Property have not lapsed, expired or been
         abandoned and no application or registration thereof is the subject of
         any legal or governmental proceeding before any governmental,
         registration or other authority in any jurisdiction. As of the date
         hereof, except as described in Section 3.12 of the Disclosure Schedule,
         there are no unresolved claims, suits or actions made and to the
         knowledge of any Seller, there has not been communicated to the Company
         the threat of any claim that the Company is in violation or
         infringement of any Intellectual Property of any other Person. Except
         as disclosed in Section 3.12 of the Disclosure Schedule, the Company is
         the owner of, or has a valid license to use, the Intellectual Property
         necessary for the conduct of its business as now conducted, without any
         known conflict with the rights of others, and the Company has not
         knowingly forfeited or otherwise relinquished any Intellectual Property
         necessary for the conduct of its business as now conducted. The Company
         has not entered into any material consent, indemnification, forbearance
         to sue, settlement agreement or cross-licensing arrangement with any
         person relating to the Intellectual Property of any third party other
         than as may be contained in the license agreements listed in Schedule
         3.12 of the Disclosure Schedule. Except as disclosed in Section 3.12 of
         the Disclosure Schedule, the Company is not under any obligation to pay
         any royalties or similar payments in connection with any license to any
         of its Affiliates. Except as set forth on Schedule 3.12 of the
         Disclosure Schedule, the Company is not, nor will it be as a result of
         the execution and delivery of this Agreement or the performance by the
         Sellers of their obligations under this Agreement, in breach of any
         license, sublicense or other agreement relating to the Intellectual
         Property. The validity and enforceability of the Intellectual Property
         and the registration thereof has not been impugned or otherwise
         affected adversely as a result of the consummation of the transactions
         contemplated by 

                                      -20-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   28
         this Agreement. No present, and to the knowledge of any Seller, no
         former, employees, officers or directors of the Company hold any right,
         title or interest directly or indirectly, in whole or in part, in or to
         any Intellectual Property.

                  (b) Except as shown in Section 3.12 of the Disclosure
         Schedule, there is no restriction affecting the use of any of the
         Intangible Assets (other than with respect to Intangible Assets that
         the Company holds by virtue of license arrangements), and no license
         has been granted by the Company with respect thereto. None of the
         Intangible Assets is currently being challenged, is involved in any
         pending or threatened administrative or judicial proceeding, or, to the
         knowledge of Company, conflicts with any rights of any other person,
         firm or corporation. The Company owns or has the right to use all
         computer software, software systems and databases and all other
         information systems necessary for the conduct of its business. The
         Company's rights in and to the Intangible Assets are sufficient and
         adequate to permit the continued conduct of its business in the manner
         now conducted, and, to the knowledge of each Seller, none of the
         Products or operations of the Company's business involves any
         infringement of any proprietary right of any other Person, except as
         may be determined in the Promega Dispute.

         SECTION 3.13. COMPLIANCE WITH LAW. Except as set forth in Section 3.13
of the Disclosure Schedule, the operations of the Company have been conducted,
in all material aspects, in accordance with all applicable laws, regulations,
orders and other requirements of all courts and other governmental or regulatory
authorities having jurisdiction over the Company and its assets, properties and
operations. None of the Sellers or the Company has received notice of any
violation of any such law, regulation, order or other legal requirement, or is
in default with respect to any order, writ, judgment, award, injunction or
decree of any federal, state or local court or governmental or regulatory
authority or arbitrator, domestic or foreign, applicable to the Company or any
of its assets, properties or operations. No Seller has knowledge of any proposed
change in any such laws, rules or regulations that would adversely affect the
transactions contemplated by this Agreement or all or a substantial part of the
assets or the businesses or prospects of the Company.

         SECTION 3.14.  LICENSES, PERMITS AND GOVERNMENTAL APPROVALS.

                  (a) Section 3.14 of the Disclosure Schedule sets forth a true
         and complete list of all material licenses of the Company (including,
         but not limited to, any environmental licenses, permits, registrations
         or authorizations), health or other permits, franchises, authorizations
         and approvals issued or granted to the Company by the United States,
         any state or local government, any foreign national or local
         government, or any department, agency, board, commission, bureau or
         instrumentality of any of the foregoing (each a "LICENSE" and,
         collectively, the "LICENSES"), and all pending applications therefor.
         Each License has been issued to, and duly obtained and fully paid for
         by, the Company and is valid, in full force and effect, and not subject
         to

                                      -21-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   29
         any pending or known threatened administrative or judicial proceeding
         to suspend, revoke, cancel or declare such License invalid in any
         respect.

                  (b) The Company has all Licenses required, and such Licenses
         are sufficient and adequate in all material respects, to permit the
         continued lawful conduct of the Company's business in the manner now
         conducted and the ownership, occupancy and operation of its real and
         personal property for their present uses. The Company is not in
         violation of any of the Licenses in any material respect. The Licenses
         have never been suspended, revoked or otherwise terminated, subject to
         any fine or penalty, or subject to judicial or administrative review,
         for any reason other than the renewal or expiration thereof nor has any
         application of the Company for any License ever been denied. The
         Company's operations are not being conducted in a manner that violates
         any of the material terms or conditions under which any License was
         granted. Except as disclosed in Section 3.14 of the Disclosure
         Schedule, to the best of Sellers' knowledge, no License will in any way
         be materially or adversely affected by, or terminate or lapse by reason
         of, the transactions contemplated by this Agreement. The Sellers have
         delivered to the Buyer or its representatives true and complete copies
         of all Licenses together with all amendments and modifications thereto.

         SECTION 3.15. ENVIRONMENTAL MATTERS. Notwithstanding anything to the
contrary contained in this Agreement and in addition to the other
representations and warranties contained herein:

                  (a) To the knowledge of any of the Sellers, the Company and
         its operations are, and in the past have been, in compliance in all
         material respects with all applicable laws, regulations and other
         requirements of governmental or regulatory authorities or duties under
         the common law relating to toxic or hazardous substances, wastes,
         pollution or to the protection of human health, safety, or the
         environment (collectively, "ENVIRONMENTAL LAWS") and have obtained and
         maintained in effect all Licenses, permits and other authorizations or
         registrations (collectively "ENVIRONMENTAL PERMITS") required under all
         Environmental Laws and are, and in the past have been, in compliance
         with all such Environmental Permits.

                  (b) To the knowledge of any of the Sellers, the Company has
         not performed or suffered any act which could give rise to, or has
         otherwise incurred, liability to any person (governmental or other)
         under CERCLA, or any other Environmental Laws, as amended, nor has the
         Company received notice of any such liability or any claim therefor or
         submitted notice pursuant to Section 103 of CERCLA to any governmental
         agency with respect to any of its assets.

                  (c) To the knowledge of any of the Sellers, no hazardous
         substance, hazardous waste, contaminant, pollutant or toxic substance
         (as such terms are defined in any applicable Environmental Law and
         collectively referred to herein as "HAZARDOUS MATERIALS") has been
         released, placed or dumped by the Company or by

                                      -22-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   30
         action of the Company otherwise come to be located on, at, beneath or
         near any of the assets or properties leased by the Company or any
         surface waters or groundwaters thereon or thereunder.

                  (d) Except as disclosed in Section 3.15 of the Disclosure
         Schedule, the Company does not own or operate, and has never owned or
         operated, aboveground or underground storage tanks containing a
         regulated substance, as such term is defined in Subchapter IX of the
         Resource Conservation and Recovery Act, 42 U.S.C. Section 6991 et seq.,
         as amended, or a surface impoundment, lagoon, landfill, PCB containing
         electrical equipment or asbestos containing materials.

                  (e) To the knowledge of any of the Sellers, with respect to
         any or all of the real properties leased by the Company: (i) there are
         no, nor have there been in the past, asbestos-containing materials,
         urea formaldehyde insulation, polychlorinated biphenyls or, to the
         knowledge of any Seller, lead-based paints present at any such
         properties; and (ii) there are no wetlands (as defined under any
         Environmental Law) located on any such properties, nor have any been
         drained, filled or otherwise altered.

                  (f) To the knowledge of any of the Sellers, except as
         disclosed in Section 3.15 of the Disclosure Schedule, none of the real
         properties leased by the Company (i) has been used or is now used for
         the generation, transportation, storage, handling, treatment or
         disposal of any Hazardous Materials or (ii) is identified on a federal,
         state or local listing of sites which require or might require
         environmental cleanup.

                  (g) To the knowledge of any of the Sellers, there are no
         ongoing investigations or negotiations, pending or threatened
         administrative, judicial or regulatory proceedings, or consent decrees
         or other agreements in effect that relate to environmental conditions
         in, on, under, about or related to the Company, its operations or the
         real properties leased by the Company.

                  (h) No Seller has been advised that, nor has any Seller sought
         advice as to whether the Company or its operations is subject to
         reporting requirements under the federal Emergency Planning and
         Community Right-to-Know Act, 42 U.S.C. Section 11001 et seq., or
         analogous state statutes and related regulations, all as amended.

         SECTION 3.16. LITIGATION. Except as set forth in Section 3.16 of the
Disclosure Schedule and except for the Promega Dispute, there are no claims,
actions, suits, proceedings, labor disputes or investigations pending or, to the
knowledge of any of the Sellers, threatened before any federal, state or local
court or governmental, administrative or regulatory authority, domestic or
foreign, or before any arbitrator of any nature, brought by or against the
Company or its officers, directors, employees, agents or any of their respective
Affiliates involving, affecting or relating to any assets, properties or
operations of the Company or the transactions contemplated by this Agreement.
Section 3.16 of the Disclosure Schedule sets forth a list and a summary
description of all such pending or known threatened actions, suits, proceedings,
disputes or investigations. None of the Sellers or the Company nor any of their

                                      -23-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   31
or the Company's assets or properties is subject to, nor to any Seller's
knowledge, does any basis exist for, any order, writ, judgment, award,
injunction or decree of any federal, state or local court or governmental or
regulatory authority or arbitrator, that materially affects the Company's
assets, properties, operations, prospects, net income or financial condition or
which would interfere with the transactions contemplated by this Agreement.

         SECTION 3.17. CONTRACTS.

                  (a) Section 3.17 of the Disclosure Schedule sets forth a
         true and complete list and a summary description showing the expiration
         dates (exclusive of renewal terms) of all contracts, agreements,
         instruments, commitments and other arrangements to which the Company is
         a party or otherwise relating to or affecting any of its assets,
         properties or operations including, without limitation, all written or
         oral, express or implied contracts, which involve an obligation or
         commitment on the part of the Company in excess of $10,000 (each, a
         "MATERIAL CONTRACT"). To the knowledge of any of the Sellers, each
         Material Contract is valid, binding and enforceable against the parties
         thereto in accordance with its terms, and in full force and effect on
         the date hereof. The Company has, in all material respects, performed
         all obligations, including, but not limited to, the timely making of
         any rental or other payments, required to be performed by it under, and
         is not in default or breach of any material provision in respect of,
         any Material Contract, and no event has occurred which, with due notice
         or lapse of time or both, would constitute such a default. The Sellers
         have delivered to the Buyer or its representatives true and complete
         originals or copies of all the Material Contracts and a copy of every
         default notice received by the Sellers or the Company during the past
         three years with respect to any of the Material Contracts.

                  (b) Except as may be disclosed in Schedule 3.17 of the
         Disclosure Schedule, to the knowledge of any of the Sellers, the
         Company is not a party to any agreement or instrument, or subject to
         any charter or other corporate restriction or any judgment, order,
         writ, injunction, decree, rule or regulation which, insofar as it
         relates to the business of the Company, materially adversely affects,
         or would in the future be reasonably expected to materially adversely
         affect, its business, prospects, operations, properties, assets or
         financial condition.

         SECTION 3.18. ACCOUNTS RECEIVABLE. All notes and accounts receivable of
the Company reflected in the Company Unaudited Interim Financial Statements, or
arising since September 27, 1997, constitute bona fide receivables of the
Company and have arisen through the ordinary course operation of the Company's
business. All notes and accounts receivable payable to or for the benefit of the
Company on the date hereof are current and collectible in amounts not less than
the aggregate amount thereof (net of reserves established in accordance with
GAAP applied consistently with prior practice) carried on the books of the
Company, and to the best of each Seller's knowledge, are not subject to any
counterclaims or set-offs. Except as set forth in Schedule 3.18, none of such
notes or accounts receivable is more than 90 days past due.

                                      -24-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   32
         SECTION 3.19. INVENTORIES.

                  (a) The inventories of the Company reflected in the Company
         Unaudited Interim Financial Statements, or acquired by the Company
         since September 27, 1997, are carried at the lower of cost or net
         realizable value determined in accordance with GAAP, and are of a type,
         quantity and quality useable and salable in the ordinary conduct of the
         Company's business. Except as disclosed in Schedule 3.19 of the
         Disclosure Schedule, all inventory is owned by the Company free and
         clear of all liens and encumbrances.

                  (b) Where necessary in connection with the manufacture of the
         Company's products, the Cell Lines, or other biological products, taken
         as a whole, are biologically active and provide the source material
         necessary to generate the biological materials included in the
         Company's products. Such Cell Lines have been properly maintained by
         the Company so as to retain their viability, minimize deterioration and
         avoid contamination, and the Company has established and maintained
         duplicate back-up stocks of the most significant of such Cell Lines
         (from the point of view of volume of sales of the Company's products
         they generate) to enable their continued production in the event of the
         expiration or contamination of the primary stocks of such Cell Lines.
         The Company has (i) manufactured or prepared the other biological
         materials included in the Company's inventory in accordance with what,
         to the knowledge of the Company constitutes good standards generally
         utilized by its competitors in the industry, (ii) maintained accurate
         quality control records by production lot of all such biological
         materials and (iii) has maintained such materials in a manner
         reasonably designed to preserve their viability and to avoid
         contamination and deterioration.

         SECTION 3.20. CATALOGS, BROCHURES AND ADVERTISEMENTS. Section 3.20 of
the Disclosure Schedule sets forth a true and complete list of catalogs, catalog
supplements, advertisements, sales brochures and marketing brochures (whether
print or other media) designed, produced and/or distributed by or for the
Company since January 1, 1996. The Sellers have delivered to the Buyer or its
representatives true and complete originals or copies of all such catalogs,
catalog supplements, advertisements, sales brochures and marketing brochures.

         SECTION 3.21. WARRANTIES. Section 3.21 of the Disclosure Schedule sets
forth the written warranties given by the Company in connection with the sale of
its Products. To the best of each Seller's knowledge the Company has given no
unwritten warranties in such connection.

         SECTION 3.22. CUSTOMERS AND SUPPLIERS. Section 3.22 of the Disclosure
Schedule sets forth a complete and correct list of (a) the ten largest suppliers
by dollar volume of the Company and the aggregate dollar volume of purchases by
the Company from such suppliers for the last fiscal year of the Company and (b)
all customers or suppliers that within the last

                                      -25-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   33
24 months have terminated any agreement, contract or other arrangement with the
Company or with whom the Company has terminated any agreement, contract or other
arrangement, in each case with or without cause, prior to the stated expiration
thereof. Except as set forth in Section 3.22 of the Disclosure Schedule, since
January 1, 1997, the Company has not at any time delivered to, or received from,
any customer or supplier any formal notice or written allegation of a default or
breach with respect to any agreement, contract or other arrangement and, to each
Seller's knowledge, none of such customers or suppliers has, or intends to
terminate or not exercise any option to renew or otherwise change significantly
its relationship with the Company. The Company has not granted any credit,
rebate, trade-in, free return or other sales terms to customers or others which
substantially differ from terms granted in the ordinary course of its business
consistent with past practice.

         SECTION 3.23. PRODUCTS LIABILITY.

                  (a) There is no notice, demand, claim, action, suit, inquiry,
         hearing, proceeding, notice of violation or investigation of a civil,
         criminal or administrative nature before any court or governmental or
         other regulatory or administrative agency, commission or authority
         against or involving any Product, or class of claims or lawsuits
         involving the same or similar Product produced, distributed or sold by
         or on behalf of the Company which is pending or, to the knowledge of
         Sellers, threatened, resulting from an alleged defect in design,
         manufacture, materials or workmanship of any Product produced,
         distributed or sold by or on behalf of the Company, or any alleged
         failure to warn, or from any breach of implied warranties or
         representations, and there has not been any Occurrence (as defined
         below) that is material to the business of the Company.

                  (b) For purposes of this Section 3.23, the term "OCCURRENCE"
         shall mean any accident, happening or event which was caused or
         allegedly caused by any alleged hazard or alleged defect in
         manufacture, design, materials or workmanship including, without
         limitation, any alleged failure to warn or any breach of express or
         implied warranties or representations with respect to, or any such
         accident, happening or event otherwise involving, a Product (including
         any parts or components) manufactured, produced, distributed or sold by
         or on behalf of the Company which is likely to result in a claim or
         loss.

         SECTION 3.24. INSURANCE.

                  (a) Section 3.24 of the Disclosure Schedule sets forth a true
         and complete list of all policies of title insurance, liability and
         casualty insurance, property insurance, auto insurance, business
         interruption insurance, tenant's insurance, workers' compensation, life
         insurance, disability insurance, excess or umbrella insurance and any
         other type of insurance insuring the properties, assets, employees
         and/or operations of the Company and indicates whether such policies
         are in the name of the Company, the Parent or an Affiliate
         (collectively, the "POLICIES"). The Sellers have furnished

                                      -26-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   34
         true, complete and accurate copies of all the Policies to the Buyer.
         All premiums payable under all such Policies have been timely paid and
         the Company has complied fully with the terms and conditions of all
         such Policies.

                  (b) Except as set forth in Section 3.24 of the Disclosure
         Schedule, all such Policies are in full force and effect and will not
         in any way be affected by or terminated or lapsed by reason of the
         consummation of the transactions contemplated by this Agreement. The
         Sellers shall use their respective best efforts to cause the Company or
         the Parent, as applicable, to maintain the coverage under all Policies
         in full force and effect through the Closing Date. Neither the Company
         nor the Parent is in default under any provisions of the Policies, and
         there is no claim by the Company or any other Person pending under any
         of the Policies as to which coverage has been questioned, denied or
         disputed by the underwriters or issuers of such Policies. Except as set
         forth in Section 3.24 of the Disclosure Schedule, none of the Sellers,
         the Company or the Parent has received any written notice from or on
         behalf of any insurance carrier or other issuer issuing such Policies
         that insurance rates or other annual premium or fee in effect as of the
         date hereof will hereafter be substantially increased (except to the
         extent that insurance rates or other fees may be increased for all
         similarly situated risks), that there will be a non-renewal,
         cancellation or increase in a deductible (or an increase in premiums in
         order to maintain an existing deductible) of any of the Policies in
         effect as of the date hereof, or that alteration of any equipment or
         any improvements to real estate occupied by or leased to or by the
         Company, purchase of additional equipment, or modification of any of
         the methods of doing business of the Company, will be required or
         suggested after the date hereof. The Policies maintained by the Company
         (and the Parent and its Affiliates on behalf of the Company) are
         adequate in accordance with the requirements of any applicable leases
         and are in at least the minimum amounts required by, and are otherwise
         sufficient for purposes of, any currently applicable law, rule, or
         regulation of any federal, state, local or foreign government, agency
         or authority, including, without limitation, environmental regulations.

         SECTION 3.25. TRANSACTIONS WITH DIRECTORS, OFFICERS AND AFFILIATES.
Except as disclosed in Section 3.25 of the Disclosure Schedule, since January 1,
1996, there have been no transactions between the Company and any director,
officer, employee, stockholder or other Affiliate of the Company or loans,
guarantees or pledges to, by or for the Company from, to, by or for any of such
persons in excess of $50,000. Since January 1, 1996, to the Sellers' knowledge,
none of the officers, directors or employees of the Company, or any spouse or
relative of any of such persons, has been a director or officer of, or has had
any direct or indirect interest in, any firm, corporation, association or
business enterprise which during such period has been a supplier, customer or
sales agent of the Company or has competed with or been engaged in any business
of the kind being conducted by the Company, except for an investment in less
than 5 percent of the outstanding equity of any such firm, corporation,
association or business enterprise, the equity of which is publicly traded.
Except with respect to their ownership interests in the Company or the Parent,
none of the Sellers or 

                                      -27-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   35
any of their Affiliates (other than the Company) owns or has any rights in or to
any of the assets, properties or rights used by the Company in the ordinary
course of its business except as disclosed in Section 3.12 of the Disclosure
Schedule.

         SECTION 3.26. PROPRIETY OF PAST PAYMENTS. Except as set forth in
Section 3.26 of the Disclosure Schedule, no finder's fee or other payment has
been, or will be, made by or on behalf of the Company in respect of, or in
connection with, any Material Contract to any person, firm, corporation or other
entity which is not a party to such Material Contract. No funds or assets of the
Company have been used for illegal purposes; no unrecorded funds or assets of
the Company have been established for any purpose; no accumulation or use of the
Company's corporate funds or assets has been made without being properly
accounted for in the respective books and records of the Company; all payments
by or on behalf of the Company have been duly and properly recorded and
accounted for in its books and records; no false or artificial entry has been
made in the books and records of the Company for any reason; no payment has been
made by or on behalf of the Company with the understanding that any part of such
payment is to be used for any purpose other than that described in the documents
supporting such payment; and the Company has not made, directly or indirectly,
any illegal contributions to any political party or candidate, either domestic
or foreign.

         SECTION 3.27. EMPLOYEE PLANS. There are no Parent Employee Benefit
Plans or Parent Pension Plans applicable to employees of the Company other than
those listed in Section 4.17 of the Disclosure Schedule.

         SECTION 3.28. LABOR MATTERS.

                  (a) Except as set forth in Section 3.28 of the Disclosure
         Schedule: (i) the Company is not a party to any outstanding employment,
         consulting or management agreements or contracts with officers or
         employees that are not terminable at will, or that provide for the
         payment of any bonus or commission; (ii) the Company is not a party to
         any agreement, policy or practice that requires it to pay termination
         or severance pay to salaried, non-exempt or hourly employees (other
         than as required by law); (iii) the Company is not a party to any
         collective bargaining agreement or other labor union contract
         applicable to persons employed by the Company nor does any Seller know
         of any activities or proceedings of any labor union to organize any
         such employees. The Sellers have furnished to the Buyer complete and
         correct copies of all such agreements (the "EMPLOYMENT AND LABOR
         AGREEMENTS"). The Company has not breached or otherwise failed to
         comply with any provisions of any Employment and Labor Agreement, and
         is in full compliance with all terms of any collective bargaining
         agreement and there are no grievances outstanding thereunder.

                  (b) Except as set forth in Section 3.28 of the Disclosure
         Schedule (i) the Company is in compliance with all applicable laws
         relating to employment and employment practices, wages, hours, and
         terms and conditions of employment and is not engaged in any unfair
         labor practice; (ii) there is no unfair labor practice charge or

                                      -28-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   36
         complaint pending before the NLRB against the Company; (iii) there is
         no labor strike, material slowdown or material work stoppage or lockout
         actually pending or, to the Sellers' knowledge, threatened against or
         affecting the Company, and the Company has not at any time experienced
         any strike, material slowdown or material work stoppage, lockout or
         other collective labor action by or with respect to employees of the
         Company; (iv) there is no representation claim or petition pending
         before the NLRB or any similar foreign agency and, to the Sellers'
         knowledge, no question concerning representation exists relating to the
         employees of the Company; (v) there are no charges with respect to or
         relating to the Company pending before the Equal Employment Opportunity
         Commission or any state, local or foreign agency responsible for the
         prevention of unlawful employment practices; and (vi) the Company has
         received no formal notice from any federal, state, local or foreign
         agency responsible for the enforcement of labor or employment laws of
         an intention to conduct an investigation of the Company and, to the
         Sellers' knowledge, no such investigation is in progress.

                  (c) The Company at all times has been in compliance with all
         terms and provisions of IRCA. All employees of the Company assigned to
         work at sites pursuant to assignment by the Company have had and will
         have had their identity and eligibility for work within the U.S.
         properly verified by the Company. At or prior to Closing, when and if
         requested by the Buyer, the Sellers shall cause the Company to provide
         copies of the I-9 Forms together with such other documentation as may
         be requested by the Buyer from time to time in order to satisfy Buyer
         that the Company has performed its obligations hereunder as required by
         the IRCA.

         SECTION 3.29. ABSENCE OF CERTAIN CHANGES OR EVENTS. Except as set forth
in Section 3.29 of the Disclosure Schedule, since September 27, 1997, the
business of the Company has been conducted in the ordinary course consistent
with past practices and there has not been any:

                  (a) amendment to the Company's articles of incorporation or
         by-laws;

                  (b) change made in the Company's authorized capital or
         outstanding securities;

                  (c) issuance, sale, delivery of, or agreement to issue, sell,
         or deliver, any capital stock, bonds, or other corporate securities of
         the Company (whether authorized and unissued or held in treasury), or
         grant of, or agreement to grant, any options, warrants, or other rights
         of the Company calling for the issue, sale, or delivery thereof;

                  (d) borrowing of, or agreement to borrow, any funds by the
         Company, and the Company has not incurred or become subject to any
         obligation or liability (absolute or contingent), except obligations
         and liabilities incurred in the ordinary course of business, none of
         which, individually or in the aggregate, are materially adverse to the

                                      -29-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   37
         business, assets, properties, operations, prospects, or condition,
         financial or otherwise, of the Company;

                  (e) payment of any obligation or liability (absolute or
         contingent), by the Company other than current liabilities reflected in
         or shown on the Company Unaudited Interim Financial Statements and
         current liabilities incurred in the ordinary course of business since
         September 27, 1997;

                  (f) increase in the salary or other compensation payable or to
         become payable by the Company to any of its officers, directors, or
         employees, or the declaration, payment, commitment, or obligation of
         any kind for the payment of additional salary or compensation to any
         such person exceeding $5,000;

                  (g) accrual or arrangement, whether direct or indirect, for,
         or payment of, bonuses or special compensation of any kind, or any
         severance or termination pay, to any present or former officer,
         director, or employee of the Company;

                  (h) adoption of any new, or amendment of any existing,
         employee benefit plan, program or arrangement;

                  (i) material adverse change in the business, assets,
         properties, operations, or condition, financial or otherwise of the
         Company;

                  (j) destruction of, damage to, or loss of, any material asset
         of the Company (whether or not covered by insurance);

                  (k) failure to keep in force and effect insurance comparable
         in amount and scope to coverage maintained by the Company (or on its
         behalf) on September 27, 1997;

                  (l) labor dispute or activity or proceeding by a labor union
         or threat thereof;

                  (m) change in accounting methods or practices (including,
         without limitation, any change in depreciation or amortization methods,
         policies, or rate) by the Company;

                  (n) failure by the Company to keep its books of account,
         records and files in the ordinary course and consistent with past
         practice;

                  (o) amendment, modification, or termination of any contract,
         lease, License, promissory note, commitment, or any other agreement,
         instrument, indebtedness, or obligation to which the Company is a
         party, or by which it or any of its assets or properties are bound,
         except those agreements, amendments, or terminations effected in the
         ordinary course of business consistent with past practices;

                                      -30-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   38
                  (p) waiver or release of any right or claim of the Company or
         cancellation of any debts or claims, except in the ordinary course of
         business;

                  (q) declaration or making of, or agreement to declare or make,
         any payment of dividends or distribution of any asset of any kind
         whatsoever in respect to the Company's capital stock, nor any purchase,
         redemption, or other acquisition or agreement to purchase, redeem, or
         otherwise acquire, any of such outstanding capital stock;

                  (r) citation received by the Company for any violations of any
         act, law, rule, regulation, or code of any governmental entity or
         agency;

                  (s) claim incurred by the Company for damages or alleged
         damages for any actual or alleged negligence or other tort or breach of
         contract (whether or not fully covered by insurance);

                  (t) sale, transfer, or disposal of any of the assets,
         properties, or rights (tangible or intangible) of the Company, except
         in the ordinary course of business;

                  (u) mortgage, pledge, or subjection to lien, charge, or other
         encumbrance, of any of the assets, properties, or rights (tangible or
         intangible) of the Company;

                  (v) agreement entered into granting any preferential rights to
         purchase any of the assets, properties, or rights (tangible or
         intangible) of the Company (including management and control thereof),
         or requiring the consent of any party to the transfer and assignment of
         any such assets, properties, or rights (including management and
         control thereof);

                  (w) capital expenditure by the Company exceeding $10,000;

                  (x) revaluation by the Company of any of its assets;

                  (y) failure by the Company to file, when due or required, any
         federal, state, local, foreign or other Tax return or report required
         to be filed or failure to pay when due any taxes, assessments, fees or
         other charges lawfully levied against the Company unless the validity
         thereof was contested in good faith and by appropriate proceedings
         diligently conducted;

                  (z) loan by the Company to any Person, guaranty by the Company
         of any loan, or incurrence by the Company of any indebtedness; or

                  (aa) agreement by the Company or the Sellers to do any of the
         things described in the preceding clauses (a) through (z).

                                      -31-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   39
         SECTION 3.30. TAX MATTERS.

                  (a) From the Company's inception through the date hereof, the
         Company has been included with the Parent in its consolidated federal
         income Tax Return as a member of an "affiliated group" (as defined in
         Section 1504(a) of the Code) of which the Parent is the common parent.

                  (b) Except as otherwise disclosed in Section 3.30 of the
         Company Disclosure Schedule, (i) the Company has filed (or joined in
         the filing of) when due all Tax Returns required by applicable law to
         be filed with respect to the Company and all Taxes shown to be due on
         such Tax Returns have been paid; (ii) all such Tax Returns were true,
         correct and complete as of the time of such filing; (iii) all Taxes
         relating to periods ending on or before the Closing Date owed by the
         Company (whether or not shown on any Tax Return) or to which the
         Company may be liable under Treasury Regulations Section 1.1502-6 (or
         analogous state or foreign provisions) by virtue of having been a
         member of any "affiliated group" (or other group filing on a combined
         or unitary basis) at any time on or prior to the Closing Date, if
         required to have been paid, have been paid (except for Taxes which are
         being contested in good faith); (iv) any liability of the Company for
         Taxes not yet due and payable, or which are being contested in good
         faith, has been provided for on the Company Financial Statements in
         accordance with GAAP; (v) there is no action, suit, proceeding,
         investigation, audit or claim now pending against, or with respect to,
         the Company in respect of any Tax or assessment, nor is any claim for
         additional Tax or assessment asserted by any Tax authority; (vi) since
         January 1, 1993, no claim has been made by any Tax authority in a
         jurisdiction where the Company does not currently file a Tax Return
         that it is or may be subject to Tax by such jurisdiction, nor to the
         knowledge of the Company is any such assertion threatened; (vii) there
         is no outstanding request for any extension of time within which to pay
         any Taxes or file any Tax Returns; (viii) there has been no waiver or
         extension of any applicable statute of limitations for the assessment
         or collection of any Taxes of the Company; (ix) no property of the
         Company is "tax-exempt use property" within the meaning of Section
         168(h) of the Code; (x) the Company is not a party to any lease made
         pursuant to former Section 168(f)(8) of the Internal Revenue Code of
         1954; (xi) no excess loss account (within the meaning of Treasury
         Regulations Section 1.1502-19) exists with respect to the Company;
         (xii) the Company has no deferred gain or loss arising from any
         intercompany transactions, within the meaning of Treasury Regulations
         Section 1.1502-13; (xiii) the Company has not filed any agreement or
         consent under Section 341(f) of the Code; (xiv) the Company is not a
         party to any agreement, whether written or unwritten, providing for the
         payment of Taxes, payment for Tax losses, entitlements to refunds or
         similar Tax matters; (xv) no ruling with respect to Taxes (other than a
         request for determination of the status of a qualified pension plan)
         has been requested by or on behalf of the Company; and (xvi) the
         Company has withheld and paid all material Taxes required to be
         withheld in connection with any amounts paid or owing to any employee,
         creditor, independent contractor or other third party.

                                      -32-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   40
         SECTION 3.31. ACCURACY OF INFORMATION. To the knowledge of each Seller,
none of the representations, warranties or statements of the Sellers contained
in this Agreement, or in the Disclosure Schedule or exhibits hereto, contains
any untrue statement of a material fact or omits to state any material fact
necessary in order to make any of such representations, warranties or statements
not misleading.

                                   ARTICLE IV.
                    REPRESENTATIONS AND WARRANTIES OF DUBBELL

         Dubbell hereby represents, warrants and agrees as follows:

         SECTION 4.1. CORPORATE ORGANIZATION. The Parent is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Arkansas and has all requisite corporate power and authority and all
governmental licenses, authorizations, permits, consents and approvals to own
its properties and assets and to conduct its businesses as now conducted. The
Parent is duly qualified to do business as a foreign corporation and is in good
standing in every jurisdiction where the character of the properties owned or
leased by it or the nature of the business conducted by it makes such
qualification necessary, except in any jurisdiction where the failure to be so
qualified would not have a material adverse effect on the business, results of
operations or the condition (financial or otherwise) of the Parent. Section 4.1
of the Disclosure Schedule sets forth all of the jurisdictions in which the
Parent is qualified to do business. The copies of the articles of incorporation
and by-laws of the Parent included as part of Section 4.1 of the Disclosure
Schedule constitute accurate and complete copies of such organizational
instruments and accurately reflect all amendments thereto through the date
hereof.

         SECTION 4.2. CAPITALIZATION. The authorized capital stock of the Parent
consists of 1,000,000 shares of Parent Common Stock of which 480,000 shares are
issued and outstanding on the date of this Agreement and of which 427,200 shares
shall be outstanding at the Closing Date as a result of the redemptions of
Parent Common Stock in connection with the Redemption Transaction. The Parent
Shares represent, and at the Closing, the Remaining Parent Shares will
represent, all of the issued and outstanding shares of the capital stock of the
Parent and are owned of record and beneficially by Dubbell, free and clear of
any lien, charge or encumbrance. All the outstanding shares of Parent Common
Stock have been duly authorized and validly issued and are fully paid and
nonassessable. Except as set forth in Section 4.2 of the Disclosure Schedule, on
the date of this Agreement there are no outstanding options, warrants,
agreements, conversion rights, preemptive rights or other rights to subscribe
for, purchase or otherwise acquire any shares of Parent Common Stock, and except
as contemplated by the Redemption Transaction, there are no outstanding
obligations or plans of the Parent to repurchase, redeem or otherwise acquire
outstanding shares of Parent Common Stock. On the Closing Date, there shall be
no outstanding options, warrants, agreements, conversion rights, preemptive
rights or other rights to subscribe for, purchase or otherwise acquire any
shares of Parent Common Stock.

                                      -33-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   41
         SECTION 4.3. SUBSIDIARIES. Except as set forth in Section 4.3 of the
Disclosure Schedule, the Parent does not own any shares of, or control, directly
or indirectly, or have any equity interest in, any Person.

         SECTION 4.4. VALIDITY OF AGREEMENT. The Parent has the corporate power
to enter into this Agreement and to carry out its obligations hereunder,
including in connection with the Redemption Transaction. The execution and
delivery of this Agreement and the performance by the Parent of its obligations
hereunder, including in connection with the Redemption Transaction have been
duly authorized by the Board of Directors of the Parent, and no other corporate
proceedings on the part of the Parent are necessary to authorize such execution,
delivery and performance. This Agreement has been duly executed by the Parent
and constitutes the valid and binding obligation of the Parent enforceable
against the Parent in accordance with its terms (subject to normal equitable
principles and subject to bankruptcy, insolvency, fraudulent conveyances and
similar laws affecting the rights of creditors).

         SECTION 4.5. NO CONFLICT OR VIOLATION. Except as set forth in Section
4.5 of the Disclosure Schedule, the execution, delivery and performance by
Dubbell and the Parent of this Agreement and the transactions contemplated
hereby, including the Redemption Transaction, do not and will not: (i) violate
or conflict with any provision of the articles of incorporation or by-laws of
the Parent; (ii) violate any provision of law, statute, judgment, order, writ,
injunction, decree, award, rule, or regulation of any court, arbitrator, or
other governmental or regulatory authority applicable to the Parent; (iii)
violate, result in a breach of, constitute (with due notice or lapse of time or
both) a default or cause any obligation, penalty, premium, right of termination
or acceleration to arise, accrue or occur under any material contract, lease,
loan agreement, mortgage, security agreement, trust indenture or other agreement
or instrument to which either Dubbell or the Parent is a party or by which
either of them is bound or to which any of their respective properties or assets
is subject; (iv) result in the creation or imposition of any lien, charge or
encumbrance of any kind whatsoever upon any of the properties or assets of the
Parent; (v) result in the cancellation, modification, revocation or suspension
of any License; or (vi) to the knowledge of Dubbell, otherwise result in the
loss of any right important or valuable to the Parent.

         SECTION 4.6. CONSENTS AND APPROVALS. Section 4.6 of the Disclosure
Schedule sets forth a true and complete list of each consent, waiver,
authorization or approval of any governmental or regulatory authority, domestic
or foreign, or any other Person, and each declaration to or filing or
registration with any such governmental or regulatory authority, that is
required of or to be made by the Parent or Dubbell in connection with the
execution, delivery and performance of this Agreement.

         SECTION 4.7. FINANCIAL STATEMENTS.

                  (a) Dubbell has heretofore furnished to the Buyer copies of
         (i) the audited consolidated balance sheet of the Parent and its
         Subsidiaries as of December 28, 1996, together with the related
         statements of income, stockholders' equity and cash flows for

                                      -34-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   42
         the year then ended and the notes thereto (the "PARENT AUDITED
         FINANCIAL STATEMENTS") and (ii) the Parent Unaudited Interim Financial
         Statements (together with the Parent Audited Financial Statements, the
         "PARENT FINANCIAL STATEMENTS"). The Parent Financial Statements,
         including the notes thereto: (i) were prepared in accordance with GAAP
         applied on a consistent basis throughout the periods covered thereby;
         (ii) present fairly the consolidated financial position, results of
         operations and cash flows of the Parent and its Subsidiaries as of such
         dates and for the periods then ended (subject, in the case of the
         Parent Unaudited Interim Financial Statements, to normal year-end audit
         adjustments consistent with prior periods) and (iii) are in all
         material respects, complete, correct and in accordance with the books
         of account and records of the Parent and its Subsidiaries.

                  (b) The Parent has no assets, properties or liabilities
         required by GAAP to be set forth in the Parent Unaudited Interim
         Financial Statements other than those reflected on the balance sheet
         included in the Parent Unaudited Interim Financial Statements.

                  (c) The Parent has no commitments to make any capital
         expenditures or to invest, advance or loan any monies to any Persons.

                  SECTION 4.8. TAX MATTERS.

                  (a) From the date of their inception through the date hereof,
         the Parent has included the Company in its consolidated federal income
         Tax Return as a member of an "affiliated group" (as defined in Section
         1504(a) of the Code) of which the Parent is the common parent.

                  (b) Except as otherwise disclosed in Section 4.8 of the
         Disclosure Schedule, (i) beginning with the fiscal ended April 29,
         1978, the Parent, the Company and each other Subsidiary of the Parent
         have filed (or joined in the filing of) when due all Tax Returns
         required by applicable law to be filed with respect to the Parent, the
         Company and each other Subsidiary of the Parent and all Taxes shown to
         be due on such Tax Returns have been paid; (ii) all such Tax Returns
         were true, correct and complete as of the time of such filing; (iii)
         all Taxes relating to periods ending on or before the Closing Date owed
         by the Parent, the Company or any other Subsidiary of the Parent
         (whether or not shown on any Tax Return) or to which the Company or any
         Subsidiary of the Parent may be liable under Treasury Regulations
         Section 1.1502-6 (or analogous state or foreign provisions) by virtue
         of having been a member of any "affiliated group" (or other group
         filing on a combined or unitary basis) at any time on or prior to the
         Closing Date, if required to have been paid, have been paid (except for
         Taxes which are being contested in good faith); (iv) any liability of
         the Parent, the Company or any other Subsidiary of the Parent for Taxes
         not yet due and payable, or which are being contested in good faith,
         has been provided for on the Parent Financial Statements in accordance
         with GAAP; (v) there is no action, suit, proceeding, investigation,
         audit or

                                      -35-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   43
         claim now pending against, or with respect to, the Parent, the Company
         or any other Subsidiary of the Parent in respect of any Tax or
         assessment, nor is any claim for additional Tax or assessment asserted
         by any Tax authority; (vi) since January 1, 1993, no claim has been
         made by any Tax authority in a jurisdiction where the Parent, the
         Company or any other Subsidiary of the Parent does not currently file a
         Tax Return that it is or may be subject to Tax by such jurisdiction,
         nor to the knowledge of Dubbell, the Parent or the Company is any such
         assertion threatened; (vii) there is no outstanding request for any
         extension of time within which to pay any Taxes or file any Tax
         Returns; (viii) there has been no waiver or extension of any applicable
         statute of limitations for the assessment or collection of any Taxes of
         the Parent, the Company or any other Subsidiary of the Parent; (ix) no
         property of the Parent or the Company is "tax-exempt use property"
         within the meaning of Section 168(h) of the Code; (x) neither the
         Parent nor the Company is a party to any lease made pursuant to former
         Section 168(f)(8) of the Internal Revenue Code of 1954; (xi) except
         with respect to Tri-State, no excess loss account (within the meaning
         of Treasury Regulations Section 1.1502-19) exists with respect to the
         Company or any other Subsidiary of the Parent; (xii) neither the
         Company nor any other Subsidiary of the Parent has any deferred gain or
         loss arising from any intercompany transactions, within the meaning of
         Treasury Regulations Section 1.1502-13; (xiii) neither the Parent, the
         Company nor any other Subsidiary of the Parent has filed any agreement
         or consent under Section 341(f) of the Code; (xiv) Dubbell is not a
         "foreign person" within the meaning of Section 1445 of the Code; (xv)
         neither the Parent, the Company nor any other Subsidiary of the Parent
         is a party to any agreement, whether written or unwritten, providing
         for the payment of Taxes, payment for Tax losses, entitlements to
         refunds or similar Tax matters; (xvi) no ruling with respect to Taxes
         (other than a request for determination of the status of a qualified
         pension plan) has been requested by or on behalf of the Parent, the
         Company or any other Subsidiary of the Parent; (xvii) the Parent has
         not been a United States real property holding corporation within the
         meaning of Section 897(c)(2) of the Code during the applicable period
         specified in Section 897(c)(1)(A)(ii) of the Code; (xviii) Since 1991,
         no member of the consolidated group of which the Parent is the common
         parent has had "personal holding company income" within the meaning of
         Section 542 of the Code; and (xix) the Parent, the Company and each
         other Subsidiary of the Parent has withheld and paid all material Taxes
         required to be withheld in connection with any amounts paid or owing to
         any employee, creditor, independent contractor or other third party.

         SECTION 4.9. HOLDING COMPANY. The Parent is, and has always been,
primarily a holding company. Although the Parent has not engaged in any separate
business activity of its own, it has, from time to time, engaged in business as
an agent or representative of the Subsidiaries for various purposes, including,
but not limited to, provision of credit, obtaining licenses and permits and
entering into contracts. Except as set forth in Section 4.9 of the Disclosure
Schedule, the Parent does not lease any real property. The Parent does not own,
and has never owned, any real property. The Parent does not have, and has never
had, any employees.

                                      -36-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   44
         SECTION 4.10. LICENSES, PERMITS AND GOVERNMENTAL APPROVALS.

                  (a) Section 4.10 of the Disclosure Schedule sets forth a true
         and complete list of all material licenses of the Parent (including,
         but not limited to, any environmental licenses, permits, registrations
         or authorizations), health or other permits, franchises, authorizations
         and approvals issued or granted to the Parent by the United States, any
         state or local government, any foreign national or local government, or
         any department, agency, board, commission, bureau or instrumentality of
         any of the foregoing (each a "PARENT LICENSE" and, collectively, the
         "PARENT LICENSES"), and all pending applications therefor. Each Parent
         License has been issued to, and duly obtained and fully paid for by,
         the Parent and is valid, in full force and effect, and not subject to
         any pending or known threatened administrative or judicial proceeding
         to suspend, revoke, cancel or declare such Parent License invalid in
         any respect.

                  (b) The Parent has all Parent Licenses required, and such
         Parent Licenses are sufficient and adequate in all respects, to permit
         the continued lawful conduct of the Parent's business in the manner now
         conducted and the ownership, occupancy and operation of its real and
         personal property for their present uses. The Parent is not in
         violation of any of the Parent Licenses in any material respect. The
         Parent Licenses have never been suspended, revoked or otherwise
         terminated, subject to any fine or penalty, or subject to judicial or
         administrative review, for any reason other than the renewal or
         expiration thereof nor has any application of the Parent for any Parent
         License ever been denied. The Parent's operations are not being
         conducted in a manner that violate any of the terms or conditions under
         which any Parent License was granted. Except as disclosed in Section
         4.10 of the Disclosure Schedule, no Parent License will in any way be
         materially and adversely affected by, or terminate or lapse by reason
         of, the transactions contemplated by this Agreement. Dubbell has
         delivered to the Buyer or its representatives true and complete copies
         of all Parent Licenses together with all amendments and modifications
         thereto. 

         SECTION 4.11. COMPLIANCE WITH LAW. Except as set forth in Section 4.11
of the Disclosure Schedule, the operations of the Parent have been conducted in
all material respects in accordance with all applicable laws, regulations,
orders and other requirements of all courts and other governmental or regulatory
authorities having jurisdiction over the Parent and its assets, properties and
operations. Neither Dubbell nor the Parent has received notice of any violation
of any such law, regulation, order or other legal requirement, or is in default
with respect to any order, writ, judgment, award, injunction or decree of any
federal, state or local court or governmental or regulatory authority or
arbitrator, domestic or foreign, applicable to the Parent or any of its assets,
properties or operations. Neither Dubbell nor the Parent has knowledge of any
proposed changes in any such laws, rules or regulations that would adversely
affect the transactions contemplated by this Agreement or all or a substantial
part of the assets or the businesses of the Parent.

                                      -37-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   45
         SECTION 4.12. ENVIRONMENTAL MATTERS. Except as set forth in Section
4.12 of the Disclosure Schedule:

                  (a) The operations of the Parent and its Subsidiaries (other
         than the Company) are, and in the past have been, in compliance in all
         material respects with all Environmental Laws and they have obtained
         and maintained in effect all Environmental Permits and are, and in the
         past have been, in compliance with all such Environmental Permits.

                  (b) Neither the Parent nor any Subsidiary (other than the
         Company) has performed or suffered any act which could give rise to, or
         has otherwise incurred, liability to any person (governmental or other)
         under CERCLA, or any other Environmental Laws, nor has the Company nor
         any Subsidiary (other than the Company) received notice of any such
         liability or any claim therefor or submitted notice pursuant to Section
         103 of CERCLA to any governmental agency with respect to any of its
         assets.

                  (c) No Hazardous Material has been released, placed, dumped or
         otherwise come to be located on, at, beneath or near any of the assets
         or properties owned or leased by the Parent or any of its Subsidiaries
         (other than the Company) or any surface waters or groundwaters thereon
         or thereunder.

                  (d) Neither the Parent nor any Subsidiary (other than the
         Company) owns or operates, and has never owned or operated, aboveground
         or underground storage tanks.

                  (e) With respect to any or all of the real properties owned or
         leased by the Parent or any of its Subsidiaries (other than the
         Company) (i) there are no, nor have there been in the past,
         asbestos-containing materials, urea formaldehyde insulation,
         polychlorinated biphenyls or, to the knowledge of Dubbell, lead-based
         paints present at any such properties; and (ii) there are no wetlands
         (as defined under any Environmental Law) located on any such
         properties, nor have any been drained, filled or otherwise altered.

                  (f) None of the real properties owned or leased by the Parent
         or any of its Subsidiaries (other than the Company) (i) has been used
         or is now used for the generation, transportation, storage, handling,
         treatment or disposal of any Hazardous Materials or (ii) is identified
         on a federal, state or local listing of sites which require or might
         require environmental cleanup.

                  (g) No condition exists on any of the real properties owned or
         leased by the Parent or any of its Subsidiaries (other than the
         Company) that upon the failure to act, the passage of time or the
         giving of notice would give rise to liability under any Environmental
         Law.

                                      -38-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   46
                  (h) There are no ongoing investigations or negotiations,
         pending or threatened administrative, judicial or regulatory
         proceedings, or consent decrees or other agreements in effect that
         relate to environmental conditions in, on, under, about or related to
         the Parent or any of its Subsidiaries (other than the Company), any of
         their operations or the real properties owned or leased by any of them.

                  (i) Neither the Parent nor any of its Subsidiaries (other than
         the Company) nor any of their operations is subject to reporting
         requirements under the federal Emergency Planning and Community
         Right-to-Know Act, 42 U.S.C. Section 11001 et seq., or analogous state
         statutes and related regulations, all as amended.

         SECTION 4.13. LITIGATION. Except as set forth in Section 4.13 of the
Disclosure Schedule, there are no claims, actions, suits, proceedings, labor
disputes or investigations pending or, to the knowledge of Dubbell, threatened
before any federal, state or local court or governmental, administrative or
regulatory authority, domestic or foreign, or before any arbitrator of any
nature, brought by or against Dubbell, the Parent or its officers, directors,
employees or agents or any of their respective Affiliates involving, affecting
or relating to any assets, properties or operations of the Parent or the
transactions contemplated by this Agreement. Section 4.13 of the Disclosure
Schedule sets forth a list and a summary description of all such pending or
known threatened actions, suits, proceedings, disputes or investigations. None
of Dubbell nor the Parent nor any of their assets or properties is subject to,
nor to Dubbell's knowledge, does any basis exist for any order, writ, judgment,
award, injunction or decree of any federal, state or local court or governmental
or regulatory authority or arbitrator, that materially and adversely affects the
Parent's assets, properties, operations, net income or financial condition or
which would interfere with the transactions contemplated by this Agreement.

                                      -39-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   47
         SECTION 4.14. CONTRACTS.

                  (a) Section 4.14 of the Disclosure Schedule sets forth a true
         and complete list and a summary description showing the expiration
         dates (exclusive of renewal terms) of all material contracts,
         agreements, instruments, commitments and other arrangements to which
         the Parent is a party or otherwise relating to or affecting any of its
         assets or properties including, without limitation, all written or
         oral, express or implied (each, a "PARENT CONTRACT"). To the knowledge
         of Dubbell, each Parent Contract is valid, binding and enforceable
         against the parties thereto in accordance with its terms, and in full
         force and effect on the date hereof. The Parent has performed in all
         material respects, all obligations, including, but not limited to, the
         timely making of any rental or other payments, required to be performed
         by it under, and is not in default or breach of any material provision
         in respect of, any Parent Contract, and no event has occurred which,
         with due notice or lapse of time or both, would constitute such a
         default. Dubbell has delivered to the Buyer or its representatives true
         and complete originals or copies of all Parent Contracts and a copy of
         every default notice received by Dubbell or the Parent during the past
         three years with respect to any of the Parent Contracts.

                  (b) To the knowledge of Dubbell, except as disclosed in
         Section 4.14 of the Disclosure Schedule and the Parent is not a party
         to any agreement or instrument, or subject to any charter or other
         corporate restriction or any judgment, order, writ, injunction, decree,
         rule or regulation which, insofar as it relates to the businesses of
         the Parent, materially adversely affects or would in the future
         materially adversely affect the Parent's business, operations,
         properties, assets or financial condition.

         SECTION 4.15. INTERCOMPANY ACCOUNTS. The Company has no obligations and
no amounts are due to the Parent or any of its Affiliates other than for goods
and services purchased or provided in the ordinary course of business.

         SECTION 4.16. PROPRIETY OF PAST PAYMENTS. Except as set forth in
Section 4.16 of the Disclosure Schedule, no finder's fee or other payment has
been, or will be, made by or on behalf of the Parent in respect of, or in
connection with, any Parent Contract to any person, firm, corporation or other
entity which is not a party to such Parent Contract. To the knowledge of
Dubbell, no funds or assets of the Parent have been used for illegal purposes;
no unrecorded funds or assets of the Parent have been established for any
purpose; no accumulation or use of the Parent's corporate funds or assets has
been made without being properly accounted for in the respective books and
records of the Parent; all payments by or on behalf of the Parent have been duly
and properly recorded and accounted for in its books and records; no false or
artificial entry has been made in the books and records of the Parent for any
reason; no payment has been made by or on behalf of the Parent with the
understanding that any part of such payment is to be used for any purpose other
than that described in the documents supporting such payment; and the Parent has
not made, directly or

                                      -40-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   48
indirectly, any illegal contributions to any political party or candidate,
either domestic or foreign.

         SECTION 4.17. EMPLOYEE PLANS.

                  (a) Section 4.17 of the Disclosure Schedule sets forth (i) any
         "employee benefit plan", as defined in Section 3(3) of ERISA, and all
         other employee benefit arrangements, policies or payroll practices,
         including, without limitation, severance pay, sick leave, vacation pay,
         salary continuation, disability, retirement, deferred compensation,
         bonus, stock purchase, stock option or other equity-based compensation,
         hospitalization, medical insurance, life insurance or scholarship
         programs, maintained by the Parent, the Company or any Subsidiary of
         the Parent or to which the Parent, the Company or any Subsidiary of the
         Parent contributed or is obligated to contribute for or with respect to
         current or former employees of the Parent, the Company or any
         Subsidiary of the Parent, but excluding any such plan, arrangement,
         policy, practice or program maintained or contributed to solely by a
         Subsidiary of the Parent other than the Company, solely for the benefit
         of employees of such Parent Subsidiary (the "PARENT EMPLOYEE BENEFIT
         PLANS"), and (ii) all "employee pension benefit plans", as defined in
         Section 3(2) of ERISA, which are subject to Title IV of ERISA or
         Section 412 of the Code and at any time during the six-year period
         ending on the date hereof were maintained or contributed to by the
         Parent, the Company, any Subsidiary of the Parent or any ERISA
         Affiliate (the "PARENT PENSION PLANS").

                  (b) None of the Parent, the Company, any Subsidiary of the
         Parent or any ERISA Affiliate has within the six-year period ending on
         the date hereof contributed to, or been obligated to contribute to, any
         Multiemployer Plan.

                  (c) The Parent Employee Benefit Plans intended to qualify and
         be tax-exempt under Sections 401 and 501 of the Code, respectively,
         have been determined by the Internal Revenue Service to be so qualified
         and tax-exempt, and nothing has occurred with respect to the operation
         of such Parent Employee Benefit Plans which could cause the loss of
         such qualification or tax exemption or the imposition of any liability,
         penalty or tax under ERISA or the Code. Any trust maintained or
         contributed to by the Parent, the Company or any Subsidiary of the
         Parent which is intended to be tax-exempt pursuant to Section 501(c)(9)
         of the Code has been determined by the Internal Revenue Service to be
         so tax-exempt, and nothing has occurred since such determination which
         could cause the loss of such tax exemption or the imposition of any
         liability, penalty or tax under ERISA or the Code.

                  (d) All contributions (including all employer contributions
         and employee salary reduction contributions) required to have been made
         under any of the Parent Employee Benefit Plans or by law (without
         regard to any waivers granted under Section 412 of the Code) to any
         funds or trusts established thereunder or in connection therewith have
         been made by the due date thereof (including any valid extension), and

                                      -41-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   49
         all contributions for any period ending on or before the Closing Date
         which are not yet due will have been paid or accrued on or prior to the
         Closing Date. No accumulated funding deficiencies exist in any of the
         Parent Pension Plans.

                  (e) There is no "amount of unfunded benefit liabilities," as
         defined in Section 4001(a)(18) of ERISA, in any of the Parent Pension
         Plans. The "benefit liabilities", as defined in Section 4001(a)(16) of
         ERISA, of each of the Parent Pension Plans do not exceed the fair
         market value of the assets of such Parent Pension Plan.

                  (f) There has been no "reportable event," as that term is
         defined in Section 4043 of ERISA and the regulations thereunder, with
         respect to any Parent Pension Plan which would require the giving of
         notice or any event requiring disclosure under Section 4041(c)(3)(C) or
         4063(a) of ERISA.

                  (g) There is no violation of ERISA with respect to the filing
         of applicable reports, documents and notices regarding the Parent
         Employee Benefit Plans with the Secretary of Labor or the Secretary of
         the Treasury or the furnishing of such documents to the participants or
         beneficiaries of the Parent Employee Benefit Plans.

                  (h) True, correct and complete copies of the following
         documents, with respect to each of the Parent Employee Benefit Plans,
         have been delivered to the Buyer: (i) all plans and related trust
         documents, and amendments thereto; (ii) the most recent Forms 5500;
         (iii) the most recent actuarial report and audited financial statement;
         (iv) the last IRS determination or opinion letter; (v) summary plan
         descriptions; (vi) written communications to employees; and (vii)
         written descriptions of all non-written agreements relating to the
         Parent Employee Benefit Plans.

                  (i) There are no pending actions, claims or lawsuits which
         have been asserted or instituted against the Parent Employee Benefit
         Plans, the assets of any of the trusts under such plans or the plan
         sponsor or, to the knowledge of Dubbell, the plan administrator or any
         fiduciary of the Parent Employee Benefit Plans with respect to the
         operation of such plans (other than routine benefit claims), nor does
         the Parent or the Company, or any Subsidiary of the Parent, or Dubbell,
         have knowledge of facts which could form the basis for any such claim
         or lawsuit.

                  (j) All amendments and actions required to bring the Parent
         Employee Benefit Plans into conformity in all respects with all of the
         applicable provisions of ERISA and other applicable laws have been made
         or taken except to the extent that such amendments or actions are not
         required by law to be made or taken until a date after the Closing
         Date.

                  (k) Any bonding required with respect to the Parent Employee
         Benefit Plans in accordance with applicable provisions of ERISA has
         been obtained and is in full force and effect.

                                      -42-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   50
                  (l) The Parent Employee Benefit Plans have been maintained in
         accordance with their terms and with all provisions of ERISA (including
         rules and regulations thereunder) and other applicable federal and
         state laws and regulations. Neither the Parent, the Company, any
         Subsidiary of the Parent or, to the knowledge of Dubbell, the Parent,
         the Company and each Subsidiary of the Parent, any "party in interest"
         (within the meaning of Section 3(14) of ERISA) or "disqualified person"
         (within the meaning of Section 4975 of the Code) with respect to any of
         the Parent Employee Benefit Plans has engaged in a "prohibited
         transaction," within the meaning of Section 4975 of the Code or Section
         406 of ERISA, with respect to which there is no statutory or
         administrative exemption. To the knowledge of Dubbell, no fiduciary has
         any liability for breach of fiduciary duty or any other failure to act
         or comply in connection with the administration or investment of the
         assets of any Parent Employee Benefit Plan.

                  (m) None of the Parent, the Company, any Subsidiary of the
         Parent or any ERISA Affiliate has terminated any Parent Pension Plan
         within the six-year period ending on the date hereof, or incurred any
         outstanding liability under Section 4062 of ERISA to the PBGC or to a
         trustee appointed under Section 4042 of ERISA. All premiums due the
         PBGC with respect to the Parent Pension Plans have been paid.

                  (n) None of the Parent, the Company or any Subsidiary of the
         Parent maintains retiree life or retiree health insurance plans which
         provide for continuing benefits or coverage for any participant or any
         beneficiary of a participant, except as may be required under COBRA.
         Each of the Parent, the Company, any Subsidiary of the Parent and any
         ERISA Affiliate which maintains a "group health plan," within the
         meaning of COBRA, has complied with the notice and health care
         continuation requirements of COBRA.

                  (o) None of the Parent, the Company or any ERISA Affiliate, or
         any organization with respect to which the Parent or the Company is a
         successor or parent corporation, within the meaning of Section 4069(b)
         of ERISA, has engaged in any transaction described in Section 4069 of
         ERISA.

                  (p) No liability under any Parent Employee Benefit Plan has
         been funded or satisfied with the purchase of a contract from an
         insurance company that is not rated AA by Standard & Poor's Corporation
         or the equivalent by each other nationally recognized rating agency.

                  (q) Except as set forth in Section 4.17 of the Disclosure
         Schedule, neither the execution and delivery of this Agreement nor the
         consummation of the transactions contemplated hereby (including the
         Redemption Transaction) will (i) result in any payment becoming due to
         any employee (current, former or retired) of the Parent, the Company or
         any Subsidiary of the Parent, (ii) increase any benefits otherwise
         payable under any Parent Employee Benefit Plan or (iii) result in the
         acceleration of the time of payment or vesting of any such benefits.

                                      -43-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   51
                  (r) None of the Parent, the Company or any Subsidiary of the
         Parent has any contract, plan or commitment, whether legally binding or
         not, to create any additional Parent Employee Benefit Plan or to modify
         any existing Parent Employee Benefit Plan, other than contemplated
         amendments thereto concerning withdrawal of the Parent and the Company
         as participating employers thereunder and vesting of participants,
         distributions to participants and related matters with respect to
         participants affected by the transactions contemplated herein.

                  (s) No stock or other security issued by the Parent, the
         Company or any Subsidiary of the Parent forms or has formed a material
         part of the assets of any Parent Employee Benefit Plan.

                  (t) There has been no "mass layoff" or "plant closing," as
         each such term is defined by WARN, with respect to the employees of the
         Parent, the Company or any Subsidiary of the Parent, with respect to
         which there could be any future liability to or in respect of such
         employees under WARN.

         SECTION 4.18. ABSENCE OF CERTAIN CHANGES OR EVENTS. Except as set forth
in Section 4.18 of the Disclosure Schedule, since September 27, 1997, there has
not been any:

                  (a) amendment to the Parent's articles of incorporation or
         by-laws;

                  (b) change made in the Parent's authorized capital or
         outstanding securities;

                  (c) issuance, sale, delivery of, or agreement to issue, sell,
         or deliver, any capital stock, bonds, or other corporate securities of
         the Parent (whether authorized and unissued or held in treasury), or
         grant of, or agreement to grant, any options, warrants, or other rights
         of the Parent calling for the issue, sale, or delivery thereof;

                  (d) borrowing of, or agreement to borrow, any funds by the
         Parent, and the Parent has not incurred or become subject to any
         obligation or liability (absolute or contingent);

                  (e) payment of any obligation or liability (absolute or
         contingent), by the Parent;

                  (f) increase in the salary or other compensation payable or to
         become payable by the Parent to any of its officers or directors, or
         the declaration, payment, commitment, or obligation of any kind for the
         payment of compensation to any such person;

                  (g) accrual or arrangement, whether direct or indirect, for,
         or payment of, bonuses or special compensation of any kind, or any
         severance or termination pay, to any present or former officer or
         director of the Parent, except for settlements of outstanding stock
         options of the Parent;

                                      -44-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   52
                  (h) adoption of any new, or amendment of any existing,
         employee benefit plan, program or arrangement except as referred to in
         Section 4.17(r);

                  (i) material adverse change in the business, assets,
         properties, operations, or condition, financial or otherwise of the
         Parent;

                  (j) destruction of, damage to, or loss of, any material asset
         of the Parent (whether or not covered by insurance);

                  (k) failure to keep in force and effect insurance comparable
         in amount and scope to coverage maintained by the Parent (or on its
         behalf) on September 27, 1997;

                  (l) change in accounting methods or practices (including,
         without limitation, any change in depreciation or amortization methods,
         policies, or rate) by the Parent;

                  (m) failure by the Parent to keep its books of account,
         records and files in the ordinary course and consistent with past
         practice;

                  (n) amendment, modification, or termination of any contract,
         lease, License, promissory note, commitment, indenture, mortgage, deed
         of trust, employee benefit plan, or any other agreement, instrument,
         indebtedness, or obligation to which the Parent is a party, or by which
         it or any of its assets or properties are bound, except those
         agreements, amendments, or terminations effected in the ordinary course
         of business consistent with past practices;

                  (o) waiver or release of any right or claim of the Parent or
         cancellation of any debts or claims, except in the ordinary course of
         business;

                  (p) declaration or making of, or agreement to declare or make,
         other than pursuant to the Redemption Transaction, any payment of
         dividends or distribution of any asset of any kind whatsoever in
         respect to the Parent's capital stock, nor, other than the Redemption
         Transaction, any purchase, redemption, or other acquisition or
         agreement to purchase, redeem, or otherwise acquire, any of such
         outstanding capital stock;

                  (q) citation received by the Parent for any violations of any
         act, law, rule, regulation, or code of any governmental entity or
         agency;

                  (r) claim incurred by the Parent for damages or alleged
         damages for any actual or alleged negligence or other tort or breach of
         contract (whether or not fully covered by insurance);

                  (s) sale, transfer, or disposal of any of the assets,
         properties, or rights (tangible or intangible) of the Parent;

                                      -45-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   53
                  (t) mortgage, pledge, or subjection to lien, charge, or other
         encumbrance, of any of the assets, properties, or rights (tangible or
         intangible) of the Parent;

                  (u) agreement entered into granting any preferential rights to
         purchase any of the assets, properties, or rights (tangible or
         intangible) of the Parent (including management and control thereof),
         or requiring the consent of any party to the transfer and assignment of
         any such assets, properties, or rights (including management and
         control thereof);

                  (v) capital expenditure by the Parent;

                  (w) revaluation by the Parent of any of its assets;

                  (x) failure by the Parent to file, when due or required, any
         federal, state, local, foreign or other tax return or report required
         to be filed or failure to pay when due any taxes, assessments, fees or
         other charges lawfully levied against the Parent unless the validity
         thereof was contested in good faith and by appropriate proceedings
         diligently conducted;

                  (y) loan by the Parent to any Person, guaranty by the Parent
         of any loan, or incurrence by the Parent of any indebtedness; or

                  (z) agreement by the Parent or Dubbell to do any of the things
         described in the preceding clauses (a) through (y).

         SECTION 4.19. PARENT'S LIABILITIES. Immediately prior to the Closing,
Parent shall have no debts, obligations or liabilities of whatsoever kind,
whether contingent or otherwise, whether known or unknown except for any
liabilities under the Severance Agreements, the Parent Lease or the Kunz and
Olander Notes to the extent that the Parent is not released thereunder.

         SECTION 4.20. OTHER PROPERTIES. Schedule 4.20 sets forth a true and
complete list of all real properties owned or leased by PFRM and Tri-State.

         SECTION 4.21. ACCURACY OF INFORMATION. To the knowledge of Dubbell,
none of the representations, warranties or statements of Dubbell contained in
this Agreement, or in the Disclosure Schedule or exhibits hereto, contains any
untrue statement of a material fact or omits to state any material fact
necessary in order to make any of such representations, warranties or statements
not misleading.

                                      -46-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   54
                                   ARTICLE V.
                   REPRESENTATIONS AND WARRANTIES OF THE BUYER

         The Buyer hereby represents, warrants and agrees as follows:

         SECTION 5.1. CORPORATE ORGANIZATION. The Buyer is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Delaware and has all requisite corporate power and authority to own its
properties and assets and to conduct its business as now conducted.

         SECTION 5.2. VALIDITY OF AGREEMENT. The Buyer has the corporate power
to enter into this Agreement and to carry out its obligations hereunder. The
execution and delivery of this Agreement and the performance by the Buyer of its
obligations hereunder have been duly authorized by the Board of Directors of the
Buyer, and no other corporate proceedings on the part of the Buyer are necessary
to authorize such execution, delivery and performance. This Agreement has been
duly executed by the Buyer and constitutes the valid and binding obligation of
the Buyer enforceable against the Buyer in accordance with its terms.

         SECTION 5.3. NO CONFLICT OR VIOLATION; NO DEFAULTS. The execution,
delivery and performance by the Buyer of this Agreement and the transactions
contemplated hereby do not and will not violate or conflict with any provision
of its Amended and Restated Certificate of Incorporation or Amended and Restated
By-Laws and do not and will not violate any provision of law, statute, judgment,
order, writ, injunction, decree, award, rule or regulation of any court,
arbitrator or other governmental or regulatory authority, nor violate or result
in a breach of or constitute (with due notice or lapse of time or both) a
default under any contract, lease, loan agreement, mortgage, security agreement,
trust indenture or other agreement or instrument to which the Buyer is a party
or by which it is bound or to which any of its properties or assets is subject,
nor result in the creation or imposition of any lien, charge or encumbrance of
any kind whatsoever upon any of its properties or assets where such violations,
breaches or defaults in the aggregate would have a material adverse effect on
the transactions contemplated hereby or on the assets, properties, business,
operations, net income or financial condition of the Buyer.

         SECTION 5.4. CONSENTS AND APPROVALS. Other than those which have been
made or obtained, no consent, approval or authorization of, or filing,
registration or qualification with, any governmental authority on the part of
the Buyer or any vote, consent or approval in any manner of the holders of any
Security (as defined in Section 2(1) of the Securities Act of 1933, as amended)
of the Buyer is required as a condition to the execution and delivery of this
Agreement.

         SECTION 5.5. INVESTMENT REPRESENTATION. The Buyer is acquiring the
Remaining Parent Shares and the Company Minority Shares solely for its own
account for investment, and not with a view toward the resale, transfer or other
distribution thereof.


                                      -47-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   55

         SECTION 5.6. FINANCIAL CAPABILITY. The Buyer has available sufficient
funds to pay the aggregate Purchase Price, including the Earn-Out Amount,
payable to the Sellers on the terms and subject to the conditions contemplated
by this Agreement.

                                   ARTICLE VI.
                                    COVENANTS

         SECTION 6.1. REDEMPTION TRANSACTION. Dubbell shall, and shall cause the
Parent to, take all actions necessary to effect the Redemption Transaction on or
immediately prior to the Closing Date.

         SECTION 6.2. CONTINUED DEVELOPMENT OF NOVAGEN BRAND PRODUCTS. During
the Earn-Out Period, the Buyer intends to continue to offer the Company's
product portfolio of Novagen Brand Products and to further develop new Novagen
Brand Products (whether internally developed or externally sourced). During the
Earn-Out Period, the Buyer will not change the brand of any Product which the
Company has offered as a Novagen Brand Product prior to the Closing Date, and
the Buyer further agrees that all future Products developed or manufactured by
the Company will carry a Novagen Part Number or Novagen Label and that all
Products sold by the Company under the name of another manufacturer will carry a
Novagen Part Number or Label. During the Earn-Out Period, new products added to
the Buyer's product portfolio will be assigned a brand based upon the Buyer's
assessment of various factors, including the Buyer's historical branding
practices, the brand of the Buyer most recognized for reaching various markets,
the fit of new products into the Buyer's existing brand product portfolio and
other strategic factors designed to maximize overall sales of the Buyer's entire
product portfolio. During the Earn-Out Period, the Buyer intends to provide
financial, management and other corporate resources for development,
manufacturing and marketing of the Products in the same manner as it would
provide for similar products developed by the Buyer. As a general matter,
modification of resource allocations may be made as a result of such business,
economic, political and other factors which a reasonable business person would
take into consideration. However, the Buyer shall retain the right to
discontinue offering any Novagen Brand Product and to make final determinations
in connection with branding new products as Novagen Brand Products or as any of
the Buyer's other brands.

         SECTION 6.3. NON-SOLICITATION OF EMPLOYEES. For the two-year period
commencing on the Closing Date, no Seller shall make, offer, solicit or induce
to enter into, any written or oral arrangement, agreement or understanding
regarding employment or retention as a consultant with any employee of the
Company, in each case without the written consent of the Buyer.

         SECTION 6.4. ACCESS TO PROPERTIES AND RECORDS. The Sellers shall
afford, and shall cause the Parent and the Company to afford, to the Buyer and
the Buyer's accountants, counsel and representatives full access during normal
business hours, without disruption to the normal operation of the Parent or the
Company, throughout the period prior to the Closing


                                      -48-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   56

Date (or the earlier termination of this Agreement pursuant to Article X hereof)
to all of the Parent's and the Company's properties, books, contracts and
records (including, but not limited to, all environmental studies, reports and
other environmental records, all auditors' work papers relating to the Parent or
the Company, supporting information for Tax returns of the Parent and the
Company and litigation files of the Parent and the Company) and, during such
period, shall furnish promptly to the Buyer all information concerning the
Parent's and the Company's business, properties, liabilities and personnel as
the Buyer may reasonably request; provided, however that such access shall not
be afforded to the properties, books, contracts and records of PFRM, except when
reasonable justification for access is shown based on possible liability to the
Parent, the Company or the Buyer. The Buyer shall be permitted, subject to any
required landlord consent, which the Sellers will use commercially reasonable
efforts to obtain, to conduct testing and analysis of soil, groundwater,
building components, tanks, containers and equipment to confirm the condition of
the real property owned or leased by the Parent or its Subsidiaries and
improvements thereon.

         SECTION 6.5. NEGOTIATIONS. From and after the date hereof, none of the
Sellers, the Parent, the Company or any officers or directors of the Parent or
the Company or anyone acting on behalf of the Sellers or such Persons shall,
directly or indirectly, encourage, solicit, engage in discussions or
negotiations with, or provide any information to, any person, firm, or other
entity or group (other than the Buyer or its representatives) concerning any
merger, sale of assets, purchase or sale of shares of capital stock or similar
transaction involving the Parent or the Company. The Sellers shall promptly
reject any such offers concerning any such transaction which they may receive or
of which they may become aware.

         SECTION 6.6. CONSENTS AND APPROVALS. The Buyer and the Sellers shall
use commercially reasonable efforts to obtain, and the Sellers shall cause the
Parent and the Company to obtain, all necessary consents, waivers,
authorizations and approvals of all governmental and regulatory authorities,
domestic and foreign, and of all other Persons required in connection with the
execution, delivery and performance by them of this Agreement and the
transactions contemplated hereby.

         SECTION 6.7. COMMERCIALLY REASONABLE EFFORTS. Upon the terms and
subject to the conditions of this Agreement, each of the parties hereto will use
commercially reasonable efforts to take, or cause to be taken, all action, and
to do, or cause to be done, all things necessary, proper or advisable consistent
with applicable law to consummate and make effective in the most expeditious
manner practicable the transactions contemplated hereby, including, without
limitation, the transfer or reissuance of any permit, license, or approval
required pursuant to Environmental Laws.

         SECTION 6.8. NOTICE OF BREACH. Through the Closing Date, each of the
parties hereto shall promptly give to the other parties written notice with
particularity upon having knowledge of any matter that may constitute a breach
of any representation, warranty, agreement or covenant contained in this
Agreement.


                                      -49-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   57

         SECTION 6.9. CONFIDENTIAL INFORMATION. No party hereto shall use for
its own benefit or disclose to any Person Confidential Information that is the
exclusive property of another party hereto without the prior written consent of
that party. "Confidential Information" shall include protocols, processes,
information regarding customers, vendors, suppliers, trade secrets, training
programs, manuals or materials, technical information, contracts, systems,
procedures, mailing lists, know-how, trade names, improvements, price lists,
financial or other data (including the revenues, costs or profits associated
with any of the Parent's or the Company's products or services), business plans,
code books, invoices and other financial statements, computer programs, software
systems, databases, discs and printouts, plans (business, technical or
otherwise), customer and industry lists, correspondence, internal reports,
personnel files, sales and advertising material, telephone numbers, names,
addresses or any other compilation of information, written or unwritten, which
is or was used in the business of the Parent, the Company, the Buyer or any of
their respective Subsidiaries or Affiliates. Confidential Information shall not
include any information that can be shown by clear and convincing documentary
evidence to have been (1) public knowledge at the time of disclosure by a party
to this Agreement, its employees or agents ("DISCLOSING PARTY") or thereafter
made public knowledge through no act or failure to act on the part of another
party to this Agreement its employees or agents ("RECEIVING PARTY") or (2) known
independently by the Receiving Party prior to disclosure by the Disclosing
Party. Notwithstanding the foregoing, each party acknowledges that technology
which is public knowledge may have specific applications to products or
processes that are not public knowledge. The possible utilization of such
technology to these specific applications developed by or for a party will be
deemed confidential and proprietary and are to be maintained as such.

         SECTION 6.10.  TAX COVENANTS.

                  (a) Dubbell shall prepare and the Parent shall file within
         five (5) days of receipt from Dubbell all Tax Returns with the
         appropriate federal, state, local and foreign governmental agencies
         relating to the Parent or the Company for periods ending on or prior to
         the Closing Date, including the consolidated federal income Tax Return
         for the year ending December 27, 1997 (the "1997 FEDERAL TAX RETURN")
         and the consolidated federal income Tax Return for the period ending on
         the Closing Date (the "1998 SHORT PERIOD FEDERAL TAX RETURN"). The
         Parent shall prepare and file, or cause to be prepared and filed, all
         Straddle Tax Returns required to be filed by the Parent or the Company
         and shall pay the Taxes shown to be due thereon, provided, however,
         that Dubbell shall promptly reimburse the Parent for the portion of
         such Taxes that constitutes a Pre-Closing Tax. Buyer shall allow
         Dubbell and his accountants to review, comment upon and reasonably
         approve without undue delay any Straddle Tax Return and Dubbell shall
         allow Buyer to review, comment upon and reasonably approve without
         undue delay the 1997 Federal Tax Return and the 1998 Short Period
         Federal Tax Return, at any time during the forty-five (45) day period
         immediately preceding the filing of such Tax Returns. Buyer and Dubbell
         agree to cause the Parent and the Company to file all Tax Returns for
         any Straddle Period on


                                      -50-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   58

         the basis that the relevant taxable period ended as of the close of
         business on the Effective Date, unless the relevant Tax authority will
         not accept a Tax Return filed on that basis.

                  (b) In the case of any Straddle Period, (i) real, personal and
         intangible property Taxes ("PROPERTY TAXES") of the Parent or the
         Company for the Pre-Closing Tax Period shall be equal to the amount of
         such property Taxes for the entire Straddle Period multiplied by a
         fraction, the numerator of which is the number of days during the
         Straddle Period that are in the Pre-Closing Tax Period and the
         denominator of which is the number of days in the Straddle Period; and
         (ii) the Taxes of the Parent or the Company (other than property Taxes)
         for the portion of the Straddle Period that constitutes a Pre-Closing
         Tax Period shall be computed as if such taxable period ended as of the
         close of business on the Effective Date.

                  (c) The Parent will cause any tax sharing agreement or similar
         arrangement with respect to Taxes involving the Parent, the Company or
         any other Subsidiary of the Parent to be terminated effective as of the
         Effective Date, to the extent any such agreement or arrangement relates
         to the Parent, the Company or any other Subsidiary of the Parent, and
         after the Effective Date the Parent and the Company shall have no
         obligation under any such agreement or arrangement for any past,
         present or future period.

                  (d) The Buyer shall pay to Dubbell within ten (10) days of
         receipt any Tax refunds received by the Buyer, the Parent or the
         Company that relate solely to any Pre-Closing Tax Period, including any
         Tax refunds related to the carryback of any losses incurred during the
         taxable year of the Parent that includes the Closing Date.

                  (e) From and after the date hereof, neither the Parent, the
         Company nor any other Subsidiary of the Parent shall, without the
         consent of Buyer, (i) make, change or revoke, or permit to be made,
         changed or revoked, any election or method of accounting with respect
         to Taxes; or (ii) enter into, or permit to be entered into, any closing
         or other agreement or settlement with respect to Taxes.

         SECTION 6.11. RELEASE OF RESIGNING DIRECTORS AND OFFICERS; ASSUMPTION
OF OBLIGATIONS.

                  (a) On or prior to the Effective Date, each of the officers
         and directors of the Parent and the Company designated by the Buyer
         shall execute a resignation and cross release under which (i) he shall
         resign effective on the Closing Date from any office held as an officer
         or director of the Parent and/or the Company; (ii) he shall release the
         Parent and/or the Company from any and all claims, costs, liabilities
         and actions that he may have against them; (iii) the Parent and/or the
         Company shall release such individual from any and all claims, costs,
         liabilities and actions that it may have against such individual except
         (x) as to any then unpaid loans made by the Parent or the Company to
         such individual, and (y) any claims, costs, liabilities and actions
         that


                                      -51-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   59

         the Parent or the Company may have against such individual by reason of
         his willful malfeasance or criminal conduct; and (iv) the Parent and/or
         the Company shall indemnify and hold harmless such individual from and
         against any and all liabilities, losses, damages, claims, costs and
         expenses that such individual may incur arising out of or related to
         his having served as an officer or director of the Parent and/or the
         Company (except those arising from his willful malfeasance or criminal
         conduct).

                  (b) On or prior to the Effective Date, Dubbell shall cause
         PFRM to assume all liabilities and the performance of all obligations
         under the Severance Agreements, the Parent Lease, the Kunz and Olander
         Notes and any and all instruments, agreements or documents to which the
         Parent is bound.

         SECTION 6.12. ACTIONS OF SELLERS. Between the date of this Agreement
and the Closing Date, the Sellers will not take or knowingly permit to be taken
any action or do or knowingly permit to be done anything in the conduct of the
business of the Parent or the Company, as applicable, or otherwise, which would
be contrary to or in breach of any of the terms, conditions or provisions of
this Agreement, or which would cause any of the representations herein to be
untrue, except as may be provided for in this Article VI. Except as otherwise
requested by the Buyer, but without making any commitment on behalf of the
Buyer, the Sellers will use commercially reasonable efforts to preserve the
businesses of the Parent and the Company, to keep the services of their present
officers and employees available and to preserve the good will of the suppliers
and customers and others having business relationships with the Parent, the
Company or the Buyer.

         SECTION 6.13. CHANGE OF NAME OF THE PARENT. Prior to the Effective
Date, Dubbell shall cause the Parent to take all actions necessary to cause the
name of the Parent to be changed to Novagen Holdings, Inc. or such other name as
the Buyer and Dubbell shall mutually agree. Additionally, the Buyer shall
execute any license or assignment required in order to enable Dubbell to
continue to use the name "Pel-Freez" in connection with the operation of
businesses not purchased by the Buyer.

         SECTION 6.14. TRANSFER OF CORPORATE BOOKS AND RECORDS. On the Closing
Date, Dubbell shall cause the Parent and the Sellers shall cause the Company to
transfer all minute books, stock registers, Tax Returns and other corporate and
business books and records (including employee personnel files) of the Parent
and the Company applicable to all periods prior to and ending on the Closing
Date (the "CORPORATE RECORDS") to the Buyer. From and after the Closing Date
until the sixth year anniversary of the Closing Date, upon reasonable notice to
the Buyer and during regular business hours, the Sellers shall have access to
the Corporate Records. The Buyer shall give each of Dubbell's Agent and the
Minority Shareholders' Agent notice 30 days prior to the disposal of any
Corporate Records. Upon such notice, the Sellers' Agents, at their election, may
request the Buyer to deliver all such documents to the Sellers' Agents, or
either of them, and may retain the same with no obligation of any kind or nature
in respect thereof to the Buyer. The Buyer shall deliver such


                                      -52-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   60

Corporate Records to the Sellers' Agents at the place where they are regularly
stored by the Buyer.

         SECTION 6.15.  EMPLOYEE RELATIONS AND BENEFITS.

                  (a) The Parent and Dubbell shall take, or cause to be taken,
         such corporate action as is necessary to cause (i) the Parent Employee
         Benefit Plans to be assumed by PFRM as of or prior to the Closing Date,
         (ii) the Parent and the Company to cease as of the Closing Date to be
         participating employers in any of the Parent Employee Benefit Plans and
         (iii) the Parent and the Company to have no liability as of and after
         the Closing Date to PFRM or any other Person in respect of any Parent
         Employee Benefit Plan.

                  (b) Dubbell shall cause PFRM and its Affiliates following the
         Closing Date, and the Parent Employee Benefit Plans, to be responsible
         for all claims of participants in the Parent Employee Benefit Plans
         (including those persons who remain employed with the Company
         immediately following the Closing Date (the "POST-CLOSING COMPANY
         EMPLOYEES")) for payments or benefits thereunder. The Parent Employee
         Benefit Plans shall be responsible for all claims of Post-Closing
         Company Employees for worker's compensation, unemployment compensation
         and other government-mandated benefits, and for weekly indemnity, life,
         hospital/medical/surgical, disability, major medical and dental
         benefits, for expenses which were incurred prior to the Closing Date
         and are payable under the terms and conditions of any of the Parent
         Employee Benefit Plans. Those employee benefit plans maintained by the
         Buyer and in which Post-Closing Company Employees participate on the
         Closing Date, and which are analogous to a plan or program described in
         the preceding sentence (the "BUYER WELFARE PLANS"), shall be
         responsible for all claims for expenses incurred on or following the
         Closing Date and which are payable under the terms and conditions of
         any of the Buyer Welfare Plans.

                  (c) Service by Post-Closing Company Employees with the Company
         shall be recognized under the Buyer Welfare Plans, and any other
         employee benefit plans maintained by the Buyer for the benefit of
         Post-Closing Company Employees, for all purposes, including but not
         limited to participation, coverage, vesting and level of benefits, as
         applicable. The Buyer shall waive or cause its insurance carriers to
         waive all limitations as to preexisting conditions, if any, with
         respect to participation and coverage requirements applicable to
         Post-Closing Company Employees under the Buyer Welfare Plans except to
         the extent that such limitations (i) prevented any person from
         participating in any Parent Employee Benefit Plan immediately prior to
         the Closing Date and (ii) remain allowable following the passage of the
         Health Insurance Portability and Accountability Act.

                  (d) If the Closing Date is prior to December 31, Post-Closing
         Company Employees shall be allowed to continue to participate for the
         remainder of the calendar


                                      -53-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   61

         year in which the Closing Date occurs, on an after-tax basis, in the
         Parent Employee Benefit Plan which provides a health care flexible
         spending account and a dependent care spending account.

                  (e) The Buyer shall cause Post-Closing Company Employees to be
         provided with severance benefits in accordance with the arrangement
         described in Section 6.15 of the Disclosure Schedule for terminations
         of employment occurring within one year of the Closing Date.

                  (f) Dubbell shall cause PFRM or such other entity as may
         maintain the Pel-Freez, Inc. 401(k) Plan (the "PEL-FREEZ 401(K) PLAN")
         following the Closing Date to cause all accounts of Post-Closing
         Company Employees in the Pel-Freez 401(k) Plan to become fully vested
         and nonforfeitable as of the Closing Date. Provided a favorable Private
         Letter Ruling is issued by the Internal Revenue Service, Dubbell shall
         cause PFRM, or such other entity as may maintain the Pel-Freez 401(k)
         Plan following the Closing Date, to allow Post-Closing Company
         Employees having account balances therein to elect to receive lump sum
         distributions of such account balances in accordance with Section
         401(k)(10) of the Code until the end of the second calendar year
         following the calendar year in which the Closing Date occurs. The Buyer
         shall cause the Code Section 401(k) Plan maintained by it to accept
         rollover contributions of such distributions in accordance with the
         requirements of the Code. The account balances in the Pel-Freez 401(k)
         Plan which are not distributed in accordance with Section 401(k)(10) of
         the Code shall be treated in accordance with the terms of the Pel-Freez
         401(k) Plan. Dubbell shall cause PFRM or such other entity as may
         maintain the Pel-Freez 401(k) Plan to apply to the Internal Revenue
         Service for the Private Letter Ruling referred to above as soon as
         practicable following the date hereof, and use its best efforts to
         obtain such Private Letter Ruling.

                  (g) Dubbell shall cause PFRM or such other entity as may
         maintain the Pel-Freez, Inc. Retirement Plan (the "DB PLAN") to cause
         all accrued benefits of Post-Closing Company Employees in the DB Plan
         to become fully vested and nonforfeitable as of the Closing Date. Such
         accrued benefits shall be payable in accordance with the terms of the
         DB Plan. Dubbell shall take, or cause to be taken, by the Parent (prior
         to the Closing Date) or PFRM or such other entity, as applicable,
         (following the Closing Date) any action required by the Pension Benefit
         Guaranty Corporation (the "PBGC") to prevent a termination of the DB
         Plan by the PBGC in a manner or under circumstances which could cause
         the Buyer, Parent, the Company or any ERISA Affiliate of any of them to
         have any liability to or in respect of the DB Plan following the
         Closing Date. Dubbell shall cause a "reportable event" filing to be
         timely made with the PBGC in connection with the transactions
         contemplated hereunder, if required pursuant to Section 4043 of ERISA
         or the regulations thereunder. Dubbell shall cause to be promptly
         forwarded to the Buyer any comments received from the PBGC by the
         Sellers, the Parent, the Company or any ERISA


                                      -54-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   62

         Affiliate of any of them (whether written or oral) following the date
         hereof regarding the DB Plan.

                  (h) Prior to or as of the Closing Date, the Sellers and the
         Parent shall take whatever action is necessary to cause any outstanding
         options, warrants and other rights to purchase stock of the Parent or
         the Company to cease to exist. The Sellers and the Parent shall obtain
         releases from each of the holders of such options, warrants or other
         rights, addressed to the Parent, confirming that such options ceased to
         exist no later than the Closing Date, and that such holder maintains no
         rights against the Parent, the Company or the Buyer, or any Affiliate
         of any of them, in respect thereof on and following the Closing Date.

                  (i) Prior to the Closing Date, the Company shall set aside
         $25,000 into a bookkeeping account denominated the "RETENTION BONUS
         POOL." This set-aside shall be recorded in the financial operations of
         the Company as a charge to earnings prior to the Closing Date.
         Immediately following the Closing Date, the Buyer shall cause the
         Retention Bonus Pool to be increased by an additional $25,000. The
         resulting $50,000 Retention Bonus Pool shall be distributed at the
         discretion of the person who is the General Manager of the Company
         ninety (90) days following the Closing Date, to those Post-Closing
         Company Employees who continue to be employed with the Company at such
         time.

         SECTION 6.16. FURTHER ASSURANCES. Upon the request of a party or
parties hereto at any time after the Closing Date, the other party or parties
will forthwith execute and deliver such further instruments of assignment,
transfer, conveyance, endorsement, direction or authorization and other
documents as the requesting party or parties or its or their counsel may
reasonably request in order to perfect title of the Buyer and its successors and
assigns to the Remaining Parent Shares and the Company Minority Shares or
otherwise to effectuate the purposes of this Agreement.

         SECTION 6.17.  POST-CLOSING MANAGEMENT OF PROMEGA DISPUTE.

                  (a)
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                  (b) The Buyer and the Company shall make Robert C. Mierendorf
         ("MIERENDORF") and other employees of the Company available for
         consultations, court


                                      -55-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   63

         appearances, settlement conferences and other meetings with Dubbell and
         legal counsel regarding the Promega Dispute as may be reasonably
         requested by Dubbell and shall make available to Dubbell upon his
         reasonable request such books and records of the Company that have
         relevance to the Promega Dispute.

                  (c)
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         SECTION 6.18. INTERCOMPANY ACCOUNTS. The Buyer shall, within 90 days of
the Closing Date, pay or cause to be paid the Intercompany/Affiliate Account of
the Company outstanding as of the Closing Date, which amount shall not exceed
$200,000, and which shall bear interest from the Closing Date at a rate of 8%
per annum on the unpaid balance thereof. The Buyer shall be entitled to credit
against such outstanding Intercompany/Affiliate Account balance the amount of
any payments made prior to the Closing Date by the Parent or the Company to
Vector Securities International, Inc. or any other obligations of the Parent or
the Company to Vector Securities, Inc. in connection with the transactions
contemplated by this Agreement and to the extent such amounts exceed the amount
of the Intercompany/Affiliate Account, the Sellers shall reimburse the Buyer for
such amounts.

         SECTION 6.19. CONTINUATION OF COMPANY'S BUSINESS. From and after the
date of this Agreement through the Effective Date, the Company shall operate the
business in the ordinary course consistent with past practice and prior to the
Closing in accordance with the business plans and budgets established by the
Company, including, without limitation, reducing the amounts due under the
Company's Intercompany/Affiliate account. From and after the Effective Date,
Dubbell shall not permit the Parent, and the Sellers and the Parent shall not
permit the Company, to take any actions with respect to their respective
operations, howsoever insignificant, without the prior consent of the Buyer,
except for the Redemption Transaction. From and after the Effective Date, the
operations of the Parent and the Company shall be conducted for the account and
benefit, and at the expense, of the Buyer as if the transactions contemplated
hereby had been consummated on the Effective Date.

         SECTION 6.20. RELEASES FROM LIABILITY. Dubbell shall use commercially
reasonable efforts to obtain, on behalf of the Parent, unconditional releases of
all liabilities or obligations


                                      -56-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   64

of the Parent under the Severance Agreements, the Parent Lease, the Kunz and
Olander Notes and any and all other instruments, agreements or documents to
which the Parent is bound.

         SECTION 6.21. ANCILLARY AGREEMENTS. On or prior to the Closing Date,
the Parent, the Company and PFRM, as applicable, shall enter into agreements
substantially in the forms of Exhibits H, I and J, and reasonably acceptable to
the Buyer. The Buyer and Dubbell shall negotiate in good faith agreements based
on the principal terms set forth on Exhibit K.

         SECTION 6.22. CLOSING DOCUMENTATION. (a) On or before December 30,
1997, the Buyer shall cause to be prepared and submitted for review by the
Sellers' attorneys, fully executed copies of each of the certificates,
agreements, opinions and other documents required under Article VIII, dated as
of the Closing Date, to be held by such attorneys pending receipt of
instructions from the Buyer that they be delivered at the Closing.

         (b) On or before December 30, 1997, the Sellers shall cause to be
prepared and submitted for review by the Buyer's attorneys, fully executed
copies of each of the certificates, agreements, opinions and other documents
required under Article VII, dated as of the Closing Date, to be held by such
attorneys pending receipt of instructions from the Sellers' Agents that they be
delivered at the Closing.

         SECTION 6.23. ACTIONS OF BUYER. Between the date of the Agreement and
the Effective Date, the Buyer will not take, or knowingly permit to be taken,
any action which might reasonably be expected to adversely impact the day-to-day
operations of the business of the Company.


                                  ARTICLE VII.
                     CONDITIONS TO OBLIGATIONS OF THE BUYER

         The obligations of the Buyer to consummate the transactions
contemplated by this Agreement are subject to the fulfillment, at or before the
Closing Date, of the following conditions, any one or more of which may be
waived by the Buyer in its sole discretion:

         SECTION 7.1. REPRESENTATIONS AND WARRANTIES OF THE SELLERS. All
representations and warranties made by the Sellers in this Agreement or in any
Ancillary Document delivered pursuant to the provisions of this Agreement in
connection with the transactions contemplated hereby that are qualified as to
materiality or as to a specified dollar amount shall be true and correct in all
respects, and those not so qualified shall be true and correct in all material
respects, on and as of the Closing Date as if again made by the Sellers on and
as of such date, except for changes contemplated in Article VI hereof, and the
Buyer shall have received a certificate dated the Closing Date and signed by
each of the Sellers to that effect.

         SECTION 7.2. PERFORMANCE OF THE SELLERS' OBLIGATIONS. The Sellers shall
have performed all obligations required under this Agreement to be performed by
them on or


                                      -57-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   65

before the Closing Date, and the Buyer shall have received a certificate dated
the Closing Date and signed by each of the Sellers to that effect.

         SECTION 7.3. REDEMPTION TRANSACTION. The Redemption Transaction shall
have been effected by Dubbell and the Parent.

         SECTION 7.4. RECEIPT OF DOCUMENTS. The Sellers shall have delivered to
the Buyer all of the following, each duly executed by the parties thereto (other
than the Buyer) and dated the Closing Date (or an earlier date satisfactory to
the Buyer), in form and substance satisfactory to the Buyer:

                  (a) EMPLOYMENT AGREEMENT. The Employment Agreement between
         Mierendorf and the Company, substantially in the form of Exhibit G
         hereto;

                  (b) RESIGNATIONS. The resignations and releases of those
         officers and directors of the Parent and the Company designated by the
         Buyer, effective the Closing Date;

                  (c) CERTIFICATE OF NON-FOREIGN STATUS. The Buyer shall have
         received a certificate from Dubbell substantially in the form of
         Exhibit D hereto;

                  (d) STOCK OPTION RELEASES. The releases of persons formerly
         holding options, warrants or other rights to purchase stock of the
         Parent or the Company, as described in Section 6.15(h);

                  (e) EVIDENCE OF RELEASE OF LIENS. Documents evidencing the
         release of all liens on assets of the Parent and the Company, including
         Form UCC-3 Termination Statements, and payoff letters from all
         appropriate lenders;

                  (f) RELEASE UNDER VECTOR AGREEMENTS. The release of the Parent
         from any and all liabilities and obligations under the Vector
         Agreements, including, without limitation, any indemnification
         obligations.

                  (g) RELEASE UNDER ANNUITY. The release of the Parent and the
         Company by David Pelphrey from any and all liabilities or obligations
         and the termination of any and all security interests and other liens
         on the property of the Parent or the Company under any annuity for his
         benefit; and

                  (h) OTHER. All documents the Buyer may reasonably require
         relating to the existence of the Parent and the Company and the
         authority of the Sellers to enter into this Agreement, all in form and
         substance reasonably satisfactory to the Buyer.

         SECTION 7.5. CONSENTS AND APPROVALS. All consents, waivers,
authorizations and approvals of any governmental or regulatory authority,
domestic or foreign, and of any other Person, including but not limited to,
those required by Environmental Laws, required in


                                      -58-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   66

connection with the Parent's and the Sellers' execution, delivery and
performance of this Agreement shall have been duly obtained and shall be in full
force and effect on the Closing Date.

         SECTION 7.6. NO VIOLATION OF ORDERS. No preliminary or permanent
injunction or other order issued by any court or governmental or regulatory
authority, domestic or foreign, nor any statute, rule, regulation, decree or
executive order promulgated or enacted by any government or governmental or
regulatory authority, which declares this Agreement invalid in any respect or
prevents the consummation of the transactions contemplated hereby, or which
materially and adversely affects the assets, properties, operations, prospects,
net income or financial condition of the Company shall be in effect.

         SECTION 7.7. NO MATERIAL ADVERSE CHANGE. During the period from the
date of this Agreement to the Closing Date, there shall not have been any
material adverse change in the assets, properties, business, operations, net
income or financial condition of the Parent or the Company. For purposes of this
Section 7.7, any claim or lawsuit brought by Promega Corporation or its
principal stockholder or any of their respective Affiliates prior to the Closing
Date against the Company, the Parent, the Buyer or any party hereto shall not,
in and of itself, be considered a material adverse change unless it is related
to a material omission by the Company or any Seller.

         SECTION 7.8. DISCHARGE OF INDEBTEDNESS; RELEASE OF LIENS. The Parent
shall have paid, and shall have caused its Subsidiaries and Affiliates to have
paid, all amounts due and owing to the Company by the Parent and such
Subsidiaries and Affiliates. All amounts due and owing to the Parent by any of
its Subsidiaries (including the Company) immediately prior to the Redemption
Transaction shall be cancelled at such time and treated as a contribution to the
capital of the respective Subsidiaries owing such amounts. The Sellers shall
have performed, or caused the Parent and the Company to perform, all acts
necessary to terminate and release all liens, security interests, charges,
interests or other encumbrances on the Remaining Parent Shares and the Company
Minority Shares and the assets of the Parent and the Company.

         SECTION 7.9. OPINION OF COUNSEL. The Buyer shall have received an
opinion, dated as of the Closing Date, from Conner & Winters, a Professional
Corporation, counsel to the Parent and Dubbell and Lathrop & Clark, counsel to
the Minority Shareholders, in form and substance reasonably satisfactory to the
Buyer and its counsel, substantially in the forms attached as EXHIBIT B hereto.

         SECTION 7.10. LEGAL MATTERS. All certificates, instruments, opinions
and other documents required to be executed or delivered by or on behalf of the
Sellers under the provisions of this Agreement, and all other actions and
proceedings required to be taken by or on behalf of the Sellers in furtherance
of the transactions contemplated hereby, shall be reasonably satisfactory in
form and substance to counsel for the Buyer.


                                      -59-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   67


                                  ARTICLE VIII.
                    CONDITIONS TO OBLIGATIONS OF THE SELLERS

         The obligations of the Sellers to consummate the transactions
contemplated by this Agreement are subject to the fulfillment, at or before the
Closing Date, of the following conditions, any one or more of which may be
waived by the Sellers' Agents.

         SECTION 8.1. REPRESENTATIONS AND WARRANTIES OF THE BUYER. All
representations and warranties made by the Buyer in this Agreement or in any
Ancillary Document delivered pursuant to the provisions of this Agreement in
connection with the transactions contemplated hereby that are qualified as to
materiality or as to a specified dollar amount shall be true and correct in all
respects, and those not so qualified shall be true and correct in all material
respects, on and as of the Closing Date as if again made by the Buyer on and as
of such date and the Sellers shall have received a certificate dated the Closing
Date and signed by an authorized officer of the Buyer to that effect.

         SECTION 8.2. PERFORMANCE OF THE BUYER'S OBLIGATIONS. The Buyer shall
have performed all obligations required under this Agreement to be performed by
it on or before the Closing Date, and the Sellers shall have received a
certificate dated the Closing Date and signed by an authorized officer of the
Buyer to that effect.

         SECTION 8.3. CONSENTS AND APPROVALS. All consents, waivers,
authorizations and approvals of any governmental or regulatory authority,
domestic or foreign, and of any other Person required in connection with the
Buyer's execution, delivery and performance of this Agreement shall have been
duly obtained and shall be in full force and effect on the Closing Date.

         SECTION 8.4. NO VIOLATION OF ORDERS. No preliminary or permanent
injunction or other order issued by any court or governmental or regulatory
authority, domestic or foreign, nor any statute, rule, regulation, decree or
executive order promulgated or enacted by any government or governmental or
regulatory authority, domestic or foreign, that declares this Agreement invalid
or unenforceable in any respect or which prevents the consummation of the
transactions contemplated hereby shall be in effect.

         SECTION 8.5. OPINION OF COUNSEL. The Sellers shall have received a
favorable opinion, dated as of the Closing Date, from Willkie Farr & Gallagher,
counsel for the Buyer, in form and substance reasonably satisfactory to the
Sellers and their counsel. substantially in the form of EXHIBIT C.

         SECTION 8.6. LEGAL MATTERS. All certificates, instruments, opinions and
other documents required to be executed or delivered by or on behalf of the
Buyer under the provisions of this Agreement, and all other actions and
proceedings required to be taken by or on behalf of the Buyer in furtherance of
the transactions contemplated hereby, shall be reasonably satisfactory in form
and substance to counsel for the Sellers.


                                      -60-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   68


                                   ARTICLE IX.
                                 INDEMNIFICATION

         SECTION 9.1.  INDEMNIFICATION BY THE SELLERS AND THE BUYER.

                  (a) The Sellers shall severally indemnify and hold the Buyer
         Indemnified Parties harmless from and against and in respect of any and
         all liabilities, losses, damages, judgments, settlements, claims, costs
         and expenses, including but not limited to reasonable attorneys' fees
         (each, a "LOSS"), arising out of or due to (i) a breach of any
         covenant, condition or agreement of the Sellers contained in this
         Agreement or any representation or warranty contained in Article III of
         this Agreement and any related certificate, schedule, exhibit or other
         document furnished by such parties pursuant to this Agreement or in
         connection with the Closing (each, an "ANCILLARY DOCUMENT"), or (ii)
         any claim or cause of action by or in respect of any person who is or
         was employed by the Company, the circumstances giving rise to which
         arose prior to the Closing Date. Notwithstanding the foregoing
         provisions of this Section 9.1(a), for purposes of this Section 9.1(a),
         the term "Loss" shall not include any amounts attributable to any
         Pre-Closing Taxes of the Company.
         [**********************************************************************
         ****************************] Sellers' liability under this Section 9.1
         (a) shall not exceed $3,000,000 in the aggregate.

                  (b) The Sellers shall severally indemnify and hold the Buyer
         Indemnified Parties harmless from and against and in respect of any and
         all Losses, arising out of or due to any claim or cause of action (1)
         arising pursuant to Environmental Laws as a result of any act,
         omission, or condition in existence or first occurring prior to the
         Closing Date at any real property owned or leased by the Company, (2)
         arising out of the presence prior to the Closing Date at any real
         property owned or leased by the Company prior to the Closing Date of
         any Hazardous Material on, at, beneath, or near any real property owned
         or leased by the Company prior to the Closing Date, (3) any violation
         prior to the Closing Date of Environmental Law by the Company, at any
         real property owned or leased by the Company prior to the Closing Date,
         or (4) the disposal, arrangement for disposal, or transportation of any
         Hazardous Materials, prior to the Closing Date by the Company or from
         any real property owned or leased by the Company prior to the Closing
         Date.

                  (c)
                    [***********************************************************
         ***********************************************************************
         **************************]

                           (i)
                    [***********************************************************
         ***********************************************************************


                                      -61-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   69

         ***********************************************************************
         ****************]

                           (ii)
               [****************************************************************
         ***********************]

                           (iii)
               [***************************************************************]

         [**********************************************************************
         ***********************************************************************
         ***********************************************************************
         ***********************************************************************
         ***********************************************************************
         ***********************************************************************
         ****************************]

                  (d) In addition to his obligations as a Seller, Dubbell shall
         indemnify and hold the Buyer Indemnified Parties harmless from and
         against and in respect of any and all Losses arising out or due to (i)
         a breach of any representation or warranty contained in Article IV of
         this Agreement and any related Ancillary Document, (ii) any failure of
         Dubbell to pay and discharge when due any Parent Liabilities, (iii) any
         claim for payments or benefits from or in respect of any of the Parent
         Employee Benefit Plans, (iv) any claim or cause of action by or in
         respect of any person who is or was employed by the Parent or any of
         its Subsidiaries, the circumstances giving rise to which arose prior to
         the Closing Date or (v) any claim or cause of action by any present or
         former shareholder of the Parent or its Affiliates (other than Dubbell)
         in such present or former shareholder's capacity as a shareholder of
         the Parent or its Affiliates against a Buyer Indemnified Party, the
         Parent or the Company arising out of any transactions in capital stock
         of the Parent or its Affiliates; provided, however, that for purposes
         of this Section 9.1(d), the term "Loss" shall not include any amounts
         attributable to Taxes of any Subsidiary of the Parent other than the
         Company, whether accrued before or after the Closing Date, and any
         Pre-Closing Taxes of the Parent; [*************************************
         ***********************************************************************
         ***********]

                  (e) In addition to his obligations as a Seller, Dubbell shall
         indemnify and hold the Buyer Indemnified Parties harmless from and
         against and in respect of any and all Losses arising out or due to any
         claim or cause of action by any party against a Buyer Indemnified
         Party, the Parent or the Company with respect to liability from any
         claim or cause of action (1) arising pursuant to Environmental Laws as
         a result of any act, omission, or condition in existence or first
         occurring prior to the Closing Date at any real property owned or
         leased by the Parent and any of its Subsidiaries, (2) arising out of
         the presence prior to the Closing Date of any Hazardous Material on,
         at,


                                      -62-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   70

         beneath, or near any real property owned or leased by the Parent or its
         Subsidiaries prior to the Closing Date, (3) any violation of
         Environmental Law prior to the Closing Date by the Parent or its
         Subsidiaries or at any real property owned or leased by the Parent or
         its Subsidiaries prior to the Closing Date, or (4) the disposal,
         arrangement for disposal, or transportation prior to the Closing Date
         of any Hazardous Materials by the Parent or its Subsidiaries or from
         any real property owned or leased by the Parent or its Subsidiaries
         prior to the Closing Date.

                  (f) In addition to his other indemnification obligations,
         Dubbell shall indemnify the Buyer Indemnified Parties and hold them
         harmless from all Losses attributable to Taxes of any Subsidiary of the
         Parent other than the Company, whether accrued before or after the
         Closing Date, and any Pre-Closing Taxes of the Parent or the Company.
         For purposes of this Agreement, "Pre-Closing Taxes" shall mean, to the
         extent such liability does not give rise to a reduction in the Purchase
         Price pursuant to Section 2.4 of this Agreement, (i) all liability for
         Taxes of the Parent or the Company for Pre-Closing Tax Periods; (ii)
         all liability resulting by reason of the several liability of the
         Parent or the Company pursuant to Treasury Regulations 1.1502-6 or any
         analogous state, local or foreign law or regulation or by reason of the
         Parent or the Company having been a member of any consolidated,
         combined or unitary group on or prior to the Closing Date; (iii) all
         liability for Taxes resulting by reason of the Redemption Transaction;
         (iv) all liability for real estate transfer Taxes or real estate gains
         Taxes arising as a result of the sale of the Parent Shares, the sale of
         the Company Minority Shares or the deemed transfer of the stock of any
         of the Subsidiaries of the Parent under this Agreement; (v) all
         liability attributable to any misrepresentation or breach of warranty
         made by Dubbell in Section 4.8 of this Agreement; (vi) all liability
         for Taxes attributable to any failure to comply with any of the
         covenants or agreements of Dubbell or the Company under this Agreement;
         (vii) all liability for Taxes resulting by reason of any item of income
         or gain of a partnership reported by the Company as a partner, to the
         extent such items are properly attributable to a Pre-Closing Tax Period
         of the partnership; and (viii) all liability for Taxes of any other
         person pursuant to any contractual agreement entered into on or before
         the Closing Date.

                  (g) The Buyer shall indemnify and hold harmless the Sellers
         from and against and in respect of any and all Losses arising out of or
         due to a breach of any representation, warranty, covenant, condition or
         agreement of the Buyer contained in this Agreement or any related
         Ancillary Document.

         SECTION 9.2.  PROCEDURES.

                  (a) If an event giving rise to indemnification under this
         Agreement occurs or is alleged and the party or parties entitled to
         receive the benefits of the indemnification provisions hereunder (the
         "AGGRIEVED PARTY") asserts that a party or parties has become obligated
         to the Aggrieved Party pursuant to Section 9.1 hereof (the
         "INDEMNIFYING PARTY"), or if any suit, action, investigation, claim or
         proceeding (each


                                      -63-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   71

         a "CLAIM") is begun, made or instituted as a result of which the
         Indemnifying Party may become obligated to the Aggrieved Party
         hereunder, the Aggrieved Party shall give written notice to the
         Indemnifying Party, promptly after such Aggrieved Party has actual
         knowledge of any Claim as to which indemnity may be sought; provided,
         however, that the failure of any Aggrieved Party to give notice as
         provided herein shall not relieve the Indemnifying Party of its
         obligations under this Section 9.2 except to the extent the
         Indemnifying Party is materially prejudiced thereby. The Indemnifying
         Party will have the right, at its option and at its sole cost and
         expense, upon timely notice to the Aggrieved Party, to assume control
         of the defense (or otherwise contest or protect the Aggrieved Party
         against any such Claim) of any Claim by counsel of the Indemnifying
         Party's choice, provided, however, such counsel is reasonably
         satisfactory to the Buyer. Failure by the Indemnifying Party to notify
         the Aggrieved Party of its election to defend any such action within a
         reasonable time, but in no event more than fifteen days after notice
         thereof shall have been given to the Indemnifying Party, shall be
         deemed a waiver by the Indemnifying Party of its right to defend such
         Claim. If the Indemnifying Party assumes the defense of any such Claim,
         the obligations of the Indemnifying Party as to such Claim shall be
         limited to taking all steps necessary in the defense or settlement of
         such Claim resulting therefrom and to holding the Aggrieved Party
         harmless to the extent required under Section 9.1 hereof, from and
         against any and all Losses caused by or arising out of any settlement
         approved by the Indemnifying Party or any judgment in connection with
         such Claim resulting therefrom. The Aggrieved Party may participate, at
         its expense, in the defense of such Claim, provided that the
         Indemnifying Party shall direct and control the defense of such Claim.
         The Indemnifying Party shall not, in the defense of such Claim
         resulting therefrom, consent to entry of any judgment, except with the
         written consent of the Aggrieved Party, or enter into any settlement,
         except with the written consent of the Aggrieved Party, which does not
         include as an unconditional term thereof the giving by the claimant or
         the plaintiff to the Aggrieved Party of a release from all liability in
         respect of such Claim. All awards and costs payable by a third party to
         the Aggrieved Party or the Indemnifying Party shall belong to the
         Indemnifying Party.

                  (b) If the Indemnifying Party shall not assume the defense of
         any such Claim resulting therefrom, the Aggrieved Party may defend
         against such Claim in such manner as it may deem appropriate and,
         unless the Indemnifying Party shall deposit with the Aggrieved Party a
         sum equivalent to the total amount demanded in such Claim, but not in
         excess of the amounts required pursuant to Section 9.1, or shall
         deliver to the Aggrieved Party a surety bond in form and substance
         reasonably satisfactory to the Aggrieved Party, but not for more than
         the amounts required pursuant to Section 9.1, the Aggrieved Party may
         settle such Claim on such terms as it may deem appropriate, and the
         Indemnifying Party shall promptly reimburse the Aggrieved Party for the
         amount of all expenses, legal or otherwise, incurred by the Aggrieved
         Party in connection with the defense against or settlement of such
         Claim to the extent provided in Section 9.1 hereof. If no settlement of
         such Claim is made, the


                                      -64-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   72

         Indemnifying Party shall promptly reimburse the Aggrieved Party for the
         amount of any judgment rendered with respect to such Claim and of all
         expenses, legal or otherwise, incurred by the Aggrieved Party in the
         defense against such Claim, to the extent so required pursuant to
         Section 9.1 hereof.

         SECTION 9.3. PROCEDURES RELATING TO TAX CLAIMS. If any Tax authority
raises any issue with Buyer, including any Tax matters which could be subject to
Dubbell's indemnification under Section 9.1(d), related to the Company or other
Subsidiary of the Parent, the Company or the Parent, then Buyer shall promptly
notify Dubbell and offer him the right to confer with such Tax authority before
any claim for Tax deficiency is raised. In addition, notwithstanding the
provisions of Section 9.2, if a Claim is made by any Tax authority which, if
successful, is likely to result in an indemnity payment to Buyer or any of its
Affiliates pursuant to this Article IX, the Buyer shall notify Dubbell of such
claim (a "TAX CLAIM"), stating the nature and basis of such claim and the amount
thereof, to the extent known. Failure to give notice under the preceding two
sentences shall not relieve Dubbell from any liability which he may have on
account of this indemnification or otherwise, except to the extent that Dubbell
is materially prejudiced thereby. Dubbell will have the right, at his option and
at his sole cost and expense, upon timely notice to the Buyer, to assume control
of any defense of any Tax Claim (other than a Tax Claim relating solely to Taxes
of the Parent or the Company for a Straddle Period) with his own counsel,
provided, however, such counsel is reasonably satisfactory to the Buyer.
Dubbell's right to control a Tax Claim will be limited to amounts in dispute
which would be paid by Dubbell or for which Dubbell would be liable pursuant to
this Article IX. Costs of such Tax Claims are to be borne by Dubbell unless the
Tax Claim relates to taxable periods of the Parent or the Company beginning
after the Effective Date or to any Straddle Period, in which event such costs
will be born by the Buyer or, in the case of the Straddle Period, will be fairly
apportioned between Dubbell and the Buyer based upon their proportionate
interests. The Buyer Indemnified Parties shall cooperate with Dubbell in
contesting any Tax Claim, which cooperation shall include the retention and,
upon Dubbell's request, the provision of records and information which are
reasonably relevant to such Tax Claim and making employees available on a
mutually convenient basis to provide additional information or explanation of
any material provided hereunder. Notwithstanding the foregoing, Dubbell shall
neither consent nor agree to the settlement of any Tax Claim with respect to any
liability for Taxes that may affect the liability for any state or federal
income tax of the Parent or the Company or any "affiliated group" (as defined in
Section 1504(a) of the Code) of which the Parent or the Company is a member for
any taxable period ending subsequent to the Effective Date without the prior
written consent of the Buyer, and neither Dubbell, nor any entity controlled by
Dubbell, shall file an amended Tax Return that may affect the liability for
Taxes of the Parent or the Company without the prior written consent of the
Buyer. The Buyer and Dubbell shall jointly control all proceedings taken in
connection with any Tax Claims relating solely to a Straddle Period.

         SECTION 9.4. LIMITATIONS ON INDEMNITY. Notwithstanding anything in this
Article IX to the contrary:


                                      -65-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   73

                  (a) No Indemnifying Party shall have any obligation to make
         any payment under Section 9.1(a) hereof with respect to any Loss
         arising out of any breach of a representation or warranty unless the
         Aggrieved Party shall have suffered or incurred aggregate Losses
         indemnifiable under this Agreement of $50,000, and then only to the
         extent such amount exceeds $50,000.

                  (b) The total liability of each Seller under Section 9.1(a),
         (b) and (c) for all claims and obligations under this Article IX shall
         not exceed the respective Seller's percentage of the Purchase Price
         received or to be received by such Seller under this Agreement as set
         forth on EXHIBIT A-2.

         SECTION 9.5. SET OFF AGAINST EARN-OUT PAYMENTS. If, pursuant to this
Agreement, an individual Seller becomes obligated to pay any sum of money to the
Buyer, then such sum may, at the election of the Buyer, be set off against and
shall apply to the Earn-Out Payments any other sums owed by the Buyer to such
Seller under Section 2.3 until such sums are completely set off. The rights of
set off and payment set forth herein shall not apply to any Tax refund due to
Dubbell hereunder, [********************************] The rights of set off and
payment set forth herein shall be in addition to, and not in limitation or a
waiver of, any rights or remedies of the Buyer under any provisions of this
Agreement, whether now or hereafter existing, at law or in equity or by Statute.

         SECTION 9.6. PURCHASE PRICE ADJUSTMENT. The parties agree to treat any
payments received under this Article IX as an adjustment to the Purchase Price
for all federal, state and local income Tax purposes.

         SECTION 9.7. INSURANCE. In calculating any Loss, there shall be
deducted any insurance recovery in respect thereof (and no right of subrogation
shall accrue hereunder to any insurer). To the extent that an Aggrieved Party
has insurance coverage with respect to any Loss, such Aggrieved Party shall, and
agrees that it will, seek to collect its damages first against such Insurance
and only secondarily from an Indemnifying Party, and in the event that any
Indemnifying Party is required to indemnify any Aggrieved Party for any such
Loss, the Indemnifying Party shall have a right of subrogation with respect to
such insurer.

         SECTION 9.8. EXCLUSIVE REMEDIES. Except as otherwise explicitly
provided in this Agreement, the sole and exclusive remedy of the Sellers and the
Buyer for breach of any of the respective representations, warranties or
covenants of the Buyer or the Sellers, respectively, in this Agreement are as
set forth in this Article IX, provided, however, that this Section 9.8 shall not
limit remedies for fraud. The Buyer acknowledges and agrees that no Seller would
have entered into this Agreement but for the inclusion herein of this Section
9.8. The Sellers each acknowledge and agree that the Buyer would not have
entered into this Agreement but for the inclusion of this Section 9.8.

         SECTION 9.9. DISCLAIMER. EXCEPT AS SPECIFICALLY SET FORTH IN THIS
AGREEMENT AND ANY OTHER DOCUMENT OR INSTRUMENT EXECUTED BY SELLERS IN CONNECTION
WITH THE TRANSACTIONS CONTEMPLATED HEREBY,


                                      -66-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   74

THE SELLERS HEREBY EXPRESSLY DISCLAIM AND NEGATE ANY REPRESENTATION OR WARRANTY
INCLUDING WITHOUT LIMITATION ANY REPRESENTATION OR WARRANTY AT COMMON LAW, BY
STATUTE, OR OTHERWISE, INCLUDING BUT NOT LIMITED TO THOSE RELATING TO (i) ANY
IMPLIED OR EXPRESS WARRANTY OF MERCHANTABILITY, (ii) ANY IMPLIED OR EXPRESS
WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE, AND (iii) ANY IMPLIED OR EXPRESS
WARRANTY OF CONFORMITY TO MODELS OR SAMPLES OF MATERIALS.

                                   ARTICLE X.
                           TERMINATION AND ABANDONMENT

         SECTION 10.1. METHODS OF TERMINATION; UPSET DATE. This Agreement may be
terminated and the transactions contemplated hereby may be abandoned at any time
before the Closing:

                  (a) by the mutual written consent of the Sellers through
         Dubbell or Dubbell's Agent and the Buyer;

                  (b) by the Buyer, if any Seller has materially breached any
         representation, warranty, covenant or agreement and such breach is
         either not capable of being cured prior to the Closing or, if such
         breach is capable of being cured is not so cured within a reasonable
         amount of time of such breach;

                  (c) by the Sellers through Dubbell or Dubbell's Agent, if the
         Buyer has materially breached any representation, warranty, covenant or
         agreement and such breach is either not capable of being cured prior to
         the Closing or, if such breach is capable of being cured is not so
         cured within a reasonable amount of time of such breach;

                  (d) by the Buyer, if any material adverse change in the
         assets, properties, business, operations, net income or financial
         condition of the Parent or the Company shall have occurred;

                  (e) by the Sellers through Dubbell or Dubbell's Agent or the
         Buyer if a court of competent jurisdiction or governmental, regulatory
         or administrative agency or commission shall have issued an order,
         decree or ruling or taken any other action (which order, decree or
         ruling the parties hereto shall use their best efforts to lift), which
         permanently restrains, enjoins or otherwise prohibits the transactions
         contemplated by this Agreement; or

                  (f) by the Sellers through Dubbell or Dubbell's Agent or the
         Buyer at any time after February 28, 1998.


                                      -67-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   75

         For purposes of this Section 10.1, any claim or lawsuit brought by
Promega Corporation or its principal stockholder or any of their respective
Affiliates prior to the Closing Date against the Company, the Parent, the Buyer
or any other party hereto shall not, in and of itself, be sufficient reason to
terminate this Agreement, provided, however, that the foregoing shall not
preclude the Buyer from terminating this Agreement as a result of a material
breach of any representation or warranty (other than Section 3.16 as it relates
to the Promega Dispute).

         SECTION 10.2. PROCEDURE UPON TERMINATION. In the event of termination
and abandonment of this Agreement pursuant to Section 10.1, written notice
thereof shall forthwith be given to the other party or parties and this
Agreement shall terminate and the transactions contemplated hereby shall be
abandoned, without further action by the Sellers or the Buyer.

                                   ARTICLE XI.
                            MISCELLANEOUS PROVISIONS

         SECTION 11.1.  REPRESENTATION OF SELLERS BY SELLERS' AGENTS.

                  (a) Each of the Sellers hereby irrevocably appoints David W.
         Dubbell (and his successors herein called "DUBBELL'S AGENT") and Robert
         C. Mierendorf (and his successors herein called the "MINORITY
         SHAREHOLDERS' AGENT") (herein called the "SELLERS' AGENTS") as his or
         her agents and attorneys-in-fact to take any action required to be
         taken by the Sellers under the terms of this Agreement, including,
         without limiting the generality of the foregoing, the giving and
         receipt of any notices to be delivered or received by or on behalf of
         any or all of the Sellers and the right to waive, modify or amend any
         of the terms of this Agreement, and agrees to be bound by any and all
         actions taken by such agents on their behalf. The Buyer shall be
         entitled to rely exclusively upon any communications given jointly by
         the Sellers' Agents, except where this Agreement specifically refers to
         Dubbell's Agent or the Minority Shareholder's Agent in which case the
         Buyer may rely on communications given by the specified agent and the
         Buyer shall not be liable in any manner whatsoever for any action taken
         or not taken in reliance upon the actions taken or not taken or
         communications made by the Sellers' Agents or either of them, as the
         case may be. The Buyer shall be entitled to disregard any notices or
         communications given or made by the Sellers unless given or made
         through the Sellers' Agents, or either of them, as the case may be.

                  (b) In the event of the death or incapacity of either of the
         Sellers' Agents or his inability to perform his functions hereunder,
         the Buyer shall be entitled to rely upon any notices or communications
         given or made solely by or to the remaining Shareholders' Agent until
         the receipt of notice of the appointment of a new agent and
         attorney-in-fact. If at any time the offices of one or both of the
         Sellers' Agents are vacant, then Dubbell or his successors in interest
         shall appoint another person to serve as Dubbell's Agent, and the
         Sellers other than Dubbell (herein called the "MINORITY


                                      -68-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   76

         SHAREHOLDERS") shall appoint another person to serve as the Minority
         Shareholders' Agent. Such appointment or appointments shall be deemed
         to have been made when the identities of the new Agent or Agents have
         been communicated to the Buyer in writing.

                  (c) The manner and form by which the Sellers shall decide upon
         any new agent and attorney-in-fact and the manner in which such
         decisions are to be communicated to the remaining Sellers' Agents shall
         be decided solely by the Sellers. The Sellers recognize, and hereby
         acknowledge, that the Sellers' Agents have an interest in the subject
         matter of this Agreement and that the appointment of such Agents as the
         Sellers' Agents constitutes an irrevocable power-of-attorney coupled
         with an interest.

                  (d) The Sellers jointly and severally shall indemnify and hold
         harmless each of the Sellers' Agents from and against any loss or cost
         which they or either of them may sustain or incur while acting as
         Sellers' Agents except that each Sellers' Agent shall bear his own
         liability and expense arising out of activities that are fraudulent or
         grossly negligent.

         SECTION 11.2. NATURE AND SURVIVAL OF REPRESENTATIONS, ETC. All
statements contained in any Ancillary Document delivered by or on behalf of the
Sellers or the Buyer pursuant to this Agreement or in connection with the
transactions contemplated hereby shall be deemed representations and warranties
by the Sellers or the Buyer hereunder. All representations and warranties and
agreements made by the parties hereto in this Agreement or pursuant hereto shall
survive the Closing hereunder and any investigation at any time made by or on
behalf of the Sellers or the Buyer. No suit or action may be commenced for
Claims under Section 9.1 at any time more than fifteen (15) months after the
Closing Date except for a suit or action brought thereunder for a breach of the
representations and warranties set forth in Sections 3.1, 3.15, 3.16 and 3.30 or
a suit or action brought to enforce the obligations of Dubbell or the other
Sellers, as applicable, under Sections 9.1(a) (with respect to a breach of any
covenant, condition or agreement under Sections 6.2, 6.3, 6.6, 6.7, 6.9, 6.10,
6.15, 6.16, 6.17, 6.20, 11.2, 11.5, 11.6, or 11.8 or Article IX), 9.1(b),
9.1(c), 9.1(d), 9.1(e) or 9.1(f) (with respect to which the applicable statute
of limitations shall apply).

         SECTION 11.3. PUBLICITY. Prior to the Closing Date, the Sellers shall
not, nor shall they permit their respective Affiliates to, issue or cause the
publication of any press release or other announcement with respect to this
Agreement or the transactions contemplated hereby without the consent of the
Buyer. The Buyer shall consult with the Sellers before issuing any press release
or otherwise making any public statement with respect to the this Agreement and
the transactions contemplated hereby and shall not publicly disclose the names
of Pel-Freez, Inc. or David W. Dubbell, except in each case as required by law.

         SECTION 11.4. SUCCESSORS AND ASSIGNS; NO THIRD-PARTY BENEFICIARIES.
This Agreement shall inure to the benefit of, and be binding upon, the parties
hereto and their


                                      -69-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   77

respective successors and assigns; provided, however, that no party shall assign
or delegate any of the obligations created under this Agreement without the
prior written consent of the other parties. Notwithstanding the foregoing, the
Buyer shall have the unrestricted right to assign this Agreement and/or to
delegate all or any part of its obligations hereunder to any Affiliate of the
Buyer or to any lender in connection with any financing, but in such event the
Buyer shall remain fully liable for the performance of all of such obligations
in the manner prescribed in this Agreement. Nothing in this Agreement shall
confer upon any Person not a party to this Agreement, or the legal
representatives of such Person, any rights or remedies of any nature or kind
whatsoever under or by reason of this Agreement.

         SECTION 11.5. BROKERS, FINDERS AND FINANCIAL ADVISORS. The Buyer, on
the one hand, and the Sellers, on the other, represent and warrant to each other
that all negotiations relative to this Agreement and the transactions
contemplated hereby have been carried on by Buyer and the Sellers directly with
each other and that no person is entitled to any broker's, finder's or financial
advisor's fee in connection with or on account of this Agreement or any
transaction herein contemplated, except that Sellers have engaged Vector
Securities, Inc. as a financial advisor and shall be obligated for its fees 
and costs.

         SECTION 11.6. FEES AND EXPENSES. All legal, accounting and other fees,
costs and expenses of the Parent, the Company and the Sellers incurred in
connection with, or arising out of their obligations contained in, this
Agreement and the transactions contemplated hereby shall be paid by the Sellers.
All legal, accounting and other fees, costs and expenses of the Buyer incurred
in connection with, or arising out of its obligations contained in, this
Agreement and the transactions contemplated hereby shall be paid by the Buyer.

         SECTION 11.7. NOTICES. All notices and other communications given or
made pursuant hereto shall be in writing and shall be deemed to have been duly
given or made if delivered personally or sent by registered or certified mail
(postage prepaid, return receipt requested) by facsimile or by air courier
guaranteeing second day delivery directed to the parties at the following
addresses:

                  (a)      If to the Buyer, to:

                   CN Biosciences, Inc.
                   10394 Pacific Center Court
                   San Diego, CA  92121
                   Attention:  James G. Stewart
                   Fax:  (619) 450-5522


                                      -70-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   78

                  with a copy to:

                  Willkie Farr & Gallagher
                  One Citicorp Center
                  153 East 53rd Street
                  New York, NY  10022
                  Attention:  Peter H. Jakes, Esq.
                  Fax:  (212) 821-8111

                  (b)      If to the Sellers' Agents, to:

                  David W. Dubbell
                  Pel-Freez, Inc.
                  205 North Arkansas
                  P.O. Box 68
                  Rogers, AR  72757
                  Fax:  (501) 636-4282

                  and:

                  Robert C. Mierendorf
                  Novagen, Inc.
                  601 Science Dr.
                  Madison, WI  53711
                  Fax:  (608) 238-1388

                  with a copy to:

                  Conner & Winters, a Professional Corporation
                  15 E. Fifth Street
                  Suite 3700
                  Tulsa, OK  74103
                  Attention:  Henry G. Will, Esq.
                  Fax: (918) 586-8982

                  and:

                  Lathrop & Clark
                  740 Regent Street
                  Suite 400
                  P.O. Box 1507
                  Madison, WI  53701
                  Attention:  Michael J. Lawton, Esq.
                  Fax: (608) 257-1507


                                      -71-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   79

                  (c)      If to the Parent, to:

                  Pel-Freez, Inc.
                  205 North Arkansas
                  P.O. Box 68
                  Rogers, AR  72757
                  Attention:  David W. Dubbell
                  Fax:  (501) 636-4282

                  with a copy to:

                  Conner & Winters, a Professional Corporation
                  15 E. Fifth Street
                  Suite 3700
                  Tulsa, OK  74103
                  Attention:  Henry G. Will, Esq.
                  Fax:  (918) 586-8982

                  (d)      If to Dubbell or Dubbell's Agent, to:

                  David W. Dubbell
                  Pel-Freez, Inc.
                  205 North Arkansas
                  P.O. Box 68
                  Rogers, AR  72757
                  Fax: (501) 636-4282

                  with a copy to:

                  Conner & Winters, a Professional Corporation
                  15 E. Fifth Street
                  Suite 3700
                  Tulsa, OK  74103
                  Attention:  Henry G. Will, Esq.
                  Fax:  (918) 586-8982

or to such other persons or at such other addresses as shall be furnished by
either party by like notice to the other, and such notice or communication shall
be deemed to have been given or made as of the date so delivered or mailed.

         SECTION 11.8. RELEASE UNDER SELLERS' ESCROW AGREEMENT. Each Seller
hereby jointly and severally indemnifies, releases and holds harmless the Buyer
from and against any Losses arising from any and all actions taken under or in
connection with the Sellers' Escrow Agreement.


                                      -72-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   80

         SECTION 11.9. ENTIRE AGREEMENT. This Agreement, together with the
Disclosure Schedule and the exhibits hereto, represent the entire agreement and
understanding of the parties with reference to the transactions set forth herein
and no representations or warranties have been made in connection with this
Agreement other than those expressly set forth herein or in the Disclosure
Schedule, exhibits, certificates and other documents delivered in accordance
herewith. This Agreement supersedes all prior negotiations, discussions,
correspondence, communications, understandings and agreements between the
parties relating to the subject matter of this Agreement and all prior drafts of
this Agreement, all of which are merged into this Agreement. No prior drafts of
this Agreement and no words or phrases from any such prior drafts shall be
admissible into evidence in any action or suit involving this Agreement.

         SECTION 11.10. WAIVERS AND AMENDMENTS. The Sellers through the Sellers'
Agents or the Buyer may by written notice to the other: (a) extend the time for
the performance of any of the obligations or other actions of the other; (b)
waive any inaccuracies in the representations or warranties of the other
contained in this Agreement; (c) waive compliance with any of the covenants of
the other contained in this Agreement; (d) waive performance of any of the
obligations of the other created under this Agreement; or (e) waive fulfillment
of any of the conditions to its own obligations under this Agreement. No waiver
by any party hereto, whether express or implied, of its rights under any
provision of this Agreement shall constitute a waiver of such party's rights
under such provision at any other time or a waiver of such party's rights under
any other provision of this Agreement. No failure by any party hereto to take
any action against any breach of this Agreement or default by another party
hereto shall constitute a waiver of the former party's right to enforce any
provision of this Agreement or to take action against such breach or default or
any subsequent breach or default by such other party. This Agreement may be
amended, modified or supplemented only by a written instrument executed by the
Buyer and the Sellers' Agents.

         SECTION 11.11. SEVERABILITY. This Agreement shall be deemed severable,
and the invalidity or unenforceability of any term or provision hereof shall not
affect the validity or enforceability of this Agreement or of any other term or
provision hereof. Furthermore, in lieu of any such invalid or unenforceable term
or provision, the parties hereto intend that there shall be added as a part of
this Agreement a provision as similar in terms to such invalid or unenforceable
provision as may be possible and be valid and enforceable.

         SECTION 11.12. TITLES AND HEADINGS. The Article and Section headings
and any table of contents contained in this Agreement are solely for convenience
of reference and shall not affect the meaning or interpretation of this
Agreement or of any term or provision hereof.

         SECTION 11.13. SIGNATURES AND COUNTERPARTS. Facsimile transmission of
any signed original document and/or retransmission of any signed facsimile
transmission shall be the same as delivery of an original. At the request of any
party, the parties will confirm facsimile transmission by signing a duplicate
original document. This Agreement may be


                                      -73-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   81

executed in two or more counterparts, each of which shall be deemed an original
and all of which together shall be considered one and the same agreement.

         SECTION 11.14. ENFORCEMENT OF THE AGREEMENT. The parties hereto agree
that irreparable damage would occur if any of the provisions of this Agreement
were not performed in accordance with their specific terms or were otherwise
breached. It is accordingly agreed that the parties shall be entitled to an
injunction or injunctions to prevent breaches of this Agreement and to enforce
specifically the terms and provisions hereto. Such remedies and all other
remedies provided for in this Agreement shall, however, be cumulative and not
exclusive and shall be in addition to any other remedies which any party may
have under this Agreement or otherwise.

         SECTION 11.15. GOVERNING LAW. This Agreement shall be governed by and
interpreted and enforced in accordance with the laws of the State of New York
without giving effect to the choice-of-law provisions thereof.

         SECTION 11.16. KNOWLEDGE. As used in this Agreement, the terms
"knowledge" or "best knowledge" or words to that effect shall, as to any person,
refer to all facts of which such person shall have written notice or actual
knowledge.


                                      -74-

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   82







         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date first above written.

                                                   SELLERS:


                                                   /s/ David W. Dubbell
                                                   ----------------------------
                                                   DAVID W. DUBBELL


                                                   /s/ Dennis Almond
                                                   ----------------------------
                                                   DENNIS ALMOND


                                                   /s/ Corrine Fetherston
                                                   ----------------------------
                                                   CORRINE FETHERSTON


                                                   /s/ Lisa Johnson
                                                   ----------------------------
                                                   LISA JOHNSON


                                                   /s/ Robert Mierendorf
                                                   ----------------------------
                                                   ROBERT MIERENDORF


                                                   /s/ Warren Kroeker
                                                   ----------------------------
                                                   WARREN KROEKER


                                                   /s/ Barbara Morris
                                                   ----------------------------
                                                   BARBARA MORRIS


                                                   /s/ Robert Novy
                                                   ----------------------------
                                                   ROBERT NOVY


                                                   /s/ Tom Van Oosbree
                                                   ----------------------------
                                                   TOM VAN OOSBREE


*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.

<PAGE>   83




                                           PEL-FREEZ, INC.

                                           By:  /s/ David W. Dubbell
                                                ----------------------------
                                                    Name:  David W. Dubbell
                                                    Title:  President

                                           CN BIOSCIENCES, INC.

                                           By:  /s/ Stelios B. Papadopoulos
                                                ----------------------------
                                                Name:  Stelios B. Papadopoulos
                                                Title:  Chief Executive Officer

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.


<PAGE>   84







                                   EXHIBIT A-1
                          SHAREHOLDERS OF NOVAGEN, INC.



<TABLE>
<CAPTION>
                                                     Number of Shares of
Name                                                 Company Common Stock
- -------------------------------------------------------------------------
<S>                                                  <C>
Dennis Almond                                                   50
Corrine Fetherston                                              25
Lisa Johnson                                                    25
Warren Kroeker                                                  50
Robert Mierendorf                                              250
Robert Novy                                                     25
Barbara Morris                                                  25
Pel-Freez, Inc.                                              4,500
Tom Van Oosbree                                                 50
</TABLE>


*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.


<PAGE>   85




                                   EXHIBIT A-2

              SHAREHOLDERS OF NOVAGEN, INC. AS OF THE CLOSING DATE



<TABLE>
<CAPTION>
                                      Number of Shares of                  Percentage of
Name                                 Company Common Stock                 Purchase Price
- --------------------                 --------------------                 --------------
<S>                                  <C>                                  <C>
Dennis Almond                                50                                   1.0%
Corrine Fetherston                           40                                   0.8%
Lisa Johnson                                 40                                   0.8%
Warren Kroeker                               50                                   1.0%
Robert Mierendorf                           200                                   4.0%
Robert Novy                                  40                                   0.8%
Barbara Morris                               40                                   0.8%
Pel-Freez, Inc.                           4,500                                  90.0%
Tom Van Oosbree                              40                                   0.8%
                                          -----                                  ------
                                          5,000                                 100.0%
</TABLE>

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   86
                                                                       EXHIBIT B

        FORM OF OPINION OF COUNSEL TO THE PARENT, THE COMPANY AND DUBBELL

1.       Dubbell owns the Remaining Parent Shares on the date hereof, free and
         clear of any lien, charge or encumbrance, and there are no issued and
         outstanding shares of capital stock of the Parent other than the
         Remaining Parent Shares.

2.       The Stock Purchase Agreement constitutes a valid and binding obligation
         of Dubbell and, to our knowledge, the Stock Purchase Agreement and all
         transactions contemplated thereby will not result in a violation of any
         of the terms and provisions of any agreement to which Dubbell may be a
         party or by which Dubbell may otherwise be bound.

3.       The Company is a corporation duly organized, validly existing and in
         good standing under the laws of the State of Arkansas and has all
         requisite corporate power and authority and all governmental licenses,
         authorizations, permits, consents and approvals to own its properties
         and assets and to conduct its businesses as now conducted and as
         proposed to be conducted. The Company is duly qualified to do business
         as a foreign corporation and is in good standing in the jurisdictions
         listed in Section 3.3 of the Disclosure Schedule, which includes every
         jurisdiction where the character of the properties owned or leased by
         it or the nature of the business conducted by it makes such
         qualification necessary.

4.       The authorized capital stock of the Company consists of 5,000 shares of
         Company Common Stock, all of which are issued and outstanding. Such
         shares of Company Common Stock represent all of the issued and
         outstanding shares of capital stock of the Company. All shares of
         Company Common Stock have been duly authorized and validly issued and
         are fully paid and nonassessable. There are no outstanding options,
         warrants, agreements, conversion rights, preemptive rights or other
         rights to subscribe for, purchase or otherwise acquire any shares of
         Company Common Stock, and there are no outstanding obligations of the
         Company to repurchase, redeem or otherwise acquire outstanding shares
         of Company Common Stock.

5.       The Company does not own any shares of, or control, directly or
         indirectly, or have any equity interest in, any Person.

6.       The execution, delivery and performance by the Dubbell of the Stock
         Purchase Agreement and the transactions contemplated thereby do not and
         will not: (i) violate or conflict with any provision of the articles of
         incorporation or by-laws of the Company; (ii) violate any provision of
         law, statute, judgment, order, writ, injunction, decree, or

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   87
         award, or, to our knowledge, rule, or regulation, of any court,
         arbitrator, or other governmental or regulatory authority applicable to
         the Company; (iii) to our knowledge, violate, result in a breach of,
         constitute (with due notice or lapse of time or both) a default or
         cause any obligation, penalty, premium, right of termination or
         acceleration to arise, accrue or occur under any material contract,
         lease, loan agreement, mortgage, security agreement, trust indenture or
         other agreement or instrument to which the Company is a party or by
         which the Company is bound or to which its properties or assets is
         subject; (iv) to our knowledge, result in the creation or imposition of
         any lien, charge or encumbrance of any kind whatsoever upon any of the
         properties or assets of the Company; or (v) to our knowledge, result in
         the cancellation, modification, revocation or suspension of any
         License.

7.       Except as have been made or obtained, no consent, waiver, authorization
         or approval of any governmental or regulatory authority, domestic or
         foreign, or any other Person, or declaration to or filing or
         registration with any such governmental or regulatory authority, is
         required of or to be made by the Company in connection with the
         execution, delivery and performance of the Stock Purchase Agreement.

8.       Except as set forth in Section 3.16 of the Disclosure Schedule, to our
         knowledge, there are no claims, actions, suits, proceedings, labor
         disputes or investigations pending or, to our knowledge, threatened
         before any federal, state or local court or governmental,
         administrative or regulatory authority, domestic or foreign, or before
         any arbitrator of any nature, brought by or against the Company or its
         officers, directors, employees, agents or any of their respective
         Affiliates involving, affecting or relating to any assets, properties
         or operations of the Company or the transactions contemplated by the
         Stock Purchase Agreement. Neither Dubbell nor the Company nor any of
         his or the Company's assets or properties is subject to, nor does any
         basis exist for, any order, writ, judgment, award, injunction or decree
         of any federal, state or local court or governmental or regulatory
         authority or arbitrator, that affects the Company's assets, properties,
         operations, prospects, net income or financial condition or which would
         interfere with the transactions contemplated by the Stock Purchase
         Agreement.

9.       The Parent is a corporation duly organized, validly existing and in
         good standing under the laws of the State of Arkansas and has all
         requisite corporate power and authority and all governmental licenses,
         authorizations, permits, consents and approvals to own its properties
         and assets and to conduct its businesses as now conducted and as
         proposed to be conducted. The Parent is duly qualified to do business
         as a

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   88
         foreign corporation and is in good standing in every jurisdiction
         listed in Section 4.1 of the Disclosure Schedule, which includes every
         jurisdiction where the character of the properties owned or leased by
         it or the nature of the business conducted by it makes such
         qualification necessary.

10.      The authorized capital stock of the Parent consists of 1,000,000 shares
         of Parent Common Stock of which 427,200 shares are outstanding on the
         date hereof. The Remaining Parent Shares represent all of the issued
         and outstanding shares of the capital stock of the Parent and are owned
         of record and beneficially by Dubbell, free and clear of any lien,
         charge or encumbrance. All the outstanding shares of Parent Common
         Stock have been duly authorized and validly issued and are fully paid
         and nonassessable. There are no outstanding options, warrants,
         agreements, conversion rights, preemptive rights or other rights to
         subscribe for, purchase or otherwise acquire any shares of Parent
         Common Stock, and there are no outstanding obligations or plans of the
         Parent to repurchase, redeem or otherwise acquire outstanding shares of
         Parent Common Stock.

11.      Except as set forth in Section 4.3 of the Disclosure Schedule, the
         Parent does not own any shares of, or control, directly or indirectly,
         or have any equity interest in, any Person.

12.      The Parent has the corporate power to enter into the Stock Purchase
         Agreement and to carry out its obligations thereunder, including in
         connection with the Redemption Transaction. The execution and delivery
         of the Stock Purchase Agreement and the performance by the Parent of
         its obligations thereunder, including in connection with the Redemption
         Transaction, have been duly authorized by the Board of Directors of the
         Parent, and no other corporate proceedings on the part of the Parent
         are necessary to authorize such execution, delivery and performance.
         The Stock Purchase Agreement has been duly executed by the Parent and
         constitutes the valid and binding obligation of the Parent enforceable
         against the Parent in accordance with its terms.

13.      The execution, delivery and performance by Dubbell and the Parent of
         the Stock Purchase Agreement and the transactions contemplated hereby,
         including the Redemption Transaction, do not and will not: (i) violate
         or conflict with any provision of the articles of incorporation or
         by-laws of the Parent; (ii) violate any provision of law, statute,
         judgment, order, writ, injunction, decree, or award, or, to our
         knowledge, rule, or regulations of any court, arbitrator, or other
         governmental or regulatory authority applicable to the Parent; (iii) to
         our knowledge, violate,

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   89
         result in a breach of, constitute (with due notice or lapse of time or
         both) a default or cause any obligation, penalty, premium, right of
         termination or acceleration to arise, accrue or occur under any
         contract, lease, loan agreement, mortgage, security agreement, trust
         indenture or other agreement or instrument to which either Dubbell or
         the Parent is a party or by which either of them is bound or to which
         any of their respective properties or assets is subject; (iv) result in
         the creation or imposition of any lien, charge or encumbrance of any
         kind whatsoever upon any of the properties or assets of the Parent; or
         (v) to our knowledge, result in the cancellation, modification,
         revocation or suspension of any License.

14.      Except as have been made or obtained, no consent, waiver, authorization
         or approval of any governmental or regulatory authority, domestic or
         foreign, or any other Person, and no declaration to or filing or
         registration with any such governmental or regulatory authority, is
         required of or to be made by the Parent or Dubbell in connection with
         the execution, delivery and performance of the Stock Purchase
         Agreement.

15.      Except as set forth in Section 4.13 of the Disclosure Schedule, to our
         knowledge, there are no claims, actions, suits, proceedings, labor
         disputes or investigations pending or, to our knowledge, threatened
         before any federal, state or local court or governmental,
         administrative or regulatory authority, domestic or foreign, or before
         any arbitrator of any nature, brought by or against Dubbell, the Parent
         or the Parent's officers, directors, employees or agents or any of
         their respective Affiliates involving, affecting or relating to any
         assets, properties or operations of the Parent or the transactions
         contemplated by the Stock Purchase Agreement. None of Dubbell nor the
         Parent nor any of their assets or properties is subject to, nor, to our
         knowledge, does any basis exist for, any order, writ, judgment, award,
         injunction or decree of any federal, state or local court or
         governmental or regulatory authority or arbitrator, that affects the
         Parent's assets, properties, operations, prospects, net income or
         financial condition or which would interfere with the transactions
         contemplated by the Stock Purchase Agreement.

16.      Opinions in similar form to the above with respect to the ancillary
         agreements by Parent and the Company where rights are being transferred
         to Parent or the Company as to due authorization, execution and
         delivery, validity and enforceability and no conflicts or consents.

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   90
         FORM OF OPINION OF COUNSEL TO THE COMPANY MINORITY SHAREHOLDERS

1.       Each of the Company Minority Shareholders owns, free and clear of any
         lien, charge or encumbrance, all of the shares of Company Common Stock
         set forth after the name of such Minority Shareholder and the Parent on
         Exhibit A-2 to the Stock Purchase Agreement.

2.       The Stock Purchase Agreement constitutes a valid and binding obligation
         of each Company Minority Shareholder and, to our knowledge, the Stock
         Purchase Agreement and all transactions contemplated thereby will not
         result in a violation of any of the terms and provisions of any
         agreement to which any Company Minority Shareholder may be a party or
         by which any Company Minority Shareholder may otherwise be bound.

3.       To our knowledge, none of the Company Minority Shareholders nor any of
         their assets or properties is subject to, nor does any basis exist for,
         any order, writ, judgment, award, injunction or decree of any federal,
         state or local court or governmental or regulatory authority or
         arbitrator, that which would interfere with the transactions
         contemplated by the Stock Purchase Agreement.

4.       Opinions in similar form to the above with respect to the Sellers'
         Escrow Agreement and the [************************] as to due
         authorization, execution and delivery, validity and enforceability and
         no conflicts or consents.

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   91
                                                                       EXHIBIT C


                       FORM OF OPINION OF BUYER'S COUNSEL

         (a) The Buyer is a corporation duly organized, validly existing and in
good standing under the laws of the State of Delaware and the Buyer has all
requisite corporate power and authority to own its properties and assets and to
conduct its business as now conducted;

         (b) The Buyer has the corporate power to enter into the Purchase
Agreement and to carry out its obligations thereunder. The execution and
delivery of the Purchase Agreement by the Buyer and the performance of the
obligations thereunder have been duly authorized by the Board of Directors of
the Buyer and no other corporate proceedings on the part of the Buyer are
necessary to authorize such execution, delivery and performance. The Purchase
Agreement has been duly executed by the Buyer and constitute the legal, valid
and binding obligations of the Buyer enforceable against it in accordance with
their terms, except as the same may be limited by bankruptcy, insolvency,
reorganization or other laws relating to or affecting the enforceability of
creditors' rights generally and except that the remedy of specific performance
or similar equitable relief may be subject to equitable defenses and to the
discretion of the court before which enforcement is sought; and

         (c) The execution, delivery and performance of the Purchase Agreement
by the Buyer do not and will not violate or conflict with any provision of the
Amended and Restated Certificate of Incorporation or Amended and Restated
By-Laws of the Buyer and do not and will not violate any provision of law, or
any order, judgment or decree of any court or other governmental or regulatory
authority, nor violate nor will result in a breach of or constitute (with due
notice or lapse of time or both) a default under any material contract, lease,
loan agreement, mortgage, security agreement, trust indenture or other agreement
or instrument known to us (after inquiry of appropriate officers of the Buyer)
to which the Buyer is a party or by which it is bound or to which its properties
or assets is subject.

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   92
                                                                       Exhibit D

                    FORM OF CERTIFICATE OF NON-FOREIGN STATUS

         Section 1445 of the Internal Revenue Code of 1986, as amended (the
"Code"), provides that a transferee of a U.S. real property interest must
withhold tax if the transferor is a foreign person. As required by Section
7.4(c) of the Stock Purchase Agreement, dated as of November __, 1997, by and
among CN Biosciences, Inc. as Buyer, David W. Dubbell, Dennis Almond, Corrine
Fetherston, Lisa Johnson, Robert Mierendorf, Warren Kroeker, Barbara Morris,
Robert Novy and Tom Van Oosbree, as Sellers and Pel-Freez, Inc. and in order to
inform Buyer that withholding of tax is not required upon the disposition of a
U.S. real property interest by the undersigned Seller, the undersigned hereby
certifies the following:

         1. Such Seller is not a foreign person, as defined in the Code and the
Treasury regulations promulgated thereunder;

         2. Such Seller's U.S. taxpayer identification number is _____________;
and

         3. Such Seller's address is ______________________________________.

         Seller understands that this certification may be disclosed to the
Internal Revenue Service by Buyer and that any false statement contained herein
could be punished by fine, imprisonment, or both.

         Under penalties of perjury I declare that I have examined this
certification and to the best of my knowledge and belief it is true, correct and
complete.




                                                       _________________________
                                                       Name of Seller

Date:  __________  __, 1998

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   93
                                                                       EXHIBIT E

                            SELLERS' ESCROW AGREEMENT


         THIS SELLERS' ESCROW AGREEMENT (this "Agreement") is entered into as of
November 25, 1997, by and among DAVID W. DUBBELL ("Dubbell"), DENNIS ALMOND,
CORRINE FETHERSTON, LISA JOHNSON, ROBERT MIERENDORF ("Mierendorf"), WARREN
KROEKER, BARBARA MORRIS, ROBERT NOVY and TOM VAN OOSBREE (collectively, together
with Dubbell and Mierendorf, the "Sellers").

         WHEREAS, Sellers, Pel-Freez, Inc., an Arkansas corporation (the
"Parent") and CN Biosciences, Inc., a Delaware corporation (the "Buyer") have
entered into a Stock Purchase Agreement dated as of November 25, 1997 (the
"Purchase Agreement"), pursuant to which, as a result of the transactions
contemplated thereby, the Parent and Novagen, Inc. will become wholly owned
subsidiaries of the Buyer; and

         WHEREAS, Section 2.3 of the Purchase Agreement contemplates the
execution and delivery of this Agreement providing for the escrow of certain
portions of the Purchase Price (as such term is defined in the Purchase
Agreement); and

         WHEREAS, simultaneously with the closing of the transactions under the
Purchase Agreement (the "Closing") certain of the Sellers have indebtedness that
must be repaid from their respective interests in the Purchase Price in order to
permit the transactions contemplated by the Purchase Agreement to be consummated
(as to any Seller, a "Seller's Obligation");

         WHEREAS, the Sellers, collectively, are responsible for certain closing
costs, including fees of investment bankers, attorneys and accountants involved
in representing the Sellers in connection with the Purchase Agreement (the
"Closing Costs"); and

         WHEREAS, the Sellers wish to make provision for the payment of the
various Seller's Obligations and Closing Costs and for the appropriate
allocation among them of the net amount of the Purchase Price, including the net
amount of the Initial Payment and the Earn Out Amount, if any (as such terms are
defined in the Purchase Agreement); and

         WHEREAS, pursuant to the terms of the Purchase Agreement, Dubbell and
Mierendorf were appointed to act as Sellers' Agents (as such term is defined in
the Purchase Agreement) and the parties now desire that Sellers' Agents also act
jointly as escrow agent pursuant to this Agreement and the Sellers' Agents are
willing to do so upon the terms and conditions hereinafter set forth;

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   94
         NOW, THEREFORE, in consideration of the premises and other good and
valuable consideration, the parties hereto hereby agree as follows:

     1. Establishment of Escrow. At the Closing, the Buyer shall deposit with
the Sellers' Agents an amount equal to the difference between the Initial
Payment of $10,500,000, less [************************************************
************************************************] ("Net Initial Payment") and 
the aggregate amount of all discharged Seller's Obligations as contemplated in 
the following paragraph (the "First Escrow Payment"). Seller's Agents shall 
acknowledge receipt thereof, as well as receipt of amounts utilized to 
discharge Sellers' Obligations, to Buyer. Sellers' Agents shall hold the First 
Escrow Payment and any funds received by them relating to the Earn Out Amount 
(in the aggregate the "Escrow Fund") in accordance with the terms of this 
Agreement. The Escrow Fund shall be deposited in an interest bearing account 
with a commercial bank having aggregate capital, surplus and undivided profits 
in excess of $100,000,000.

2. Instructions on Payment of Seller's Obligations. On or prior to the Closing
Date, any Seller having Seller's Obligation shall so notify the Sellers' Agents,
specifying the amount of such Obligation, calculated through the Closing Date,
and the name of the creditor to whom such obligation is due and account number
of such creditor to which funds should be delivered to discharge such
obligation, and such Seller shall instruct the Sellers' Agents, in turn, to
instruct the Buyer to deduct from the amount of the Initial Payment and pay
directly to the creditor such Seller's Obligation. No Seller shall so instruct,
nor shall the Sellers' Agents instruct, the Buyer to pay directly any amount in
excess of the Net Initial Payment multiplied by the individual Seller's
percentage in Schedule B.

3. Initial Disbursements of Escrow Funds

         (a) The Sellers' Agents shall set aside separate funds out of the
Escrow Funds ("Segregated Cost Fund") in an amount equal to two hundred percent
(200%) of the estimated costs and expenses to be incurred in connection with the
transactions contemplated under the Purchase Agreement (the "Transaction Costs")
as set forth on Schedule A. Schedule A represents Sellers' Agents best current
estimates of Transaction Costs, but the items listed and the amounts related
thereto, as well as the list of advisors, may change prior to the Closing Date.
In all cases, amounts paid for actual Transaction Costs shall be paid only
against delivery of properly supported invoices from the appropriate advisor. To
the extent that any advisor acting on behalf of the Sellers demands partial
payment prior to the Closing Date for approved expenses or fees, such amounts
may be advanced by Pel-Freez Rabbit Meat, Inc. on behalf of the Sellers, with
appropriate approval of the


                                      -2-
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   95
Sellers' Agents, and any amounts so advanced will be repaid following the
Closing Date out of the Segregated Cost Fund.

         (b) Within three business days following the Closing Date, the Sellers'
Agents shall make payments to individual Sellers which payments as to each
individual Seller shall be calculated as follows:

                  (i) Net Initial Payment multiplied by such Seller's ownership
percentage as set forth in Schedule B, less

                  (ii) such Seller's pro rata share of Transaction Costs
calculated by multiplying Transaction Costs by the percentage interest set forth
in Schedule B, less

                  (iii) amounts paid directly by Buyer at closing for repayment
of such Seller's obligations as contemplated by paragraph 2 hereof.

                  The amounts so calculated shall be paid in accordance with
instructions of Sellers' Agents.

         (c) Upon determination of the actual Transaction Costs by the parties
hereto, which shall be within 30 days following the closing date hereof, the
Sellers' Agents shall pay from the Segregated Cost Fund all actual Transaction
Costs. Immediately following the payment and settlement of all Transaction
Costs, the Sellers' Agents shall distribute the entire remaining balance of the
Segregated Cost Fund, including any investment gains, to Sellers in the
percentage interest set forth in Schedule B.

4. Deposit and Disbursement of Earn-Out Amount.

         (a) In accordance with the Purchase Agreement, if an Earn-Out Amount is
due to the Sellers, including audit adjustments, then Buyer shall, on or prior
to the March 31 following each of the years ending December 31, 1998, 1999 and
2000, deposit with the Sellers' Agents the sum equal to the aggregate Earn-Out
Amount due to the Sellers, which such amount shall be held by Sellers' Agents in
the Escrow Fund.

         (b) Within 10 business days following the receipt of any Earn-0ut
Amount Sellers' Agents shall distribute such amount to the Sellers as follows:
(i) for any Earn-Out Amount received for the year ending December 31, 1998,
distribute amounts up to the first $80,000, including any investment gains, to
the Sellers in the percentage interest set forth in Schedule C, and distribute
any amounts exceeding $80,000, including any investment gains, in the percentage
interest set forth in Schedule D; and (ii) for any Earn-Out Amount received for
each of the years ending December 31, 1999, and December 31, 2000, respectively,
distribute amounts up to the first $160,000 in each year, including any
investment


                                      -3-
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   96
gains in the percentage interest set forth in Schedule C, and distribute any
amounts exceeding $160,000 in each year, including any investment gains, in the
percentage interest set forth in Schedule D. Any amounts to be distributed to
the Sellers under this Section 4 and Section 3, above may be made by wire
transfer, certified check or any other mutually agreeable means between the
Sellers' Agents and the Sellers.

5. Net Worth Adjustment.

The Purchase Agreement provides for adjustments to the Purchase Price (as such
term is defined in the Purchase Agreement) which may be paid to the Sellers'
Agents. In the event that the adjustment to the purchase price results in
additional proceeds to Sellers, such amounts shall be distributed by the
Sellers' Agents in accordance with the percentage interest set forth in Schedule
B. In the event that the adjustment to the purchase price results in amounts
being owed to Buyers, upon the request of the Sellers' Agents, the Sellers shall
promptly pay to the Sellers' Agents their individual share of such amount owed
in accordance with the percentage interest set forth in Schedule B.

6. Termination.

Upon distribution to the Sellers of any final Earn-Out Amount earned for the
year ended December 31, 2000, including any investment gains, or upon
determination that no earnout amounts are due for such period, this Agreement
shall terminate in accordance with its own terms; [*****************************
********************************************************************************
********************************************************************************
*****************************************************************]

7. Duties of Sellers' Agents.

         (a) Sellers' Agents shall invest any funds held hereunder only as
directed in or pursuant to this Agreement.

         (b) Sellers' Agents shall not be liable, except for their own gross
negligence or willful misconduct, and, except with respect to claims based upon
such gross negligence or willful misconduct that are successfully asserted
against Sellers' Agents, the other parties hereto shall jointly and severally
indemnify and hold harmless Sellers' Agents from and against any and all losses,
liabilities, claims, actions, damages and expenses, including reasonable
attorneys' fees and disbursements, arising out of or in connection with this
Agreement. Without limiting the foregoing, Sellers' Agents shall in no event be
liable in connection with their investment or reinvestment of any cash held by
them hereunder in good faith, in accordance with the terms hereof, including,
without limitation, any liability for


                                      -4-
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   97
any delays (not resulting from their gross negligence or willful misconduct) in
the investment, reinvestment or distribution of the Escrow Fund, or any loss of
interest incident to any such delays.

         (c) Sellers' Agents shall be entitled to rely upon any order, judgment,
certification, demand, notice, instrument or other writing delivered to them
hereunder without being required to determine the authenticity or the
correctness of any fact stated therein or the propriety or validity of the
service thereof. Sellers' Agents may act in reliance upon any instrument or
signature believed by them to be genuine and may assume that the person
purporting to give receipt or advice or make any statement or execute any
document in connection with the provisions hereof has been duly authorized to do
so. Sellers' Agents may conclusively presume that the undersigned representative
of any party hereto which is an entity other than a natural person has full
power and authority to instruct Sellers' Agents on behalf of that party unless
written notice to the contrary is delivered to Sellers' Agents.

         (d) Sellers' Agents may act pursuant to the advice of counsel with
respect to any matter relating to this Agreement and shall not e liable for any
action taken or omitted by them in good faith in accordance with such advice.

         (e) In their capacity as Sellers' Agents, Sellers' Agents do not have
any interest in the Escrow Fund deposited hereunder and are serving as escrow
holder only while having only possession thereof. Any payments of income from
this Escrow Fund shall be subject to withholding regulations then in force with
respect to United States taxes. The Sellers will provide Sellers' Agents with
appropriate Internal Revenue Service Forms W-9 for tax identification number
certification. This Section 6(e)and Section 6(b) above shall survive
notwithstanding any termination of this Agreement.

         (f) In the event of any disagreement between the other parties hereto
resulting in adverse claims or demands being made in connection with the Escrow
Fund or in the event that Sellers' Agents are in doubt as to what action they
should take hereunder, Sellers' Agents shall be entitled to retain the Escrow
Fund until Sellers' Agents shall have received (i) a final non-appealable order
of a court of competent jurisdiction directing delivery of the Escrow Fund or
(ii) a written agreement executed by the other parties hereto directing delivery
of the Escrow Fund, in which event Sellers' Agents shall disburse the Escrow
Fund in accordance with such order or agreement. Any court order shall be
accompanied by a legal opinion by counsel for the presenting party satisfactory
to Sellers' Agents to the effect that the order is final and non-appealable.
Sellers' Agents shall act on such court order and legal opinion without further
question.


                                      -5-
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   98
         (g) The parties hereto agree that Sellers' Agents shall not receive a
fee for their services as escrow agent under this Agreement. Sellers' Agents
shall be entitled to reimbursement for all customary out of pocket expenses
incurred by them for acting as escrow agent hereunder. Such reimbursement shall
be paid from the Escrow Fund from time to time as such costs are incurred by
Sellers' Agents.

         (h) Sellers' Agents shall, upon request from any individual Seller,
make available to such Seller supporting documentation showing amounts computed
pursuant to this Agreement. If any Seller shall dispute any calculation made by
the Sellers' Agents under this Agreement, such Seller shall notify the Sellers'
Agents of the nature and amount of such dispute. If the Sellers' Agents and such
Seller, after reasonable efforts, are unable to resolve such dispute, such
Seller shall have the right to engage an independent accountant to examine and
opine on the calculations made hereunder. Costs of such independent accountant
shall be borne by the Seller, if such accountant confirms the calculations of
the Sellers' Agents, or by the Sellers' Agents if such accountant confirms in
favor of such Seller the amounts so disputed.

8. Limited Responsibility.

         This Agreement expressly sets forth all the duties of Sellers' Agent
with respect to any and all matters pertinent hereto. No implied duties or
obligations shall be read into this Agreement against Sellers' Agents.

9. Resignation of Sellers' Agents.

         (a) A Sellers' Agent may resign as escrow agent and be discharged from
his duties or obligations hereunder by giving at least 30 days written notice to
the other parties hereto specifying a date when such resignation shall take
effect; provided, however, that no such resignation shall become effective until
the appointment of a successor escrow agent which shall be accomplished as
follows: the parties hereto shall use their best efforts to mutually agree on a
successor escrow agent within 30 days after receiving such notice of
resignation. If the parties fail to agree on a successor escrow agent within
such time, the resigning Sellers' Agent shall have the right to appoint his
successor escrow agent.

         (b) The successor escrow agent shall execute and deliver an instrument
accepting his appointment and agreeing to be bound by the terms and conditions
of this Agreement and shall, without further acts, be vested with all the
rights, powers, and duties of the predecessor escrow agent as if originally
named as escrow agent hereunder. Upon the effective appointment of a successor


                                      -6-
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<PAGE>   99
escrow agent, the resigning Sellers' Agent shall be discharged from any further
duties under this Agreement.

10. Notices.

All notices, consents, waivers and other communications required or permitted to
be given under this Agreement must be in writing and will be deemed to have been
duly given (a) when delivered by hand (with written confirmation of receipt),
(b) when sent by facsimile (with electronic confirmation of receipt), or (c) on
the third day after being sent by a nationally recognized overnight delivery
service (receipt requested), in each case to the appropriate addressees and
facsimile numbers set forth below (or to such other addresses ad facsimile
numbers as a party may designate by notice to the other parties):

         Sellers' Agents or Sellers:         David W. Dubbell
                                             Pel-Freez, Inc.
                                             205 North Arkansas
                                             P.O. Box 68
                                             Rogers, Arkansas  72757
                                             Facsimile No.: (501) 636-4282

                                             and

                                             Robert C. Mierendorf
                                             Novagen, Inc.
                                             601 Science Drive
                                             Madison, Wisconsin  53711
                                             Facsimile No.:  (608) 238-1388

         With a copy to:                     Conner & Winters
                                             3700 First Place Tower
                                             15 East 5th Street
                                             Tulsa, Oklahoma 74103-4344
                                             Attention: Henry G. Will
                                             Facsimile No.: (918) 586-8982


11. Counterparts.

This Agreement may be executed in one or more counterparts, each of which will
be deemed to be an original land all of which, when taken together, will be
deemed to constitute one and the same.

12. Section Headings.

The headings of sections in this Agreement are provided for convenience only and
will not affect its construction or interpretation.


                                      -7-
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<PAGE>   100
13. Waiver.

The rights and remedies of the parties to this Agreement are cumulative and not
alternative. Neither the failure nor any delay by any party in exercising any
right, power, or privilege under this Agreement or the documents referred to in
this Agreement will operate as a waiver of such right, power, or privilege, and
no single or partial exercises of any such right, power, or privilege will
preclude any other or further exercise of such right, power, or privilege or the
exercise of any other right, power, or privilege. To the maximum extent
permitted by applicable law, (a) no claim or right arising out of this Agreement
or the documents referred to in this Agreement can be discharged by one party,
in whole or in part, by a waiver or renunciation of the claim or right unless in
writing signed by the other party; (b) no waiver that may be given by a party
will be applicable except in the specific instance for which it is given; and
(c) no notice to or demand on one party will be deemed to e a waiver of any
obligation of such party or of the right of the party giving such notice or
demand to take further action without notice or demand as provided in this
Agreement or the documents referred to in this Agreement.

13. Exclusive Agreement and Modification.

This Agreement supersedes all prior agreements among the parties with respect to
its subject matter and constitutes (along with the documents referred to in this
Agreement) a complete and exclusive statement of the terms of the agreement
between the parties with respect to its subject matter. This Agreement may not e
amended except by a written agreement executed by all of the parties hereto.







                      [THIS SPACE INTENTIONALLY LEFT BLANK]


                                      -8-
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<PAGE>   101
14. Governing Law.

This Agreement shall be governed by the laws of the State of New York, without
regard to conflicts of law principles.

IN WITNESS WHEREOF, the parties have executed and delivered this Agreement as of
the date first above written.



SELLERS' AGENTS:                             SELLERS:


- -----------------------                      --------------------------
David W. Dubbell                             David W. Dubbell


- -----------------------                      ---------------------------
Robert Mierendorf                            Dennis Almond


                                             --------------------------
                                             Corrine Fetherston


                                             ---------------------------
                                             Lisa Johnson


                                             ---------------------------
                                             Robert Mierendorf


                                             ---------------------------
                                             Warren Kroeker


                                             ---------------------------
                                             Barbara Morris


                                             ---------------------------
                                             Robert Novy


                                             ---------------------------
                                             Tom Van Oosbree


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<PAGE>   102
                                   SCHEDULE A


                                TRANSACTION COSTS

Estimated Costs and Expenses:

<TABLE>
<S>                                                                     <C>     
Vector Securities International, Inc.                                   $450,000
Conner and Winters                                                       170,000
Coopers and Lybrand                                                      170,000
Gary Speed                                                                10,000
                                                                        --------
             TOTAL                                                      $800,000
                                                                        ========
</TABLE>

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   103
                                   SCHEDULE B


                           STOCK OWNERSHIP PERCENTAGE

<TABLE>
<CAPTION>
Name of Seller                                   Seller's Stock Ownership Percentage
- --------------                                   -----------------------------------
<S>                                              <C>  
David W. Dubbell                                                 90.0%
Corrine Fetherston                                                0.8%
Lisa Johnson                                                      0.8%
Robert Mierendorf                                                 4.0%
Barbara Morris                                                    0.8%
Robert Novy                                                       0.8%
Tom Van Oosbree                                                   0.8%
Dennis Almond                                                     1.0%
Warren Kroeker                                                    1.0%
                                                                ------
               TOTAL                                            100.0%
                                                                ======
</TABLE>

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   104
                                   SCHEDULE C


                          SELLERS' THRESHOLD PERCENTAGE


<TABLE>
<CAPTION>
Name of Seller                                      Seller's Threshold Percentage
- --------------                                      -----------------------------
<S>                                                 <C>
David W. Dubbell                                              90%
Corrine Fetherston                                          1-1/3
Lisa Johnson                                                1-1/3
Robert Mierendorf                                           1-1/3
Barbara Morris                                              1-1/3
Robert Novy                                                 1-1/3
Tom Van Oosbree                                             1-1/3
Dennis Almond                                                   1
Warren Kroeker                                                  1
                                                             ----
               TOTAL                                         100%
                                                             ====
</TABLE>

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   105
                                   SCHEDULE D


                          SELLERS' INCENTIVE PERCENTAGE

<TABLE>
<CAPTION>
Name of Seller                                      Seller's Incentive Percentage
- --------------                                      -----------------------------
<S>                                                 <C>
David W. Dubbell                                                 50%
Corrine Fetherston                                                8
Lisa Johnson                                                      8
Robert Mierendorf                                                 8
Barbara Morris                                                    8
Robert Novy                                                       8
Tom Van Oosbree                                                   8
Dennis Almond                                                     1
Warren Kroeker                                                    1
                                                                ---
               TOTAL                                            100%
                                                                === 
</TABLE>

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   106
                                                                       EXHIBIT F

[This page has been intentionally omitted and filed separately with the
Commission pursuant to a request for confidential treatment.]

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with the Commission pursuant to a request for confidential treatment.
<PAGE>   107
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Commission pursuant to a request for confidential treatment.]


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Commission pursuant to a request for confidential treatment.]


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Commission pursuant to a request for confidential treatment.]


                                      -9-
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Commission pursuant to a request for confidential treatment.]


                                      -10-
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Commission pursuant to a request for confidential treatment.]


                                      -11-
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<PAGE>   117
                                                                       EXHIBIT G

                              EMPLOYMENT AGREEMENT


         EMPLOYMENT AGREEMENT, dated as of the ___ day of ________, 199_,
between CN Biosciences, Inc., a Delaware corporation (the "Company") and Robert
C. Mierendorf (the "Employee").

         1. Effective Date. This Employment Agreement shall become effective on
the ___ day of _______, 199_ (the "Effective Date").

         2. Employment. The Company hereby employs the Employee and the Employee
hereby accepts employment all upon the terms and conditions herein set forth.

         3. Duties. The Employee is engaged as President and General Manager of
Novagen, a wholly owned subsidiary of CN Biosciences, Inc. located in Madison,
WI, and will report to the Chairman and Chief Executive Officer of the Company
and hereby promises to perform and discharge well and faithfully all duties of
this position.

         4. Extent of Services. The Employee shall devote his entire time,
attention and energies to the business of the Company and shall not during the
term of this Employment Agreement be engaged in any other business activity
whether or not such business activity is pursued for gain, profit or other
pecuniary advantage; but this shall not be construed as preventing the Employee
from investing his personal assets in businesses which do not compete with the
Company in such form or manner as will not require any services on the part of
the Employee in the operation of the affairs of the companies in which such
investments are made and in which his participation is solely that of an
investor, nor shall this be construed as preventing the Employee from purchasing
securities in any corporation whose securities are regularly traded provided
that such purchases shall not result in his collectively owning beneficially at
any time one percent (1%) or more of the equity securities of any corporation
engaged in a business competitive to that of the Company, without the express
prior written consent of the Company.

         5. Compensation.

                  (a) For services rendered under this Employment Agreement, the
Company shall pay the Employee a salary at the rate of $_______ per annum (the
"Base Salary"), payable (after deduction of applicable payroll taxes as an
employee in

                                                      Initials: _____      _____

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   118
the State of Wisconsin) in equal bi-weekly installments. The Employee shall also
be eligible for and participate in such fringe benefits as shall be generally
provided to executives of the Company, including medical insurance and
retirement programs which may be adopted from time to time during the term
hereof by the Company. On an annual basis, the Company shall review Employee's
salary and make such adjustment as may be warranted based upon Employee
performance, Company financial performance, economic conditions, etc.

                  (b) At the conclusion of each Fiscal Year, the Employee shall
be eligible for, and the Company in its sole discretion, may award an executive
bonus up to a maximum of 30% of Base Salary, based upon a number of factors
including achievement of the Company's financial objectives, Employee
performance and achievement of mutually acceptable objectives and input from the
Compensation Committee of the Board of Directors.

         6. Paid Time Off. During the term of this Employment Agreement, the
Employee shall be entitled to paid time off consistent with the Company's "Cal
Time" policy regarding vacation and sick time. For purposes of determining the
amount of such benefit, Employee's term of employment shall be determined based
upon the hire date at Novagen, prior to acquisition by the Company.

         7. Expenses. During the term of this Employment Agreement, the Company
shall reimburse the Employee for all reasonable out-of-pocket expenses incurred
by the Employee in connection with the business of the Company and in
performance of his duties under this Employment Agreement upon the Employee's
presentation to the Company of an itemized accounting of such expenses with
reasonable supporting data.

         8. Term.

                  (a) The Employee's employment under this Employment Agreement
shall commence on the Effective Date and shall expire on the two year
anniversary date thereof. Notwithstanding the foregoing, the Company may at its
election, terminate the Employee's employment hereunder as follows:

                           (i) Upon thirty (30) days notice if the Employee
becomes physically or mentally incapacitated or is injured so that he is unable
to perform the services required of him hereunder and such inability to perform
continues for a period in excess of ninety (90) days and is continuing at the
time of such notice; or


                                                      Initials: _____      _____

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<PAGE>   119
                           (ii) For "Cause" upon notice of such termination to
the Employee. For purposes of this Employment Agreement, the Company shall have
"Cause" to terminate its obligations hereunder upon (A) the reasonable
determination by the Chief Executive Officer that the Employee has ceased to
perform his duties hereunder (other than as a result of his incapacity due to
physical or mental illness or injury), which failure amounts to an intentional
and extended neglect of his duties hereunder, (B) the Chief Executive Officer's
reasonable determination that the Employee has engaged or is about to engage in
conduct materially injurious to the Company, (C) the Employee's having been
convicted of a felony, or (D) A material breach by the Employee of any of the
other covenants or representations herein; or

                           (iii) Without Cause by honoring the terms of a
separate Severance Agreement executed between the Company and Employee.

                           (iv) Upon the death of the Employee.

                  (b) Not later than ninety (90) days prior to the expiration of
the stated term of this Employment Agreement, the parties shall begin to
negotiate in good faith the terms of any extension of this Employment Agreement,
provided that neither party shall be under any obligation to enter into such an
extension. In the case of a renewal and unless otherwise agreed to in writing by
both parties, the terms and conditions of this Employment Agreement shall apply
to any renewals or extensions thereto.

         9. Stock Options. The Company will grant incentive stock options to
Employee at the earliest practicable date following the Effective Date of this
Employment Agreement. The Company anticipates the granting of ________ options
to purchase the Company's common stock, at the fair market value of the stock on
the date which the Stock Option Committee of the Board of Directors meets to
finalize such grant. It is anticipated that such options will vest 20% per year
from the date of grant.

         10. Representations. The Employee hereby represents to the Company that
(a) he is legally entitled to enter into this Employment Agreement and to
perform the services contemplated herein and is not bound under any employment
or consulting agreement to render services to any third party, (b) he has the
full right, power and authority, subject to no rights of third parties, to grant
to the Company the rights contemplated by paragraph 11 hereof, and (c) he does
not now have, nor within the last three years has he had, any ownership interest
in any business enterprise (other than interest in publicly traded corporations
where his ownership does not exceed one percent (1%) or more of the equity
capital) which is a customer of the Company, any

                                                      Initials: _____      _____

                                      -3-
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<PAGE>   120
of its subsidiaries, or from which the Company or any of its subsidiaries
purchases any goods or services or to whom such corporations owe any financial
obligations or are required or directed to make any payments.

         11. Inventions.

                  (a) The Employee hereby sells, transfers and assigns to the
Company or to any person, or entity designated by the Company all of the entire
right, title and interest of the Employee in and to all inventions, ideas,
disclosures and improvements, whether patented or unpatented, and copyrightable
material, made or conceived by the Employee, solely or jointly, during the term
hereof which relate to methods, apparatus, designs, products, processes or
devices, sold, leased, used or under consideration or development by the Company
or any of its subsidiaries, or which otherwise relate to or pertain to the
business, functions or operations of the Company or any of its subsidiaries or
which arise from the efforts of the Employee during the course of his employment
for the Company or any of its subsidiaries. The Employee shall communicate
promptly and disclose to the Company, in such form as the Company requests, all
information, details and data pertaining to the aforementioned inventions,
ideas, disclosures and improvements; and the Employee shall execute and deliver
to the Company such formal transfers and assignments and such other papers and
documents as may be necessary or required of the Employee to permit the Company
or any person or entity designated by the Company to file and prosecute the
patent applications and, as to copyrightable material, to obtain copyright
thereof. Any invention relating to the business of the Company and its
subsidiaries and disclosed by the Employee within one year following the
termination of this Agreement shall be deemed to fall within the provisions of
this paragraph unless proved to have been first conceived and made following
such termination.

                  (b) The Employee has been notified and understands that the
provisions of this Section 11 do not apply to any of the aforementioned
inventions, ideas, disclosures and improvements that qualify fully under the
provisions of Section 2870 of the California Labor Code, which states as
follows:

                           (i) Any provision in an employment agreement which
provides that an employee shall assign, or offer to assign, any of his or her
rights in an invention to his or her employer shall not apply to an invention
that the employee developed entirely on his or her own time without using the
employer's equipment, supplies, facilities, or trade secret information except
for those inventions that either:

                                                      Initials: _____      _____

                                      -4-
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with the Commission pursuant to a request for confidential treatment.
<PAGE>   121
                                    (a) Relate at the time of conception or
reduction to practice of the invention to the employer's business, or actual or
demonstrably anticipated research or development of the employer.

                                    (b) Result from any work performed by the
employee for the employer.

                           (ii) To the extent a provision in an employment
agreement purports to require an employee to assign an invention otherwise
excluded from being required to be assigned under subsection (i), the provision
is against the public policy of this state and is unenforceable.

         12. Insurance. The Company may, at its election and for its benefit,
insure the Employee against accidental loss or death, and the Employee shall
submit to such physical examination and supply such information as may be
required in connection therewith. The Company will ensure that Employee, as an
officer of the Company, is added to the Company's insurance policy for Officers
and Directors Liability insurance.

         13. Notices. Any notice required or permitted to be given under this
Employment Agreement shall be sufficient if in writing and if sent by registered
mail to Mr. Robert C. Mierendorf at his home address as reflected on the records
of the Company, in the case of the Employee, or Mr. Stelios B. Papadopoulos,
Chief Executive Officer, CN Biosciences, Inc., 10394 Pacific Center Court, San
Diego, CA 92121, in the case of the Company.

         14. Waiver of Breach. A waiver by the Company or the Employee of a
breach of any provision of this Employment Agreement by the other party shall
not operate or be construed as a waiver of any subsequent breach by the other
party.

         15. Governing Law. This Employment Agreement shall be governed by and
construed and enforce in accordance with the laws of the State of California
without giving effect to the choice of law or conflict of laws provisions
thereof.

         16. Assignment. This Employment Agreement may be assigned, without the
consent of the Employee, by the Company to any person, partnership, corporation,
or other entity which has purchased substantially all the assets of the Company,
provided such assignee assumes all the liabilities of the Company hereunder.

         17. Entire Agreement. This Employment Agreement contains the entire
agreement of the parties and supersedes any and all agreements, letter of intent
or

                                                      Initials: _____      _____

                                      -5-
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with the Commission pursuant to a request for confidential treatment.
<PAGE>   122
understandings between the Employee and (a) the Company, (b) any member of the
Calbiochem Novabiochem Group or (c) any of the Company's principal shareholders,
affiliates or subsidiaries regarding employment. This Employment Agreement may
be changed only by an agreement in writing signed by a party against whom
enforcement of any waiver, change, modification, extension or discharge is
sought.

                                                      Initials: _____      _____

                                      -6-
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   123
         IN WITNESS WHEREOF, the parties have executed this Employment Agreement
as of the day first herein above written.

                                    CN BIOSCIENCES, INC.



                                    By:_________________________________________
                                             Stelios B. Papadopoulos
                                             Chief Executive Officer



                                    By:_________________________________________
                                             Robert C. Mierendorf
                                             Employee


                                                      Initials: _____      _____

                                      -7-
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   124
                                    EXHIBIT H


                        ASSIGNMENT AND LICENSE AGREEMENT


         This Agreement is made this ___ day of ___________, 199__, by and among
NOVAGEN, INC. (the "Company"), a corporation organized and existing under the
laws of the State of Arkansas; PEL-FREEZ, INC. (the "Parent"), a corporation
organized and existing under the laws of the State of Arkansas; and PEL-FREEZ
RABBIT MEAT, INC. ("PFRM"), a corporation organized and existing under the laws
of the State of Arkansas.

                                    RECITALS:

         A. The Company or the Parent currently owns all right, title and
interest in and to the Patent Right and possesses the rRTF Technology.

         B. The Company and the Parent are being acquired by CN Biosciences,
Inc. (the "Buyer") under a Stock Purchase Agreement, dated _____________ (the
"SPA"), pursuant to which the Buyer will acquire control of all of the issued
and outstanding stock of the Company (the transaction contemplated under the SPA
is hereinafter referred to as the "Transaction").

         C. As part of the consideration under the SPA, the Company, or the
Parent, as applicable, agrees to transfer and/or assign all right, title and
interest in and to the rRTF Technology and the Patent Right to PFRM under the
terms and conditions hereinafter set forth.

         D. The parties acknowledge that in order to practice the rRTF
Technology and the Patent Right and produce rRTF products, PFRM must obtain
certain rights to other technologies which the Company currently possesses under
the Existing Licenses. PFRM desires the Company's assistance in obtaining such
rights and the Company is willing to provide such assistance. Until PFRM can
obtain such rights, the Company is willing to enter into an agreement to
manufacture and sell rRTF products exclusively for PFRM.

                                    AGREEMENT

         NOW, THEREFORE, in consideration of the mutual covenants and promises
set forth below and in the PSA, and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties agree as
follows:

                             ARTICLE I - DEFINITIONS

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   125
         1.1 "Patent Right" means pending U.S. Patent Application 08/683,007,
entitled _____________, any patent issuing therefrom, any reissues,
reexaminations, or extensions thereof, and any corresponding foreign patents or
patent applications.

         1.2 "rRTF" shall mean recombinant rabbit tissue factor.

         1.3 "rRTF Technology" means the production protocols, biological
materials and know-how necessary for the production of rRTF together with the
process disclosed in the Patent Right.

         1.4 "Research Reagent Market" means the sale of packaged quantities of
rRTF in up to 1.0 mg containers for use in academic and commercial product
research applications.

         1.5. "Licensed Products" means any products, except coagulation
diagnostic products, that employ or are in any way produced by the practice of
an invention claimed in the Patent Right or that would otherwise constitute
infringement of any claims of the Patent Right.

         1.6 "Licensed Territory" is Worldwide.

         1.7 "Existing Licenses" means the licenses entered into by the Company
granting it certain rights necessary to practice the rRTF Technology and produce
rRTF products and that are set forth on the attached Appendix 1.

                      ARTICLE II - ASSIGNMENT AND TRANSFER

         2.1 The Company and/or Parent, as applicable, hereby sell, assign and
transfer to PFRM all right, title and interest in and to the Patent Right,
except as specifically provided herein, and agree to take all steps necessary to
record such assignment with the United States Patent and Trademark Office.
Furthermore, the Company and/or Parent, as applicable, agree to transfer all
right, title and interest in and to, and possession of any and all rRTF
Technology to PFRM as soon as practicable following the closing of the
Transaction, as set forth in the PSA.

         2.2 Upon the assignment and transfer set forth in Section 2.1 above,
the Company and Parent shall be prohibited from practicing any part of the rRTF
Technology, except that the Company shall not be prohibited from using
generalized know-how also utilized in the manufacture of rRTF for manufacture of
non-rRTF products, provided that (i) such know-how was also used by Company in
the manufacture of such other products as of the date of the closing


                                       2
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   126
of the Transaction or (ii) such know-how is now, or at any time in the future
becomes, generally known or available to the public through no fault of the
Company or the Parent.

              ARTICLE III - EXISTING LICENSES AND SUPPLY AGREEMENT

         3.1 The Company and PFRM hereby acknowledge and agree that the Company
shall continue to hold and benefit from the Existing Licenses, provided,
however, that the Company agrees that it shall not exercise any rights under
such licenses to do any of the following, except with the prior written consent
of PFRM:

                  (a) make or sell coagulation diagnostic products;

                  (b) sublicense rights to any third party to make, use or sell
coagulation diagnostic products; or

                  (c) assert rights to prevent PFRM from obtaining and
exercising rights to practice the technologies that are the subject of the
Existing Licenses to make, have made, use or sell coagulation diagnostic
products or to sublicense such rights.

         3.2 The Company shall use its best efforts to assist PFRM in obtaining
licenses (or sublicenses) from the licensors of the Existing Licenses that are
necessary to practice the rRTF Technology and to make, use, and sell rRTF
products on terms comparable to those contained in the Existing Licenses. Upon
request by PFRM, the Company shall release any rights it has under the Existing
Licenses related to coagulation diagnostic products, provided that the Company
receive $5,000 as consideration for releasing such rights.

         3.3 Recognizing that PFRM cannot practice the rRTF Technology and make,
use, and sell rRTF products until it can obtain the rights discussed in this
Article III, the parties agree to negotiate and execute a supply agreement,
pursuant to which the Company will manufacture and sell exclusively for PFRM
between 500 and 800 milligrams of rRTF product in accordance with agreed upon
specifications at a price to PFRM of $156/mg.

                           ARTICLE IV - LICENSE GRANT

         4.1 PFRM hereby grants to the Company a nonexclusive license, limited
to the Research Reagent Market, under the Patent Right and the rRTF Technology
to make, use and sell Licensed Products in the Licensed Territory.


                                       3
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   127
                               ARTICLE V - ROYALTY

         5.1 In consideration for the license granted in Article IV, the Company
agrees to pay to PFRM a royalty on sales of Licensed Products equal to $54/mg.
If, however, the Licensed Product is purchased by the Company directly from PFRM
for resale, the cost of such product to the Company, including royalty, shall be
$156/mg.

                        ARTICLE VI - PAYMENTS AND REPORTS

         6.1 The Company shall provide PFRM with a written report of all sales
of Licensed Products for which a royalty is due or payable under this Agreement.
Such report shall be due within thirty (30) days of the end of each calendar
quarter, whether or not royalties are due, and shall be accompanied by a payment
to PFRM of all earned royalties due under Section 5.1.

         6.2 The Company shall keep books and records sufficient to verify the
accuracy and completeness of the Company's accounting referred to above,
including without limitation, the manufacture, use and sale of Licensed Products
for which a royalty is due hereunder and shall make such books and records
available for inspection by PFRM, or its designee, upon reasonable notice and
during normal hours of operation.

                    ARTICLE VII - SUBLICENSING AND ASSIGNMENT

         7.1 The Company is not granted the right to sublicense any rights under
the Patent Right or the rRTF Technology granted hereunder.

                      ARTICLE VIII - CHALLENGE TO VALIDITY

         8.1 In the event the Company or a third party contests or otherwise
challenges the validity of the Patent Right, the Company shall continue to pay
royalties with respect to the patent as if such contest or challenge were not
underway until the patent is adjudicated invalid or unenforceable by a court of
last resort. In the event any such claims are ultimately held valid by a court
of last resort, then the Company shall reimburse PFRM for its actual expenses,
including reasonable attorneys fees, incurred in defending said contest of
validity.

                        ARTICLE IX - TERM AND TERMINATION


                                       4
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   128
         9.1 The term of the license granted hereunder shall begin on the
effective date of this Agreement and continue until the Patent Right is no
longer an enforceable patent unless this Agreement is otherwise terminated as
provided herein or as permitted by law.

         9.2 If the Company at any time defaults in the timely payment of any
monies due to PFRM or commits any breach of any covenant herein contained, and
the Company fails to remedy any such breach or default within thirty (30) days
after written notice thereof, PFRM may, at its option, terminate this Agreement
and the license granted hereunder by giving written notice of such termination
to the Company.

         9.3 This Agreement may be terminated at any time upon the mutual
written agreement of the parties.

                             ARTICLE X - WARRANTIES

         10.1 The Company represents and warrants that as of the effective date
of this Agreement, it has the power to enter into this Agreement.

         10.2 PFRM represents and warrants that it has the power to enter into
this Agreement and that, upon the assignment and transfer of the Patent Right
and rRTF Technology as provided herein, it has the right to grant the license
granted to the Company in this Agreement. However, nothing in this Agreement
shall be construed as:

                  (a) A warranty or representation by PFRM as to the validity or
scope of the Patent Right;

                  (b) A warranty or representation that anything made, used, or
sold under the license granted hereunder shall not infringe the patent rights of
third parties; or

                  (c) An obligation to furnish any know-how or any services
other than those specified in this Agreement.

         10.3 The Company represents and warrants that it is relying solely on
its own technical expertise in the manufacture, use and sale of Licensed
Products, and is not relying on PFRM in any way.


                                       5
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   129
                           ARTICLE XI - MISCELLANEOUS

         11.1 This Agreement constitutes the entire agreement between the
parties relating to the subject matter hereof and all prior negotiations,
representations, agreements and understandings are merged into, extinguished by,
and completely expressed in this Agreement. Neither party shall be bound by any
definition, condition, warranty, or representation other than as expressly
stated in this Agreement or as subsequently set forth in a writing signed by the
party to be bound thereby.

         11.2 If any provision of this Agreement shall be held unenforceable or
invalid, that provision shall be considered severable from this Agreement and
shall neither act to terminate this Agreement nor affect the validity of the
remaining provisions.

         11.3 The parties hereto are independent contractors and not joint
venturers or partners.

         11.4 This Agreement may not be amended or modified except by mutual
written agreement. Neither party may waive or release any of its rights or
interests in this Agreement except in writing. Failure to assert any right
arising from the Agreement shall not be deemed or construed as a waiver of such
right.

         11.5 This Agreement shall be governed by and construed in accordance
with the laws of the State of Delaware.

         11.6 Any notice or payment required to be given pursuant to this
Agreement shall be in writing and shall be deemed to have been given at the
earlier of the time when actually received as a consequence of any effective
method of delivery, including but not limited to personal delivery, transmission
by facsimile or delivery by a professional courier service or the time when sent
by certified or registered mail, addressed to the other party at the appropriate
address below or at such changed address as the parties shall have specified by
written notice, provided that any notice of change of address shall be effective
only upon actual receipt:

         To Company/Parent:         Novagen, Inc.
                                    Attn: _______________
                                    _____________________
                                    _____________________
                                    _____________________


                                       6
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   130
         To PFRM:                   Pel-Freez Rabbit Meat, Inc.
                                    Attn: _____________________
                                    ___________________________
                                    ___________________________


                                       7
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   131
         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed as of the date first written above.

                                    NOVAGEN, INC.

                                    By:      ___________________________
                                    Its:     ___________________________

                                    PEL-FREEZ, INC.

                                    By:      ___________________________
                                    Its:     ___________________________

                                    PEL-FREEZ RABBIT MEAT, INC.

                                    By:      ___________________________
                                    Its:     ___________________________


                                       8
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   132
                                   APPENDIX 1

         1. Research License dated February 1, 1990, between Novagen, Inc. and
Associated Universities, Inc., operator of Brookhaven National Laboratory, for
technology represented by U.S. Patent Application Serial No. 002,408 (now U.S.
Patent ___________________ (Studier et al), issued ___________), entitled,
"Cloning and Expression of the Gene for Bacteriophage T7 RNA Plymerase."

         2. License dated June 20, 1994, as amended July 11, 1995, between
Novagen, Inc. and Associated Universities, Inc., operator of Brookhaven National
Laboratory, for technology represented by U.S. Patent 4,952,496 (Studier et al),
issued August 28, 1990, entitled, "Cloning and Expression of the Gene for
Bacteriophage T7 RNA Polymerase."

         3. License dated May 26, 1995, between Novagen, Inc. and Genetics
Institute, Inc., for certain patent rights relating to thioredoxin fusion
expression systems and recombinant enterokinase cleavage enzyme.

         4. License dated May 11, 1995, between Novagen, Inc. and the President
and Fellows of Harvard College, for certain biological materials identified as
the trxB strain of E. coli developed by Dr. Jonathan Beckwith and Alan Derman
("Beckwith Plasmid Strain").

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   133
                                    EXHIBIT I


                                BEVSCO AGREEMENT


         This Agreement is made this ___ day of ___________, 199__, by and among
NOVAGEN, INC. (the "Company"), a corporation organized and existing under the
laws of the State of Arkansas; PEL-FREEZ, INC. (the "Parent"), a corporation
organized and existing under the laws of the State of Arkansas; and PEL-FREEZ
RABBIT MEAT, INC. ("PFRM"), a corporation organized and existing under the laws
of the State of Arkansas.

                                    RECITALS:

         A. The Company and the Parent are being acquired by CN Biosciences,
Inc. (the "Buyer") under a Stock Purchase Agreement, dated _____________ (the
"SPA"), pursuant to which the Buyer will acquire control of all of the issued
and outstanding stock of the Company (the transaction contemplated under the SPA
is hereinafter referred to as the "Transaction").

         B. The Parent entered into license agreements related to the
baculovirus expression vector system with: (i) BevsCo, Inc. ("BEVSCO"), dated
August 30, 1995 (the "BEVSCO License"); and (ii) Texas A&M University System
("TAMUS"), dated September 12, 1995 (the "TAMUS License"). (The BEVSCO License
and the TAMUS License are hereinafter collectively referred to as the "BEVS
Licenses" and BEVSCO and TAMUS are hereinafter referred to as the "BEVS
Licensors".)

         C. PFRM desires rights similar to those granted to the Company and/or
the Parent under the BEVS Licenses and further wishes to limit the Company's and
the Parent's exercise of their respective rights under such licenses.

                                    AGREEMENT

         NOW, THEREFORE, in consideration of the mutual covenants and promises
set forth below and in the SPA, and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties agree as
follows:

         1. BEVS LICENSES. The parties hereby acknowledge that the Company, or
the Parent, as applicable, shall retain the BEVS Licenses, provided, however,
that the Company and the Parent agree that neither shall exercise any rights
under such licenses to do any of the following, except with the prior written
consent of PFRM, such consent not to be unreasonably withheld:

                  (a) make, use or sell coagulation diagnostic products;

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   134
                  (b) sublicense rights to any third party to make, use or sell
coagulation diagnostic products; or

                  (c) assert rights to prevent PFRM from obtaining and
exercising rights to use the technology that is the subject of the BEVS Licenses
to make, have made or sell coagulation diagnostic products or to sublicense such
rights (collectively, the "Licensed Rights").

         2. ASSISTANCE. The Company or the Parent shall use its commercially
reasonable efforts to assist PFRM in obtaining licenses from the BEVS Licensors
to exercise the Licensed Rights on terms comparable to those contained in the
BEVS Licenses. Upon request by PFRM, the Company or the Parent shall use
commercially reasonable efforts to negotiate with BEVSCO and/or TAMUS to release
or assign, transfer or otherwise provide to PFRM all the Company's or the
Parent's rights under the BEVS Licenses related to coagulation diagnostic
products (but not with respect to any academic and commercial product research
applications), provided that PFRM shall pay to the Company $50,000 as
consideration for the transfer of such rights.

         3. SUPPLY AGREEMENT. In the event that PFRM is unable to obtain a
license from BEVSCO or TAMUS to exercise the Licensed Rights on terms acceptable
to PFRM, the Company shall enter into good faith negotiations with PFRM
regarding a supply agreement, pursuant to which PFRM would release the Company
from the restrictions set forth in Section 1 and the Company would manufacture
and sell exclusively to PFRM any coagulation product requested by PFRM subject
to the BEVS Licenses at a price approximately equal to 1.5 times the direct cost
to develop and manufacture such product.

         4. TERM. The term of this Agreement shall begin on the effective date
of this Agreement and continue for a period of ________ years. This Agreement
may be renewed upon such termination by written notice signed by both parties.

         5. ASSIGNMENT. This Agreement may not be transferred or assigned by
either party, except with the prior written consent of the other party, which
consent shall not be unreasonably withheld, provided, however, the Company may
assign its rights under this Agreement in connection with the transfer of all or
substantially all of the assets of the Company or may assign such rights to any
affiliate.

         6. MISCELLANEOUS.

                  (a) This Agreement constitutes the entire agreement between
the parties relating to the subject matter hereof and all prior negotiations,
representations, agreements and understandings are merged into, extinguished by,
and completely expressed in this Agreement. Neither party shall be bound by any
definition, condition, warranty, or representation other than as expressly
stated in this Agreement or as subsequently set forth in a writing signed by the
party to be bound thereby.


                                        2
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with the Commission pursuant to a request for confidential treatment.
<PAGE>   135
                  (b) If any provision of this Agreement shall be held
unenforceable or invalid, that provision shall be considered severable from this
Agreement and shall neither act to terminate this Agreement nor affect the
validity of the remaining provisions.

                  (c) The parties hereto are independent contractors and not
joint venturers or partners.

                  (d) This Agreement may not be amended or modified except by
mutual written agreement. Neither party may waive or release any of its rights
or interests in this Agreement except in writing. Failure to assert any right
arising from the Agreement shall not be deemed or construed as a waiver of such
right.

                  (e) This Agreement shall be governed by and construed in
accordance with the laws of the State of Delaware.

                  (f) Any notice given pursuant to this Agreement shall be in
writing and shall be deemed to have been given at the earlier of the time when
actually received as a consequence of any effective method of delivery,
including but not limited to personal delivery, transmission by facsimile or
delivery by a professional courier service or the time when sent by certified or
registered mail, addressed to the other party at the appropriate address below
or at such changed address as the parties shall have specified by written
notice, provided that any notice of change of address shall be effective only
upon actual receipt:

         To Company/Parent:         Novagen, Inc.
                                    Attn: _______________
                                    _____________________
                                    _____________________

         To PFRM:                   Pel-Freez Rabbit Meat, Inc.
                                    Attn: _____________________
                                    ___________________________
                                    ___________________________

         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed as of the date first written above.

                                    NOVAGEN, INC.

                                    By:      ___________________________
                                    Its:     ___________________________


                                       3
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with the Commission pursuant to a request for confidential treatment.
<PAGE>   136
                                    PEL-FREEZ, INC.

                                    By:      ___________________________
                                    Its:     ___________________________

                                    PEL-FREEZ RABBIT MEAT, INC.

                                    By:      ___________________________
                                    Its:     ___________________________


                                       4
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   137
                                                                       Exhibit J


                              ASSIGNMENT AGREEMENT

         This ASSIGNMENT AGREEMENT ("Assignment") is made as of this ____ day of
December, 1997 by and between MAI SYSTEMS CORPORATION ("MAI"), PEL-FREEZ, INC.
("PFI"), PEL-FREEZ RABBIT MEAT, INC. ("PFRMI") and NOVAGEN, INC. ("NOVAGEN").

         In consideration of the mutual promises and covenants contained herein,
MAI, PFI and NOVAGEN agree as follows:

         1. Acquisition. On March 7, 1997 Oracle Corporation, through its
Datalogix International, Inc. division ("Datalogix"), sold to MAI certain of the
assets of Datalogix relating to the CIMPRO product line, including a Software
License and Support Agreement with PFI (the "CIMPRO Agreement"), by and between
PFI as licensee and Datalogix as licensor. MAI represents that it is the owner
of the CIMPRO Software and the authorized licensor under the CIMPRO Agreement.

         2. Assignment of CIMPRO AGREEMENT. PFI has advised MAI that it desires
to assign to PFRMI and Novagen certain of its rights under the CIMPRO Agreement
as follows: PFI and Novagen shall receive one "Site License" and 30 PC user
licenses as defined in the CIMPRO Agreement, and (b) and PFRMI shall receive two
"Site Licenses," 66 PC user licenses and "40+" module as defined in the CIMPRO
Agreement.

         3. Consent to Assignment to PFRMI and NOVAGEN. Conditioned upon PFRMI's
and NOVAGEN's agreement to be bound by the terms and conditions of the CIMPRO
Agreement, MAI hereby consents to the assignment of the CIMPRO Agreement from
PFI to PFRMI and NOVAGEN effective upon the full execution of this assignment by
all parties referenced in Section 1.

         4. Acknowledgment by MAI That Software Support Fees Paid Through
September 30, 1998. MAI hereby acknowledges that all software support fees have
been paid for the CIMPRO Agreement (e.g. for all 3 site licenses and all 96 PC
user licenses and the 40+ module) through September 30, 1998.

         5. Ability to Transfer License from NOVAGEN to PFRMI. MAI hereby
consents to the possible future transfer of the license assigned to NOVAGEN
herein, from NOVAGEN to PFRMI, provided that PFRMI agrees to be bound by all the
conditions of the CIMPRO Agreement.

[SIGNATURE BLOCKS ON NEXT PAGE]

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   138
                  IN WITNESS WHEREOF, MAI, PFI, PFRMI and NOVAGEN have executed
this Assignment as of the dates set forth below.

PEL-FREEZ, INC.                             PEL-FREEZ RABBIT MEAT, INC.



By: _________________________               By: ________________________

Name: _______________________               Name: ______________________

Title: ______________________               Title: _____________________

Date: _______________________               Date: ______________________

MAI SYSTEMS CORPORATION                     NOVAGEN, INC.

By: _________________________               By: ________________________

Name: Luke Brown                            Name:
Title: Vice President                       Title:

Date: _______________________               Date: ______________________


                                       2
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   139
                                                                       EXHIBIT K

         The following are the principal terms of agreements to be negotiated in
good faith prior to the Closing.

1.       HUMAN HERPES VIRUS 6 ANTIBODIES (HHV6 AB)

         The parties will agree that all know-how, production protocols and
biological materials necessary for the production of Human Herpes Virus 6
antibodies (collectively, "HHV6 AB") and all patent rights to the process
disclosed in pending U.S. Application 08/683,060 shall be transferred from the
Parent to PFRM. The Company shall not be prohibited from using after Closing
generalized know-how also utilized in the manufacture of HHV6 for other non-HHV6
products if such know-how was also used to manufacture other products as of
Closing by the Company or if such know-how is in the public domain.

         PFRM and the Company shall negotiate in good faith the terms of a
nonexclusive license for the use of the HHV6 AB rights in the manufacture and
sale of research reagents in the Research Reagent Market. The "Research Reagent
Market" shall constitute academic and commercial product research applications.
The Company shall not sell any kit containing the HHV6 AB or HHV6 AB as reagents
to be used for diagnostic purposes or for inclusion in a diagnostic kit.

2.       OEM SUPPLY AGREEMENT FOR E. COLI BLOCKER, PELLET PAINT(TM) AND PCR
         MARKER.

         PFRM and the Company shall negotiate in good faith the terms of a
supply agreement for the Company to manufacture on a nonexclusive OEM basis E.
coli blocker, Pellet Paint(TM) and PCR marker. The agreement shall be for the
following volumes and prices:

<TABLE>
<CAPTION>
PRODUCT                                 PRICE                                  QUANTITY
<S>                                     <C>                                    <C>                   
E. COLI BLOCKER                         $2,828.00/                             from 100 liter fermentation
                                        cell pellet
PELLET PAINT(TM)                           $10.00                                 100 microliter package
PCR MARKER                              $46/Unit                               50-300
                                        $40/Unit                               301-500
</TABLE>

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   140
<TABLE>
<CAPTION>
PRODUCT                                 PRICE                                  QUANTITY
<S>                                     <C>                                    <C>                   
                                        $35/Unit                               501-800
</TABLE>

All technology rights, not otherwise used by PFRM as of Closing for the
manufacture of other products or in the public domain, related to these products
shall remain with the Company, including rights to the trademark Pellet
Paint(TM). PFRM shall not be licensed to use the mark Pellet Paint(TM), except
with attribution on the same page in all product literature and labels that the
mark is found that it is the trademark of the Company.

3.       DIAGNOSTIC APPLICATION RIGHTS, GENERALLY

         The Company shall not be prohibited from using after Closing
generalized know-how also utilized in the manufacture of non-diagnostic products
if such know-how was also used to manufacture such products as of Closing by the
Company or if such know-how is in the public domain or independently developed.
In any event, the Company will agree that it shall not (1) use any such rights
for the manufacture or sale of transplantation and coagulation diagnostic
products, (2) sublicense such rights to any third party for transplantation and
coagulation diagnostic products or (3) assert such rights to prevent PFRM from
using such rights to make, have made or sell or sublicense others to make, have
made or sell such transplantation and coagulation diagnostic products.

4.       RED NOVA(R) LYSATE TECHNOLOGY RIGHTS

         The Company has developed a special protocol for the manufacture of a
raw material for the Company's Red Nova(R) Lysate (Red Nova(R) Technology). PFRM
agrees not to use the Company Red Nova(R) Lysate Technology (or the registered
trademark for such product), except however, that PFRM shall not be precluded
from using any (1) technology it previously used, (2) technology it
independently developed without reference to the Company Red Nova(R) Lysate
technology, (3) information in the public domain or (4) information lawfully
obtained without reference to the Company Red Nova(R) Lysate Technology or
confidential information of the Company. A copy of the Company Red Nova(R)
Lysate Technology shall be preserved for evidentiary purposes by counsel for the
parties.

         PFRM and the Company shall negotiate in good faith the terms of a
supply agreement for the Company to supply the following quantities at the
stated price:


                                       2
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with the Commission pursuant to a request for confidential treatment.
<PAGE>   141
<TABLE>
<CAPTION>
PRODUCT                                 PRICE/QUANTITY
- -------                                 --------------
<S>                                     <C>              
Red Nova(R) Lysate                      $15.26/milliliter
</TABLE>

5.       INTER-COMPANY AGREEMENT

         The parties shall negotiate in good faith the terms of a continuing
cooperation agreement related to shared leasehold space in Madison, Wisconsin,
the use by the Company of a DNA sequencer, the use by PFRM of the Company
supplies and the reimbursement by PFRM of local telephone expenses charged to
the Company. PFRM shall continue to occupy the leasehold space which consists of
a maximum of the same area occupied at time of closing for an additional
six-month term and thereafter on a month-to-month basis, provided that either
party may give 90 days notice of termination following the end of the six-month
term. The rent (including appropriate utilities) shall be determined on a pro
rata basis based upon the relative square footage of usable space occupied. PFRM
will obtain appropriate insurance for its employee(s).

6.       THE ANTHONY NOLEN BONE MARROW TRUST RIGHTS

         All contractual rights between the Parent and The Anthony Nolen Bone
Marrow Trust shall be transferred from the Parent to PFRM.

7.       MOLECULAR BIOLOGY APPLICATION RIGHTS, GENERALLY

         PFRM will not assert any rights or any claim against the Company for
the Company products sold prior to the Closing.


                                       3
*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.
<PAGE>   142
[All schedules listed in the Table of Contents have been intentionally omitted.
The Registrant hereby agrees to furnish supplementally a copy of any omitted
schedule to the Commission upon request.]

*Portions of this document have been intentionally omitted and filed separately
with the Commission pursuant to a request for confidential treatment.


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