STRATEGIC DIAGNOSTICS INC/DE/
10-K, 1997-04-14
MISCELLANEOUS CHEMICAL PRODUCTS
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                          SECURITIES AND EXCHANGE COMMISSION
                                Washington, D.C. 20549
                                 ____________________
                                           
                                      FORM 10-K
(Mark One)
[X]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE 
     ACT OF 1934 [FEE REQUIRED]

                        For the Fiscal Year Ended December 31, 1996

[ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES 
     EXCHANGE ACT OF 1934 [NO FEE REQUIRED]

                     For the Transition Period From _________ to _________

                                Commission File Number 0-68440

                                   STRATEGIC DIAGNOSTICS INC.
                      (Exact name of Registrant as specified in its charter)
                                      ____________________

                   Delaware                                56-1581761
           (State or other jurisdiction of              (I.R.S. employer
           incorporation or organization)               identification no.)
                128 Sandy Drive
                Newark, Delaware                             19713
      (Address of principal executive offices)             (Zip Code)

        Registrant's telephone number, including area code:  (302) 456-6789
                                       ____________________

         Securities registered pursuant to Section 12(b) of the Act:  None

            Securities registered pursuant to Section 12(g) of the Act:

                     Common Stock, par value $.01 per share
                                 (Title of class)

    Indicate by check mark whether the Registrant: (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.  Yes  X     No __

    Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of Registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [X] 

    The aggregate market value of the voting stock held by non-affiliates of
the Registrant was $14,629,871 as of March 31, 1997.

    On March 31, 1997 the Registrant had outstanding 13,057,672 shares of 
Common Stock, $.01 par value.

                        DOCUMENTS INCORPORATED BY REFERENCE

    Portions of the definitive proxy statement (the "Definitive Proxy
Statement") to be filed with the Securities and Exchange Commission relative to
the Company's 1997 Annual Meeting of Stockholders are incorporated by reference
into Part III of this Report.


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                                TABLE OF CONTENTS

Item                                                                 Page
- ----                                                                 ----

PART I.................................................................1
     ITEM 1.   BUSINESS................................................1
           Overview....................................................1
           General Development of Business.............................1
           Immunoassay Technology......................................4
           Markets and Products........................................6
           Sales and Marketing Strategy...............................11
           Regulatory Approvals.......................................12
           Manufacturing..............................................14
           Research and Development...................................15
           Proprietary Technology and Patents.........................16
           Competition................................................18
           Employees..................................................18
     ITEM 2.   PROPERTIES.............................................19
     ITEM 3.   LEGAL PROCEEDINGS......................................19
     ITEM 4.   SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
           ...........................................................19
     ITEM 4(a).EXECUTIVE OFFICERS OF THE REGISTRANT...................20

PART II...............................................................22
     ITEM 5.   MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED 
                 STOCKHOLDER MATTERS..................................22
     ITEM  6.  SELECTED CONSOLIDATED FINANCIAL DATA...................23
     ITEM  7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                 CONDITION AND RESULTS OF OPERATIONS .................23
     ITEM  8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA ...........28
     ITEM  9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON
                 ACCOUNTING AND FINANCIAL DISCLOSURE..................29

PART III..............................................................30
     ITEM 10.  DIRECTORS AND EXECUTIVE OFFICERS OF REGISTRANT.........30
     ITEM  11. EXECUTIVE COMPENSATION.................................30
     ITEM 12.  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS
                 AND MANAGEMENT.......................................30
     ITEM 13.  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
               .......................................................30

PART IV...............................................................31
     ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON 
                FORM 8-K..............................................31

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                                 PART I

ITEM 1.   BUSINESS

Overview

    Strategic Diagnostics Inc. (the "Company") develops, manufactures, and 
markets immunoassay-based test kits for rapid and inexpensive detection of a 
wide variety of substances in three primary market segments:  water quality, 
industrial testing, and agricultural. The Company is a leader in the field of 
immunoassay research, development and manufacturing and develops products in 
markets where the attributes of immunoassay technology (i.e., speed, 
ease-of-use, low cost-per-test, quantitation, and flexibility) meet specific 
customer needs. The substances detected by the Company's test kits include 
chemicals used to treat drinking water, proprietary chemicals used in 
industrial processes, environmental contaminants, pesticides, genetically 
engineered traits in plants, and diseases of commercial crops.

    The Company's kits for the detection of pesticides and environmental 
contaminants (D TECH-Registered Trademark-, EnviroGard-TM-, EnSys RISc-TM- 
and RaPID Assay-Registered Trademark-), are well recognized in the 
immunoassay field testing market. The Company sells its environmental 
products in the U.S. through its direct sales force and through distributors 
in Europe and the rest of the world. The Company's  one-step strip tests 
hold a leading position in the emerging market of genetically engineered crop 
testing.  In addition to products serving the three primary market segments, 
the Company also manufactures and sells Macra-Registered Trademark- Lp(a), an 
immunoassay test kit for medical applications, which is a leading method for 
measuring lipoprotein(a) in human serum.

    In addition to developing, manufacturing and marketing immunoassay test 
kits, the Company provides fully integrated monoclonal antibody development 
and production, as well as large scale manufacturing services, to 
pharmaceutical and medical diagnostic companies through its wholly-owned 
subsidiary, TSD BioServices, Inc.

General Development of Business

Developments in 1996

    Prior to December 30, 1996, the Company was named EnSys Environmental 
Products, Inc. ("EnSys").  On December 30, 1996, EnSys merged with a 
privately held company, Strategic Diagnostics Inc. ("SDI"), with EnSys being 
the surviving entity, but changing its name to Strategic Diagnostics Inc.  

    On March 29, 1996, EnSys acquired from Millipore Corporation 
("Millipore") certain assets which consisted primarily of inventory, 
work-in-progress, equipment, intellectual property rights, contract rights 
and customer lists, of Millipore's EnviroGard-TM- product line.  In exchange 
for such assets, EnSys paid to 

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Millipore $1,000,000 in cash and issued to Millipore 1,100,000 shares of 
EnSys Common Stock, which represented approximately 15% of the outstanding 
Common Stock of EnSys after the acquisition. The EnviroGard-TM- product line 
consists of immunoassay-based test systems used in the detection of 
environmental contaminants and pesticide residues.

    On August 30, 1996, SDI acquired all of the stock of Ohmicron Corporation 
and its subsidiaries ("Ohmicron"), excluding Ohmicron Medical Diagnostics, 
Inc. which was spun-off to its stockholders prior to the acquisition date. 
Ohmicron stockholders received common stock of SDI representing approximately 
26% of the fully diluted equity of SDI (as defined in the Ohmicron 
acquisition agreement) as of June 30, 1996.  Ohmicron developed, 
manufactured and marketed immunoassay-based products which measure 
contaminants in water, soil and food and employ magnetic particle immunoassay 
technology for  precise determination of very low concentrations of 
contaminants. 

    The rationale employed by both SDI and EnSys regarding market 
consolidation led to the merger of the two companies on December 30, 1996.  
SDI merged into EnSys and the name of the surviving corporation was changed 
to Strategic Diagnostics Inc.  Grover C. Wrenn, Chief Executive Officer 
of EnSys prior to the merger, was named Chairman of the Board of Directors of 
the Company, and Richard C. Birkmeyer, President and Chief Executive Officer 
of SDI prior to the merger, and the other principal executive officers of 
SDI, retained their respective roles in the Company.  The EnSys facility in 
North Carolina was closed and operations were moved to the SDI facilities in 
Newark, Delaware, and Newtown, Pennsylvania.

    The Company believes that its competitiveness will be enhanced by virtue 
of its larger size, broader product line and the achievement of operational 
economies of scale. The Company believes that the expansion of its industrial 
testing product line resulting from its consolidation activities 
significantly enhances its ability to provide customers with the most 
appropriate test for each specific application.  The Company believes that 
its products in the water quality, industrial testing and agricultural 
markets are unique and fill a potentially large, unmet need.  The Company 
also believes that the products and technology currently being developed have 
broad application in diverse markets.

    The Company believes that its established product base, quality 
manufacturing expertise, experienced sales and marketing organization, 
established network of distributors, corporate partner relationships, and 
proven research and development expertise are critical elements of its 
potential for future success.

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Developments Prior to 1996

    SDI was founded to develop and commercialize rapid, field-portable 
immunoassay tests primarily for non-medical diagnostic testing applications 
in water quality, industrial testing  and agricultural markets.  SDI's core 
expertise was research, development and manufacturing of immunoassays, 
including immunogen and antibody development (especially monoclonal 
antibodies), immunoreagent development, assay development and manufacturing.

    SDI's founders initiated commercial operations in 1990 with a contract 
from a corporate partner to develop and manufacture a rapid field test to 
detect corrosion causing sulfate-reducing bacteria.  The sale and marketing 
of the resulting product, RapidChek-Registered Trademark- SRB, was the 
responsibility of the corporate partner, Conoco Specialty Products, Inc.

    The initial corporate partnering agreement is illustrative of one of the 
strategies SDI used to grow its business.  Corporate partners who had 
identified a market opportunity provided funding to SDI to develop and 
manufacture immunoassay products to meet the identified market need.  Most of 
the corporate partner agreements were written so that SDI retained the right, 
or had a right of first refusal, to manufacture the finished product, and the 
technology developed during the course of the project was co-owned by SDI and 
its partner. In this way, SDI developed proprietary core technology and built 
a manufacturing base of commercial products.  This strategy has proven an 
effective way for the Company to identify new market areas, to enhance its 
product pipeline and to provide funding for research and development.  The 
Company plans to continue this partnering strategy for the foreseeable future.

    Another key strategy that SDI used to develop its business was the 
formation in 1991 of TSD BioServices, a joint venture between SDI and a 
subsidiary of Taconic Farms, Inc. ("Taconic Farms") of Germantown, NY. 
Taconic Farms is a privately held company whose business is the production 
and sale of mice and rats, primarily to the research community. The mission 
of TSD BioServices was to supply antibodies, especially monoclonal 
antibodies, immunochemical reagents and related services to medical 
diagnostic and pharmaceutical companies, as well as the research community.

    The TSD BioServices business provided SDI with a critical mass of 
technology related to the development and production of antibodies with which 
to support its own product development activities. Late in 1996, in order to 
consolidate and streamline activities associated with the TSD BioServices 
business, Taconic Farms and SDI dissolved the original joint venture between 
the two companies and SDI established TSD BioServices, Inc. ("TSD") as a 
wholly-owned subsidiary.  Taconic Farms is the exclusive supplier of mice for 
TSD production contracts.

    Another key factor in the growth of SDI occurred in 1992, when SDI 
entered into a research, development and manufacturing agreement with EM 
Industries, Inc. ("EM Industries") an affiliate of Merck KGaA, Darmstadt, 
Germany. This collaboration produced the D TECH-Registered Trademark- product 
line for rapid

                                       3

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detection of priority pollutants in the field.  EM Science, Inc., a 
subsidiary of EM Industries, sold and marketed the D TECH-Registered 
Trademark- product directly to the U.S. market through a dedicated sales 
force of approximately 6 full time individuals. During 1996, sales through EM 
Industries accounted for 11% of the Company's revenues.  Late in 1996, in 
order to facilitate and enhance the marketing of the D TECH-Registered 
Trademark- product line, SDI and EM Industries restructured their corporate 
partnering arrangement such that the Company now markets and sells the D 
TECH-Registered Trademark- product line.  EM Industries received certain 
royalty rights  and shares of stock in the Company and is represented on the 
Company's Board of Directors.

Immunoassay Technology

    An immunoassay is an analytical test which uses antibodies to detect the 
presence of a target compound in a complex sample matrix with high degrees of 
precision and accuracy.

    The technology was first developed more than 25 years ago and has 
replaced many laboratory diagnostic tests in the medical industry. The pace 
in which immunoassays have been adopted in the medical arena has been driven 
in large part by three factors: (1) a demand for analyses which were 
otherwise unavailable through conventional methods; (2) a desire for 
analytical methods which could yield results  more quickly than conventional 
methods; and (3) a need for more specific and accurate data. Currently, 
immunoassays are used extensively in the medical arena to detect drugs of 
abuse, therapeutic drugs, steroid and thyroid hormones, and microorganisms 
like those causing hepatitis and AIDS.  One well-known application of 
immunoassay technology is the home pregnancy test kit. This test illustrates 
many of the benefits of immunoassay technology, namely, it provides an 
inexpensive, rapid, accurate result in an easy to use format that can be used 
in the privacy of one's own home. 

    The Company has applied immunoassay technology to a variety of industrial 
and agricultural applications. As with medical applications, immunoassay 
technology has demonstrated its value in these markets by virtue of its 
ability to yield specific, accurate, cost-effective and timely data in a 
manner previously unavailable.

    The major attributes of immunoassay technology can be summarized as 
follows:

Sensitivity:  Immunoassays can measure extremely low concentrations of 
              compounds (routinely as low as parts per billion; i.e., one 
              millionth of one gram in a liter of liquid).

Specificity:  Immunoassays can measure one specific compound out of a 
              chemical "soup," reducing the need for sample preparation.

Speed:        Total time to obtain a test result ranges from 1 minute to 
              several hours as compared to several days to several weeks with 
              many competing laboratory testing methods.

Cost:         Price per test for immunoassays range from $1 to $50; price per 
              test for similar laboratory testing can range from $5 to $1,000.

Accuracy:     Immunoassays are typically as or more accurate than their 
              laboratory counterparts.

                                       4

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Flexibility:  Immunoassays can be developed in a wide variety of test 
              formats, including multiple sample laboratory-based tests, 
              disposable, single-use units, and large automated instruments.  
              They can be designed for use by non-technical persons on-site 
              under a variety of field conditions for testing of diverse 
              sample types.

    Once an antibody reagent that has the desired performance characteristics 
(sensitivity and specificity) has been identified, it must be incorporated 
into a test format which is appropriate for the customer's application. In 
the human clinical chemistry market, antibodies are employed as reagents on 
large, automated instruments that can analyze hundreds of samples per hour. 
In contrast, antibodies can also be packaged into single use, disposable 
formats. Immunoassays can be designed to be highly quantitative or yield a 
simple yes/no result. The type of test format chosen for any given 
application depends on the needs of the customer and may include factors such 
as ease-of-use, cost per test, number of samples to be tested, the location 
the test will be performed and experience of the user.

    The Company has expertise and proprietary technology surrounding the 
development and manufacture of primarily five immunoassay formats: latex 
filtration, magnetic particle, one-step strip tests, coated-tube and 
microtiter plate. Latex filtration assays offer ease-of-use, field 
portability and semi-quantitative results and are ideally suited for on-site, 
field screening applications where limited numbers of samples are to be 
analyzed.

    Magnetic particle assays have a greater number of steps and require more 
technical expertise to execute than latex filtration assays, but are more 
suited to processing a larger number of samples at a single time, can be 
highly quantitative, and are relatively inexpensive on a cost-per-test basis. 
These characteristics make magnetic particle immunoassays effective 
measurement tools in both laboratory and certain field applications, 
especially where highly precise results are required.

    Lateral flow immunoassay strips, often referred to as  one-step tests, 
require only that the user apply a prepared sample to the test strip to 
obtain the test result--much like pH or Litmus paper tests. The low cost and 
simplicity of these tests make them ideally suited for a wide range of 
applications in many different markets. The current state-of-the-art of 
lateral flow immunoassays is such that the results obtained using these tests 
are qualitative, not quantitative, which imposes limits on the applicability 
of the format.

    Coated-tube immunoassays are well suited for analyzing relatively large 
numbers of samples in the field, yield a semi-quantitative result and are 
intermediate in their ease-of-use and cost-per-test.

    Microtiter plate assays are well established in the medical diagnostic 
industry and offer many of the advantages of magnetic particle assays, 
including quantitative results and the capacity to analyze large numbers of 
samples at a relatively low cost-per-test. Special laboratory equipment, 
relatively high levels of technical training, and a time-to-result measured 
in hours limits this test format to laboratory applications.

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    All measurement technologies, including immunoassays, have strengths and 
limitations. The Company's expertise with multiple immunoassay formats, 
coupled with a thorough understanding of the needs of a market and specific 
customer applications, has allowed the Company to develop a diverse array of 
immunoassay products to meet the analytical needs of multiple, sizable 
markets.

Markets and Products

    The Company sells products in the water quality, industrial testing and 
agricultural market segments through its direct sales force in the United 
States, through a network of over 40 distributors in North America, Europe 
and Asia, and through its corporate partners.

    Product revenues in the industrial testing market segment were 29% of 
total product revenue in 1994, 32% of total product revenue in 1995, and 26% 
of total product revenue in 1996.

    Product revenues in the agricultural market segment were 4% of total 
product revenue in 1994, 22% of total product revenue in 1995, and 30% of 
total product revenue in 1996.

    Product revenues in other markets (primarily attributable to sales of 
Macra-Registered Trademark- Lp(a) test kits) were 67% of total product 
revenue in 1994, 45% of total product revenue in 1995, and 27% of total 
product revenue in 1996.

    Water Quality

    The Company believes that all of its products sold in this market provide 
high value testing solutions to fill largely unserviced analytical needs in 
this critical and highly regulated industry.  The Company markets established 
products such as those for the detection of pesticides, as well as emerging 
products for the detection of pathogenic microorganisms and toxic chemicals 
resulting from chlorine disinfection of drinking water.  Also included in 
this market segment are products currently under development for the 
detection of water treatment polymers used to clarify water and prevent scale 
formation.

    Water Treatment Polymers.  The water treatment market encompasses both 
industrial and municipal water treatment systems. Water treatment chemicals, 
typically polymers, are critical to preparing finished drinking water in 
municipal settings and to controlling water quality in industrial settings. 
Competition between water treatment chemical manufacturers is intense and new 
chemicals have evolved to the point that some of the more effective chemicals 
are quite expensive.  Cost effective use of these chemicals requires careful 
control of polymer concentrations throughout the system in which they are 
being employed. Certain of these polymers are toxic and occasionally have 
been implicated in fish kills when industrial effluents have been discharged 
to natural bodies of water. As a result, there may be increased regulatory 
pressure to measure the amount of chemicals being discharged into surface 
waters.

    The Company, working in collaboration with its corporate partners, has 
developed highly sensitive and accurate immunoassays for the detection of a 
number of water treatment polymers.  These immunoassays have been field 
tested and have been demonstrated to be a reliable and cost-effective way to 
measure water treatment polymers in samples from municipal water supplies, 
boilers, cooling towers, and other process and raw water sources. Some 
specific applications are:  (i) measuring concentrations of chemicals to 
allow more efficacious use of costly compounds, (ii) detecting the presence 
of particular compounds in effluent discharge in order to gauge regulatory 
compliance, and (iii) monitoring processes to prevent fouling of highly 
expensive systems (like reverse osmosis) by excess polymer. The Company is 
currently commercializing multiple tests in this area.  To date, the Company 
has not derived significant revenues from this product line.

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    Cryptosporidium and Giardia. During 1994, EnSys entered into an exclusive 
five year license agreement, under which it would manufacture and sell 
Hydrofluor-TM-, an EPA-accepted immunoassay-based method for detecting the 
pathogenic protozoa Cryptosporidium  and Giardia  in water.  According to the 
EPA, Cryptosporidium  and Giardia  cause more outbreaks of disease than any 
other water-born pathogens. The Hydrofluor-Combo-TM- test kit is the American 
Society for Testing and Materials ("ASTM") standard method for detection of 
these pathogenic protozoa and has been designated as the method for use in 
complying with the EPA's Information Collection Rule to establish the extent 
of contamination in the nation's drinking water.

    Total Trihalomethanes.  Trihalomethanes are regulated, toxic by-products
which result from chlorine disinfection of drinking water.  The Company's test
is a non-immunoassay-based test for the detection of total trihalomethanes
("TTHMs").  This recently introduced, inexpensive test  detects TTHMs at levels
much lower than EPA regulated levels, and correlates well with standard EPA
laboratory methods.  The EPA is currently reviewing the Company's TTHM method
for use in drinking water compliance testing.

    RaPID Assay-Registered Trademark- and EnviroGard-TM-.  The RaPID
Assay-Registered Trademark- and EnviroGardTM pesticide test kits are being used
by water quality researchers, resource managers, regulators and drinking water
system operators for surface and groundwater monitoring, drinking water source
and supply management, and chemical fate and transport studies.  Users of the
Company's water quality pesticide products include federal agencies, such as the
U.S. Geological Survey and Department of Agriculture, state environmental and
health departments, drinking water utilities, and environmental engineering
companies.

    Industrial Testing

    The industrial testing market segment is comprised of immunoassays for
pesticides, pollutants, proprietary chemicals and industrial markers.  Products
in this market are developed and marketed in collaboration with the Company's
corporate partners.

    Proprietary Chemicals.  The proprietary chemical market segment includes
tests, commissioned by chemical manufacturers, that specifically measure the
particular compound of interest. In the chemical market segment the benefits of
immunoassay testing have led to three key applications: (1) regulatory
registration, in which immunoassay data is generated to support the registration
of a product with the EPA; (2) detection, to determine whether a target compound
is present in a complex matrix; and (3) monitoring, in which tests are performed
to determine chemical concentrations for control purposes.

    The application of immunoassay technology in conjunction with regulatory 
registration is significant because of the requirement that large scale 
chemical manufacturers register their chemicals under the Federal 
Insecticide, Fungicide and Rodenticide Act ("FIFRA") with the EPA. As part of 
this registration process, manufacturers must provide extensive data for both 
registration and post-registration analyses regarding toxicity and 
environmental impact. For many new compounds, certain aspects of this 
analysis require sensitivity which instrument-based testing cannot achieve. 
For others, no classical analytical methods are available to measure the 
compound. In either case, the EPA requires the manufacturer to supply a 
method to monitor the compound in the environment. The Company is currently 
commercializing four tests in this area and agreements are in place for the 
development of seven additional tests.

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    Industrial Markers.  The Company is collaborating with a corporate 
partner in this market segment, which consists of test kits that detect 
marked products. The product marking technology is based on the incorporation 
of trace levels of inert chemicals or markers into solid or liquid products 
or on the surface of the products. The use of these markers, in conjunction 
with immunoassay techniques for marker detection, allows for the covert 
marking and testing of nearly any product. This technology can help prevent 
revenue loss due to counterfeiting and product diversion, limit a 
manufacturer's exposure to unwarranted product liability, and enhance process 
efficiency and product quality assurance.

    Pollutants.  Analysis of soil, water and waste samples to determine the 
presence of hazardous chemicals has become increasingly important in 
connection with the environmental remediation and environmental monitoring 
activities. These activities are largely the result of environmental 
legislation such as the Resource Conservation and Recovery Act ("RCRA"), the 
Comprehensive Environmental Response, Compensation and Liability Act 
("CERCLA"), Toxic Substances Control Act, ("TSCA"), the Safe Drinking Water 
Act ("SDWA") and the Federal Water Pollution Control Act (the "Clean Water 
Act").  It is estimated that environmental testing is provided by 
approximately 1,200 commercial environmental testing laboratories, as well as 
"in-house" laboratories at industrial and disposal facilities.  Market 
research reports estimate that commercial environmental testing laboratories 
accounted for approximately one half of all environmental tests performed and 
had revenues exceeding $1.1 billion in 1995.

    Environmental remediation activities require a substantial amount of 
testing in connection with the clean-up of contaminated sites.  After initial 
characterization of toxic chemicals at a site, substantial testing typically 
is required to complete an assessment of the site to determine the extent and 
location of contamination and the appropriate remediation plan.  Upon the 
commencement of the remediation project, additional testing is necessary to 
determine the effectiveness of the remediation measures.  In addition, 
ongoing testing to monitor soil and groundwater is often required after 
completion of the remediation activities.  The contaminants of primary 
concern for remediation activities include petroleum fuel products, 
polyaromatic hydrocarbons ("PAH"s), polychlorinated biphenyls ("PCB"s), 
benzene, certain metals and chlorinated solvents.

    Environmental monitoring activities under SDWA and the National Pollution 
Discharge Elimination System ("NPDES") regulations under the Clean Water Act 
require periodic testing for various hazardous chemicals.  The nation's 
approximately 58,000 drinking water systems test for contaminants such as 
metals, benzene, other volatile organic compounds and microbiological 
contamination.  Approximately 6,400 major industrial and municipal waste 
water treatment facilities monitor and test waste water for contaminants such 
as chlorinated solvents, metals and volatile organic compounds.  Hazardous 
waste handling and disposal companies carry out large volumes of analytical 
work, including pre-acceptance testing to determine the suitability of waste 
streams for disposal and routine testing of incoming shipments.  In addition, 
the ongoing management of chemicals in the petrochemical and pesticide 
industries results in the need to test samples at many points in the 
production, use and disposal cycle.  Electrical utilities have on-going 
analytical needs pertaining to disposal of PCB containing materials.

    Pesticide Residues.  The entrance of pesticides into the water supply as 
a result of agricultural and residential runoff continues to be a problem 
requiring analytical testing.  In areas of substantial agricultural activity, 
drinking water is tested for several pesticides in order to ensure compliance 
with Federal regulations.  Imported grains, fruits and vegetables are tested 
for the presence of pesticide residues prior to use in the U.S.  In addition, 
pesticide residues in crops call for extensive testing at the time of 
pesticide registration or reregistration under FIFRA.  In spite of their 

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banned status, pesticides such as DDT and chlordane still persist in soil at 
sites where they were stored or distributed.  The clean-up of these sites 
requires the use of specific analytical methods of pesticide detection.

    Pollutant Test Products.  The Company sells four different format 
immunoassays for detection of environmental pollutants, latex filtration 
tests (D TECH-Registered Trademark-), coated-tube tests (EnSys RIScTM  and 
EnviroGardTM), magnetic particle tests (RaPID Assay-Registered Trademark-) 
and microtiter plate tests (EnviroGardTM).  Each of the four different test 
formats have performance characteristics that make them more or less suited 
for a particular customer application.  The Company positions the sale of its 
environmental products so as to provide the customer with the best product 
for their specific application.

    The D TECH-Registered Trademark- and EnSys RIScTM tests do not require 
refrigeration which make them ideally suited for on-site, field applications. 
All of the environmental test kits include components for the extraction of 
target analytes from the sample and subsequent analysis. Sample preparation 
time is typically less than five minutes per sample.  All of the Company's  
test kits are capable of analyzing at least ten samples per hour and some 
allow analysis of as many as forty samples per hour.  Generally, less than 
four hours of training is required before an operator can effectively use the 
tests.

    D TECH.-Registered Trademark-  The D TECH-Registered Trademark- tests are 
a latex filtration immunoassy format and provide for rapid, easy to use, 
on-site, field screening analysis of soil and water samples containing EPA 
Priority Pollutants like PCBs, PAHs, trinitrotoluene ("TNT"), benzene, 
toluene, ethylbenzene and xylene (collectively, "BTEX") and others.  D 
TECH-Registered Trademark- is very simple to use, requires little or no user 
training, yields a semi-quantitative result and is ideally suited for true 
field applications where limited numbers of samples are to be analyzed at one 
time.

    RaPID Assay-Registered Trademark-.  The RaPID Assay-Registered 
Trademark-magnetic particle immunoassay product line currently contains kits 
and accessories for detection of 21 different pesticides (herbicides, 
insecticides and fungicides), and 6 toxic organic compounds. The magnetic 
particle test format is ideally suited for applications requiring highly 
precise determination of contaminant concentrations.  Like the Company's 
other immunoassay tests, RaPID Assay-Registered Trademark- is fast and easy 
to perform, but not as field-portable.  RaPID Assay-Registered Trademark- 
pesticide test kits are used for quantitation of pesticides in water, soil 
and food. RaPID Assay-Registered Trademark- test kits for toxic organic 
chemicals are used for measuring contaminant concentrations in both water and 
soil.

    EnviroGardTM and EnSys RIScTM.  Like D TECH-Registered Trademark- and 
RaPID Assay-Registered Trademark- these coated-tube and microtiter plate 
format testing products detect some of the most commonly encountered toxic 
chemicals found in soil, water and on surfaces at contaminated sites, 
including PCBs, fuel products, PCP, TNT, benzene, PAHs, crude oil, and 
pesticides.  Additionally, the EnviroGardTM products detect pesticides in 
drinking water and foodstuffs.  The coated-tube format tests are used 
extensively to analyze relatively large numbers of samples in the field and 
yield a semi-quantitative result.  The EnviroGardTM microtiter plate kits are 
designed for use in the laboratory and are ideally suited for analysis of 
large numbers of samples where determination of exact concentrations of 
contaminants are required.

    Agricultural

    The agricultural market segment includes tests for genetically engineered 
crops and two plant fungi, Rice Blast and Botrytis.

                                       9

<PAGE>

    Genetically Engineered Crops.  Agricultural companies are developing 
varieties of commercially important crops like corn, cotton and soybean that 
have new additional genes which confer some commercial advantage to the 
plant, such as insect or pesticide resistance or enhanced growth or 
nutritional characteristics.  Industry experts predict that roughly one 
quarter of the acreage used to grow corn in the U.S. will be planted with 
genetically engineered seed by the year 2000, in comparison to only 0.5% in 
1996.

    The Company's first test in this market was commissioned by a large 
agricultural chemical company which developed proprietary varieties of 
insect-resistant corn and cotton using genetic engineering technology. Not 
all the seed produced by a genetically engineered plant contains the gene for 
the desired trait, and therefore not all the plants arising from a batch of 
seed will express the desired characteristic. The Company markets a simple  
one-step strip test (GeneCheck-TM- B.t.k ) which is used in the field to 
determine if an individual plant contains the new genetic trait.  The product 
is used by commercial seed producers to insure that each plant harvested for 
seed contains the resistance gene.  This type of test can also be used for 
enforcement purposes in crops where unscrupulous individuals could harvest 
and sell or plant the seed instead of purchasing it from authorized dealers.

    Sales of the GeneCheck-TM- B.t.k. product have been increasing since its 
introduction in the third quarter of 1995 and the Company believes sales will 
continue to grow in 1997.  Additional tests for genetically engineered plants 
are currently under development.

    Rice Blast.  Rice blast is a fungus that can devastate a rice crop. 
Worldwide, over 360 million acres of land are planted with rice. Countries 
such as Thailand, China, Japan and Indonesia are dependent on rice both as a 
food source and for export revenues. The RapidChek-Registered Trademark- 
Blast Finder is a very simple, field-portable test kit (in the latex 
filtration format), which allows early detection of the fungus on growing 
rice plants. Early detection allows treatment of the rice with fungicides 
before the crop is severely damaged.  The Company and its marketing affiliate 
have worked with the International Rice Research Institute to demonstrate the 
test kit internationally and the government of Thailand has taken an 
aggressive role in evaluating the test kit.  To date, the Company has only 
derived modest revenues from this product line.

    Botrytis.   Botrytis, or gray mold, affects a wide variety of food crops 
including grapes, strawberries, cucumbers, lettuce and others.  The Company's 
RapidChek-Registered Trademark- Botrytis test was originally developed to 
serve the wine industry and has been field tested in California. The 
California Department of Food and Agriculture ("CDFA") acts as a liaison 
between the grape growers and the wineries and oversees testing of the 
harvested grapes in the field.  Truckloads of harvested grapes are sampled as 
they leave the field and the grapes are visually inspected for botyytis 
infection.  Botrytis levels are used to establish pricing and the growers, 
vintners and the CDFA all have a vested interest in methods for more 
accurately determining levels of infection in harvested grapes.  As a result 
of this and other work, the use of immunoassays for grape inspection has been 
promulgated in the California Code of Regulations.  While the 
RapidChek-Registered Trademark- Botrytis test was originally developed for 
grape testing, the Company believes that the larger opportunity 

                                      10

<PAGE>

for this product is the testing of fresh fruits and vegetables during 
import/export and is seeking to expand the application of this product to 
that market.

    Other Products

    Macra-Registered Trademark- Lp(a).   Macra-Registered Trademark- Lp(a) is 
a microtiter plate assay that measures a lipoprotein found in human serum. 
This lipoprotein has been shown to be an indicator of risk for myocardial 
infarction, heart disease and stroke. The product is currently for research 
use only, however, a 510(k) application has been submitted to the FDA. A 
great deal of clinical data has been generated with the Macra-Registered 
Trademark- Lp(a) kit because of its leading market position, and its use in 
benchmark projects such as the Framingham Study, a multi-generational 
analysis of coronary risk factors.

    RapidChek-Registered Trademark- SRB.  Sulfate Reducing Bacteria ("SRB"s) 
are environmentally significant because they generate hydrogen sulfide gas 
and cause corrosion of stainless steel pumps, pipelines, and drilling rigs 
and result in the souring of oil reserves. SRBs can be controlled by the 
addition of treatment chemicals. Historically, the majority of testing in 
this market was performed using a culture method called the American 
Petroleum Institute Recommended Procedure No. 38. This method requires that 
samples be incubated from 14-28 days before a result is obtained. RapidChek 
SRB test is a simple to use, field portable test that provides the user with 
accurate results in 20 minutes and allows for an immediate, more cost 
effective application of treatment chemicals.

    BiMelyze.  In 1994, EnSys entered into a three year sales and marketing 
agreement for the distribution of the BiMelyze test, an immunoassay-based 
test for detecting mercury in soil and water. Sales of the BiMelyze test have 
not been significant to date, and there can be no assurance that significant 
sales will be realized under this agreement in the future.

Sales and Marketing Strategy

    As a result of the recent consolidation of the SDI, EnSys, Ohmicron and 
EnviroGardTM businesses, the Company has formed an experienced sales and 
marketing organization of 25 individuals. In addition to its direct sales 
force, the Company sells product through an extensive network of 
distributors, and through its corporate partners.

    The Company uses a number of strategies for the sale of its products 
worldwide.  In the U.S., the major route of sale of its industrial testing 
products is through a national field sales force in defined sales 
territories. The field sales force is augmented by an in-house sales force, 
which in addition to selling product directly to customers, provides 
marketing and logistical support to the field sales personnel and an 
interface between customers and technical support.

                                      11

<PAGE>

    In September 1993, EnSys opened a European headquarters and sales 
operation in London, England, and the sale of the EnSys RIScTM and 
EnviroGardTM products in Europe were principally directed through that 
office. Ohmicron sold the RaPID Assay-Registered Trademark- product line 
through over 40 distributors in North and South America, Europe, the Far 
East, Australia/New Zealand and South Africa. More recently, the Company has 
restructured the organization to coordinate selling of the RaPID 
Assay-Registered Trademark- abroad through its London office.  Sales and 
distribution of the D TECH-Registered Trademark- product line outside of the 
U.S. is handled exclusively by Merck KGaA, Darmstadt, Germany. 

    During 1994, EnSys signed a distribution and supply agreement with a 
catalog distribution company  to distribute the EnSys products to 
environmental laboratories.  The Company's agreement   grants certain 
exclusive catalog distribution rights subject to a minimum annual purchase 
commitment.   To date, sales through this catalog distribution channel have 
not been significant and have not met the minimum annual purchase commitment 
specified in the agreement. Either party can cancel the existing agreement 
with 90 days written notice.

    Sales of  the Company's products for detecting water treatment polymers, 
proprietary chemicals, industrial markers, genetically engineered crops and 
Rice Blast are through the Company's corporate partners.  The 
RapidChek-Registered Trademark- SRB test kit is sold directly by the Company 
and through five international distributors. The Company has arrangements 
with three international distributors for sale of the Macra-Registered 
Trademark- Lp(a) test kit.

Regulatory Approvals

    The environmental legislation and regulations that the Company believes 
are most applicable to its current business are RCRA, CERCLA, TSCA, FIFRA and 
the Pure Food and Drug Act.  As the Company expands its product line to meet 
the environmental monitoring needs of municipalities and industrial 
facilities, the SDWA, the Clean Water Act and the NPDES permitting program 
under the Clean Water Act also will be significant to the Company's business. 
 These laws regulate the management, disposal and clean-up of hazardous 
substances and protect the nation's ground and surface water and drinking 
water supplies.  In addition, regulatory responsibilities in a number of 
areas have been delegated to state agencies and state and local laws and 
regulations impose additional restrictions and requirements.  While 
environmental regulations overseas vary, many countries, particularly in 
Europe, have counterparts to the U.S. legislation.

    The Company believes that regulatory acceptance, though not required for 
the use of its products in most cases, is a significant factor in gaining 
market acceptance.  There are three main areas in which the Company is 
seeking regulatory acceptance for its products: hazardous waste testing 
methods, water testing methods and FDA 510(k) approval for Macra-Registered 
Trademark- Lp(a).

                                      12

<PAGE>

    Hazardous Waste Testing Methods.  EPA SW-846 ("SW-846") is the compendium 
of analytical and test methods published by the EPA's Office of Solid Waste 
(the "OSW").  A number of provisions of the EPA's hazardous waste regulations 
under RCRA mandate the use of SW-846 methods.  In other contexts, SW-846 is a 
guidance document setting forth acceptable, although not required, methods to 
be implemented by the user in response to sampling and analysis requirements. 
 Some states also require the use of SW-846 methods under their hazardous 
waste programs.  While SW-846 methods are technically only applicable to 
regulatory programs under RCRA, other federal, state and local environmental 
programs, including CERCLA and TSCA, often refer to and rely on SW-846 
methods for purposes of remediation and monitoring. 

    The process for a method to be incorporated into EPA SW-846 generally 
takes approximately 24 to 36 months.  The OSW evaluates the applicant's test 
results and obtains additional information or conducts its own tests if 
necessary. After a method is deemed acceptable, it is published by the EPA in 
draft form ("EPA Draft Method").  Periodically, the EPA updates SW-846 
through a notice in the Federal Register referencing the EPA Draft Methods 
published since the last update.  Following a comment period, the EPA Draft 
Methods are referenced in the Federal Register as a Final Rule and 
incorporated into SW-846.  The new test methods for the third update of the 
third edition of SW-846 were proposed in the Federal Register in July 1995.  
The comment period closed in December 1995 and the comments are currently 
being evaluated.  The final methods are expected to be promulgated in 1997. 
The following table summarizes the EPA approval status of the Company 
products:

<TABLE>
<CAPTION>


EPA SW-846
 Method
Validations              D TECH-Registered Trademark-     EnSys RISc-TM-       EnviroGard-TM-     RaPIDA ssay-Registered Trademark-

<S>                      <C>                              <C>                  <C>                <C>
4010     PCP                                                Soil & Water       Soil & Water                     Soil
4015     2,4-D                                              Soil & Water           Soil                         Soil
4020     PCB                       Soil                      Soil & Oil            Soil                         Soil
4030     TPH                                                    Soil               Soil                      per CalEPA
4035     PAH                                                 Soil (APAH)        Soil (APAH)                  Soil (APAH)
                                                                                                             Soil (CPAH
4040                                                                                Soil
Toxaphene                                                                           Soil
4041                                                                                Soil
Chlordane
4042     DDT
4050     TNT                   Soil & Water                                      Soil & Water                 Soil & Water
4051     RDX                   Soil & Water
4670     Triazines                                                                                                Water
8510     RDX                                                    Soil
8515     TNT                                                    Soil
</TABLE>


    Water Testing Methods.  Water testing methods approved for use in 
compliance with the SDWA are published periodically in the Federal Register. 
Newly developed methods are reviewed by the EPA's Environmental Monitoring 
and Systems Laboratory in Cincinnati to determine whether they are (i) an 
acceptable version of a previously approved method or (ii) a new method in 
need of a comparability study and proceed through a comment and approval 
procedure.  The EPA has recently begun a program aimed 

                                      13

<PAGE>

at expediting the approval of new methods that involves the cooperation of 
the Solid Waste, Drinking Water, and Waste Water methods groups. 

    The Company's TTHM water test has been accepted as Draft Method 8530 by 
OSW and will receive further consideration by the Drinking Water Methods 
Group. In addition, the RaPID Assay-Registered Trademark- Atrazine test was 
accepted as a quantitative method through the OSW and by the Association of 
Official Analytical Chemists (the "AOAC"), and it is anticipated that the EPA 
Office of Drinking Water will adopt this method for compliance in the 
enforcement of the Drinking Water Regulations for Triazines under the SDWA. 
More recently, the Company's RaPID Assay-Registered Trademark- for Spinosad 
has been adopted by the EPA as the official enforcement method for this 
pesticide. The Hydrofluor-Combo-TM- test kit is the ASTM standard method for 
detection of these pathogenic protozoa and has been designated as the method 
for use in complying with the EPA's Information Collection Rule to establish 
the extent of contamination in the nation's drinking water.

    Tests for water treatment polymers, genetically engineered traits in 
plants, and fungal plant pathogens are currently unregulated. However, 
agencies such as the EPA, the FDA and the Food Safety and Inspection Service 
of the U.S. Department of Agriculture are engaged in testing environmental 
samples and, together with AOAC International, maintain compilations of 
official methods for use in testing for environmental contaminants in certain 
market segments. Some of these organizations also issue procedures and 
guidelines for validating new methods.

Manufacturing

    The Company currently manufactures over 150 different test kits for the 
detection of a wide array of analytes in five immunoassay formats; one-step 
strip tests, coated-tubes, latex filtration, magnetic particles and 
microtiter plates.  In addition to test kits, the Company supplies its 
customers with ancillary equipment and supplies including spectrophotometers, 
pipettes, balances, timers and the like.

    The kit manufacturing process consists mainly of critical reagent 
production and in-process testing, filling and dispensing, labeling, kit 
assembly, quality control, packaging and shipping.  The Company's Technical 
Reagents Manufacturing group produces critical reagents from its laboratories 
in Newark, Delaware. Sub-assemblies and finished kits are manufactured and 
shipped world-wide out of the Company's Newark, Delaware and Newtown, 
Pennsylvania facility. 

    Biological materials are primarily developed and produced in-house, 
however, some reagents are licensed from third parties or purchased from 
commercial sources.  A crucial step in the Company's manufacturing process is 
the stabilization of the immunoreagents utilizing proprietary lyophilization 
techniques.  In general, raw materials used by the Company in its products 
are obtainable from multiple sources.  The Company purchases instruments and 
ancillary equipment from outside vendors.  A number of the instruments sold 
by the Company were developed to be used exclusively with the Company's 
products and are subject to specific supply agreements.

    The Company manufactures its products in accordance with the FDA's Good 
Manufacturing Practices ("GMP") guidelines and has put in place systems 
designed to control all elements of the manufacturing process including raw 
materials, inventory, processes, documents, work-in-process, lot 

                                      14

<PAGE>

records, equipment and training.  The Company is presently integrating its 
inventory control, purchasing, manufacturing scheduling, order processing and 
shipping system.

    The Company's manufacturing organization, including the Technical 
Reagents Manufacturing group, consists of approximately 30 individuals.  The 
Company believes the existing facilities and equipment are sufficient to 
support a significantly larger manufacturing base.  Manufacturing operations 
are currently running  a single shift.

Research and Development

    The Company engages in substantial research and development activities 
involving antibody and immunoassay development.  In the three years ended 
December 31, 1996, 1995 and 1994, SDI incurred approximately $1,569,000, 
$2,272,000 and $2,832,000, respectively in research and development 
expenditures, substantially all of which has been customer-sponsored.  The 
Company's laboratory facilities located in Newark, Delaware, were designed 
and built specifically for conducting research and development relating to 
antibody and immunoassay technology.  These facilities include the 
state-of-the art, GMP, American Association for Accreditation of Laboratory 
Animal Care ("AAALAC") approved, TSD monoclonal antibody development and 
large scale production facility.  The Company has assembled a scientific 
staff with extensive experience in the development of monoclonal and 
polyclonal antibodies, immunogens and assay reagents.  The Company's assay 
development scientists are experienced in developing tests in a variety of 
different immunoassay formats including one-step strips, latex filtration, 
magnetic particles, coated tubes and microtiter plates.  Research and 
development personnel have complementary skills in several advanced research 
disciplines, including synthetic organic chemistry, protein chemistry, 
biochemistry, immunology, immunochemistry, microbiology and soil science.  In 
addition to the technical expertise resident within research and development, 
TSD provides the Company scientists, as well as its outside clients, with 
large scale GMP production, bioprocessing, purification and quality control 
of antibodies and reagents.

    The Company's research and development activities are focused on 
developing products to expand its manufacturing base and leverage its Sales 
and Marketing organization.  The Company is a recognized leader in the field 
of contract antibody and immunoassay research and development in the 
industrial, water quality and agricultural sectors, and markets its services 
primarily to large chemical and pharmaceutical companies.  Product 
development is typically performed in collaboration with a corporate partner 
that has identified a specific market need and provides funds to the Company 
to develop an assay. Research and development contracts are typically 
structured such that technology developed within the program is co-owned by 
the Company and its partner and the Company maintains exclusive manufacturing 
rights.

    To the extent the Company believes that improvements to existing products 
significantly enhance competitiveness, expand a market or improve market 
penetration, the Company has periodically funded such efforts.  In the 
markets where the Company has chosen to compete, rapid field screening tests 
are highly valued and the Company is actively engaged in developing 
proprietary technology to better meet those needs and enhance the Company's 
overall performance.  Prior to the merger with SDI, EnSys was developing 
one-step strip test products for the industrial testing market, and the 
Company is continuing with that development program.

                                      15

<PAGE>

    The Company's technology organization, including research and 
development, TSD, Technical Reagents Manufacturing, and Technical Marketing 
Support consists of approximately 35 individuals, of whom 15 hold advanced 
academic degrees.

Proprietary Technology and Patents

    The Company's products are based on the use of proprietary reagents, 
technology and test systems developed by its scientists.  Accordingly, the 
Company has implemented a number of procedures to safeguard the proprietary 
nature of its technology.  The Company requires its employees and consultants 
to execute confidentiality agreements upon the commencement of an employment 
or consulting relationship with the Company, and all employees are required 
to agree to assign to the Company all rights to any inventions made during 
their employment or relating to the Company's activities.

    Additionally, the Company seeks to protect its technology and processes 
through the patent process.  The Company currently holds eight issued U.S. 
patents and the claims for another three are in a state of allowance.  Two 
additional U.S. patents have been licensed for exclusive use by the Company 
and eight U.S. patent applications are pending.

- --------------------------------------------------------------------------
U.S. Patent                           Title
- ----------------------------------------------------------------------------

4,999,286          Sulfate reducing bacteria determination and control
5,200,346          Aldicarb immunoassay by sulfone equivalents
5,411,869          Immunological analogs for captan
5,449,611          PAH immunoassay method, its components and akit for 
                   use in performing the same
5,484,709          Immunoassay method for detecting an immunologically 
                   non-remarkable compound
5,547,877          Methods for the rapid detection of toxic halogenated 
                   hydrocarbons and kits useful in performing the same 
5,554,730          Fungus extraction method and kit
5,576,187          Standards for phosphorothioate insecticide immunoassays
Allowed            PAH immunoassay method, its components and a kit for use 
                   in performing the same
Allowed            Kits and processes for extraction of analytes from solid 
                   materials
Allowed            A petroleum immunoassay method, its components and a kit 
                   for performing the same 
5,429,952          Marking of products to establish identity and source
(Biocode
License)
- ----------------------------------------------------------------------------

    The Company believes that low-cost, easy to use, rapid field screening 
tests have the potential to be significant products in its chosen markets. 
Therefore, the Company is aggressively developing technology relating to 
immunoassay formats with those features.  One of the Company's pending U.S.

                                      16

<PAGE>

patent applications has to do with what the Company believes is a novel latex 
filtration test format, and two of the Company's pending applications involve 
one-step strip test formats.  In addition to the assay format patent 
applications, the Company has pending applications relating to immunoassays 
for trichloroethylene ("TCE") and PCB, standards for immunoassays used to 
detect volatile aromatic hydrocarbons, and a non-immunoassay chemical test 
for quantitation of crude oil contamination of soil.

    There can be no assurance that the Company's patent applications will 
result in the issuance of any patent or that any patents issued to the 
Company would provide protection that is sufficiently broad to protect the 
Company's technology and products.  In addition, the Company cannot be 
certain that it was the first creator of inventions covered by pending patent 
applications or that it was the first to file patent applications for such 
inventions.

    In addition to seeking patent protection for the Company's proprietary 
information, the Company also relies upon trade secrets, know-how and 
continuing technical innovation to maintain competitiveness.  The Company has 
developed a number of proprietary technologies which  it has chosen not to 
patent including stabilization systems for reagents, chemical syntheses for 
conjugates, immunogens and analyte analogs, and strategies relating to 
antibody development. Regarding the latter, the Company's extensive expertise 
has enabled it to develop antibodies and products that are unique to the 
industry including monoclonal antibodies to the explosive RDX, BTEX and TCE.

    Library of monoclonal antibodies to clinical analytes.  SDI acquired 42 
monoclonal antibodies for clinical diagnostic applications in 1993. These 
antibodies are being licensed by numerous diagnostic companies for use in 
commercial assays. The Company has several outstanding licenses to a variety 
of diagnostic companies.

    Monoclonal antibody to Lp(a).  The Company has licensed the exclusive use 
of the monoclonal antibody which confers the specificity in the 
Macra-Registered Trademark- Lp(a) test.

    Detection of marked polymers.  A method of detecting water treatment 
polymers is to chemically couple an unrelated "marker" substance to the 
polymers and use antibodies and immunoassays to detect the marker. This 
technology has been patented by Biocode Incorporated (U.S. Patent 5,429,952). 
The Company has licensed the exclusive rights to this technology for the 
detection of water treatment polymers.

    Magnetic particles.  Under two license agreements, the Company has been 
granted the right and license throughout the world to use magnetocluster 
technology in connection with the Company's RaPID Assay-Registered 
Trademark-products for the detection of environmental analytes. This license 
carries royalties starting at 4% of net sales of such products each year and 
declining to 2% based upon the volume of sales in such year. In addition, it 
has been agreed that all of the Company's requirements of uncoupled 
magnetocluster particle reagents are to be supplied until September 1997 on 
specified terms.

    Antibodies to Heavy Metals.  The Company has funded research for the 
development of an immunoassay-based test for the detection of heavy metals 
(e.g., lead and mercury).  As part of that agreement, the Company has an 
option to license certain patent rights resulting from that research. There 
can be no assurance that the Company will exercise the option, or that any 
products can be developed as a result of this research.

                                      17

<PAGE>

Competition

    Many of the Company's potential competitors are large companies with 
substantially greater resources than the Company.  To the extent that any 
such companies enter one or more of the Company's markets, the Company's 
operations could be materially adversely affected.  The Company  anticipates 
increased competition as potential competitors perceive that the Company's 
markets have become commercially proven.  Other companies may be developing 
products for one or more of  the  Company's markets that could be competitive 
with the Company's products. Nevertheless, the Company believes that its 
competitiveness has been significantly enhanced as a result of the 
consolidation of the SDI, EnSys, Ohmicron and EnviroGardTM businesses. 

    Currently, there are no similar significant competing immunoassay 
products for the Company's RapidChek-Registered Trademark- Rice Blast, 
Botrytis and SRB, GeneCheck-TM- B.t.k., industrial marker or water treatment 
polymer tests.  The Company holds U.S. patents relating to the Rice Blast and 
SRB tests and believes they will help to provide a competitive advantage in 
the event that competing products enter the market.  The Company's water 
treatment polymer tests are unique to the industry and the Company has 
secured an exclusive license for use of Biocode's patented marker technology 
with these products.  

    A number of companies already have, and are actively pursuing, products 
for the detection of Cryptosporidium  and Giardia in drinking water and it is 
likely that the Company's Hydrofluor products will face increasing 
competition in the future.  Hydrofluor currently benefits from its 
designation as the ASTM standard method for detection of these protozoa and 
from its selection by the EPA as the method for use in complying with the 
EPA's Information Collection Rule to establish the extent of contamination in 
the nation's drinking water.

    The Company's Macra-Registered Trademark- Lp(a) product competes with 
other existing immunoassay tests in the marketplace, but as a result of its 
quality performance and having been first to the research market, it  
benefits from the fact that a large quantity of clinical data has been 
generated by researchers and clinicians using the test in large prospective 
studies.  The Company is seeking to use this data to help secure 510(k) 
approval from the FDA.  The Company believes that FDA approval will further 
solidify Macra-Registered Trademark- Lp(a)'s market position.

Employees

    As of December 31, 1996, The Company employed 95 full time and 3 part 
time individuals including 81 regular and 17 contract employees.  All of the 
Company's employees have executed agreements with the Company agreeing not to 
disclose the Company's proprietary information, assigning to the Company all 
rights to inventions, and prohibiting them from competing with the 
Company during their employment.  None of the Company's employees is covered 
by collective bargaining agreements.  The Company believes that its relations 
with its employees are good.

                                      18

<PAGE>

ITEM 2.     PROPERTIES

    The Company is headquartered in Newark, Delaware, and occupies 
approximately 26,000 square feet of space under three operating leases that 
expire in October 2000, October 2001 and November 2003, respectively. The 
Company also leases approximately 21,000 square feet of space formerly leased 
by Ohmicron in Newtown, Pennsylvania. This lease expires June 30, 1998.

    Prior to the merger with SDI, EnSys leased approximately 18,000 square 
feet of space in one building in the Research Triangle Park area in North 
Carolina under a ten-year lease that expires in 1999 with a renewal option 
through 2004. Following the merger, the Company closed the North Carolina 
operation and the Company is in the process of locating a tenant to occupy 
the facility and terminating its obligation's under the lease.  The Company 
leases regional sales offices in London, England, Newport Beach, California, 
and Chestnut Hill, Massachusetts. The Company also leases warehouse space of 
1,600 square feet or less with leases that run one year or less. The Company 
believes that its equipment and facilities are adequate for its present 
purposes.

ITEM 3.  LEGAL PROCEEDINGS

    The Company is not a party to any material legal proceedings.

ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

    On December 30, 1996, EnSys held a special meeting of its stockholders to 
consider and vote upon the following proposals:

    1.   Approval and adoption of the Agreement and Plan of Merger with SDI 
and the transactions contemplated thereby.

    2.   Approval and adoption of the amendment and restatement of EnSys' 
Certificate of Incorporation to (i) change the corporate name of the 
surviving corporation, (ii) increase the number of authorized shares of  
EnSys capital stock, and (iii) reclassify the board of directors.

    3.   Approval and adoption of  amendments to the EnSys 1995 Stock 
Incentive Plan.

    All such proposals were approved by the stockholders.  The number of 
votes cast for, against or withheld, as well as the number of abstentions and 
broker non-votes as to each such matter was as follows:

<TABLE>
<CAPTION>

                      Votes For        Votes Against or Withheld        Abstentions and Broker Non-votes
                      ---------        -------------------------        --------------------------------
<S>                   <C>              <C>                              <C>
Proposal 1:           5,375,834                151,244                              263,754
Proposal 2(i):        5,363,403                186,429                              241,000
Proposal 2(ii):       4,924,903                601,075                              264,824
Proposal 2(iii):      5,030,003                489,575                              271,254
Proposal 3:           5,302,048                222,130                              266,654
</TABLE>

                                      19

<PAGE>

ITEM 4(a).    EXECUTIVE OFFICERS OF THE REGISTRANT

The executive officers of the Company, their positions with the Company and 
ages are as follows:

<TABLE>
<CAPTION>


Name                         Age       Position
- ----                         ---       ---------
<S>                          <C>       <C>
Richard C. Birkmeyer          43       President and Chief Executive Officer
Martha C. Reider              42       Vice President- Manufacturing
Anne F. Cavanaugh             37       Vice President- TSD BioServices
Arthur A. Koch, Jr.*          43       Vice President- Finance and Chief Financial Officer
Gregory J. Bell**             37       Vice President- Finance and Chief Financial Officer
James W. Stave, Ph.D.         42       Vice President- Research and Development
_______________________________________________________________________________
</TABLE>

*   Beginning on April 14, 1997
**  Resigned as of March 31, 1997

    Richard C. Birkmeyer, age 43, cofounded SDI in 1990 and has served as its 
President and Chief Executive Officer and a director since inception.  Prior 
to founding SDI, Mr. Birkmeyer was employed by E.I. du Pont de Nemours 
("DuPont") from 1983 to 1990, where he most recently served as a product 
manager.  Mr. Birkmeyer received a Ph.D. in Biochemistry/Immunology from the 
State University of New York at Binghamton and his B.S. in Biology from the 
State University of New York at Plattsburgh.  In addition, Mr. Birkmeyer 
completed post-doctoral research in immunogenetics at Iowa State University.

    Martha C. Reider, age 42, cofounded SDI in 1990 and has served as Vice 
President -- Manufacturing and Secretary since inception.  From inception to 
December 30, 1996, Ms. Reider was a director of SDI. Prior to founding SDI, 
Ms. Reider worked for DuPont from 1976 to 1990 where she most recently served 
as supervisor of Quality Control and Quality Assurance.  Ms. Reider received 
her B.A. in Biological Sciences from Ohio Northern University.

    Anne F. Cavanaugh, age 37, cofounded SDI in 1990 and has served as a Vice 
President in various capacities since its inception  and is presently 
responsible for operations of TSD BioServices, Inc..  From  inception to 
December 30, 1996, Ms. Cavanaugh was a director of SDI.  Prior to founding 
SDI, Ms. Cavanaugh was employed by Terumo Medical Corporation and the 
Rockefeller University.  Ms. Cavanaugh received her B.S. in Biochemistry from 
East Stroudsburg University and has attended the University of Delaware's MBA 
program.

    Arthur A.  Koch, Jr., age 43, joined the Company in April 1997 as Vice 
President -- Finance and Chief Financial Officer.  Prior to joining the 
Company, Mr. Koch was Vice President and Chief Financial Officer of 
Paracelsian, Inc., a publicly held biotechnology company.  From 1992 to 1995, 
Mr. Koch was Vice President and Chief Financial Officer of IBAH, Inc. a 
contract clinical research organization.  Mr. Koch received a B.A.in Business 
Administration from Temple University and is a Certified Public Accountant.

    Gregory J. Bell, age 37, joined SDI in June 1993 as Vice President 
- --Finance and Chief Financial Officer.  From 1989 to 1993, Mr. Bell served as 
Director of Finance and Administration of Enzymatics, Inc., a public company 
that developed and manufactured medical diagnostics test kits.  Prior to 
joining

                                      20

<PAGE>

Enzymatics, Mr. Bell spent more than seven years at Arthur Andersen & Co., 
where he was most recently a manager in Arthur Andersen's emerging business 
practice group.  Mr. Bell received his B.S. in Accounting from the 
Pennsylvania State University and is a Certified Public Accountant.

    James W. Stave, age 42, joined SDI in March 1991 as a research group 
leader.  Subsequently, Dr. Stave was promoted to director of Research and 
Development, in October 1993 was promoted to Vice President -- Research and 
Development.  Prior to joining SDI, Dr. Stave worked for DuPont, Molecular 
Genetics, Inc. and the U.S. Department of Agriculture.  Dr. Stave received 
his Ph.D. in Microbiology from the University of Maryland and his B.S. in 
Biology from Michigan Technological University.

    Key employees, their positions with the Company, and their ages  are as 
follows:

    Ralph E. Stever, age 51, joined SDI in August 1996 as Director of Sales. 
From January 1993 to July 1996, Mr. Stever was employed by Ohmicron where he 
most recently served as Vice President of Sales and Marketing. From 1983 to 
1993, Mr. Stever was Director of Sales of Becton Dickinson Instrument 
Systems. Mr. Stever received his B.S. degree in Marketing from Bradley 
University.

    Joseph X. Dautlick, age 54, joined SDI in January 1994 as Marketing 
Manager and now serves as Director of Marketing.  Prior to joining SDI Dr. 
Dautlick worked 17 years in DuPont's Medical Diagnostics Division as Product 
Manager, Technical Manager, Marketing Manager-Europe and Strategic Planning 
Manager.  He then joined Ohmicron as Marketing Manager for 3 years.  Dr. 
Dautlick received his Ph.D. from the University of Pittsburgh School of 
Medicine and his B.S. from Lafayette College.

    Unless otherwise noted, all executive officers and key employees 
identified above joined the Company in December 1996 after the consummation 
of the merger between EnSys and SDI.

                                      21

<PAGE>

                                      PART II

ITEM 5.    MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER 
           MATTERS

    The Company's Common Stock is traded on Nasdaq National Market System 
under the stock symbol "SDIX."  Set forth below are the high and low sales 
prices for the shares of Common Stock of the Company as reported by Nasdaq.

                                       Common Stock Price Range

    Fiscal Year Ended                       High           Low
    -------------------                   --------       --------
    December 31, 1997: 
    First Quarter                           2 1/16         1 3/4     

    December 31, 1996:
    First Quarter                           2 1/2          1
    Second Quarter                          2 1/4          1 3/8
    Third Quarter                           2 1/4          1 3/8
    Fourth Quarter                          2 3/8          1 3/8

    December 31, 1995:
    First Quarter                           3 3/8          1 5/8
    Second Quarter                          3 3/8          2 3/8
    Third Quarter                           4              2 1/4
    Fourth Quarter                          4 1/4          3 1/4

    On March 31, 1997, there were approximately 132 holders of record of the 
Common Stock of the Company.  The Company has never paid cash dividends on 
its Common Stock, and the Company has no intention to pay cash dividends in 
the foreseeable future.

    In January 1996, SDI conducted a private placement of its Series A 
Redeemable Convertible Preferred Stock pursuant to which 685,952 shares were 
issued upon conversion of $1,624,000 of aggregate principal and accrued 
interest related to previously issued convertible notes and 211,201 shares 
were issued to new investors for an aggregate of $500,000.  With respect to 
the conversion of notes into the Series A Redeemable Convertible Preferred 
Stock, SDI relied upon Section 3(a)(9) of the Securities Act of 1933, as 
amended (the "Securities Act") as an exemption from registration under the 
Securities Act.  With respect to the offering to new investors, based on the 
limited nature of the offering  and the fact that such investors consisted 
solely of accredited investors,  SDI relied upon Section 4(2) of the 
Securites Act as an exemption from registration, including Regulation D 
thereunder.

    As previously described, in March 1996 Ensys acquired certain assets of 
Millipore and in consideration therefor issued shares of EnSys common stock 
to Millipore's stockholders in addition to cash consideration.  EnSys relied 
upon Section 4(2) of the Securities Act as an exemption from registration.

                                      22
<PAGE>

ITEM  6.      SELECTED CONSOLIDATED FINANCIAL DATA


   The selected historical financial data of SDI as of December 31, 1995 and
1996 and for each of the three years in the period ended December 31, 1996 is
derived from the audited financial statements of SDI included elsewhere herein. 
The selected historical financial data as of December 31, 1992, 1993 and 1994 
and for the years ended December 31, 1992 and 1993 is derived from the 
financial statements of SDI not included herein. The following selected 
historical financial data should be read in conjunction with "Management's 
Discussion and Analysis of Financial Condition and Results of Operations" and 
the Consolidated Financial Statements and Notes thereto included elsewhere 
herein.
 
                (in thousands, except share and per share data)
 
<TABLE>
<CAPTION>
                                                                                    YEAR ENDED DECEMBER 31,
                                                                     -----------------------------------------------------
                                                                       1992       1993       1994       1995      1996(1)
                                                                     ---------  ---------  ---------  ---------  ---------
<S>                                                                  <C>        <C>        <C>        <C>        <C>
STATEMENT OF OPERATIONS DATA:
REVENUES:
  Product-related..................................................  $     137  $     551  $   1,192  $   1,605      3,402
  Contract and other...............................................      1,102      2,064      2,580      2,084      2,435
                                                                     ---------  ---------  ---------  ---------  ---------
  Total revenues...................................................      1,239      2,615      3,772      3,689      5,837
 
OPERATING EXPENSES:
  Manufacturing....................................................        208        791        910      1,288      2,839
  Acquired research and development................................         --         --         --         --      8,266
  Research and development.........................................      1,027      1,735      2,832      2,272      1,569
  Selling, general and administrative..............................        348      1,013      1,385      1,190      1,737
                                                                     ---------  ---------  ---------  ---------  ---------
  Total operating expenses.........................................      1,583      3,539      5,127      4,750     14,411
                                                                     ---------  ---------  ---------  ---------  ---------
Operating loss.....................................................       (344)      (924)    (1,355)    (1,061)    (8,574)
 
OTHER INCOME (EXPENSE):
  Interest income..................................................         10         46         20          8         11
  Interest expense.................................................        (14)       (50)        (8)      (214)        (3)
                                                                     ---------  ---------  ---------  ---------  ---------
Other income (expense), net........................................         (4)        (4)        12       (206)         8
Equity in income (loss) of TSD BioServices.........................       (150)       (60)        42         41        178
                                                                     ---------  ---------  ---------  ---------  ---------
Net loss...........................................................       (498)      (988)    (1,301)    (1,226)    (8,388)
Accretion of redeemable convertible preferred stock liquidation
 value(2)..........................................................         --       (192)      (367)      (367)      (635)
Net loss applicable to common stockholders.........................  $    (498) $  (1,180) $   1,668) $  (1,593) $  (9,023)
                                                                     ---------  ---------  ---------  ---------  ---------
                                                                     ---------  ---------  ---------  ---------  ---------
Net loss per share applicable to common stockholders...............  $    (.17) $    (.40) $    (.55) $    (.46) $   (2.12)
                                                                     ---------  ---------  ---------  ---------  ---------
                                                                     ---------  ---------  ---------  ---------  ---------
Shares used in computing net loss per share applicable to
 common stockholders...............................................  2,957,000  2,957,000  3,041,000  3,464,000  4,248,000
                                                                     ---------  ---------  ---------  ---------  ---------
                                                                     ---------  ---------  ---------  ---------  ---------
</TABLE>


<TABLE>
<CAPTION>
                                                                                DECEMBER 31
                                                    ---------------------------------------------------------
                                                      1992        1993        1994        1995        1996(1)
                                                    ---------   ---------   ---------   ---------    --------
<S>                                                 <C>         <C>         <C>         <C>          <C> 
BALANCE SHEET DATA:
Cash and cash equivalents.........................  $      93   $   1,259   $      67   $      35    $    917
Working capital (deficit).........................        (51)      1,288         126        (891)      7,170
Total assets......................................        611       3,044       2,106       2,076      14,581
Long-term debt, less current portions (including                                                             
  capital lease obligations)......................        500           0           0           0          50
Redeemable convertible preferred stock (2)........          0       3,145       3,512       3,879        --  
Accumulated deficit (3)...........................     (1,084)     (1,094)     (2,763)     (4,356)    (13,379)
Stockholders' equity (deficit)....................       (168)     (1,050)     (2,580)     (4,064)     10,673 
</TABLE>
 
- ------------------------------
 
(1) The unaudited pro forma results for the year ended December 31, 1996,
    assuming the Ensys merger, Ohmicron acquisition and the TSD dissolution had
    occurred on January 1, 1996 would have resulted in pro forma revenue of 
    $12,700,000 and a pro forma net loss of $5,973,000 or $0.47 pro forma net 
    loss per share. See Note 3 to the consolidated financial statements.
 
(2) The redeemable convertible preferred stock was reclassified into
    stockholders' equity in connection with the Ensys Merger. No additional
    accretion will be recorded on preferred stock.

(3) There have been no common stock dividends declared or paid since the 
    inception of SDI.


ITEM  7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION      
         AND RESULTS OF OPERATIONS 

Forward Looking Statements

    This Form 10-K contains certain forward looking statements reflecting the
Company's current expectations.  Investors are cautioned that all forward
looking statements involve risks and uncertainties, which may cause actual
results to differ from those anticipated at this time.  Such risks and
uncertainties include, without limitation, changes in demand for products,
delays in product development, failure to obtain necessary regulatory approvals,
modifications to development and sales relationships, the ability of the Company
to integrate acquired businesses and achieve anticipated synergies, and
competition.  

Overview

    The Company is the entity resulting from the combination of EnSys, 
Ohmicron and SDI.  On August 30, 1996, Ohmicron was merged with and into SDI, 
with certain Ohmicron stockholders and note holders receiving shares of SDI 
common stock.  On December 30, 1996, SDI was merged with and into EnSys.  The 
surviving entity was then renamed Strategic Diagnostics Inc.  Each of these 
transactions was accounted for as a purchase transaction with SDI as the 
acquiring company and, therefore, the surviving company for financial 
reporting purposes.  As a result, the historical financial information 
discussed includes the results of SDI for all periods presented and the 
actual results of Ohmicron from August 30, 1996 and EnSys from December 30, 
1996.

    EnSys was formed in 1987 to develop proprietary biotechnology based test 
systems designed for the fast and inexpensive detection of various chemicals 
in soil and water samples.  EnSys raised approximately $30 million in equity 
financing, including approximately $16 million from the sale of 1,800,000 
shares of EnSys common stock in its initial public offering in October 1993.  
Since 1991, EnSys commercialized eleven immunoassay test kits and four other 
test kits for the detection of various environmental contaminants.  EnSys 
marketed and sold these test kits and other associated products and services 
to environmental consulting and engineering firms, hazardous waste processing 
firms, environmental testing laboratories, and various state and federal 
agencies through distributors and a regionally based direct sales force in 
the U.S. EnSys also marketed and sold its products in Europe through EnSys 
(Europe) Limited, a wholly-owned subsidiary of EnSys.  In March 1996, EnSys 
acquired from Millipore certain assets, which consisted primarily of 
inventory, work-in-process, equipment, intellectual property rights, contract 
rights and customer lists related to Millipore's EnviroGard-TM- product line 
for $1,000,000 and 1,100,000 shares of EnSys common stock.

                                      23

<PAGE>

    Ohmicron was founded in 1984 and began marketing its RAPID 
Assay-Registered Trademark- products in 1991 to the same general market and 
in the same fashion as previously described for EnSys.

    Since its inception in 1990, SDI has focused on using proprietary 
technology and know-how to develop, manufacture, and market immunoassay test 
kits for applications primarily in the water quality, industrial testing and 
agricultural  markets. Commercial operations were initiated with a contract 
from the Company's first corporate partner to develop an immunoassay test to 
detect certain corrosion causing bacteria.  This product was introduced in 
late 1991 and SDI purchased all rights and technology related to this product 
in 1994.

    In February 1992, SDI entered into a $3.9 million research and 
development partnership with EM Industries for the development and 
manufacture of a line of immunoassay test kits capable of identifying and 
quantifying targeted priority pollutants.  The first products under this 
agreement were introduced in 1993. Through August 1996, these products were 
manufactured by SDI and marketed by EM Industries.  In September 1996, EM 
Industries and SDI reached an agreement whereby the February 1992 agreement 
was terminated, together with EM Industries' marketing rights thereunder, in 
exchange for certain specified royalty payments to EM Industries and shares 
of SDI common stock.  The marketing activities with respect to such products 
are now the responsibility of the Company.

    Since 1992, SDI has entered into research and development agreements with 
multiple corporate partners that have led to the introduction of various 
products to the water quality, industrial testing, agricultural and other 
markets.  These agreements generally provide that sales and marketing costs 
associated with a new product are borne by the corporate partner.  In 
addition, the Company currently sells directly other products which it has 
developed and/or acquired.

Results of Operations

    As described above, the historical financial information discussed below 
includes the results of operations of SDI for all periods presented and the 
actual results of Ohmicron from August 30, 1996 and EnSys from December 30, 
1996.

    Year ended December 31, 1996 versus year ended December 31, 1995

    Revenues. Revenues increased 58% to $5,837,000 in 1996 from $3,689,000 in 
1995.  This $2,148,000 increase is the result of a $1,797,000 (112%) increase 
in product related revenues and a $351,000 (17%) increase in contract and 
other revenues.  Product related revenues increased to $3,402,000 in 1996 
from $1,605,000 in 1995.  This was due to overall increased sales for certain 
of SDI's new products, especially the first of SDI's strip assays which was 
introduced in mid-1995, improved priority pollutant sales over the prior 
year, and product related revenues generated by TSD in the fourth quarter of 
1996 subsequent to its establishment as a wholly-owned subsidiary of SDI.  
The product revenues do not include any revenues from any of SDI's industrial 
testing kits in the fourth quarter of 1996, since SDI licensed these products 
to EnSys in October 1996.  However, they do include approximately $537,000 in 
product revenues from the sale of SDI inventory, at cost, to EnSys in 
connection with the license agreement. Product related revenues are expected 
to significantly increase in 1997 due to the mergers completed in 1996 and 
the inclusion of revenues of TSD for a full year.  Contract  and other 
revenues increased to $2,435,000 in 1996 from $2,084,000 in 1995 primarily 
due to a $300,000 license fee from EnSys and $367,000 in revenues from one-

                                      24

<PAGE>

time contracting of SDI personnel services by EnSys and Ohmicron prior to and 
in connection with the mergers, which was offset by a $200,000 decrease in 
contract revenue received from EM Industries in 1996 due to the completion of 
the EM Industries contract.  While research and development contracts are 
anticipated to continue to be integral to the Company's overall business 
strategy, the Company anticipates little or no growth in overall contract 
revenues over the short-term. 

    During 1997, a significant portion of the Company's revenues will be 
generated from the environmental remediation industry.  Historically, 
remediation activities have followed seasonal patterns with lower levels of 
activity during the period from October to March.  Therefore, the Company's 
sales in a particular quarter in 1997 may not be indicative of its revenues 
for any subsequent quarter during the year.

    Manufacturing Expenses.  Manufacturing expenses increased 120% to 
$2,839,000 in 1996 from $1,288,000 in 1995.  This $1,551,000 increase was 
primarily a result of the overall increase in product related sales during 
the year versus the prior year, and, to a lesser extent, the assumption of 
the expenses associated with the former Ohmicron manufacturing facility in 
September 1996.  Due to the anticipated post-merger increase in product 
related sales in 1997, manufacturing expenses are expected to increase 
accordingly.  The Company's overall gross profit margins on product related 
sales are anticipated to improve due to an increase in sales of its products, 
efficiencies gained through consolidation and the elimination of product 
sales at cost to EM Industries and EnSys that occurred in 1996.

    Research and Development Expenses. Research and development expenses 
decreased 31% to $1,569,000 in 1996 from $2,272,000 in 1995.  This decrease 
was primarily the result of a reduction of research and development personnel 
and certain salaries and related expenses, beginning in the third quarter of 
1995. Due to planned internal research and development activities, in 
addition to research and development activities performed under contracts for 
third parties, overall research and development expenses are anticipated to 
slightly increase in 1997.

    Acquired Research and Development Expenses.  Acquired research and 
development expenses were $8,266,000 in 1996.  These expenses were entirely 
due to the merger transactions with Ohmicron and EnSys, which resulted in 
acquired research and development expenses of $3,913,000 and $4,353,000, 
respectively.

    Selling, General and Administrative Expenses. Selling, general and 
administrative expenses increased 46% to $1,737,000 in 1996 from $1,190,000 
in 1995.  This increase was primarily due to the salaries and related 
expenses associated with the additional hiring of sales and marketing 
personnel required in connection with SDI's acquisition of Ohmicron and the 
Company's direct selling of its products, as well as additional accounting 
and administrative support personnel necessitated by the mergers and the 
overall growth of the Company.  It is anticipated that selling, general and 
administrative expenses will increase from 1996 levels during 1997 due to the 
inclusion of  a full year of the  selling expenses described above in 1997, 
as well as increased general and administrative expenses associated with the 
Company being a publicly held entity in 1997.

    Interest Income and Interest Expense.  Interest income increased $3,000 
to $11,000 in 1996 from $8,000 in 1995 due to increased cash balances from a 
January 2, 1996 preferred stock financing.  Due to cash, cash equivalents and 
marketable securities received in connection with the EnSys/SDI merger, 
overall interest income is expected to significantly increase in 1997.  
Interest expense decreased to $3,000 in 1996 

                                      25

<PAGE>

from $214,000 in 1995 primarily due to the conversion of $1,500,000 in notes 
payable and related interest to preferred stock in connection with a January 
1996 financing.  Due to interest expense on capital lease obligations assumed 
in connection with the 1996 mergers, overall interest expense is expected to 
increase nominally in 1997.

    Equity in Income of TSD BioServices.  Equity in income of  the TSD 
BioServices partnership increased $137,000 to $178,000 in 1996 from $41,000 
in 1995.  This increase was primarily due to a significant increase in 
revenues for the partnership during 1996 versus the prior year.  In October 
1996, the TSD BioServices partnership was dissolved and its assets were 
liquidated, in connection with which certain of the rights and assets of the 
TSD BioServices partnership were distributed to TSD BioServices, Inc., a 
newly-formed, wholly-owned subsidiary of SDI.  As a result of the dissolution 
and the related distribution of certain of the partnership's rights and 
assets, revenues earned and expenses incurred after September 30, 1996 
associated with the rights  and assets so distributed were included in the 
revenues and expenses of SDI through TSD BioServices, Inc.

    Provision for Income Taxes. Due to net operating loss carry forwards, the 
Company has made no provision for income taxes for 1996.  Although net 
operating loss carry forwards were obtained in connection with the mergers 
discussed above, the use of these carry forwards, if any, will be limited in 
future years pursuant to the "change in ownership" rules under Section 382 of 
the Internal Revenue Code.

Year ended December 31, 1995 versus year ended December 31, 1994

    Revenues.  Products related revenues increased $413,000 (35%) to 
$1,605,000 in 1995 from $1,192,000 in 1994.  This increase was primarily due 
to the introduction of four new products during the year, increased sales of 
commercial cell lines to third parties and increased royalties from EM 
Industries. Contract and other revenues decreased $496,000 (19%) to 
$2,084,000 in 1995 from $2,580,000 in 1994 due to a reduction of contract 
funding by EM Industries to $600,000 in 1995 from $1,709,000 in 1994.  
Despite the reduction in funding from EM Industries during the year, overall 
revenues decreased by only $83,000 (2%) to $3,689,000 in 1995 from $3,772,000 
in 1994 due to an overall increase in product related revenues and existing 
or new research contract programs outside of the EM Industries agreement.

    Manufacturing Expenses.  Manufacturing expenses increased 42%, to 
$1,288,000 in 1995 from $910,000 in 1994.  This increase was primarily the 
result of an increase in overall product sales, especially the EM Industries 
product line, and the cost associated with new product introductions.  Under 
SDI's agreement with EM Industries, SDI's sales of product to EM Industries 
generally provided no profit margin in 1995, except for royalties.

    Research and Development Expenses. Research and development expenses 
decreased 20%, to $2,272,000 in 1995 from $2,832,000 in 1994.  This decrease 
was primarily the result of a reduction of research and development personnel 
and certain salaries in the third quarter of 1995, coupled with decreased 
field trial, consulting and other research and development expenses as 
products previously under development were completed and transferred to 
manufacturing.

    Selling, General and Administrative Expenses.  Selling, general and 
administrative expenses decreased 14%, to $1,190,000 in 1995 from $1,385,000 
in 1994 primarily due to a reduction in selling, general and administrative 
personnel and certain salaries in the third quarter of 1995.

                                      26

<PAGE>

    Interest Income and Interest Expense.  Interest income decreased 60% to 
$8,000 in 1995 from $20,000 in 1994.  This decrease was primarily the result 
of less funds available during the year due to utilization of available cash 
and cash equivalents for operating needs.  Interest expense increased to 
$214,000 in 1995 from $8,000 in 1994 primarily due to interest on bridge 
loans from stockholders and interest expense imputed on certain warrants 
issued in connection with the bridge loans.

Liquidity and Capital Resources

    The Company's working capital, which consists principally of cash, cash 
equivalents and marketable debt investments was $7,170,000 at December 31, 
1996 versus a working capital deficit $891,000 at December 31, 1995.  This 
increase was due to the SDI/EnSys merger on December 30, 1996 and the 
conversion of notes payable held by SDI stockholders to SDI preferred stock 
on January 2, 1996. Cash, cash equivalents and marketable debt investments, 
which consist primarily of money market instruments, U.S. corporate 
obligations and other securities of agencies of the U.S. government were 
$6,627,000 at December 31, 1996 versus $35,000 at December 31, 1995 due to 
the SDI/EnSys merger.  The Company considers all of its investments to be 
available-for-sale and plans to use the proceeds from sales or maturities of 
these investments to finance future operating needs. The Company's investment 
policy is to limit exposure at any one institution.

    Accounts receivable and inventory balances increased in 1996 over 1995 
due to the mergers occurring in 1996.  The Company incurred a net loss in 
1996 of $122,000 (after exclusion of $8,266,000 in charges for acquired 
research and development incurred in connection with the mergers) versus a 
net loss of $1,226,000 during 1995.  This large decrease in the net loss is 
attributable to additional product related revenues generated in 1996 over 
1995 and to cost reduction efforts begun in late 1995.  The Company used 
$370,000 in cash to fund operations in 1996 versus $1,017,000 in 1995 and 
purchased $67,000 in property and equipment during 1996.

    The Company believes that its current cash, cash equivalents and 
marketable debt investments will be sufficient to meet its funding needs for 
at least the next 18 months.  However, the Company's ability to meet its 
long-term working capital and capital expenditure requirements will depend on 
a number of factors, including the success of the Company's current and 
future products, the focus and direction of the Company's research and 
development programs, competitive and technological advances, future 
relationships with corporate partners, government regulation and the 
Company's marketing and distribution strategy. Accordingly, there can be no 
assurance that the Company will be able to meet these long-term requirements. 

                                      27

<PAGE>

ITEM     8.   FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA 


    The following consolidated financial statements of the Company and its 
subsidiaries are included as part of this Form 10-K:
                                                                          Page

Report of Independent Public Accountants                                   F-1

Consolidated Balance Sheets as of December 31, 1996 and 1995               F-2

Consolidated Statements of Operations for each of the years
    in the three year period ended December 31, 1996                       F-3  

Consolidated Statements of Stockholders' Equity (Deficit) for each
    of the years in the three year period ended December 31, 1996          F-4

Consolidated Statements of Cash Flows for each of the years
    in the three year period ended December 31, 1996                       F-5

Notes to Consolidated Financial Statements                                 F-6

                                      28



<PAGE>
                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS
 
    To Strategic Diagnostics Inc.:
 
    We have audited the accompanying consolidated balance sheets of Strategic
Diagnostics Inc. (a Delaware corporation) and subsidiaries as of December 31,
1996 and 1995, and the related consolidated statements of operations,
stockholders' equity (deficit) and cash flows for each of the three years in
the period ended December 31, 1996. These financial statements are the
responsibility of the Company's management. Our responsibility is to express
an opinion on these financial statements based on our audits.
 
    We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of
material misstatement. An audit includes examining, on a test basis, evidence
supporting the amounts and disclosures in the financial statements. An audit
also includes assessing the accounting principles used and significant
estimates made by management, as well as evaluating the overall financial
statement presentation.  We believe that our audits provide a reasonable
basis for our opinion.
 
    In our opinion, the financial statements referred to above present fairly,
in all material respects, the financial position of Strategic Diagnostics Inc.
and subsidiaries as of December 31, 1996 and 1995, and the results of their
operations and their cash flows for each of the three years in the period ended
December 31, 1996, in conformity with generally accepted accounting principles.
 



                                       ARTHUR ANDERSEN LLP

Philadelphia, Pa.,
  March 31, 1997
 
                                       F-1
<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
                          CONSOLIDATED BALANCE SHEETS
                       (in thousands, except share data)
 
<TABLE>
<CAPTION>
                                                                                                     DECEMBER 31,
                                                                                                 --------------------
                                                                                                   1996       1995
                                                                                                 ---------  ---------
<S>                                                                                              <C>        <C>
                                            ASSETS
CURRENT ASSETS:
  Cash and cash equivalents                                                                      $     917  $      35
  Short-term investments                                                                             5,710         --
  Receivables                                                                                        2,334        560
  Inventories                                                                                        1,557        447
  Other current assets                                                                                 510        328
                                                                                                 ---------  ---------
      Total current assets                                                                          11,028      1,370
                                                                                                 ---------  ---------
PROPERTY AND EQUIPMENT:
  Equipment                                                                                          1,002        530
  Furniture and fixtures                                                                                66         24
  Leasehold improvements                                                                               198         29
                                                                                                 ---------  ---------
                                                                                                     1,266        583
  Less- Accumulated depreciation and amortization                                                     (538)      (334)
                                                                                                 ---------  ---------
      Net property and equipment                                                                       728        249
                                                                                                 ---------  ---------
OTHER ASSETS:
  Restricted cash                                                                                      119         49
  Prepaid rent                                                                                         171         68
  Note receivable                                                                                      341         --
  Deposits and other                                                                                    84        180
  Investment in TSD BioServices                                                                         --        160
  Intangible assets                                                                                  2,110         --
                                                                                                 ---------  ---------
      Total other assets                                                                             2,825        457
                                                                                                 ---------  ---------
                                                                                                 $  14,581  $   2,076
                                                                                                 ---------  ---------
                                                                                                 ---------  ---------
                        LIABILITIES AND STOCKHOLDERS' EQUITY (DEFICIT)
CURRENT LIABILITIES:
  Accounts payable                                                                               $   1,566  $     222
  Accrued expenses                                                                                   2,066        328
  Deferred revenue                                                                                     141        211
  Current portion of capital lease obligations                                                          85         --
  Notes payable                                                                                         --      1,500
                                                                                                 ---------  ---------
      Total current liabilities                                                                      3,858      2,261
                                                                                                 ---------  ---------
CAPITAL LEASE OBLIGATIONS                                                                               50         --
                                                                                                 ---------  ---------
REDEEMABLE CONVERTIBLE PREFERRED STOCK                                                                  --      3,879
                                                                                                 ---------  ---------
COMMITMENTS AND CONTINGENCIES (NOTE 14)
STOCKHOLDERS' EQUITY (DEFICIT):
  Preferred stock, $.01 par value, 17,500,000 shares authorized, no shares issued and
    outstanding                                                                                         --         --
  Series A preferred stock, $.01 par value, 2,164,362 shares authorized, issued and outstanding         22         --
  Common stock, $.01 par value, 35,000,000 and 5,913,638 shares authorized, 13,055,170 and
    3,463,702 issued and outstanding in 1996 and 1995, respectively                                    131         47
  Additional paid-in capital                                                                        23,905        294
  Accumulated deficit                                                                              (13,379)    (4,356)
  Deferred compensation                                                                                 (6)       (49)
                                                                                                 ---------  ---------
      Total stockholders' equity (deficit)                                                          10,673     (4,064)
                                                                                                 ---------  ---------
                                                                                                 $  14,581  $   2,076
                                                                                                 ---------  ---------
                                                                                                 ---------  ---------
</TABLE>
        The accompanying notes are an integral part of these statements.
 
                                       F-2
<PAGE>
                           STRATEGIC DIAGNOSTICS INC.
 
                                AND SUBSIDIARIES
 
                     CONSOLIDATED STATEMENTS OF OPERATIONS
 
                (in thousands, except share and per share data)
 
<TABLE>
<CAPTION>
                                                                                  YEAR ENDED DECEMBER 31,
                                                                          ----------------------------------------
                                                                              1996          1995          1994
                                                                          ------------  ------------  ------------
<S>                                                                       <C>           <C>           <C>
NET REVENUES:
  Product related                                                         $      3,402  $      1,605  $      1,192
  Contract and other                                                             2,435         2,084         2,580
                                                                          ------------  ------------  ------------
      Total net revenues                                                         5,837         3,689         3,772
                                                                          ------------  ------------  ------------
OPERATING EXPENSES:
  Manufacturing                                                                  2,839         1,288           910
  Research and development                                                       1,569         2,272         2,832
  Acquired research and development                                              8,266            --            --
  Selling, general and administrative                                            1,737         1,190         1,385
                                                                          ------------  ------------  ------------
      Total operating expenses                                                  14,411         4,750         5,127
                                                                          ------------  ------------  ------------
      Operating loss                                                            (8,574)       (1,061)       (1,355)
INTEREST (EXPENSE) INCOME, net                                                       8          (206)           12

EQUITY IN INCOME OF TSD BIOSERVICES                                                178            41            42
                                                                          ------------  ------------  ------------
NET LOSS                                                                        (8,388)       (1,226)       (1,301)
ACCRETION OF REDEEMABLE CONVERTIBLE PREFERRED STOCK LIQUIDATION VALUE             (635)         (367)         (367)
                                                                          ------------  ------------  ------------
NET LOSS APPLICABLE TO COMMON STOCKHOLDERS                                $     (9,023) $     (1,593) $     (1,668)
                                                                          ------------  ------------  ------------
                                                                          ------------  ------------  ------------
NET LOSS PER SHARE APPLICABLE TO COMMON STOCKHOLDERS                      $      (2.12) $      (0.46) $      (0.55)
                                                                          ------------  ------------  ------------
                                                                          ------------  ------------  ------------
SHARES USED IN COMPUTING NET LOSS PER SHARE APPLICABLE TO COMMON
  STOCKHOLDERS                                                               4,248,000     3,464,000     3,041,000
                                                                          ------------  ------------  ------------
                                                                          ------------  ------------  ------------
</TABLE>
 
        The accompanying notes are an integral part of these statements.
 
                                      F-3


<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT)
                                 (in thousands)

<TABLE>
<CAPTION>
                                                                SERIES A                ADDITIONAL
                                                     PREFERRED  PREFERRED    COMMON       PAID-IN    ACCUMULATED      DEFERRED
                                                       STOCK      STOCK       STOCK       CAPITAL      DEFICIT      COMPENSATION
                                                     ---------  ---------  -----------  -----------  ------------  ---------------
<S>                                                  <C>        <C>        <C>          <C>          <C>           <C>
BALANCE, JANUARY 1, 1994                             $      --  $      --   $      40    $      43    $   (1,095)     $     (38)
Exercise of warrants                                        --         --           7           (7)           --             --
Issuance of warrants in connection with debt                --         --          --           23            --             --
Amortization of deferred compensation                       --         --          --           --            --             10
Issuance of warrant to Conoco                               --         --          --          105            --             --
Accretion of redeemable convertible preferred stock         --
  liquidation value                                                    --          --           --          (367)            --
Net loss                                                    --         --          --           --        (1,301)            --
                                                     ---------  ---------       -----   -----------  ------------           ---
BALANCE, DECEMBER 31, 1994                                  --         --          47          164        (2,763)           (28)
Issuance of warrants in connection with debt                --         --          --           75            --             --
Amortization of deferred compensation                       --         --          --           --            --             34
Issuance of common stock options                            --         --          --           55            --            (55)
Accretion of redeemable convertible preferred stock         --
  liquidation value                                                    --          --           --          (367)            --
Net loss                                                    --         --          --           --        (1,226)            --
                                                     ---------  ---------       -----   -----------  ------------           ---
BALANCE, DECEMBER 31, 1995                                  --         --          47          294        (4,356)           (49)
Amortization of deferred compensation                       --         --          --           --            --             43
Accretion of redeemable convertible preferred stock         --
  liquidation value                                                    --          --           --          (635)            --
Acquisition of Ohmicron Corporation                         --         --          31        4,017            --             --
Acquisition of EnSys Environmental Products, Inc.           --         --          53       13,006            --             --
Conversion of redeemable convertible preferred to           --
  Series A preferred stock                                             22          --        6,588            --             --
Net loss                                                    --         --          --           --        (8,388)            --
                                                     ---------  ---------       -----   -----------  ------------           ---
BALANCE, DECEMBER 31, 1996                           $      --  $      22   $     131    $  23,905    $  (13,379)     $      (6)
 
<CAPTION>
 
                                                       TOTAL
                                                     ---------
<S>                                                  <C>
BALANCE, JANUARY 1, 1994                             $  (1,050)
Exercise of warrants                                        --
Issuance of warrants in connection with debt                23
Amortization of deferred compensation                       10
Issuance of warrant to Conoco                              105
Accretion of redeemable convertible preferred stock
  liquidation value                                       (367)
Net loss                                                (1,301)
                                                     ---------
BALANCE, DECEMBER 31, 1994                              (2,580)
Issuance of warrants in connection with debt                75
Amortization of deferred compensation                       34
Issuance of common stock options                            --
Accretion of redeemable convertible preferred stock
  liquidation value                                       (367)
Net loss                                                (1,226)
                                                     ---------
BALANCE, DECEMBER 31, 1995                              (4,064)
Amortization of deferred compensation                       43
Accretion of redeemable convertible preferred stock
  liquidation value                                       (635)
Acquisition of Ohmicron Corporation                      4,048
Acquisition of EnSys Environmental Products, Inc.       13,059
Conversion of redeemable convertible preferred to
  Series A preferred stock                               6,610
Net loss                                                (8,388)
                                                     ---------
BALANCE, DECEMBER 31, 1996                           $  10,673
</TABLE>
 
        The accompanying notes are an integral part of these statements.
 
                                      F-4
<PAGE>
                           STRATEGIC DIAGNOSTICS INC.
 
                                AND SUBSIDIARIES
 
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (in thousands)
 
<TABLE>
<CAPTION>
                                                                                         YEAR ENDED DECEMBER 31,
                                                                                     -------------------------------
                                                                                       1996       1995       1994
                                                                                     ---------  ---------  ---------
<S>                                                                                  <C>        <C>        <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net loss                                                                           $  (8,388) $  (1,226) $  (1,301)
  Adjustments to reconcile net loss to cash used in operating activities-
  Acquired research and development write off                                            8,266         --         --
  Issuance of warrant to Conoco                                                             --         --        105
    Depreciation and amortization                                                          181        135        100
    Equity in income of investment in TSD BioServices                                     (178)       (41)       (42)
    Amortization of deferred compensation                                                   43         34         10
    Imputed interest on note payable                                                        --         75         23
    (Increase) decrease in-
      Receivables                                                                         (753)         1         40
      Inventories                                                                          208        (70)       (87)
      Other current assets                                                                (696)        33       (104)
      Prepaid rent                                                                        (103)        21         23
      Other assets                                                                         159        (66)       (81)
    Increase (decrease) in-
      Accounts payable                                                                     472       (262)       253
      Accrued expenses                                                                     589        138        (28)
      Deferred revenue                                                                    (170)       211         --
                                                                                     ---------  ---------  ---------
      Net cash used in operating activities                                               (370)    (1,017)    (1,089)
                                                                                     ---------  ---------  ---------
CASH FLOWS FROM INVESTING ACTIVITIES:
  Restricted cash                                                                           56         26         --
  Investment in TSD BioServices                                                             --         --        (30)
  Proceeds from Ohmicron and EnSys acquisitions                                            807         --         --
  Purchases of property and equipment                                                      (67)       (41)       (73)
                                                                                     ---------  ---------  ---------
      Net cash provided by (used in) investing activities                                  796        (15)      (103)
                                                                                     ---------  ---------  ---------
CASH FLOWS FROM FINANCING ACTIVITIES:
  Proceeds from note payable                                                                --      1,000        500
  Payment on note payable                                                                   --         --       (500)
  Repayments on capital lease obligations                                                  (17)        --         --
  Proceeds from sale of redeemable convertible preferred stock, net                        473         --         --
      Net cash provided by financing activities                                            456      1,000         --
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                                       882        (32)    (1,192)
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR                                                35         67      1,259
                                                                                     ---------  ---------  ---------
CASH AND CASH EQUIVALENTS, END OF YEAR                                               $     917  $      35  $      67
                                                                                     ---------  ---------  ---------
                                                                                     ---------  ---------  ---------
SUPPLEMENTAL CASH FLOW DISCLOSURE:
  Cash paid for interest                                                             $       3  $      --  $      53
                                                                                     ---------  ---------  ---------
                                                                                     ---------  ---------  ---------
</TABLE>
 
        The accompanying notes are an integral part of these statements.
 
                                       F-5

<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
           
                  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)
 
1. BACKGROUND:
   -----------
 
Business
- --------
Strategic Diagnostics Inc. (the "Company") develops, manufactures and
markets immunoassay based test kits for rapid and inexpensive detection of a
wide variety of substances in the water quality, industrial and agricultural
market segments.
 
Business Risks
- --------------
The Company is subject to risks of entities in similar stages of
development. These risks include the Company's ability to successfully develop,
produce and market its products and its dependence on its key collaborative
partners and management personnel. Management believes that its current cash
resources are sufficient to fund operations into 1998.
 
Basis of Presentation
- ---------------------
The historical financial statements presented herein include the
consolidated financial statements of Strategic Diagnostics Inc. ("SDI") for all
periods and the actual results of Ohmicron Corporation ("Ohmicron") from August
30, 1996 (Note 3) and EnSys Environmental Products, Inc. ("EnSys") from
December 30, 1996 (Note 3). As used herein, unless the context requires
otherwise, the Company collectively refers to SDI and its subsidiaries for
the periods indicated. All intercompany balances and transactions have been
eliminated in consolidation.
 
Use of Estimates
- ----------------
The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affect the reported amount of assets and liabilities and
disclosure of contingent assets and liabilities at the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting period. Actual results could differ from those estimates.
 
2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES:
   -------------------------------------------
Net Loss Applicable to Common Stockholders
- ------------------------------------------
Net loss per share applicable to common stockholders for all periods 
presented is calculated by dividing net loss applicable to common 
stockholders by the weighted average number of shares outstanding. All shares 
and per share amounts have been adjusted retroactively to give effect to the 
equivalent number of shares received by the SDI stockholders in the Easys 
Merger discussed in Note 3.  This retroactive adjustment is reflected in the 
net loss per share calculations and the Notes to the Consolidated Financial 
Statements.
 
                                       F-6


<PAGE>

                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
     
                  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)
 
Net loss applicable to common stockholders is the sum of the net loss plus
the accretion of the redeemable convertible preferred stock liquidation value.
Effective December 30, 1996, the redeemable convertible preferred stock was
converted into shares of a newly issued class of Series A Preferred Stock
(Note 9). No additional accretion will be recorded.

Statement of Cash Flows
- -----------------------
The Company considers all highly liquid instruments purchased with an
original maturity of three months or less to be cash equivalents.
 
Accounts Receivable
- -------------------
The Company classifies both its billed and unbilled receivables as accounts
receivable. As of December 31, 1996 and 1995, the allowance for doubtful
accounts was $180 and $11, respectively. In 1996, 1995 and 1994, approximately
$2, $10 and $3 of write-offs were charged to this allowance which was offset by
approximately $81, $9 and $4 charged to earnings in each of the respective
years. At December 31, accounts receivable consisted of the following:
 
<TABLE>
<CAPTION>
                                                1996       1995
                                              ---------  ---------
          <S>                                 <C>        <C>
          Accounts receivable                 $   1,739  $     560
          Unbilled accounts receivable              595        --
                                              ---------  ---------
                                              $   2,334  $     560
                                              ---------  ---------
                                              ---------  ---------
</TABLE>


If receivables become uncollectible or unbillable, the Company's policy is
to charge these write-offs against the allowance. The Company continually
reviews the realizability of its receivables and charges current period 
earnings for the amount deemed unrealizable.
 
Inventories
- ----------- 
The Company's inventories, which consist primarily of test kit components
and accessories, are valued at the lower of cost or market. Cost is determined
using standard costs which approximate average cost. Realization of the
Company's inventories is dependent upon the successful marketing of its
products. At December 31, inventories consisted of the following:
 
<TABLE>
<CAPTION>
                                                            1996       1995
                                                          ---------  ---------
     <S>                                                  <C>        <C>
     Raw materials                                        $     626  $     383
     Work in progress                                           356         46
     Finished goods                                             575         18
                                                           ---------  ---------
                                                          $   1,557  $     447
                                                           ---------  ---------
                                                           ---------  ---------
</TABLE>
 
                                      F-7


<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
                  
                  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                  
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)
 
LONG-LIVED ASSETS
- ----------------- 
In March 1995, the Financial Accounting Standards Board ("FASB") issued SFAS
No. 121, "Accounting for the Impairment of Long-Lived Assets and for Long-Lived
Assets to be Disposed Of," which requires impairment losses to be recorded on
long-lived assets used in operations when indicators of impairment are present.
SFAS No. 121 also addresses accounting for long-lived assets where disposal is
expected. Management continually evaluates whether events or circumstances have
occurred that indicate that the remaining useful lives of the fixed assets and
other assets should be revised or that the remaining balance of such assets may
not be recoverable based upon expectations of future undiscounted cash flows in
accordance with SFAS No. 121. The Company adopted SFAS No. 121 effective
January 1, 1996. As of December 31, 1996, management believes no write-downs or
reserves are required.
 
Property and Equipment
- ---------------------- 
Property and equipment are stated at cost. Depreciation and amortization is
computed using the straight-line method over the estimated useful lives
(generally three to five years) of the assets.
 
Revenue Recognition
- ------------------- 
Product related revenues are recognized upon product shipment or based upon
management's estimate of the percentage of the project completed (Note 12).
Revenue recognized under the Company's collaborative agreements is recorded
upon completion of certain performance requirements of the contracts. License
revenue is recognized upon transfer of such licenses.
 
Research and Development
- ------------------------
Research and development costs are charged to expense as incurred.
 
Fair Value of Financial Instruments
- ----------------------------------- 
The Company's financial instruments consist primarily of cash and cash
equivalents, short-term investments, accounts payable, accrued expenses and
capital lease obligations. The book values of cash and cash equivalents,
short-term investments, accounts receivable, accounts payable and accrued
expenses are considered to approximate their respective fair values. None of
the Company's capital lease obligations that are outstanding as of December
31, 1996 have readily ascertainable market values; however, the carrying values
are considered to approximate their respective fair values.
  


                                       F-8
<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
                  
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)
 
Income Taxes
- ------------
As of December 31, 1996, the Company had a federal net operating loss
carryforward of approximately $2,722, which will begin to expire in the year
2009 if not previously used. The net operating loss carryforwards differ from
the accumulated deficit principally due to differences in the recognition of
certain research and development expenses, depreciation and amortization, other
non-deductible reserves and the accretion of preferred stock for financial and
federal income tax reporting.

Significant components of SDI's deferred tax assets for federal and state
tax purposes as of December 31 are as follows:
 
<TABLE>
<CAPTION>
                                                      1996       1995
                                                    ---------  ---------
     <S>                                             <C>        <C>
     Net operating loss carryforwards               $     925  $     969
     Other non-deductible reserves                         95         --
     Depreciation and amortization                        (46)       (36)
                                                    ---------  ---------
     Total deferred tax assets                            974        933
     Valuation allowance for deferred tax assets         (974)      (933)
                                                    ---------  ---------
     Net deferred tax assets                        $      --  $      --
                                                    ---------  ---------
                                                    ---------  ---------
</TABLE>
 
In connection with the merger with EnSys and the Ohmicron acquisition (Note
3), the Company acquired certain net operating losses. The amounts of such
losses were approximately $22,180 at September 30, 1995 and $15,155 as of
December 31, 1995, respectively. The amount of net operating loss carryforwards
(including those of SDI) which can be utilized in any one period, if any, will
be limited by federal income tax regulations since a cumulative change in
ownership of more than 50% has occurred within a three year period. The
Company has recorded a 100% valuation allowance on such items, as determined.
 
Reclassification
- ----------------
Certain reclassifications have been made to the prior year financial
statements to conform to current year financial statement presentation.

                                 F-9


<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
                
                  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                  
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)

3. MERGERS AND ACQUISITIONS
   ------------------------

Merger with EnSys Environmental Products, Inc.
- ---------------------------------------------- 
On December 30, 1996, the Company merged with and into EnSys Environmental
Products, Inc. (the "Merger"). The Merger agreement provided that SDI common
and preferred stockholders receive .7392048 shares of EnSys stock for each
share of SDI Common or Preferred Stock. This resulted in the former SDI
stockholders owning 5,780,136 shares of EnSys Common Stock and 2,164,362
shares of EnSys Series A Convertible Preferred Stock or approximately 52%
of the 15,219,532 voting shares outstanding after the Merger. In addition
to the common and preferred stock noted above, current SDI option and warrant
holders received options and warrants to purchase .7818026 shares of EnSys
Common Stock for each option or warrant held. Upon consummation of the Merger,
SDI option and warrant holders received options and warrants for the purchase
of 383,216 and 599,644 shares, respectively, of EnSys Common Stock. The
difference in exchange ratios between stockholders and option and warrant
holders is due to the stock preferences received by SDI's preferred
stockholders upon exchange of their shares. The cost of receiving these
preferences was shared by all SDI stockholders upon exchange of their shares,
but was not borne by the SDI option and warrant holders.
 
The Merger was accounted for as a purchase transaction with SDI as the
acquiring company. Based on the $1.75 per share closing price of EnSys Common
Stock on October 14, 1996, (date of transaction public announcement) the
estimated total purchase price of EnSys was $16,133, which consists of the
following: (i) the $12,731 market value of the outstanding shares of EnSys
Common Stock (7,275,034 shares multiplied by $1.75 per share), (ii) the $328
fair value of the outstanding options and warrants to purchase EnSys Common
Stock and (iii) estimated transaction costs of approximately $3,074. Since SDI
is the acquirer for accounting purposes, the EnSys options and warrants are
required to be valued for purchase accounting purposes as if they are
additional consideration in the transaction. The valuation for EnSys options
and warrants was provided by an investment banking firm using a traditional
valuation approach. Of the approximately $3,074 of estimated transaction costs,
approximately $457 relates to severance payments to former EnSys employees,
$362 to facility termination and moving and $36 to employee relocation. In
connection with the Merger, approximately 35 EnSys employees were terminated in
December 1996.
 
In connection with the Merger, all identifiable assets acquired by SDI
including intangible assets were assigned a portion of the cost of the acquired
company based on an independent valuation of EnSys' assets. Such allocation
included the identification and evaluation of each development project to
determine if technological feasibility had been achieved and if there were any
alternative future uses. EnSys' primary research and development focus, the 

                                    F-10


<PAGE>

                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
                
                  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                  
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)


"One Step" assay, is currently under development. If such technology is not 
fully developed on a timely basis, the existing products may not be 
competitive enough to satisfy the technical requirements of a changing market 
or be cost effective despite demonstration of research prototypes by EnSys.  
The costs of developing the remaining technology for the "One Step" assay is 
significant. As a result of the substantial time and effort to produce the 
product in accordance with all functions and specification, it has been 
determined that technological feasibility has not been achieved. In 
addition,since alternative uses of this developmental technology do not 
exist, the costs of such technology has been charged to expense in accordance 
with SFAS No. 2.  Based on the foregoing purchase price, the amount allocated 
to acquired research and development of $4,353 was charged to the statement 
of operations at the effective date of the Merger. The remaining amount of 
intangible assets of approximately $1,167 includes approximately $472 for 
developed technology, $55 for assembled workforce and $640 for goodwill. The 
intangible assets purchased will be amortized on a straight-line basis over 
7-10 years.
 
Acquisition of Ohmicron Corporation
- -----------------------------------
On August 30, 1996, SDI acquired Ohmicron and certain of its wholly owned 
subsidiaries for 2,268,456 shares of common stock. Prior to the acquisition, 
Ohmicron spun-off certain assets and liabilities of another of its 
wholly-owned subsidiaries, Ohmicron Medical Diagnostics, Inc. The acquisition 
of Ohmicron was recorded as a purchase transaction accounting using the fair 
market value of the SDI common stock issued to Ohmicron. The total purchase 
price of approximately $4,503, including transaction and other costs of $533, 
has been allocated to the fair market value of the assets acquired and 
liabilities assumed. Based on the foregoing estimated purchase price, the 
amount allocated to acquired research and development of $3,913 was charged 
to the statement of operations at the time of the acquisition. In connection 
with the Ohmicron transaction, all identifiable assets acquired including 
intangible assets were assigned a portion of the cost of the acquired company 
based on an independent valuation of Ohmicron's assets. Such allocation 
included the evaluation of each development project identified to determine 
if technological feasibility had been achieved and if there were any 
alternative future uses. Based on this analysis, it has been determined that 
technological feasibility has not been achieved, and that alternative uses of 
this developmental technology do not exist.  The cost of such technology has 
therefore been charged to expense in accordance with SFAS No. 2, "Accounting 
for Research and Development Costs."  The remaining amount of intangible 
assets of approximately $590 included approximately $384 for developed 
technology, $103 for assembled workforce and $103 for goodwill. The 
intangible assets purchased will be amortized on a straight-line basis over 
7-10 years. The fair market value of the common stock issued to Ohmicron was 
based on several factors including recent equity transactions, as well as the 
subsequently negotiated merger with EnSys. Recent equity transactions 
included the January 2, 1996 sale of 897,154 shares of redeemable convertible 
preferred stock at $2.37 per share.
 
                                       F-11


<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)


The redeemable convertible preferred stock was mandatorily redeemable and
received dividends, registration rights and senior liquidation rights to the
common stock. The common stock was valued at $1.75 per share reflecting a
discount from the redeemable convertible preferred stock due to the difference
in preferences between the two classes of stock.
 
TSD BioServices Dissolution
- ---------------------------
In October 1996, SDI entered into an agreement with Taconic Farms, Inc. 
("Taconic") to dissolve TSD BioServices, a partnership between Taconic and 
SDI and to liquidate its assets, in connection with which certain of the 
rights and assets were distributed to SDI. Upon dissolution, certain rights 
and assets formerly owned by the joint venture were placed in a wholly-owned 
subsidiary of SDI. The agreement to dissolve TSD BioServices provides that 
each of the former partners receive rights to perform services that were 
considered to be either a core part of that partner's expertise, or an area 
in which the partner wanted to increase its market presence or technical 
competency. The dissolution agreement also provided that certain services 
previously provided by TSD BioServices, such as ascites production and sales 
and marketing, would be subcontracted to Taconic by SDI in the future based 
on established fees set annually.  For accounting purposes, this transaction 
will be treated as a purchase, with the consideration provided being SDI's 
investment of $338 which approximates the fair market value of the assets 
received.
 
                                       F-12


<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                               DECEMBER 31, 1996
                  (in thousands, except share and per share data)

Unaudited ProForma Combined Results of Operations
- -------------------------------------------------
The following table summarizes the unaudited pro forma combined results of
operations for the years ended December 31, 1996 and 1995, assuming that the
Merger, the Ohmicron acquisition and the TSD dissolution had occurred on
January 1, 1996:

<TABLE>
<CAPTION>
                                            YEAR ENDED DECEMBER 31,
                                            -----------------------
                                              <C>        <C>
                                                1996       1995
                                             ---------  ---------
                                                  (unaudited)
<S>                                           <C>        <C>
Revenues                                     $  12,700  $  11,184
                                             ---------  ---------
                                             ---------  ---------
Net loss                                     $  (5,973) $  (7,721)
                                             ---------  ---------
                                             ---------  ---------
Net loss per share                           $   (0.47) $   (0.66)
                                             ---------  ---------
                                             ---------  ---------
</TABLE>
 
The above pro forma information excludes the $8,266 one-time charge to 
earnings for acquired research and development. The shares used in computing 
pro forma net loss per common share assumes that the Merger with EnSys, the 
acquisition of Ohmicron and the TSD BioServices dissolution had occurred on 
January 1, 1996.  In addition the pro forma information excludes accretion of 
preferred stock (Note 2).
 
Supplemental Disclosure of Cash Flow Information
- ------------------------------------------------ 
The following table displays the net non cash assets that were acquired
during 1996 as a result of the Merger and the Ohmicron acquisition:
 
<TABLE>
           <S>                                                    <C>
           Non cash (assets) liabilities:
               Short term investments                              $  (5,710)
               Receivables                                              (808)
               Inventories                                            (1,318)
               Property and equipment                                   (443)
               Restricted cash                                          (126)
               Note receivable                                          (357)
               Intangibles                                            (2,135)
               Accounts payable                                        1,483
               Accrued expenses including acquisition costs            1,128
               Deferred revenue                                          100
               Capital lease obligations                                 152
                                                                     ---------
(                                                                      (8,034)
               Issuance of common stock                               17,107
               Acquired research and development                      (8,266)
                                                                     ---------
           Net cash acquired in business acquisitions              $     807
                                                                     ---------
                                                                     ---------
</TABLE>
  
                                     F-13


<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)
 
4. SHORT-TERM INVESTMENTS:
   ----------------------- 
At December 31, 1996, short-term investments consisted of the following:
 
<TABLE>
<CAPTION>
                                                                          Unrealized    Carrying
                                                   Principal     Cost     Gain/(Loss)     Value
                                                   ---------   ---------  -----------  -----------
<S>                                                <C>        <C>          <C>          <C>
Cash equivalents                                   $   3,502   $   3,502    $ --       $   3,502
Securities of agencies of the U.S. government            689         686      --             686
Commercial paper                                       1,525       1,522      --           1,522
                                                   ---------  -----------   ---------   ---------
                                                   $   5,716   $   5,710    $ --         $  5,710
                                                   ---------  -----------   ---------   ---------
                                                   ---------  -----------   ---------   ---------
</TABLE>

The Company considers its investments as being available for sale in
accordance with SFAS No. 115 "Accounting for Certain Investments in Debt and
Equity Securities." The Company classifies these investments as short term and
records them at fair market value. Contractual maturities of the Company's
investments in debt securities as of December 31, 1996 are $5,287 in 1997, $284
in 1999 and $139 in 2002.
 
5. OTHER ASSETS:    
   -------------
In December 1993, the Company purchased all product rights, technology, 
patents, trademarks and other rights for its RapidChek-Registered Trademark- 
Sulfate Reducing Bacteria product from Conoco Specialty Products Inc. 
("Conoco") for $225. This acquisition was being amortized over 10 years. In 
1996, the unamortized cost of this asset of $159 was charged to expense as 
management believed that such asset was not realizable.
 
Note Receivable
- --------------- 
The company maintains a note receivable from a former executive of EnSys.
The original loan amount was $350 and is secured by the individual's
personal residence. The loan bears interest at 5.8% per annum. At December 31,
1996, the outstanding loan balance was approximately $346 of which
approximately $6 in principal is payable annually through the year 2000 with
the balance payable in January 2001.
 
Investment in TSD BioServices
- ----------------------------- 
Included in the 1995 financial statements is $160 representing the Company's 
50% interest in TSD BioServices under the equity method of accounting. 
Summarized financial information of TSD BioServices is as follows:
 
<TABLE>
<CAPTION>
                                             1995       1994
                                          ---------  ---------
<S>                                        <C>        <C>
Total assets                              $     656  $     502
                                          ---------  ---------
                                          ---------  ---------
Partners' capital                         $     320  $     238
                                          ---------  ---------
                                          ---------  ---------
Revenues                                  $   1,641  $   1,351
                                          ---------  ---------
                                          ---------  ---------
Net income                                $      82  $      84
                                          ---------  ---------
                                          ---------  ---------
</TABLE>
 
                                       F-14


<PAGE>

                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
                               DECEMBER 31, 1996
               (in thousands, except share and per share data) 

In October 1996, the Company entered into an agreement to dissolve TSD 
BioServices (Note 3) and certain rights and assets formerly owned by the 
joint venture were placed into a wholly-owned subsidiary of the Company. 
Prior to the dissolution in 1996, the partnership generated $1,737 of 
revenues and equity in income of TSD BioServices to the Company of $178.

6. ACCRUED EXPENSES:
   -----------------
<TABLE>
<CAPTION>
                                          1996       1995
                                        ---------  ---------
<S>                                     <C>        <C>
Legal and professional                  $     260  $      99
Interest                                       --        124
Merger costs                                1,069         --
Other                                         737        105
                                        ---------  ---------
                                        $   2,066  $     328
                                        ---------  ---------
                                        ---------  ---------
</TABLE>
 
7. NOTES PAYABLE:
   -------------- 
In August 1992, EM Industries, Inc. ("EM"), an affiliate of E Merk (Note 11)
loaned the Company $500 at an annual interest rate of 8%. This loan, along with
$53 in accumulated interest, was repaid in March 1994.
 
In October 1994 and April 1995, the holders of the redeemable convertible
preferred stock provided $500 and $1,000, in working capital loans to the
Company. These notes bore interest at 9% and 10% per annum, respectively, and
each became due during 1995. In addition, 89,349 and 223,372 warrants were
issued, respectively, for the purchase of common stock of the Company at an
exercise price of $2.37 per share. The warrant values deemed for accounting
purposes were $23 and $75, respectively, which were recorded as an asset and
amortized over the term of the loans. The warrants have an exercise period of
five years.
 
In January 1996, the Company converted the $1,500 of Notes Payable and $124
of accrued interest into 685,952 shares of redeemable convertible preferred
stock (Note 9).

                                       F-15


<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)
 
8. CAPITAL LEASES
   --------------
The Company leases equipment under capital lease agreements which expire at
various dates through 2001. Certain of the leases contain options to purchase
the equipment at the end of the respective lease terms. As of December 31, 1996,
future minimum capital lease payments are as follows:
 
<TABLE>
                   <S>                               <C>
                   1997                                $      98
                   1998                                       33
                   1999                                       16
                   2000                                       12
                   2001                                        8
                                                       ---------
                                                             167
                   Less--amount representing
                     interest                                (32)
                                                       ---------
                   Present value of minimum
                     lease payments                          135
                   Less--current portion of capital
                     lease obligations                       (85)
                                                       ---------
                                                       $      50
                                                       =========
</TABLE>

9. SERIES A PREFERRED STOCK:
   -------------------------
In June 1993, the Company sold 1,267,208 shares of redeemable convertible
preferred stock and received proceeds of $3,000 less $47 of transaction costs.
In connection with the 1996 financing, the Company converted the $1,500 of
notes payable and $124 of accrued interest into 685,952 shares of redeemable
convertible preferred stock at $2.37 per share (Note 7) and received an
additional investment of $500 for the purchase of 211,202 shares less
transaction costs of $27. All such shares were redeemable with cumulative
dividends, at the option of the holders, as defined, beginning in 1998.
Dividends have been accreted through the Merger (Note 3).
 
In connection with the Merger, the redeemable convertible preferred stock
plus cumulative dividends were converted into 2,164,362 shares of a newly
issued class of Series A Preferred Stock ("Series A"). The Series A has no
redemption provisions outside the control of the Company. As a result, the
Series A is now classified as a component of stockholders' equity.

                                       F-16


<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)

The Series A is convertible into one share of common stock at the option of
the holder at any time, or at the option of the Company if the closing share
price of the Company's common stock exceeds $4.50 per share for a period of 45
business days. The Series A carries an aggregate liquidation preference of
$6,378. The Series A contains no annual dividend provisions and is only
redeemable in the event the Company converts the Series A into securities of a
lesser value, as defined.
 
10. STOCK OPTIONS AND WARRANTS:
    ---------------------------
Stock Options
- -------------
EnSys had two stock option plans (the "1993 Plan" and the "1995 Plan") which
authorized the granting of incentive and nonqualified stock options to
officers, key employees, directors and consultants. Incentive stock options
are granted at not less than 100% of fair market value at the date of grant
(110% for stockholders owning more than 10% of the Company's common stock).
Non qualified stock options are granted at not less than 85% of fair market
value at the date of grant. All previously issued SDI options were converted
into the 1995 Plan. A maximum of 1,700,000 shares of common stock are issuable
under the 1995 Plan and Options to purchase up to 300,000 shares of common
stock had been authorized under the 1993 Plan.
 
Certain additional options have been granted outside the plans. These
options generally follow the provisions of the 1995 Plan.
 
Information with respect to the stock options granted under the plans and
options granted separately from the plans is summarized as follows:
 
<TABLE>
<CAPTION>
                                                         PRICE     AGGREGATE 
                                          NUMBER          RANGE      PRICE   
                                          ---------      -------   --------- 
<S>                                       <C>            <C>        <C>      
Balance, January 1, 1994                  169,353      $     .19   $     32
Granted                                   116,098            .64         74
Canceled                                   (7,036)           .64         (5)
                                          ---------      --------  --------- 
Balance, December 31, 1994                278,415        .19-.64         101
Granted                                   146,275        .19-.64          39
Canceled                                  (27,402)           .64         (18)
                                          ---------      --------- ----------
Balance, December 31, 1995                 397,288       .19-.64         122
Options acquired in conjunction with
    the Merger                             461,023      .25-7.50       1,226
Granted                                    200,000     2.00-2.20         420
Canceled                                   (14,072)          .64          (9)
                                          ---------      --------- ----------
Balance, December 31, 1996..............  1,044,239    $ .19-7.50   $   1,759 
                                          ---------      --------- ----------
                                          ---------      --------- ----------


</TABLE>

                                   F-17

<PAGE>

                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)


    As of December 31, 1996, 818,829 options were exercisable with an aggregate
exercise price of $1,411 and 955,761 options were available for future grant
under the Plans.
 
    For options granted, the Company recognizes as deferred compensation the
excess of the deemed value for accounting purposes of the common stock issuable
upon the exercise of options over the aggregate exercise price of such options.
The deferred compensation is amortized over the vesting period of the shares and
options.
 
    In October 1995, the FASB issued SFAS No. 123, "Accounting for Stock-Based
Compensation." Effective January 1, 1995, the Company has elected to adopt the
disclosure requirement of this pronouncement. Had compensation cost for the
Company's stock option plans been determined based upon the fair value at the
grant date for awards under SFAS 123, the Company's net loss applicable to
common stockholders for 1996 and 1995 would have been $9,113 and $1,610 and net
loss per share applicable to common stockholders would have been $2.15 and
$0.46, respectively. Because the SFAS 123 method of accounting has not been
applied to options granted prior to January 1, 1995, the resulting pro forma
compensation cost, and thus pro forma net loss, may not be representative of
that to be expected in future years.
 
    The weighted average fair value at the date of grant for options granted
during 1995 and 1996 is estimated at $.47 and $1.46 per share, respectively,
using the Black-Scholes option-pricing model. The assumptions used in the
Black-Scholes model are as follows: dividend yield of 0%, expected volatility of
80%, risk-free interest rate of 6.51% in 1995 and 6.37% in 1996, and an expected
option life of 6 years.
 
Warrants
- -------- 
    In December 1994, in connection with a prior collaboration agreement, the
Company issued to Conoco a warrant that enables Conoco to purchase 164,179
shares of the Company's common stock for an exercise price of one dollar. In
connection with this exchange, the Company recorded a charge of $105 in 1994 in
the statement of operations reflecting the fair value of the warrant. If Conoco
exercises this warrant, and the Company completes an equity financing with
aggregate proceeds of $7 million or greater, then Conoco has the right to
require the Company to repurchase the warrant at a price equal to 164,179 shares
multiplied by the price per share received in the equity financing. The warrant
expires in November 1999. 

                              F-18

<PAGE>

                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)


In 1993, the Company issued warrants for the purchase of 5,473 shares of 
common stock at $.19 per share. These warrants expire in 1998.

    In connection with the original issuance of the redeemable convertible
preferred stock and the notes payable issued in October 1995 and April 1995
which were subsequently converted to redeemable convertible stock in January
1996, the Company granted warrants to purchase a total of 429,992 shares of
common stock at an exercise price of $2.37. The warrants have an exercise price
of five years from the dates of grant.
 
    At December 31, 1996, the Company maintains 3,530 of outstanding warrants
granted by EnSys. These warrants contain an exercise price of $4.96 per share
and expire in 2001.
 
11. EM COLLABORATIVE AGREEMENT:
    --------------------------- 
    In February 1992, SDI entered into an agreement with EM for the development
and manufacture of a product line of immunoassays capable of identifying and
quantifying certain substances found on the priority pollutant list published
by the Environmental Protection Agency. In connection with this agreement, the
Company received $400, $600 and $1,709 in 1996, 1995 and 1994, respectively,
for the achievement of certain defined development milestones. In September
1996, the Company acquired the product rights to the D TECH-Registered 
Trademark- product line from EM in exchange for a royalty payment based on
sales of specified products into selected markets and 48,048 shares of common
stock.
 
    The Company made this acquisition in connection with the Ohmicron
Acquisition and charged the related cost to acquired research and development.
 
12. REVENUES:
    --------- 
    The Company earns revenue in two major areas: product related revenues and
contract and other revenues.

                                       F-19
<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)
 
Product Related Revenues
- ------------------------ 
    The Company generates product revenue through: (i) the sale of products it
has developed or acquired and (ii) through its TSD subsidiary on a percentage of
completion basis. Under percentage of completion, revenues earned and related
costs incurred are recorded based on management's estimates of the percentage of
completion of each project. Product sales are made to collaborative partners,
distributors or directly to the end users of the products. Included in product
related revenues are royalties earned through the sale of antibodies to a
distributor, who pays a royalty based on sales. In addition, from 1994 through
August 1996, the Company began receiving royalties based on EM sales of products
developed by SDI for EM (Note 11). Royalties earned from EM were $23, $35 and $7
in 1996, 1995 and 1994, respectively.
 
Contract and Other Revenues
- --------------------------- 
    The Company has entered into various assay development and other
collaborative arrangements. Revenue recognized under such collaborative
agreements is recorded upon completion of certain performance requirement of the
contracts. Other revenues consist primarily of license revenue which is
recognized upon the transfer of such license.
 
Major Customers
- --------------- 
    During 1994, EM (Note 11) was the Company's only major customer, providing
revenues of $1,900. During 1995, EM and two customers accounted for 26%, 17% and
14% of the Company's revenue, respectively. During 1996, EM and EnSys (Note 3)
accounted for 11% and 19% of the Company's revenues, respectively.
 
13. TSD BIOSERVICES TRANSACTIONS:
    -----------------------------
    TSD BioServices purchased certain supplies, raw materials and services 
from Taconic and the Company. In 1996, 1995 and 1994, the Company included in 
revenues $53, $275 and $208 of contract and other revenues resulting from 
transactions with TSD BioServices. In October 1996, TSD BioServices was 
dissolved (see Note 3).
 
    In 1991, TSD BioServices entered into a five-year management agreement 
with each of its partners. The agreements provided that the partners could 
charge TSD BioServices for work performed on behalf of the partnership by any 
of the partners' principals. TSD BioServices partners elected not to charge 
TSD BioServices for these and certain other expenses related to the 
partnership, but rather elected to absorb such costs in the parent 
organizations. Such costs were immaterial and the management agreement was 
terminated in 1996.
 
                                       F-20
<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                               DECEMBER 31, 1996
                (in thousands, except share and per share data)
 
14. COMMITMENTS AND CONTINGENCIES:
    ------------------------------
    The Company leases its office and manufacturing facilities and other
equipment under operating leases. Rent expense for the years ended December 31,
1996, 1995 and 1994, was $250, $226 and $226, respectively. Future commitments
under these noncancelable leases at December 31, 1996, are as follows:
 

              1997                             $     577
              1998                                   499
              1999                                   349
              2000                                   152
              2001                                    93
              2002 and thereafter                    115
                                               ---------
                                               $   1,785
                                               ---------
                                               ---------


    In July 1993, the Company purchased certain equipment, inventory, cell 
lines and product rights and other assets for Macra-Registered Trademark- 
Lp(a) from Terumo Medical Corporation ("Terumo") for $128. In connection with 
this agreement, the Company agreed to pay Terumo a royalty on net sales of 
the Macra-Registered Trademark- Lp(a) product. The royalty is based on a 
specified formula, but generally requires the Company to pay a 6% royalty on 
the net sales of Macra-Registered Trademark- products, with a minimum royalty 
payment each year of $10. The Company paid Terumo $15, $25 and $43 in 
royalties under this agreement in 1996, 1995 and 1994, respectively.
 
    The Company is also party to various claims arising in the ordinary course
of business. Although the ultimate outcome of these matters is presently not
determinable, management, after consultation with legal counsel, does not
believe that the outcome of these matters will have a material adverse effect on
the Company's financial position or results of operations.
 
15. RETIREMENT SAVINGS PLAN:
    ------------------------ 
    In 1992, the Company instituted a retirement savings plan qualified under
Section 401(k) of the Internal Revenue Code. The plan allows for eligible
employees to contribute a portion of their gross wages to the plan. The Company
matches employees' contributions on a 50% basis up to 6% of gross wages. In
1996, 1995 and 1994, the Company recognized expense of $51, $51 and $30,
respectively, associated with this plan.
 
                                       F-21
<PAGE>

ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
         FINANCIAL DISCLOSURE

    Not Applicable.



                                      29

<PAGE>

                                   PART III


ITEM 10.      DIRECTORS AND EXECUTIVE OFFICERS OF REGISTRANT

The information contained under the caption "Election of a Class of Directors"
and the information contained under the caption "Section 16(a) Beneficial
Ownership Reporting Compliance" in the Company's Definitive Proxy Statement is
incorporated herein by reference.


ITEM  11.      EXECUTIVE COMPENSATION

The information contained under the caption "Executive Compensation" in the
Company's Definitive Proxy Statement is incorporated herein by reference.


ITEM 12.       SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The information contained under the caption "Stock Ownership of Principal
Stockholders and Management" in the Company's Definitive Proxy Statement is
incorporated herein by reference.


ITEM 13.       CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

The information contained under the caption "Certain Relationships and Related
Transactions" in the Company's Definitive Proxy Statement is incorporated herein
by reference.
 

                                      30

<PAGE>

                                   PART IV

ITEM 14.       EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

(a) 1.    Financial Statements

    See the Consolidated Financial Statements which begin on
    page F-1 of this Report.


     2.   Financial Statement Schedules

     Financial statement schedules are omitted because they are
     either not required or not applicable or the required
     information is reflected in the financial statements or
     notes thereto.



    3.    Exhibits 

<TABLE>
<CAPTION>

                                                                                           Previous
Exhibit                                                                                    Exhibit
Number                                                                                     Number
- -------                                                                                    --------
<S>        <C>                                                                     <C>     <C>
 3.1       Fourth Amended and Restated Certificate of Incorporation of the 
           Company                                                                 (1)        4.1

 3.2       Amended and Restated Bylaws of the Company                              (1)        4.2

 4.1       Reference is made to Exhibits 3.1 and 3.2

 4.2       Forms of Warrants to Purchase Common Stock of the Company               (1)        4.4

 10.1      Warrant Agreement dated June 1, 1991 between John Hancock               (2)        10.5
           Leasing Corporation and the Company, as amended December 19, 
           1991

 10.2*     EnSys Environmental Products, Inc. 1990 Stock Option Plan               (2)        10.16

 10.3*     EnSys Environmental Products, Inc. 1993 Stock Incentive Plan            (2)        10.17

 10.4*     Amended and Restated EnSys Environmental Products, Inc. 1995 
           Stock Incentive Plan                                                    (3)

 10.5      EnSys Environmental Products, Inc. 401(k) Plan Adoption 
           Agreement                                                               (2)        10.18

 10.6      Lease Agreement dated June 1, 1989, between the Company and             (2)        10.20
           Imperial Center Partnership and Petula Associates, Ltd. for premises 
           at 4222 Emperor Boulevard, Morrisville, North Carolina, as 
           amended December 22, 1991 and April 7, 1993

 10.7      Master Lease Agreement by and between the Company and John              (2)        10.22
           Hancock Leasing Corporation dated April 8, 1991
</TABLE>

                                      31


<PAGE>
<TABLE>
<CAPTION>

<S>        <C>                                                                     <C>      <C>

 10.8      Master Equipment Lease Agreement by and between the Company             (2)        10.23
           and Ally Capital Corporation dated October 20, 1992

 10.9      License Agreement by and between the Company and Meridian               (4)        10.22
           Diagnostics, Inc. dated July 24, 1994

 10.10     Asset Purchase Agreement among EnSys, Millipore Corporation,            (5)        2.1
           and ImmunoSystems, Inc.

 10.11     Agreement and Plan of Merger by and between EnSys and Strategic         (1)        2.1
           Diagnostics Inc. dated as of October 11, 1996

 10.12     Form of Lock-Up Letter Agreement dated December 30, 1996                (1)        10.29
           between the Company and each of Richard Birkmeyer; Anne 
           Cavanaugh; Martha Reider; DSV Partners IV; Edison Venture Fund 
           II, L.P.; Edison Venture Fund, II-P.A., L.P.; The Perkin-Elmer 
           Corporation; EM Industries, Incorporated and CIP Capital L.P.

 10.13     Form of Stockholder Voting Agreement                                    (1)        10.30

 10.14*    Employment Agreement dated December 30, 1996 by and between 
           Richard C. Birkmeyer and the Company

 10.15*    Employment Agreement dated December 30, 1996 by and between 
           Grover C.Wrenn and the Company

 10.16     Registration Rights Agreement dated December 30, 1996 between 
           the Company and the stockholders listed therein

 10.17     Lease Agreement dated June 24, 1996 by and between Lang 
           Associates and Strategic Diagnostics Inc.

 10.18     Industrial Lease dated October 26, 1993, by and between Tober & 
           Agnew Properties, Inc. and Strategic Diagnostics Incorporated

 10.19     Industrial Lease dated August 9, 1990, by and between Tober & 
           Agnew Properties, Inc. and Strategic Diagnostics Incorporated

 10.20     Industrial Lease dated June 7, 1991 by and between Tober & 
           Agnew Properties, Inc. and TSD BioServices

 21.1      Subsidiaries of the Company 

 24        Consent of Arthur Andersen LLP

 27        Financial Date Schedule
</TABLE>

_____________________________________________
(1) Incorporated by reference to the designated exhibit of the EnSys 
Registration Statement on Form S-4 ( No. 333-17505) filed on December 9, 1996.

(2) Incorporated by reference to the designated exhibit of the EnSys 
Registration Statement on Form S-1 ( No. 33-68440) filed on September 3, 1993.

(3) Incorporated by reference to Appendix F to the Joint Proxy 
Statement/Prospectus contained in the EnSys Registration Statement on Form S-4 
(No. 333-17505) filed on December 9, 1996.

(4) Incorporated by reference to the designated exhibit of the EnSys Form 10-K 
for the fiscal year ended December 31, 1994.

(5) Incorporated by reference to the designated exhibit of the EnSys Form 10-Q 
for the fiscal quarter ended March 31, 1996.

*Management contract or compensatory plan.

(b)  Reports on Form 8-K

          None.


                                      32
<PAGE>

                                    SIGNATURES

    Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed 
on its behalf by the undersigned, thereunto duly authorized.

                                            STRATEGIC DIAGNOSTICS INC.


Dated: April 11, 1997                    By:    /s/ Richard C. Birkmeyer
                                                -------------------------------
                                                    Richard C. Birkmeyer
                                                    President and Chief 
                                                     Executive Officer

    Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
Registrant and in the capacities indicated and on the dates indicated.

<TABLE>
<CAPTION>

Signatures                       Title                                             Date Signed
- ----------                       -----                                             -----------
<S>                              <C>                                               <C>
/s/ Richard C. Birkmeyer
- ----------------------------       President, Chief Executive                        April 11, 1997
Richard C. Birkmeyer               Officer and Director 
                                   (Principal Executive Officer)

/s/ Gregory J. Bell
- ----------------------------       Chief Financial Officer                           April 11, 1997
Gregory J. Bell                    (Principal Financial and 
                                   Accounting Officer)      
                                   

/s/ Richard J. Defieux
- ----------------------------       Director                                          April 11, 1997
Richard J. Defieux

/s/ Robert E. Finnigan, Ph.D
- ----------------------------       Director                                          April 11, 1997
Robert E. Finnigan, Ph.D

/s/ Kathleen E. Lamb
- ----------------------------       Director                                          April 11, 1997
Kathleen E. Lamb

/s/ Stephen O. Jaeger
- ----------------------------       Director                                          April 11, 1997
Stephen O. Jaeger

/s/ Curtis Lee Smith, Jr.
- ----------------------------      Director                                           April 11, 1997
Curtis Lee Smith, Jr.

/s/ Grover C. Wrenn
- ----------------------------      Director                                           April 11, 1997
Grover C. Wrenn  

</TABLE>


                                      33

<PAGE>


                                                                   Exhibit 10.14

                                 EMPLOYMENT AGREEMENT
                                           

    THIS EMPLOYMENT AGREEMENT made as of the 30th day of December 1996, by and 
between ENSYS ENVIRONMENTAL PRODUCTS, INC., a Delaware corporation whose name 
is being changed to STRATEGIC DIAGNOSTICS INC. as of the date hereof (the 
"Company," which is also hereinafter referred to as the "Employer"), and 
RICHARD C. BIRKMEYER (the "Executive").

                                     WITNESSETH:

    WHEREAS, Employer agrees to retain the services of Executive, and 
Executive agrees to work for Employer, all pursuant to the terms and 
conditions hereinafter set forth;

    NOW, THEREFORE, FOR AND IN CONSIDERATION of the premise, the mutual 
promise, covenants and agreements contained herein, and other good and 
valuable consideration, the receipt and sufficiency of which are hereby 
acknowledged, the parties hereto hereby agree as follows:

   1. Employment.  The Employer agrees to employ the Executive and the 
Executive agrees to be employed by the Employer on the terms and conditions 
hereinafter set forth.

   2. Capacity.  The Executive shall serve as the Chief Executive Officer of 
Employer.  The Executive shall render such services to the Company as are 
customary for such position and perform all other services incident thereto.

   3. Effective Date and Term.  Subject to the provisions of Section 6, the 
Executive's employment under this Agreement shall remain in effect for the 
period commencing on the date hereof and terminating on December 31, 1997 
("Initial Term") and shall be automatically extended for periods of one year 
commencing on December 31, 1997 and on each December 31 thereafter, unless 
either the Executive or the Employer gives written notice to the other not 
less than sixty (60) days prior to the date of any such anniversary, of such 
party's election not to extend the term of the Executive's employment 
hereunder.

   4. Compensation and Benefits.  The regular compensation and benefits 
payable to the Executive under this Agreement shall be as follows:

      (a) Salary.  For all services rendered by the Executive under this 
Agreement, the Employer shall pay the Executive a salary at the rate, of 
$164,000 per year, subject to an annual increase of not less than five 
percent (5%) of the then current annual salary, as determined by the Board of 
Directors or the Compensation Committee in accordance with the usual practice 

<PAGE>

of the Employer with respect to review of compensation for its senior 
executives.  The Executive's salary shall be payable in periodic installments 
in accordance with the Employer's usual practice for its senior executives.

      (b) Bonus.  In addition to salary under Section 4(a), the Executive 
shall be entitled to participate in a bonus plan under which he may be 
entitled to receive an annual bonus in an amount, up to 75 % of such salary, 
as shall be determined by the Compensation Committee of the Employer's Board 
of Directors in the beginning of each of the Employer's fiscal years under 
this Agreement commencing with fiscal 1997.  The Compensation Committee and 
the Executive shall establish reasonable performance goals and targets for 
such bonus- Upon completion of each year, the Compensation Committee shall 
review the actual performance against such performance targets and goals and 
notify the Executive of the amount of the award.  Initially, the target 
annual bonus will be 30% of Executive's salary.  The Executive's bonus shall 
be paid to him within ninety (90) days after the end of the fiscal year to 
which it relates, whether he remains an employee of the Employer at the date 
of payment or not.

      (c) Regular Benefits.  The Executive shall also be entitled to 
participate in any and all employee benefit plans, medical insurance plans, 
life insurance plans, disability income plans, retirement plans and other 
benefit plans from time to time in effect for senior executives of the 
Employer.  Such participation shall be subject to (i) the terms of the 
applicable plan documents, (ii) generally applicable policies of the Employer 
and (iii) the discretion of the Board of Directors of the Employer or any 
administrative or other committee provided for in or contemplated by such 
plan, except that all waiting periods for eligibility to participate in 
employee benefit plans shall be waived by the Employer to the extent 
permissible.  The Employer shall also pay the premiums that come due under 
Paul Revere Life insurance Company Disability Income Policies 01024761080 and 
01026933250.

      (d) Perquisites.  The Executive shall be entitled to receive fringe 
benefits ordinarily and customarily provided by the Employer to its senior 
officers during the term of his employment hereunder.  In any event, the 
Employer shall provide the Executive with fringe benefits no less favorable 
to the Executive than those provided by the Employer to any other employee.

      (e) Business Expenses.  The Employer shall promptly reimburse the 
Executive for all travel and other business expenses, including, without 
limitation, cellular phone expenses, incurred by him in the performance of 
his duties and responsibilities, subject to such reasonable requirements with 
respect to substantiation and documentation as may be specified by the 
Employer.

      (f) Equity Award.  The Executive is hereby granted options to purchase 
100,000 shares of the Employer's common stock under the Employer's 1995 Stock 
Incentive Plan at an exercise price of $2.00 per share (the "Option").  The 
Option will be granted pursuant to an Incentive Stock Option Agreement to be 
executed contemporaneously herewith in

                                       2
<PAGE>

substantially the form of Exhibit A attached hereto and incorporated herein 
by this reference.  The grant of options pursuant to this Section 4(e) shall 
be without prejudice to further grants to the Executive in the future under 
any plan adopted by the Employer.

   5. Extent of Service.  During his employment hereunder, the Executive 
shall, subject to the direction and supervision of the Board of Directors of 
the Employer, devote his full business time, all reasonable efforts and 
business judgment, skill and knowledge to the advancement of the Employer's 
interests and to the discharge of his duties and responsibilities hereunder, 
except for reasonable time spent for service on the boards of directors of 
other corporations, vacations, civic and charitable activities, and 
management of personal investments.

   6. Termination and Termination Benefits.  Notwithstanding the provisions 
of Section 3, the Executive's employment hereunder shall terminate under the 
following circumstances:

      (a) Death.  In the event of the Executive's death during the 
Executive's employment hereunder, the Executive's employment shall terminate 
on the date of his death; provided, however, that the Employer shall continue 
to pay an amount equal to the Executive's salary to the Executive's 
beneficiary designated in writing to the Employer prior to his death (or to 
his estate, if he fails to make such designation or such beneficiary 
predeceases him) for a period of twelve months after the date of the 
Executive's death, at the salary rate in effect on the date of his death, 
without an increase for any portion of such twelve (12) month period, said 
payments to be made on the same periodic dates as salary payments have been 
made to the Executive had he not died.

      (b) Termination by the Employer for Cause.  The Executive's employment 
hereunder may be terminated without further liability on the part of the 
Employer effective immediately by a majority vote of all of the members of 
the Board of Directors of the Employer (excluding the Executive) for cause by 
written notice to the Executive setting forth in reasonable detail the nature 
of such cause.  Only the following shall constitute "cause" for such 
termination:

          (i)     The Executive commits an act constituting fraud or material 
                  misrepresentation with respect to the Employer;

          (ii)    The Executive embezzles funds or assets from the Employer; 

          (iii)   Conviction of the Executive of a felony involving moral 
                  turpitude (excluding motor vehicle violations); or

          (iv)    Gross and willful failure to perform a substantial portion 
                  of his duties and responsibilities hereunder, which failure 
                  continues for more than thirty (30) days after written 
                  notice given to the Executive pursuant to a majority vote of 
                  all of the members of the

                                       3

<PAGE>

                  Board of Directors of the Employer, such vote to set forth 
                  in reasonable detail the nature of such failure.

      (c) Termination by the Executive.  The Executive's employment hereunder 
may be terminated effective immediately by the Executive by written notice to 
the Board of Directors of the Employer, provided that the Executive shall 
receive the benefits specified in Section 6(e) if he terminates his 
employment in the event of the following (any of which being referred to 
herein as "Good Reason"):

          (i)     Failure of such Board of Directors to elect the Executive 
                  to the office of Chief Executive Officer of the Employer or 
                  to continue the Executive in such office;

          (ii)    Failure by the Employer to comply with the provisions of 
                  Section 4(a) or 4(c) or any other material breach by the
                  Employer of any other provision of this Agreement; or

          (iii)   Election by the Employer not to extend the term of the 
                  Executive's employment hereunder in accordance with the
                  provisions of Section 3.

      (d) Termination by the Employer Without Cause.  The Executive's 
employment with the Employer may be terminated without cause by a majority of 
all of the members of the Board of Directors of the Employer (excluding the 
Executive) on written notice to the Executive.

      (e) Certain Termination Benefits.  Unless otherwise specifically 
provided in this Agreement or otherwise required by law or by the terms of 
any employee benefit plan and other compensation plans, programs and 
structures, or fringe benefit programs in which the Executive is a 
participant at the time of the termination of his employment with the 
Company, all compensation and benefits payable to the Executive under this 
Agreement shall terminate on the date of termination of Executive's 
employment hereunder.  Notwithstanding the foregoing, in the event of 
termination by the Executive for Good Reason pursuant to Section 6(c) or by 
the Employer pursuant to Section 6(d), the Executive shall be entitled to the 
following benefits:

          (i)     The Employer shall continue to pay an amount equal to the 
                  Executive's salary to the Executive (or the Executive's
                  beneficiary designated in writing to the Employer prior
                  to his death or to his estate, if he fails to make such 
                  designation or such beneficiary predeceases him) during a 
                  period (the "Severance Period") which shall extend for a 
                  period of twelve (12) months after the date of the Executive's
                  termination, at the salary rate in effect on the date of his
                  termination, said payments to be made on the same periodic 



                                       4

<PAGE>
                  
                  dates as salary payments would have been made to the Executive
                  had his employment not been terminated; provided that in the
                  event that the Employer shall default in the timely payment of
                  any amount due to the Executive under this Section 6(e) or in
                  the performance of any of its other obligations under this 
                  Section 6(e), the Executive, at his option, may accelerate the
                  remaining payments that would become due to him hereunder and 
                  such amounts thereupon shall be due and payable forthwith.
         
          (ii)    During the Severance Period, the Executive shall continue to 
                  receive all benefits described in Sections 4(c) existing on
                  the date of termination (except for any cash bonus plans which
                  shall be prorated through the date of termination).  For 
                  purposes application of such benefits the Executive shall be
                  treated as if he had remained in the employ of the Employer,
                  with a total annual salary at the rate in effect on the date 
                  of termination.
         
          (iii)   In addition to, but not in limitation of, the rights which 
                  the Executive otherwise may have and except as expressly
                  provided in any award subsequent to the grant of the stock 
                  options contemplated by Section 4(f), any restrictions 
                  remaining on any restricted shares issued to the Executive 
                  under the Employer's restricted plans shall immediately lapse,
                  any performance shares issued to the Executive under the 
                  Employer's incentive stock plans shall immediately vest, and 
                  any stock options and stock appreciation rights granted to the
                  Executive shall become exercisable immediately, and the 
                  Executive may exercise all such options or stock appreciation 
                  rights within the later of the remainder of their term or 
                  one year after the expiration of the Severance Period.

          (iv)    If, in spite of the provisions of Section 6(e)(ii) 
                  above, benefits or service credits under any benefit plan 
                  shall not be payable or provided under any such plan to 
                  the Executive, or to the Executive's dependents, 

                                       5
                  
<PAGE>
                  
                  beneficiaries or estate, because the Executive is no 
                  longer deemed to be an employee of the Employer, the 
                  Employer shall pay or provide for payment of such 
                  benefits and service credits for such benefits to the 
                  Executive, or to the Executive's dependents, 
                  beneficiaries or estate; provided, however, that the 
                  Employer shall have no obligations with respect to the 
                  federal or state income tax treatment of the exercise of 
                  any stock options or other stock rights held by the 
                  Executive under any of the Employer's stock incentive 
                  plans.

      (f) No Set-off.  The amounts payable to Executive under Section 6(e) 
shall be treated as damages but as severance compensation to which the 
Executive is entitled by on of termination of his employment, and the 
Employer shall not be entitled to any set-off against, or reduction of, such 
amounts for any reason whatsoever.  Notwithstanding any other provision of 
this Agreement, the Executive shall be under no obligation to seek or accept 
any employment after termination of employment with the Employer for any 
reason.

   7. Disability.  If, due to physical or mental illness, the Executive shall 
be disabled so as to be unable to perform substantially all of his duties and 
responsibilities hereunder, the Employer, acting through its Board of 
Directors, may designate another executive to act in his place during the 
period of such disability.  Notwithstanding any such designation, the 
Executive shall continue to receive his full salary and benefits under 
Section 4 of this Agreement for a minimum of nine (9) months (net of any 
amounts paid to the Executive during such nine (9) month period pursuant to 
Employer's disability income plan, if any), and shall continue to participate 
in the Employer's benefit plans and to receive other benefits as specified in 
Section 4 until the expiration of his term of employment hereunder.  If any 
questions shall arise as to whether during any period the Executive was 
disabled so as to be unable to perform substantially all of his duties and 
responsibilities hereunder due to physical or mental illness, the Executive 
may, and at the request of the Employer will, submit to the Employer a 
certification in reasonable detail by a physician selected by the Executive 
or his guardian to whom the Employer has no reasonable objection as to 
whether the Executive was so disabled and such certification shall for the 
purposes of this Agreement be conclusive of the issue.  If such question 
shall arise and the Executive shall fail to submit such certification, the 
Employer's determination of such issue shall be binding on the Executive.

   8. Withholding.  All payments made by the Employer under this Agreement 
shall be net of any tax or other amounts required to be withheld by the 
Employer under applicable law.

   9. Non-Disclosure, Non-Competition and Non-Solicitation Covenants.

      (a) Definitions.  For purposes of this Section 9, the following terms 
shall have the following respective meanings:

                                       6

<PAGE>

          (i)     "Competitive Position" shall mean (i) the direct or indirect 
                  equity ownership or control of all or any portion
                  of a "Competitor" (as hereinafter defined), or (ii) any 
                  employment, consulting, partnership, advisory, directorship, 
                  agency, promotional or independent contractor arrangement 
                  between Executive and any Competitor whereby Executive is 
                  required to perform services substantially similar to those 
                  that he is to perform for Employer hereunder.

          (ii)    "Competitor" shall refer to any person or entity engaged, 
                  wholly or partly, in the business of distributing, 
                  manufacturing, marketing, selling,servicing, repairing 
                  environmental testing devices.

          (iii)   "Confidential Information" shall mean any and all proprietary
                  and confidential data or information of Employer or any of 
                  its affiliates, other than "Trade Secrets" (as hereinafter 
                  defined), which is of tangible or intangible value to
                  Employer or any of its affiliates and is not public 
                  information or is not generally known or available to 
                  Employer's competitors but is known only to Employer or its
                  affiliates and their employees, independent contractors or 
                  agents to whom it must be confided in order to apply it to 
                  the uses intended.

          (iv)    "Restricted Territory" shall mean the United States of 
                  America.

          (v)     "Trade Secrets" shall mean all knowledge, data and 
                  information of Employer or any of its affiliates which is 
                  defined as a "trade secret" under applicable law.

          (vi)    "Work Product shall mean all work product, property, data,
                  documentation, "know-how", concepts, plans, inventions, 
                  improvements, techniques,processes or information of any kind,
                  prepared, conceived, discovered, developed or created by 
                  Executive in connection with the performance of his services
                  hereunder.

      (b) Acknowledgments.  Executive hereby acknowledges and agrees that 
during the term of this Agreement (i) Executive will frequently be exposed to 
certain Trade Secrets and Confidential Information; (ii) Executive's 
responsibilities on behalf of Employer will extend to all geographical areas 
of the Restricted Territory; and (iii) any competitive activity on 
Executive's part during the term of this Agreement, or any competitive 
activity on Executive's part in the Restricted Territory for a reasonable 
period thereafter, would necessarily involve Executive's use of Employer's 
Trade Secrets and Confidential Information and would unfairly threaten 
Employer's legitimate business interests, including its substantial 
investment in the proprietary aspects of its business and the goodwill 
associated with its customer base.  Moreover, Executive acknowledges that, in 
the event of the termination of this Agreement, Executive would have 
sufficient skills to find alternative, commensurate work in his field of 
expertise that would not involve a violation of any of the provisions of this 
Section 9. Therefore, Executive acknowledges and agrees that it is reasonable 
for Employer to require Executive to abide by the covenants set forth in this 
Section 9. The parties acknowledge and agree that if the nature of 
Executive's responsibilities for or on behalf of Employer or the geographical 
areas in which Executive must fulfill such responsibilities materially 

                                       7

<PAGE>

change, the parties will execute appropriate amendments to the scope of the 
covenants in this Section 9.

      (c) Nondisclosure: Ownership of Proprietary Property.

          (i)     In recognition of Employer's need to protect its 
                  legitimate business interests, Executive hereby covenants 
                  and agrees that: (A) with regard to each item 
                  constituting a Trade Secret, at all times during which 
                  such item shall constitute a Trade Secret (before or 
                  after termination of this Agreement); and (B) with regard 
                  to any Confidential information, at all times during the 
                  term of this Agreement and for a period of three (3) 
                  years following the expiration or termination of this 
                  Agreement for any reason, Executive shall regard and 
                  treat each item constituting a Trade Secret and all 
                  Confidential Information as strictly confidential and 
                  wholly owned by Employer and will not, for any reason, in 
                  any fashion, either directly or indirectly, use, sell, 
                  lend, lease, distribute, license, give, transfer, assign, 
                  show, disclose, disseminate, reproduce, copy, 
                  misappropriate or otherwise communicate any such item or 
                  information to any third party for any purpose other than 
                  in accordance with this Agreement or as required by 
                  applicable law.
                    
          (ii)    Executive shall immediately notify Employer of any 
                  intended or unintended, unauthorized disclosure or use of 
                  any Trade Secrets or Confidential Information by 
                  Executive or any other person or entity of which 
                  Executive becomes aware.  Executive shall cooperate fully 
                  with Employer in the procurement of any protection of 
                  Employer's rights to or in any of the Trade Secrets or 
                  Confidential Information.
                              
          (iii)   Immediately upon expiration or termination of this Agreement
                  for any reason, or if  notice of termination is required 
                  hereunder, upon receipt of such notice, or at any time after
                  such termination or notice upon the specific request of 
                  Employer, Executive shall return to Employer all written 
                  or descriptive materials of any kind in Executive's 
                  possession or to which Executive has access that 
                  constitute or contain any Confidential information or 
                  Trade Secrets, and the confidentiality obligations 
                  described in this Agreement shall continue until their 
                  expiration under the terms of this Agreement.
                  
          (iv)    To the greatest extent possible, any Work Product 
                  shall be deemed to be "work made for hire" (as defined in 

                                       8
                  
<PAGE>
                  
                  the Copyright Act, 17 U.S.C.A. Section 101 et seq., as 
                  amended) and owned exclusively by Employer.  Executive 
                  hereby unconditionally ad irrevocably transfers and 
                  assigns to Employer all rights, title and interest 
                  Executive currently has or in the future may have, by 
                  operation of law or otherwise, in or to any Work product, 
                  including, without limitation, all patents, copyrights, 
                  trademarks, service marks and other intellectual property 
                  rights.  Executive agrees to execute and deliver to 
                  Employer any transfers, assignments, documents or other 
                  instruments which Employer may deem necessary or 
                  appropriate to vest complete title and ownership of any 
                  Work Product, and all rights therein, exclusively in 
                  Employer.
                  
      (d) Non-competition.  In recognition of Employer's need to protect its 
legitimate business interests, Executive hereby covenants and agrees that 
during the term of this Agreement, Executive will not, either directly or 
indirectly, alone or in conjunction with any other party, accept, enter into 
or take any action in furtherance of a Competitive Position.  Executive 
further agrees that for three (3) years following expiration or termination 
of this Agreement for any reason, Executive will not, either directly or 
indirectly, alone or in conjunction with any other party, accept, enter into 
or take any action in furtherance of a Competitive Position within the 
Restricted Territory (other than action to reject an offer of a Competitive 
Position or to notify Employer of the offer pursuant to the requirements of 
the next sentence of this Section 9(d)).

      (e) Non-solicitation of Customers.  Executive hereby covenants and agrees 
that (i) during the term of this Agreement, Executive will not, either 
directly or indirectly, alone or in conjunction with any other party, 
solicit, divert or appropriate or attempt to solicit, divert or appropriate 
any customer or actively sought prospective customer of Employer for the 
purpose of providing such customer or actively sought prospective customer 
with services or products competitive with those offered by Employer during 
the term of this Agreement; and (ii) for a period of three (3) years 
following expiration or termination of the term of this Agreement for any 
reason, Executive will not, either directly or indirectly, alone or in 
conjunction with any other party, solicit, divert or appropriate, or attempt 
to solicit, divert or appropriate any customer or actively sought prospective 
customer of Employer for the purpose of providing such customer or actively 
sought prospective customer with services or products competitive with those 
offered by Employer during the term of this Agreement.

      (f) Nonsolicitation of Employer Personnel.  Executive hereby agrees that 
during the term of this Agreement, except to the extent that he is required 
to do so in connection with his responsibilities hereunder, Executive will 
not, either directly or indirectly, alone or in conjunction with any other 
party, solicit or attempt to solicit any employee, consultant, contractor or 
other personnel of Employer to terminate, alter or lessen such party's 
affiliation with Employer or to violate the terms of any agreement or 
understanding between such party and Employer.  Executive further agrees that 

                                       9

<PAGE>

during the three (3) year period following expiration or termination of this 
Agreement for any reason, Executive will not, either directly or indirectly, 
alone or in conjunction with any other party, solicit or attempt to solicit 
any "key" (as that term is hereinafter defined) employee, consultant, 
contractor or other personnel of Employer to terminate, alter or lessen that 
party's affiliation with Employer or to violate the terms of any agreement or 
understanding between such party and Employer.  For purposes of the preceding 
sentence "key" employees, consultants, contractors or other personnel of 
Employer are those with knowledge of or access to Employer's Trade Secrets or 
Confidential Information.

      (g) Remedies.  Executive agrees that damages at law for Executive's 
violation of any of the covenants in this Section 9 would not be an adequate 
or proper remedy and that, should Executive violate or threaten to violate 
any of the provisions of such covenants, Employer or its successors or 
assigns shall be entitled to seek a temporary or permanent injunction against 
Executive in any court having jurisdiction prohibiting any further violation 
of any such covenants, in addition to any award or damages (compensatory, 
exemplary or otherwise) for such violation.  The Executive agrees not to 
raise as a defense to such action that Employer has an adequate remedy at law.

      (h) Partial Enforcement.  Employer has attempted to limit the rights of 
Executive to compete only to the extent necessary to protect Employer from 
unfair competition. Employer, however, agrees that, if the scope of 
enforceability of any of these restrictive covenants is in any way disputed 
at any time, a court or other trier of fact may modify and enforce such 
covenant to the extent that it believes to be reasonable under the 
circumstances existing at the time.

      (i) Survival.  Notwithstanding any expiration or termination of this 
Agreement, the provisions of this Section 9 shall survive and remain in full 
force and effect, as shall any other provision hereof that, by its terms or 
reasonable interpretation thereof, sets forth obligations that extend beyond 
the termination of this Agreement.

   10. Assignment; Successors and Assigns, etc.  Neither the Employer nor the 
Executive may make any assignment of this Agreement or any interest herein, 
by operation of law or otherwise, without the prior written consent or the 
other party and without such consent any attempted transfer or assignment 
shall be null and of no effect; provided, however, that the Employer may 
assign its rights under this Agreement without the consent of the Executive 
in the event the Employer shall hereafter effect a reorganization, 
consolidate with or merge into any other Person, or transfer all or 
substantially all of its properties or assets to any other Person.  This 
Agreement shall inure to the benefit of and be binding upon the Employer and 
the Executive, their respective successors, executors, administrators, heirs 
and permitted assigns. In the event of the Executive's death prior to the 
completion by the Employer of all payments due him under this Agreement, the 
Employer shall continue such payments to the Executive's beneficiary 
designated in writing to the Employer prior to his death (or to his estate, 
if he fails to make such designation or such beneficiary predeceases him).

                                       10

<PAGE>

   11. Payments to the Executive.  The Employer shall pay the reasonable 
attorneys' fees and disbursements incurred by the Executive in connection 
with the preparation and negotiation of this Agreement.  If litigation shall 
be instituted to enforce or interpret any provision hereof and the Executive 
shall prevail, the Employer will reimburse the Executive for his reasonable 
attorneys' fees and disbursements incurred in such proceeding and will pay 
prejudgment interest at the legal rate then in effect on any money judgment 
or award obtained by the Executive in such proceeding.

   12. Enforceability.  The unenforceability or invalidity of any provision 
of this Agreement shall not affect the validity or enforceability of the 
remaining provisions hereof, but such remaining provisions shall be construed 
and interpreted in such a manner as to carry out fully the intent of the 
parties hereto; provided, however, that should any judicial body interpreting 
this Agreement deem any provision hereof to be unreasonably broad in time, 
territory, scope or otherwise, it is the intent and desire of the parties 
hereto that such judicial body, to the greatest extent possible, reduce the 
breadth of such provision to the maximum legally allowable parameters rather 
than deeming such provision totally unenforceable or invalid.

   13. Waiver.  No waiver, termination or discharge of this Agreement, or any 
of the terms or provisions hereof, shall be binding upon either party hereto 
unless confirmed in writing.  No waiver by either party hereto of any term or 
provision of this Agreement or of any default hereunder shall affect such 
party's right thereafter to enforce such term or provision or to exercise any 
right or remedy in the event of any other default, whether or not similar.

   14. Notices.

      (a) All notices, consents, requests and other communications hereunder 
shall be in writing and shall be sent by hand delivery, by certified or 
registered mail (return-receipt requested), by facsimile or by a recognized 
national overnight courier service as set forth below.

        If to Employer:    Strategic Diagnostics Inc.
                           128 Sandy Drive
                           Newark, Delaware 19713-1147
                           Attn:     Chairman of the Board

        with a copy to:    William B. Marianes, Esq.
                           Troutman Sanders LLP
                           600 Peachtree Street, N.E.
                           Suite 5200
                           Atlanta, Georgia 30308-2216

        If to Executive:   Richard C. Birkmeyer
                           c/o Strategic Diagnostics Inc.
                           128 Sandy Drive  
                           Newark, Delaware 19713-1147

                                       11

<PAGE>

      (b) Notices delivered pursuant to this Section 14 hereof shall be 
deemed given: at the time delivered, if personally delivered, three (3) 
business days after being deposited in the mail, if mailed; and one (1) 
business day after timely delivery to the courier, if by overnight courier 
service. 

      (c) Either party hereto may change the address to which notice is to be 
sent by written notice to the other party hereto in accordance with this 
Section 14.

   15. Headings.  The titles, captions and headings contained in this 
Agreement are inserted by convenience of reference only and are not intended 
to be part of or to affect in any way the meaning or interpretation of this 
Agreement.

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

   17. Amendment.  This Agreement may be amended or modified only by a 
written instrument signed by the Executive and by a duly authorized 
representative of the Employer.

   18. Governing Law.  This is a Delaware contract and shall be construed 
under and be governed in all respects by the laws of the State of Delaware.

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

                             "Employer"

ATTEST:                      ENSYS ENVIRONMENTAL PRODUCTS, INC.


/s/ DAN DAMSTRA              By:       /s/ GROVER C. WRENN     
- ----------------------                 -----------------------
              
                             Title:    PRESIDENT & CEO                        
                                       -----------------------  

                             "Executive"

WITNESS:                     RICHARD C. BIRKMEYER
- ----------------------       ---------------------------------  


                                       12
                                                                              
<PAGE>

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

                             "Employer"

ATTEST:                      ENSYS ENVIRONMENTAL PRODUCTS, INC.


- ----------------------       By:------------------------------ 
                                                   
                             Title:--------------------------- 
                     



                             "Executive"

WITNESS:                     RICHARD C. BIRKMEYER


 /s/ ANNE CAVANAUGH          /s/ RICHARD C. BIRKMEYER        
- ----------------------       --------------------------------  

                                       13

<PAGE>


                                      Exhibit A
                       Form of Incentive Stock Option Agreement
  
                                 AMENDED AND RESTATED
                          ENSYS ENVIRONMENTAL PRODUCTS, INC.
                              1995 STOCK INCENTIVE PLAN
                           INCENTIVE STOCK OPTION AGREEMENT

100,000                                          December 30, 1996 
No. of Shares                                    Date of Grant


    Pursuant to the Amended and Restated EnSys Environmental Products, Inc. 
1995 Stock Incentive Plan (the "Plan"), EnSys Environmental Products, Inc. 
(the "Company") hereby grants to Richard C. Birkmeyer (the "Optionee") an 
option (the "Option") to purchase on or prior to December 30 , 2006 (the 
"Expiration Date') all or any part of One Hundred Thousand (100,000) shares 
(the "Option Shares") of "Stock" (as defined in Section 2 of the Plan) at a 
price of $ per share of Stock in accordance with the schedule set forth in 
Section 1 hereof and subject to the terms and conditions set forth 
hereinafter and in the Plan.  This Option shall be construed in a manner to 
qualify it as an incentive stock option under Section 422 of the Internal 
Revenue Code of 1986, as amended (the "Code"), to the maximum extent 
permitted.

   1. Vesting of Option.  Subject to the provisions of Sections 4 and 5 hereof
and the discretion of the "Board" (as defined in Section 1 of the Plan) to 
accelerate the vesting schedule hereunder, this Option shall become vested 
and exercisable with respect to the following number of Option Shares 
according to the timetable set forth below:

                   Number of Shares of Stock   Cumulative Number of
                     Vested and Becoming      Shares of Stock Available
   Date             Available for Exercise         for Exercise
   ----             ----------------------         ------------

December 30, 1996           25,000                    25,000

December 30, 1996           25,000                    50,000

December 30, 1996           25,000                    75,000

December 30, 1996           25,000                   100,000


   2. Manner of -Exercise.  The Optionee may exercise this Option only in the 
following manner: from time to time on or prior to the Expiration Date of 
this Option, the Optionee may give written notice to the Board of his 
election to purchase some or all of the vested Option Shares purchasable at 
the time of such notice as determined in accordance with the cumulative 
number of shares of Stock available for exercise specified in the third 
column of the schedule set forth in Section 1 hereof.  Said notice shall 
specify the number of shares of Stock to be purchased. 

      (a) Payment of the purchase price for the Option Shares may be made by 

                                       14

<PAGE>

one or more of the following methods: (i) in cash, by certified or bank check 
or other instrument acceptable to the Board; or (ii) in the form of shares of 
Stock that are not then subject to restrictions under any Company plan 
(subject to the Board's discretion); or (iii) by the Optionee delivering to 
the Company a properly executed exercise notice together with irrevocable 
instructions to a broker to promptly deliver to the Company cash or a check 
payable and acceptable to the Company to pay the option purchase price; 
provided that in the event the Optionee chooses to pay the option purchase 
price as so provided, the Optionee and the broker shall comply with such 
procedures and enter into such agreements of indemnity and other agreements 
as the Board shall prescribe as a condition of such payment procedure.  
Payment instruments will be received subject to collection.

      (b) The delivery of certificates representing the Option Shares will be 
contingent upon the Company's receipt from the Optionee of full payment 
therefor, as set forth above, and any agreement, statement or other evidence 
as the Company may require to satisfy itself that the issuance of Option 
Shares to be purchased pursuant to the exercise of Options under this 
Agreement and any subsequent resale of the shares of Stock will be in 
compliance with applicable laws and regulations.

      (c) If requested upon the exercise of this Option, certificates for 
shares may be issued in the name of the Optionee jointly with another person 
or in the name of the executor or administrator of the Optionee's estate.

      (d) Notwithstanding any other provision hereof or of the Plan, no 
portion of this Option shall be exercisable after the Expiration Date hereof.

   3. Non-transferability of Option.  This Option shall not be transferable 
by the Optionee otherwise than by will or by the laws of descent and 
distribution and this Option shall be exercisable, during the Optionee's 
lifetime, only by the Optionee or his legal representative.

   4. Termination of Employment.  If the Optionee's employment by the Company 
or a Subsidiary (as defined in Section 1 of the Plan) is terminated, the 
period within which to exercise the Option shall be subject to the provisions 
set forth below.  For this purpose, an approved leave of absence or a 
transfer of employment from the Company to a Subsidiary, from a Subsidiary to 
the Company or from a Subsidiary to another Subsidiary shall not be deemed a 
"termination of Optionee's employment.'

      (a) Termination Due to Death.  If the Optionee's employment terminates 
by reason of death, any Option held by the Optionee may be exercised, to the 
extent exercisable at the date of death, by the Optionee's legal 
representative or legatee for a period of 180 days from the date of death or 
until the Expiration Date, if earlier.

      (b) Termination Due to Disability.  If the Optionee's employment 
terminates by reason of Disability (as defined in Section 1 of the Plan), any 

                                       15

<PAGE>

Option held by the optionee may be exercised, to the extent exercisable on 
the date of termination, for a period of twelve months from the date of 
termination or until the Expiration Date, if earlier.

      (c) Termination for Cause.  If the Optionee's employment terminates for 
Cause (as defined in Section 1 of the Plan), any Option held by the Optionee 
shall terminate immediately and be of no further force and effect.

      (d) Other Termination.  If the Optionee's employment terminates for any 
reason other than death, Disability or Cause, and unless otherwise determined 
by the Board, any Option held by the Optionee may be exercised, to the extent 
exercisable on the date of termination for a period of one year from the date 
of termination or until the Expiration Date, if earlier.

      (e) Termination without Cause or for Good Reason.  Notwithstanding 
anything herein to the contrary, in the event the Company terminates 
Optionee's employment without Cause or Optionee terminates his employment for 
Good Reason' (as hereinafter defined), all of the Options granted pursuant 
to Section 1 hereof shall immediately become vested and exercisable in 
accordance with the terms hereof.  For purposes of this Agreement, each of 
the following events shall constitute  Good Reason' for Optionee to terminate 
his employment with the Company:

          (i)     Failure of the Board to elect Optionee to the 
                  office of Chief Executive Officer of the Company or to 
                  continue the Optionee in such office;

          (ii)    Any material breach by the Company of any provision of 
                  any Employment Agreement then in effect with Optionee; or

          (iii)   Election by the Company not to extend the term of 
                  Optionee's employment under any Employment Agreement then 
                  in effect with Optionee.

   5. Change of Control.  In the event of a "Change of Control" (as defined 
in Section 12 of the Plan), each Option will automatically become exercisable 
to the extent provided in Section 12 of the Plan, as in effect on the date of 
grant of this Option.

   6. Option Shares.  The Option Shares are shares of Stock of the Company as 
constituted on the date of this Option, which are subject to adjustment as 
provided in Section 3(b) of the Plan.

   7. No Special Employment Rights.  This Option will not confer upon the 
Optionee any right with respect to continuance of employment by the Company 
or a Subsidiary, nor will it interfere in any way with right of the 
Optionee's employer to terminate the Optionee's employment at any time.

                                       16

<PAGE>

   8. Rights as a Shareholder.  The Optionee shall have no rights as a 
shareholder with respect to any shares of Stock which may be purchased by 
exercise of this Option unless and until a certificate or certificates 
representing such shares are duly issued and delivered to the Optionee.  
Except as otherwise expressly provided in the Plan, no adjustment shall be 
made for dividends or other rights for which the record date is prior to the 
date such stock certificate is issued.

   9. Qualification under Section 422.  It is understood and intended that 
the option granted hereunder shall qualify as an "incentive stock option" as 
defined in Section 422 of the Code to the maximum extent permitted by law.  
Accordingly, the Employee understands that the loss of the benefits of an 
incentive stock option under Section 422 of the Code may result from a sale 
or other disposition of any shares of Stock acquired upon exercise of the 
Option within the one-year period beginning on the day after the day of the 
transfer of such shares of Stock to him, nor within the two-year period 
beginning on the day after the grant of the Option.  If the Employee intends 
to dispose or does dispose (whether by sale, gift, transfer or otherwise) of 
any such shares of Stock within said periods, he will notify the Company 
within thirty (30) days after such disposition.  In addition, no more than 
$100,000 of the aggregate fair market value (as defined in the Plan) of Stock 
Options (as defined in Section 1 of the Plan) granted under the Plan may 
become exercisable for the first time by the Optionee during any calendar 
year and be treated as incentive stock options under Section 422 of the Code.

  10. Tax Withholding.  No later than the date as of which part or all of the 
value of any of the Option Shares first becomes includable in the Optionee's 
gross income for Federal tax purposes, the Optionee shall make arrangements 
with the Company in accordance with Section 8 of the Plan regarding the 
payment of any federal, state or local taxes required to be withheld with 
respect to the income.

  11. The Plan.  In the event of any discrepancy or inconsistency between 
this Agreement and the Plan, the terms and conditions of the Plan shall 
control, provided that, it is understood and acknowledged that in the event 
of any termination of Optionee's employment other than due to death, 
disability or for cause, the provisions of Sections 4(d) and 4(e) of this 
Agreement shall control.

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

  13. Miscellaneous.  Notices hereunder shall be mailed or delivered to the 
Company at its principal place of business and shall be mailed or delivered 
to Optionee at the address set forth below or, in either case, at such other 
address as one party may subsequently furnish to the other party in writing.

                                       17

<PAGE>

                        ENSYS ENVIRONMENTAL PRODUCTS, INC.


                        By:       /s/ ROBERT E. FINNIGAN               
                           ------------------------------------------
                           Member of the Compensation Committee of the Board of
                           Directors of EnSys Environmental Products, Inc.


    Receipt of the foregoing Option is acknowledged and its terms and 
conditions are hereby agreed to:

                                                                     
                           ------------------------------------------
                           Richard C. Birkmeyer (Optionee)

Date:------------------    Address:----------------------------------
                              
                           ------------------------------------------

                                       18



<PAGE> 

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

  13. Miscellaneous.  Notices hereunder shall-be mailed or delivered to the 
Company at its principal place of business and shall be mailed or delivered 
to optioned at the address set forth below or, in either case, at such other 
address as one party may subsequently furnish to the other party in writing.

                        ENSYS ENVIRONMENTAL PRODUCTS, INC.


                        By: ------------------------------------------
                            Member of the Compensation Committee of 
                            the Board of Directors of EnSys Environmental
                            Products, Inc.


    Receipt of the foregoing Option is acknowledged and its terms and 
conditions are hereby agreed to:

                                    /s/  RICHARD C. BIRKMEYER               
                             ------------------------------------------
                             Richard C. Birkmeyer (Optionee)

Date:   December 30, 1996    Address:      10 Stage Rd.                    
       ------------------             ----------------------------     
                                           Newark, DE  19711                  
                             -------------------------------------   

                                       19

<PAGE>


                                                                 Exhibit 10.15

                              STRATEGIC DIAGNOSTICS INC.
                                   128 Sandy Drive
                             Newark, Delaware 19173-1147

                                  December 30, 1996

Mr. Grover C. Wrenn
c/o Strategic Diagnostics Inc.
128 Sandy Drive
Newark, Delaware 19173-1147

Dear Mr. Wrenn:

    This letter sets forth the. agreement between you and Strategic 
Diagnostics Inc. (formerly named EnSys Environmental Products, Inc. 
("Company")) regarding your continued role in the Company following today's. 
consummation of the Company's merger with Strategic Diagnostics Inc.

    We have agreed that, effective today, you will cease serving the company 
as President and Chief Executive officer and that, pursuant to action 
previously taken by the.  Company's Board of Directors, you will become 
Chairman of the Company's Board of Directors to serve at the will of the 
Board in accordance with the Bylaws. In addition to the duties set forth in 
the Bylaws. you will assist the Company in investor relations matters, 
including providing counsel as to public statements, relationships with the 
investment community and presentations to analysts, and as to such other 
matters as you agree to undertake at the request of the Board.  While you 
will remain an employee of the Company, this position will not require your 
full working time and attention, and you will be free to pursue other 
employment if you wish.

    As compensation for the services described above, you will receive 
salary at the rate of $200,000 per year, subject to an annual increase as 
determined by the compensation Committee of the Board of Directors.  Forty 
percent (40%) of your salary shall be payable in periodic installments in 
accordance with the Company's usual practice for its senior executives.  
Each month, you will provide the Board with a written summary of your 
activities as Chairman.  To the extent that the services described in your 
summary occupied more than eight days during the month (representing an 
average of two days out of each of four five-day work weeks), you will be 
entitled to an additional pro rata portion of your salary.

    As Chairman, you also will be entitled to (i) to continue to participate 
in any and all employee benefit plans, medical insurance plans, life 
insurance plans, disability income plans, retirement plans and other benefit 
plans from time to time in effect for senior executives of the Company, (ii) 
to receive fringe benefits ordinarily and customarily provided by the 
Company to its senior officers, and (iii) to receive prompt reimbursement 
for all travel and other business expenses incurred by you in the 
performance of your duties and responsibilities.

    As further compensation, you have been granted effective today, an 
option in the form attached to purchase 100,000 shares of the Company's 
common stock under the Company's 1995 Stock Incentive Plan at an exercise 
price equal to today's fair market value.  The grant of an option pursuant 
to this paragraph shall be without prejudice to further grants to you in the 
future under any plan adopted by the Company.

    We also have agreed that the Employment Agreement between you and the 
Company dated April 11, 1995 will terminate today and that you will be 
entitled to receive the benefits described in Section 6(e)(i)-(iv) of that 
Agreement in addition to the compensation and benefits described above.  The 
Company shall not be entitled to any set-off against, or reduction of, such 
amounts for any reason whatsoever.

    The Company shall reimburse up to $5,000 of documented attorneys' fees 
and disbursements incurred by you in connection with the preparation and 
negotiation of this Agreement.  This paragraph does not extend to 
reimbursement of attorneys' fees and disbursement associated with any 
amendment or termination of this Agreement or any other matter.


                                   Very truly yours,
 
                                   STRATEGIC DIAGNOSTICS INC.
                                   (formerly named ENSYS
                                   ENVIRONMENTAL PRODUCTS, INC.)


                                   By:     /s/ Robert E. Finnigan
                                       -----------------------------

                                   Title:  Director
                                          --------------------------

Agreed and accepted as of
the date first above written:


 /s/Grover C. Wrenn
- ---------------------------------
Grover C. Wrenn


<PAGE>

                                                        EXHIBIT 10.16




                                   December 30, 1996 





To each of the Original Holders
listed on the signature
pages hereto

Dear Sirs:

         This agreement is made in connection with the Agreement and Plan of
Merger, dated as of October 11, 1996 (the "Merger Agreement") by and between
Strategic Diagnostics Inc., a Delaware corporation ("SDI") and EnSys
Environmental Products, Inc., a Delaware corporation (the "Company"), pursuant
to which SDI shall be merged with and into the Company in accordance with the
applicable provisions of the Delaware General Corporation Law and the terms of
the Merger Agreement.  The merger consideration received by the Original Holders
(as hereinafter defined) includes, common stock, par value $.01, of the Company
(the "Common Stock"), Series A Convertible Preferred Stock (the "Preferred
Stock"), par value $.01, of the Company that is convertible into shares of
Common Stock, and warrants (the "Warrants") to purchase shares of Common Stock. 
The Company covenants and agrees with each of you (the "Original Holders") as
follows:

         1.   Certain Definitions.  As used in this Agreement, the following
terms shall have the following respective meanings:

              "Commission" shall mean the Securities and Exchange Commission,
or any other federal agency at the time administering the Securities Act.

              "Common Stock" shall mean the Common Stock, $0.01 par value, of
the Company, as constituted as of the date of this Agreement.

              "Conversion Shares" shall mean shares of Common Stock issued upon
conversion of the Preferred Shares, together with any shares of Common Stock
issued on or with respect to other Conversion Shares by way of a stock split,
stock dividend or the like.

              "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended, or any similar federal statute, and the rules and regulations of the
Commission thereunder, all as the same shall be in effect at the time.

<PAGE>

              "Perkin-Elmer Shares" shall mean 1,308,724 shares of Common Stock
issued pursuant to the Merger Agreement to The Perkin-Elmer Corporation.

              "Preferred Shares" shall mean an aggregate of 2,164,362 shares of
Preferred Stock issued pursuant to the Merger Agreement to DSV Partners IV,
Edison Venture Fund II, L.P. and Edison Venture Fund II-Pa, L.P. 

              "Registration Expenses" shall mean the expenses so described in
Section 8.

              "Restricted Stock" shall mean the Conversion Shares, Perkin-Elmer
Shares, and Warrant Shares, excluding Conversion Shares, Perkin-Elmer Shares,
and Warrant Shares which (a) have been registered under the Securities Act
pursuant to an effective registration statement filed thereunder and disposed of
in accordance with the registration statement covering them or (b) are eligible
for public sale without limitation as to amount pursuant to Rule 144 or Rule 145
under the Securities Act.

              "Securities Act" shall mean the Securities Act of 1933, as
amended, or any similar federal statute, and the rules and regulations of the
Commission thereunder, all as the same shall be in effect at the time.

              "Selling Expenses" shall mean the expenses so described in
Section 8.

              "Transfer" shall include any disposition of any Preferred Shares,
Perkin-Elmer Shares, Conversion Shares and Warrant Shares or of any interest
therein which would constitute a sale thereof within the meaning of the
Securities Act.

              "Warrant Shares" shall mean shares of Common Stock issued upon
exercise of the Warrants, together with any shares of Common Stock issued on or
with respect to other Warrant Shares by way of stock split, stock dividend or
the like.

         2.   Restrictive Legend.  The Preferred Shares, Perkin-Elmer Shares,
Conversion Shares and Warrant Shares shall not be transferable, except upon the
conditions specified in Sections 2 and 3 hereof, which conditions are intended
to ensure compliance with the provisions of the Securities Act in respect of the
Transfer thereof.  Each certificate representing Preferred Shares, Perkin-Elmer
Shares, Conversion Shares or Warrant Shares shall, except as otherwise provided
in this Section 2 or in Section 3, be stamped or otherwise imprinted with a
legend substantially in the following form:

                                       2

<PAGE>

    "THIS SECURITY HAS NOT BEEN REGISTERED FOR SALE UNDER THE SECURITIES
    ACT OF 1933 AND MAY NOT BE TRANSFERRED OR OTHERWISE DISPOSED OF EXCEPT
    IN COMPLIANCE WITH THAT CERTAIN REGISTRATION RIGHTS AGREEMENT, DATED
    DECEMBER 30, 1996 AMONG THE COMPANY AND THE SIGNATORIES THERETO AND
    THE SECURITIES ACT OF 1933, AS AMENDED."

         3.   Notice of Proposed Transfer.  Prior to any proposed Transfer of
any Preferred Shares, Perkin-Elmer Shares, Conversion Shares or Warrant Shares
(other than under the circumstances described in Sections 4 or 5), the holder
thereof shall give written notice to the Company of its intention to effect such
Transfer.  Each such notice shall describe the manner of the proposed Transfer
and, if requested by the Company, shall be accompanied by an opinion of counsel
satisfactory to the Company to the effect that the proposed Transfer may be
effected without registration under the Securities Act, whereupon the holder of
such stock shall be entitled to Transfer such stock in accordance with the terms
of its notice; provided, however, that no such opinion of counsel shall be
required for a Transfer to one or more partners of an Original Holder (in the
case of an Original Holder that is a partnership) or to an affiliated
corporation of an Original Holder (in the case of an Original Holder that is a
corporation), if, with respect to such Transfer, the transferee agrees in
writing to be subject to the terms of Sections 2, 3 and 10 hereof, to the same
extent as if such transferee were originally a signatory to this Agreement. 
Each certificate for Preferred Shares, Perkin-Elmer Shares, Conversion Shares or
Warrant Shares transferred as above provided shall bear the legend set forth in
Section 2, except that such certificate shall not bear such legend if (i) such
Transfer is in accordance with the provisions of Rule 144 (or any other rule
permitting public sale without registration under the Securities Act) or (ii)
the opinion of counsel referred to above is to the further effect that the
transferee and any subsequent transferee (other than an affiliate of the
Company) would be entitled to Transfer such securities in a public sale without
registration under the Securities Act.  The restrictions provided for in this
Section 3 shall not apply to securities which are not required to bear the
legend prescribed by Section 2 in accordance with the provisions of that
Section.

         4.   Required Registration.  (a) At any time after the date which is
six (6) months from the date of this Agreement, any two (2) of the three (3)
holders of Restricted Stock acting together as a group may request on two (2)
separate occasions the Company to register under the Securities Act all or any
portion of the shares of Restricted Stock held by such requesting holders for
sale in the manner specified in such notice, provided that the shares of
Restricted Stock for which registration has been

                                       3

<PAGE>


requested shall constitute at least the lesser of (i) 50% of the total shares 
of Restricted Stock originally issued to such holders, or (ii) the remaining 
shares of Restricted Stock held by such holders, but in any event not less 
than 1,500,000 shares of Restricted Stock.  For purposes of this Section 4 
and Sections 5, 12(a) and 12(d), the term "Restricted Stock" shall be deemed 
to include the number of shares of Restricted Stock which would be issuable 
to a holder of Preferred Shares upon conversion of all shares of Preferred 
Stock held by such holder at such time and the number of shares of Restricted 
Stock which would be issuable to a holder of Warrants upon exercise of all 
Warrants held by such holder at such time, provided, however, that the only 
securities which the Company shall be required to register pursuant hereto 
shall be shares of Common Stock, and provided, further, however, that, in any 
underwritten public offering contemplated by this Section 4 or Section 5, the 
holders of Preferred Shares and Warrants shall be entitled to sell such 
Preferred Shares and Warrants to the underwriters for conversion or exercise, 
respectively, and sale of the shares of Common Stock issued upon conversion 
thereof.  Notwithstanding anything to the contrary contained herein, no 
request may be made under this Section 4 within 180 days after the effective 
date of a registration statement filed by the Company covering a firm 
commitment underwritten public offering in which the holders of Restricted 
Stock shall have been entitled to join pursuant to Section 5 and in which 
there shall have been effectively registered at least fifty percent (50%) of 
the shares of Restricted Stock as to which registration shall have been 
requested.

              (b)  Following receipt of any notice under this Section 4, the
Company shall immediately notify all holders of Restricted Stock from whom
notice has not been received and shall use all reasonable efforts to register
under the Securities Act, for public sale in accordance with the method of
disposition specified in such notice from requesting holders, the number of
shares of Restricted Stock specified in such notice (and in all notices received
by the Company from other holders within 30 days after the giving of such notice
by the Company).  If such method of disposition shall be an underwritten public
offering, the Company may designate the managing underwriter of such offering,
subject to the approval of the holders of a majority of the shares of Restricted
Stock to be sold in such offering, which approval shall not be unreasonably
withheld, conditioned or delayed.  The Company shall be obligated to register
Restricted Stock pursuant to this Section 4 on two occasions only, provided,
however, that such obligation shall be deemed satisfied only when a registration
statement covering at least the lesser of (i) 50% of the total shares of
Restricted Stock originally issued or (ii) 75% of the shares of Restricted Stock
specified in notices

                                       4

<PAGE>


received as aforesaid, for sale in accordance with the method of disposition 
specified by the requesting holders, shall have become effective; provided, 
further, however, that any registration proceeding begun pursuant to this 
Section 4 which is subsequently withdrawn at the request of the holders of a 
majority of the shares of Restricted Stock requested to be registered shall 
count toward such two registration statements which the holders of the shares 
of Restricted Stock have the right to cause the Company to effect pursuant to 
this Section 4.

              (c)  The Company shall be entitled to include in any registration
statement referred to in this Section 4, for sale in accordance with the method
of disposition specified by the requesting holders, shares of Common Stock to be
sold by the Company for its own account, or any issued and outstanding shares of
Common Stock to be sold by others except as and to the extent that, in the
opinion of the managing underwriter (if such method of disposition shall be an
underwritten public offering), such inclusion would adversely affect the
marketing of the Restricted Stock to be sold.

         5.   Incidental Registration.  If the Company at any time (other than
pursuant to Section 4) proposes to register any of its securities under the
Securities Act for sale to the public, whether for its own account or for the
account of other security holders or both (except with respect to registration
statements on Forms S-4 or another form not available for registering the
Restricted Stock for sale to the public), each such time it will give written
notice to all holders of outstanding Restricted Stock of its intention so to do.
Upon the written request of any such holder received by the Company within 30
days after the giving of any such notice by the Company, to register any of its
Restricted Stock (which request shall state the intended method of disposition
thereof), the Company will use all commercially reasonable efforts (subject to
the rights of any holders of securities of the Company, other than the Company,
included in such registration) to cause the Restricted Stock as to which
registration shall have been so requested to be included in the securities to be
covered by the registration statement proposed to be filed by the Company, all
to the extent requisite to permit the sale or other disposition by the holder
(in accordance with its written request) of such Restricted Stock so registered.
In the event that any registration pursuant to this Section 5 shall be, in whole
or in part, an underwritten public offering of Common Stock, the number of
shares of Restricted Stock as a group to be included in such an underwriting may
be reduced (pro rata among the holders of Restricted Stock based upon the number
of shares of Restricted Stock owned by such holders) if and to the extent that
the managing underwriter shall be of the opinion that such inclusion would
adversely affect the

                                       5

<PAGE>


marketing of the securities to be sold by the Company or other holder of 
securities of the Company.  Notwithstanding the foregoing provisions, the 
Company may withdraw any registration statement referred to in this Section 5 
without thereby incurring any liability to the holders of Restricted Stock.

         6.   Holdback Agreement.  If the Company at any time shall register
shares of Common Stock under the Securities Act (including any registration
pursuant to Sections 4 and 5) for sale to the public, the Original Holders shall
not sell publicly, make any short sale of, grant an option for the purchase of,
or otherwise dispose of, any shares of Restricted Stock (other than those shares
of Common Stock included in such registration pursuant to Sections 4 or 5)
without the prior written consent of the Company for a period designated by the
Company in writing to the holders of shares of Restricted Stock, which period
shall not begin more than 10 days prior to the effectiveness of the registration
statement pursuant to which such public offer will be made and shall not last
more than 180 days after the effective date of such registration statement.

         7.   Registration Procedures.  If and whenever the Company is required
by the provisions of Sections 4 or 5 to use all reasonable efforts or all
commercially reasonable efforts to effect the registration of any shares of
Restricted Stock under the Securities Act, the Company will, as expeditiously as
possible:

              (a)  prepare and file with the Commission a registration
statement on Form S-1 or Form S-3 if available with respect to such securities
and use all reasonable efforts to cause such registration statement to become
and remain effective for the period of the distribution contemplated thereby
(determined as hereinafter provided) (subject, in the case of any Incidental
Registration, to the rights of the Company to abandon any such registration as
set forth in Section 5);

              (b)  with respect to any registration pursuant to Section 4,
prepare and file with the Commission such amendments and supplements to such
registration statement and the prospectus used in connection therewith as may be
necessary to keep such registration statement effective for the period specified
above and comply with the provisions of the Securities Act with respect to the
disposition of all Restricted Stock covered by such registration statement in
accordance with the sellers' intended method of disposition set forth in such
registration statement for such period;

              (c)   furnish to each seller of Restricted Stock and to each
underwriter such number of copies of the registration

                                       6

<PAGE>


statement and the prospectus included therein (including each preliminary 
prospectus) as such persons reasonably may request in order to facilitate the 
public sale or other disposition of the Restricted Stock covered by such 
registration statement;

              (d)  use all reasonable efforts to register or qualify the
Restricted Stock covered by such registration statement under the securities or
"blue sky" laws of such jurisdictions as the sellers of Restricted Stock or, in
the case of an underwritten public offering, the managing underwriter reasonably
shall request, provided, however, that the Company shall not for any such
purpose be required to qualify generally to transact business as a foreign
corporation in any jurisdiction where it is not so qualified, to consent to
general service of process in any such jurisdiction or submit to liability for
state or local taxes where it is not otherwise liable for such taxes;

              (e)  use all reasonable efforts to list the Restricted Stock
covered by such registration statement with any securities exchange on which the
Common Stock of the Company is then listed;

              (f)  immediately notify each seller of Restricted Stock and each
underwriter under such registration statement, at any time when a prospectus
relating thereto is required to be delivered under the Securities Act, of the
happening of any event of which the Company has knowledge as a result of which
the prospectus contained in such registration statement, as then in effect,
includes an untrue statement of a material fact or omits to state a material
fact required to be stated therein or necessary to make the statements therein
not misleading in light of the circumstances then existing;

              (g)  if the offering is underwritten and at the request of any
seller of Restricted Stock, use all reasonable efforts to furnish on the date
that Restricted Stock is delivered to the underwriters for sale pursuant to such
registration: (i) an opinion, dated such date, of the counsel representing the
Company for the purposes of such registration, in form and substance as is
customarily given to underwriters in an underwritten public offering, addressed
to the underwriters, if any, and to the seller or sellers making such request;
and (ii) at the request of either the underwriters or sellers of Restricted
Stock, a letter dated such date from the independent public accountants retained
by the Company, addressed to the underwriters and to such seller, stating that
they are independent public accountants within the meaning of the Securities Act
and that, in the opinion of such accountants, the financial statements of the
Company included in the registration statement or the prospectus, or any
amendment or supplement

                                       7

<PAGE>


thereof, comply as to form in all material respects with the applicable 
accounting requirements of the Securities Act, and such letter shall 
additionally cover such other financial matters (including information as to 
the period ending no more than five business days prior to the date of such 
letter) with respect to such registration as such underwriters reasonably may 
request; and

              (h)  make reasonably available for inspection by each seller of
Restricted Stock, any underwriter participating in any distribution pursuant to
such registration statement, and any attorney, accountant or other agent
retained by such seller or underwriter, all financial and other records,
pertinent corporate documents and properties of the Company, and use all
reasonable efforts to cause the Company's officers, directors and employees to
supply all information reasonably requested by any such seller, underwriter,
attorney, accountant or agent in connection with such registration statement, in
each case as and to the extent necessary to permit the sellers to conduct a
reasonable investigation within the meaning of the Securities Act.  To minimize
disruption and expense to the Company during the course of the registration
process, the sellers will act through a single law firm and a single accounting
firm and will enter into confidentiality agreements with the Company in form and
substance reasonably satisfactory to the Company and the sellers prior to
receiving any confidential or proprietary information of the Company.

         For purposes of Section 7(a) and 7(b) and of Section 4(c), the period
of distribution of Restricted Stock in a firm commitment underwritten public
offering shall be deemed to extend until each underwriter has completed the
distribution of all securities purchased by it, and the period of distribution
of Restricted Stock in any other registration shall be deemed to extend until
the earlier of the sale of all Restricted Stock covered thereby, or nine (9)
months after the effective date thereof.

         In connection with each registration hereunder, the sellers of
Restricted Stock will furnish to the Company in writing such information with
respect to themselves and the proposed distribution by them as reasonably shall
be necessary in order to assure compliance with federal and applicable state
securities laws.

         In connection with each registration pursuant to Sections 4 or 5
covering an underwritten public offering, the Company and each seller agree to
enter into a written agreement with the managing underwriter selected in the
manner herein provided in such form and containing such provisions as are

                                       8

<PAGE>

customary in the securities business for such an arrangement between such
underwriter and companies of the Company's size and investment stature.

         8.   Expenses.  All expenses (both third party and internal) incurred
by the Company in complying with Sections 4 and 5, including, without
limitation, all registration and filing fees, printing expenses, fees and
disbursements of counsel and independent public accountants for the Company,
fees and expenses (including counsel fees) incurred in connection with complying
with state securities or "blue sky" laws, fees of the National Association of
Securities Dealers, Inc., transfer taxes, fees of transfer agents and
registrars, costs of insurance, but excluding any Selling Expenses, are called
"Registration Expenses".  All underwriting discounts and selling commissions
applicable to the sale of Restricted Stock, and all fees and disbursements of
legal counsel for the sellers of Restricted Stock, are called "Selling
Expenses".

         The Company will pay all Registration Expenses in connection with each
registration statement under Sections 4 or 5. All Selling Expenses in connection
with each registration statement under Sections 4 or 5 shall be borne by the
participating sellers in proportion to the number of shares sold by each, or by
such participating sellers other than the Company (except to the extent the
Company shall be a seller) as they may agree.

         9.   Indemnification and Contribution.  (a) In the event of a
registration of any of the Restricted Stock under the Securities Act pursuant to
Sections 4 or 5, the Company will indemnify and hold harmless each seller of
such Restricted Stock thereunder, each underwriter of such Restricted Stock
thereunder and each other person, if any, who controls such seller or
underwriter within the meaning of the Securities Act, against any losses,
claims, damages or liabilities, joint or several, to which such seller,
underwriter or controlling person may become subject under the Securities Act or
otherwise, insofar as such losses, claims, damages or liabilities (or actions in
respect thereof) arise out of or are based upon any untrue statement or alleged
untrue statement of any material fact contained in any registration statement
under which such Restricted Stock was registered under the Securities Act
pursuant to Sections 4 or 5, any preliminary prospectus or final prospectus
contained therein, or any amendment or supplement thereof, or arise out of or
are based upon the omission or alleged omission to state therein a material fact
required to be stated therein or necessary to make the statements therein not
misleading, and will reimburse each such seller, each such underwriter and each
such controlling person for any legal or other expenses reasonably incurred by

                                       9

<PAGE>

them in connection with investigating or defending any such loss, claim, damage,
liability or action, provided, however, that the Company will not be liable in
any such case if and to the extent that any such loss, claim, damage or
liability arises out of or is based upon an untrue statement or alleged untrue
statement or omission or alleged omission so made in conformity with information
furnished by any such seller, any such underwriter or any such controlling
person in writing specifically for use in such registration statement or
prospectus.

              (b)  In the event of a registration of any of the Restricted
Stock under the Securities Act pursuant to Sections 4 or 5, each seller of such
Restricted Stock thereunder, severally and not jointly, will indemnify and hold
harmless the Company, each person, if any, who controls the Company within the
meaning of the Securities Act, each officer of the Company who signs the
registration statement, each director of the Company, each underwriter and each
person who controls any underwriter within the meaning of the Securities Act,
against all losses, claims, damages or liabilities, joint or several, to which
the Company or such officer, director, underwriter or controlling person may
become subject under the Securities Act or otherwise, insofar as such losses,
claims, damages or liabilities (or actions in respect thereof) arise out of or
are based upon any untrue statement or alleged untrue statement of any material
fact contained in the registration statement under which such Restricted Stock
was registered under the Securities Act pursuant to Sections 4 or 5, any
preliminary prospectus or final prospectus contained therein, or any amendment
or supplement thereof, or arise out of or are based upon the omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, and will reimburse the
Company and each such officer, director, underwriter and controlling person for
any legal or other expenses reasonably incurred by them in connection with
investigating or defending any such loss, claim, damage, liability or action,
provided, however, that such seller will be liable hereunder in any such case if
and only to the extent that any such loss, claim, damage or liability arises out
of or is based upon an untrue statement or alleged untrue statement or omission
or alleged omission made in reliance upon and in conformity with information
pertaining to such seller, as such, furnished in writing to the Company by such
seller specifically for use in such registration statement or prospectus, and
provided, further, however, that the liability of each seller hereunder shall
not in any event exceed the proceeds received by such seller from the sale of
Restricted Stock covered by such registration statement.

                                      10

<PAGE>

              (c)  Promptly after receipt by an indemnified party hereunder of
notice of the commencement of any action, such indemnified party shall, if a
claim in respect thereof is to be made against the indemnifying party hereunder,
notify the indemnifying party in writing thereof, but the omission so to notify
the indemnifying party shall not relieve it from any liability which it may have
to such indemnified party other than under this Section 9 and shall only relieve
it from any liability which it may have to such indemnified party under this
Section 9 if and to the extent the indemnifying party is prejudiced by such
omission.  In case any such action shall be brought against any indemnified
party and it shall notify the indemnifying party of the commencement thereof,
the indemnifying party shall be entitled to participate in and, to the extent it
shall wish, to assume and undertake the defense thereof with counsel
satisfactory to such indemnified party, and, after notice from the indemnifying
party to such indemnified party of its election so to assume and undertake the
defense thereof, the indemnifying party shall not be liable to such indemnified
party under this Section 9 for any legal expenses subsequently incurred by such
indemnified party in connection with the defense thereof other than reasonable
costs of investigation and of liaison with counsel so selected, provided,
however, that, if the defendants in any such action include both the indemnified
party and the indemnifying party and the indemnified party shall have reasonably
concluded that there may be reasonable defenses available to it which are
different from or additional to those available to the indemnifying party or if
the interests of the indemnified party reasonably may be deemed to conflict with
the interests of the indemnifying party, the indemnified party shall have the
right to select a separate counsel and to assume such legal defenses and
otherwise to participate in the defense of such action, with the expenses and
fees of such separate counsel and other expenses related to such participation
to be reimbursed by the indemnifying party as incurred.

              (d)  In order to provide for just and equitable contribution to
joint liability under the Securities Act in any case in which either (i) any
holder of Restricted Stock exercising rights under this Agreement, or any
controlling person of any such holder, makes a claim for indemnification
pursuant to this Section 9 but it is judicially determined (by the entry of a
final judgment or decree by a court of competent jurisdiction and the expiration
of time to appeal or the denial of the last right of appeal) that such
indemnification may not be enforced in such case notwithstanding the fact that
this Section 9 provides for indemnification in such case, or (ii) contribution
under the Securities Act may be required on the part of any such selling holder
or any such controlling person in circumstances for which indemnification is
provided under this Section 9; then, and in

                                      11

<PAGE>

each such case, the Company and such holder will contribute to the aggregate 
losses, claims, damages or liabilities to which they may be subject (after 
contribution from others) as is appropriate to reflect the relative fault of 
the Company and such holder in connection with the statements or omissions 
which resulted in such losses, claims, damages or liabilities, as well as the 
relative benefit received by the Company and such holder as a result of the 
offering in question, it being understood that the parties acknowledge that 
the overriding equitable consideration to be given effect in connection with 
this provision is the ability of one party or the other to correct the 
statement or omission which resulted in such losses, claims, damages or 
liabilities, and that it would not be just and equitable if contribution 
pursuant hereto were to be determined by pro rata allocation or by any other 
method of allocation which does not take into consideration the foregoing 
equitable considerations; provided, however, that, in any such case, (A) no 
such holder will be required to contribute any amount in excess of the public 
offering price of all such Restricted Stock offered by it pursuant to such 
registration statement; and (B) no person or entity guilty of fraudulent 
misrepresentation (within the meaning of Section 11(f) of the Securities Act) 
will be entitled to contribution from any person or entity who was not guilty 
of such fraudulent misrepresentation.

         10.  Removal of Legends, Etc.  Notwithstanding the foregoing
provisions of Sections 2 through 9 hereof, the restrictions imposed by Sections
2 through 9 on the transferability of any Preferred Shares, Conversion Shares,
Warrant Shares and Perkin-Elmer Shares shall cease and terminate when (a) any
such Preferred Shares, Perkin-Elmer Shares, Conversion Shares or Warrant Shares
are sold or otherwise disposed of in accordance with the intended method of
disposition by the seller or sellers thereof set forth in a registration
statement or such other method contemplated by Section 3 hereof that does not
require that the securities transferred bear the legend set forth in Section 2
hereof, or (b) the holder of such Preferred Shares, Perkin-Elmer Shares,
Conversion Shares or Warrant Shares has met the requirements for transfer
pursuant to subparagraph (k) of Rule 144 (as amended from time to time)
promulgated by the Commission under the Securities Act.  Whenever the
restrictions imposed by Sections 2 through 9 hereof have terminated, a holder of
a certificate for such Preferred Shares, Perkin-Elmer Shares, Conversion Shares
or Warrant Shares as to which such restrictions have terminated shall be
entitled to receive from the Company, without expense, a new certificate not
bearing the restrictive legend set forth in Section 2 hereof and not containing
any other reference to the restrictions imposed by this Agreement.

                                      12

<PAGE>

         11.  Changes in Common Stock or Preferred Stock.  If, and as often as,
there is any change in the Common Stock or the Preferred Stock by way of a stock
split, stock dividend, combination or reclassification, or through a merger,
consolidation, reorganization or recapitalization, or by any other means,
appropriate adjustment shall be made in the provisions hereof so that the rights
and privileges granted hereby shall continue with respect to the Common Stock or
the Preferred Stock as so changed.

         12.  Rule 144 Reporting.  With a view to making available the benefits
of certain rules and regulations of the Commission which may at any time permit
the sale of the Restricted Stock to the public without registration, at all
times the Company agrees to:

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

              (b)  use all reasonable efforts to file with the Commission in a
timely manner all reports and other documents required of the Company under the
Securities Act and the Exchange Act; and

              (c)  furnish to each holder of Restricted Stock forthwith upon
request a written statement by the Company as to its compliance with the
reporting requirements of such Rule 144 and of the Securities Act and the
Exchange Act, a copy of the most recent annual or quarterly report of the
Company, and such other reports and documents so filed by the Company as such
holder may reasonably request in availing itself of any rule or regulation of
the Commission allowing such holder to sell any Restricted Stock without
registration.

         13.  Representations and Warranties of the Company.  The Company
represents and warrants to each of the Original Holders as follows:

              (a)  The execution, delivery and performance of this Agreement by
the Company have been duly authorized by all requisite corporate action and will
not violate any provision of law, any order of any court or other agency of
government, the Charter or By-laws of the Company or its subsidiaries or any
provision of any indenture, agreement or other instrument to which it or its
subsidiaries or any or their properties or assets is bound, or conflict with,
result in a breach of or constitute (with due notice or lapse of time or both) a
default under any such indenture, agreement or other instrument or result in the
creation or imposition of any lien, charge or encumbrance of any

                                      13

<PAGE>

nature whatsoever upon any of the properties or assets of the Company or its 
subsidiaries.

              (b)  This Agreement has been duly executed and delivered by the
Company and constitutes the legal, valid and binding obligation of the Company,
enforceable in accordance with its terms.

         14.  Miscellaneous.

              (a)   All covenants and agreements contained in this Agreement by
or on behalf of any of the parties hereto shall bind and inure to the benefit of
the respective successors and assigns of the parties hereto (including without
limitation transferees of any Preferred Shares or Restricted Stock), whether so
expressed or not, provided, however, that registration rights conferred herein
on the holders of Preferred Shares, Perkin-Elmer Shares, Warrants, or Restricted
Stock, shall only inure to the benefit of a transferee of Preferred Shares,
Perkin-Elmer Shares, Warrants, or Restricted Stock, if (i) there is transferred
to such transferee at least 20% of the total shares of Restricted Stock
originally issued pursuant to the Merger Agreement to the direct or indirect
transferor of such transferee or (ii) such transferee is a partner, shareholder
or affiliate of a party hereto.

              (b)  All notices, requests, consents and other communications
hereunder shall be in writing and shall be mailed by certified or registered
mail, return receipt requested, postage prepaid, or telexed, in the case of
non-U.S. residents, addressed as follows:

                   if to the Company, at:

                   Strategic Diagnostics Inc.
                   128 Sandy Drive
                   Newark, DE 19713-1147
                   Attn: President

                   if to any Original Holder, at the most recent address given
by such party to the Company;

                   if to any subsequent holder of Preferred Shares,
Perkin-Elmer Shares, Warrants, or Restricted Stock, to it at such address as may
have been furnished to the Company in writing by such holder;

or, in any case, at such other address or addresses as shall have been furnished
in writing to the Company (in the case of a holder of Preferred Shares,
Perkin-Elmer Shares or Restricted Stock) or

                                      14

<PAGE>

to the holders of Preferred Shares, Perkin-Elmer Shares or Restricted Stock 
(in the case of the Company) in accordance with the provisions of this 
paragraph.

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

              (d)  This Agreement may not be amended or modified, and no
provision hereof may be waived, without the written consent of the Company and
the holders of at least two-thirds of the outstanding shares of Restricted
Stock.  In addition, the Agreement may not be amended in a manner that is
materially adverse to the rights of the parties hereunder without the written
consent of the holders of at least a majority of the outstanding shares of
Restricted Stock. 

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

              (f)  The obligations of the Company to register shares of
Restricted Stock under Sections 4 or 5 shall terminate on the fifth anniversary
of the date of this Agreement.

              (g)  Notwithstanding the provisions of Section 6(a), the
Company's obligation to file a registration statement, or cause such
registration statement to become and remain effective, shall be suspended for a
period not to exceed 90 days in any 12-month period if there exists at the time
material non-public information relating to the Company which, in the reasonable
opinion of the Company, should not be disclosed.

              (h)  From the date of this Agreement, the Company shall not grant
to any third party any registration rights more favorable than any of those
contained herein, so long as any of the registration rights under this Agreement
remains in effect.

              (i)  If any provision of this Agreement shall be held to be
illegal, invalid or unenforceable, such illegality, invalidity or
unenforceability shall attach only to such provision and shall not in any manner
affect or render illegal, invalid or unenforceable any other provision of this
Agreement, and this Agreement shall be carried out as if any such illegal,
invalid or unenforceable provision were not contained herein.

                  [REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]

                                      15

<PAGE>


         Please indicate your acceptance of the foregoing by signing and
returning the enclosed counterpart of this letter, whereupon this Agreement
shall be a binding agreement between the Company and you.

                                  Very truly yours,

                                  ENSYS ENVIRONMENTAL
                                  PRODUCTS, INC.


                                  By: /s/Grover C. Wrenn
                                      -----------------------------
                                      Title: President and Chief
                                             Executive Officer


AGREED TO AND ACCEPTED as of
the date first above written.


DSV PARTNERS IV

By: DSV Management, Ltd.,
    its general partner

By:  /s/Mort Collins
     ----------------------------
     General Partner


EDISON VENTURE FUND II, L.P.

By: Edison Partners II, L.P.,
    General Partner

By:  /s/Richard J. Defieux
     ----------------------------
    General Partner


EDISON VENTURE FUND II-PA, L.P.

By: Edison Partners II, L.P.,
    General Partner

By:  /s/Richard J. Defieux    
     ----------------------------
    General Partner


THE PERKIN-ELMER CORPORATION


By:  /s/Stephen O. Jaeger     
     ----------------------------


                               16


<PAGE>

                                                                   Exhibit 10.17

                                   LEASE AGREEMENT
                                           
1.  Parties

    This Agreement, MADE THE 24th day of  June one thousand nine hundred and 
ninety-six (1996), by and between LANG ASSOCIATES (hereinafter called 
Lessor), of the one part, and STRATEGIC DIAGNOSTICS, INC. (hereinafter called 
Lessee), of the other part.

2.  Premises

    WITNESSETH THAT:  Lessor does hereby demise and let unto Lessee all that 
certain premises commonly known as 300 Pheasant Run - Lot #53 - Newtown 
Industrial Commons -25,600 square feet - Building #2 - Tax Parcel #29-10-133 
- - L.A. Plaza, Unit 2 A, B, C and D in the County of Bucks State of 
Pennsylvania, to be used and occupied as Office, Research and Warehouse Space 
and for no other purpose.

3.  Term

    For the term of beginning the 1st day of July one thousand nine hundred 
and ninety-six (1996), and ending the 30th day of June one thousand nine 
hundred and ninety-eight (1988).

4.  Minimum Rent

    For the minimum Term rental of Three Hundred Twenty-Five Thousand Thirty 
One and 57/100 Dollars ($25,031.57) lawful money of the United States of 
America, payable in monthly installments in advance during the said term of 
this lease, or any renewal hereof, in sums of Thirteen Thousand Four Hundred 
Seven and 17/100 Dollars ($13,307.17) on the 1st day of each month, rent to 
begin from the 1st day of August, 1996, the first installment to be paid at 
the time of signing this lease.  The first rental payment to be made during 
the occupancy of the premises shall be adjusted to pro-rate a partial month 
of occupancy, if any, at the inception of this lease.

5.  (a) Place of Payment

         All rents shall be payable without prior notice or demand at the 
office of Lessor RE/MAX Properties, Ltd., 210 Penns Trail, Newtown, PA  18940 
or at such other place as Lessor may from time to time designate by notice in 
writing.

6.  (b) Agency

         It is hereby expressly agreed and understood that the said RE/MAX 
Properties, Ltd. is acting as agent only and shall not in any event be held 
liable to the owner or to Lessee for the fulfillment or non-fulfillment of 
any of the terms or conditions of this lease, or for any action 

<PAGE>

or proceedings that may be taken by the
owner against Lessee, or by Lessee against the owner.

7.  Termination of Lease.

    [DELETED BY THE PARTIES]

8.  Security Deposit.

    Lessee shall, upon execution hereof, deposit with Lessor as security for 
the performance of all the terms, covenants, and conditions of this lease, 
the sum of Thirteen Thousand Four Hundred Seven and 17/100 ($13,407.17) 
Dollars, to be held as security for the full and faithful performance by 
Lessee of Lessee's obligations under this Lease and for the payment of 
damages to the demised premises.  If the demised premises is residential 
property, said security deposit is to be held by Lessor as an Escrow Fund 
pursuant to the terms and provisions of the Penna Act of Assembly approved 
December 29, 1972, Act. No. 363.  Except for such sum as shall be lawfully 
applied by Lessor to satisfy valid claims against Lessee arising from 
defaults under this lease or by reason of damages to the demised premises, 
the Security Deposit or Escrow Fund shall be returned to Lessee at the 
expiration of the term of this lease or any renewal or extension thereof but 
in the case of residential property only as provided for in the said Act of 
Assembly.  It is understood that the said deposit is not to be considered as 
the last rental due under the lease.

9.  Special Clauses

    A.   Lessee shall have the option of changing the ending date of this 
Lease to June 30, 1997.  If Lessee chooses to exercise this option, written 
notice of this intent shall be sent Certified Mail to Agent for Lessor by no 
later than February 1, 1997.  If Lessee chooses this option, a fee of 
$46,915.00 shall be due and payable to Lessor and received at the office of 
the Agent of Lessor no later than February 28, 1997.

    B.   As of July 31, 1996, Lessee will vacate 5,000 square feet (Unit 2A) 
of the above described space (see attached diagram) and will then have a 
total space of 20,600 square feet.

*   C.   Rental for month of July, 1996 shall be $16,666.66 for 25,600 square 
feet.

10.  Addendum

    The Lessor and Lessee agree for themselves, their respective heirs and 
successors and assigns to the herein described term and also to those set 
forth in the addendum attached hereto entitled "TERMS AND CONDITIONS," (PART 
TWO) all of which are to be regarded as binding and as strict legal 
conditions.

LESSEE___ LESSEE___ LESSEE___ LESSOR___ LESSOR___ LESSOR___

                                       -2-

<PAGE>

                                    LEASE AGREEMENT
                                 Terms and Conditions
                           Part Two of a Two Part Agreement

11.  Special Clauses

12.  Inability to give Possession

    If Lessor is unable to give Lessee possession of the demised premises, as 
herein provided, by reason of the holding over of a previous occupant, or by 
reason of any cause beyond the control of the Lessor, the Lessor shall not be 
liable in damages to the Lessee therefor, and during the period that the 
Lessor is unable to give possession, all rights and remedies of both parties 
hereunder shall be suspended, and if Lessor is unable for any reason to give 
possession of the demised premises within 5 days of Lessee's demand therefor 
following commencement of the term hereof Lessee shall have the option, by 
notice to Lessor, to cancel this lease agreement and receive return of any 
prepaid rents and security deposit in full and final settlement of any and 
all claims against Lessor.

13.  Additional Rent 

    (a)  Damages for Default

         Lessee agrees to pay as rent in addition to the minimum rental 
herein reserved any and all sums which may become due by reason of the 
failure of Lessee to comply with all the covenants of this lease and pay any 
and all damages, costs and expenses which the Lessor may suffer or incur by 
reason of any default of the Lessee or failure on his part to comply with the 
covenants of this lease, and each of them, and also any and all damages of 
the demised premises caused by any act or neglect of the Lessee.

    (b)  Taxes

         Lessee further agrees to pay as rent in addition to the minimum 
rental herein reserved all taxes assessed or imposed upon the demised 
premises and/or the building of which the demised premises is a part during 
the term of this lease, in excess of and over and above those assessed or 
imposed at the time of making this lease.  The amount due hereunder on 
account of such taxes shall be apportioned for that part of the first and 
last calendar years covered by the term hereof.  The same shall be paid by 
Lessee to Lessor on or before the first day of July of each and every year.

    (c)  Fire Insurance Premiums

         Lessee further agrees to pay to Lessor as additional rent all 
increase or increases in fire insurance premiums upon the demised premises 
and/or the building of which the demised 

                                       -3-

<PAGE>

premises is a part, due to an increase in the rate of fire insurance in 
excess of the rate on the demised premises at the time of making this lease, 
if said increase is caused by any act or neglect of the Lessee or the nature 
of the Lessee's business.

    (d)  Water Rent

         Lessee further agrees to pay as additional rent, if there is a 
metered water connection to the said premises, all charges for water consumed 
upon the demised premises in excess of the yearly minimum meter charge and 
all charges for repairs to the said meter or meters on the premises, whether 
such repairs are made necessary by ordinary wear and tear, freezing, hot 
water, accident or other causes, immediately when the same become due.


14.  Affirmative Covenants of Lessee

    Lessee covenants and agrees that he will without demand

    (a)  Payment of Rent

         Pay the rent and all other charges herein reserved as rent on the 
days and times and at the place that the same are made payable, without fail, 
and if Lessor shall at any time or times accept said rent or rent charges 
after the same shall have become due and payable, such acceptance shall not 
excuse delay upon subsequent occasions, or constitute or be construed as a 
waiver of any of Lessor's rights. Lessee agrees that any charge or payment 
herein reserved, included or agreed to be treated or collected as rent and/or 
any other charges or taxes, expenses, or costs herein agreed to be paid by 
the Lessee may be proceeded for and recovered by the Lessor by distraint or 
other process in the same manner as rent due and in arrears.

    (b)  Cleaning, Repairing, etc.

         Keep the demised premises clean and free from all ashes, dirt and 
other refuse matter; replace all glass windows, doors, etc., broken; keep all 
waste and drain pipes open; repair all damage to plumbing and to the premises 
in general; keep the same in good order and repair as they now are, 
reasonable wear and tear and damage by accidental fire or other casualty not 
occurring through negligence of Lessee or those employed by or acting for 
Lessee alone excepted.  The Lessee agrees to surrender the demised premises 
in the same condition in which Lessee has herein agreed to keep the same 
during the continuance of this lease.

    (c)  Requirements of Public Authorities

         Comply with any requirements of any of the constituted public 
authorities, and with the terms of any State or Federal statute or local 
ordinance or regulation applicable to Lessee or his use of the demised 
premises, and save Lessor harmless from penalties, fines, costs or damages 
resulting from failure to do so.

                                       -4-

<PAGE>

    (d)  Fire

         Use every reasonable precaution against fire.

    (e)  Rules and Regulations

         Comply with rules and regulations of Lessor promulgated as 
hereinafter provided.

    (f)       Surrender of Possession

         Peaceably deliver up and surrender possession of the demised 
premises to the Lessor at the expiration or sooner termination of this lease, 
promptly delivering to Lessor at his office all keys for the demised premises.

    (g)       Notice of Fire, etc.

         Give to Lessor prompt written notice of any accident, fire, or 
damage occurring on or to the demised premises.  

    (h)       Condition of Pavement

         Lessee shall be responsible for the condition of the pavement, curb, 
cellar doors, awnings and other erections in the pavement during the term of 
this lease; shall keep the pavement free from snow and ice; and shall be and 
hereby agrees that Lessee is solely liable for any accidents, due or alleged 
to be due to their defective condition, or to any accumulations of snow and 
ice.

    (i)       Agency on Removal

         The Lessee agrees that if, with the permission in writing of Lessor, 
Lessee shall vacate or decide at any time during the term of this lease, or 
any renewal thereof, to vacate the herein demised premises prior to the 
expiration of this lease, or any renewal hereof, Lessee will not cause or 
allow any other agent to represent Lessee in any sub-letting or reletting of 
the demised premises other than an agent approved by the Lessor and that 
should Lessee do so or attempt to do so, the Lessor may remove any signs that 
may be placed on or about the demised premises by such other agent without 
any liability to Lessor or to said agent, the Lessee assuming all 
responsibility for such action.

    (j)  Indemnification
    
         Indemnify and save Lessor harmless from any and all loss occasioned 
by Lessee's breach of any of the covenants, terms and conditions of this 
lease, or caused by his family, guest, visitors, agents or employees.

                                       -5-

<PAGE>

15.  Negative Covenants of Lessee

    Lessee covenants and agrees that he will do none of the following things 
without the consent in writing of Lessor, which consent Lessor shall not 
unreasonably withhold, and without providing Lessor with reimbursement for 
any expense incurred or incidental to Lessee's proposed action:

    (a)       Use of Premises

         Occupy the demised premises in any other manner or for any other 
purpose than as above set forth.

    (b)       Assignment and Subletting

         Assign, mortgage or pledge this lease or under-let or sub-lease the 
demised premises, or any part thereof, or permit any other person, firm or 
corporation to occupy the demised premises, or any part thereof; nor shall 
any assignee or sub-lessee assign, mortgage or pledge this lease or such 
sub-lease, without an additional written consent by the Lessor, and without 
such consent no such assignment, mortgage or pledge shall be valid.  If the 
Lessee becomes embarrassed or insolvent, or makes an assignment for the 
benefit of creditors, or if a petition in bankruptcy is filed by or against 
the Lessee or a bill in equity or other proceeding for the appointment of a 
receiver for the Lessee is filed, or if the real or personal property of the 
Lessee shall be sold or levied upon by any Sheriff, Marshall or Constable, 
the same shall be a violation of this covenant.

    (c)       Signs
    
         Place or allow to be placed any stand, booth, sign or show case upon 
the doorsteps, vestibules or outside walls or pavements of said premises, or 
paint, place, erect or cause to be painted, placed or erected any sign, 
projection or device on or in any part of the premises.  Lessee shall remove 
any sign, projection or device painted, placed or erected, if permission has 
been granted and restore the walls, etc., to their former conditions, at or 
prior to the expiration of this lease. In case of the breach of this covenant 
(in addition to all other remedies given to Lessor in case of breach of any 
conditions or covenants of this lease) Lessor shall have the privilege of 
removing said stand, booth, sign, show case, projection or device, and 
restoring said walls, etc., to their former condition, and Lessee, at 
Lessor's option, shall be liable to Lessor for any and all expenses so 
incurred by Lessor.

    (d)       Alterations, Improvements

         Make any alterations, improvements, or additions to the demised 
premises. All alterations, improvements, additions or fixtures, whether 
installed before or after the execution of this lease, shall remain upon the 
premises at the expiration or sooner determination of this lease 


                                       -6-

<PAGE>

and become the property of Lessor, unless Lessor shall, prior to the 
determination of this lease, have given written notice to Lessee to remove 
the same, in which event Lessee will remove such alterations, improvements 
and additions and restore the premises to the same good order and condition 
in which they now are.  Should Lessee fail so to do, Lessor may do so, 
collecting, at Lessor's option, the cost and expense thereof from Lessee as 
additional rent.

    (e)  Machinery

         Use or operate any machinery that, in Lessor's opinion, is harmful 
to the building or disturbing to other tenants occupying other parts thereof.

    (f)       Weights

         Place any weights in any portion of the demised premises beyond the 
safe carrying capacity of the structure.

    (g)       Fire Insurance

         Do or suffer to be done, any act, matter or thing objectionable to 
the fire insurance companies whereby the fire insurance or any other 
insurance now in force or hereafter to be placed on the demised premises, or 
any part thereof, or on the building of which the demised premises may be a 
part, shall become void or suspended, or whereby the same shall be rated as a 
more hazardous risk than at the date of execution of this lease, or employ 
any person or persons objectionable to the fire insurance companies or carry 
or have any benzine or explosive matter of any kind in and about the demised 
premises.  In case of a breach of this covenant (in addition to all other 
remedies given to Lessor in case of the breach of any of the conditions or 
covenants of this lease) Lessee agrees to pay to Lessor as additional rent 
any and all increase or increases of premiums on insurance carried by Lessor 
on the demised premises, or any part thereof, or on the building of which the 
demised premises may be a part, caused in any way by the occupancy of Lessee.

    (h)       Removal of Goods

         Remove, attempt to remove or manifest an intention to remove 
Lessee's goods or property from or out of the demised premises otherwise than 
in the ordinary and usual course of business, without having first paid and 
satisfied Lessor for all rent which may become due during the entire term of 
this lease.

    (i)       Vacate Premises

         Vacate or desert said premises during the term of this lease, or 
permit the same to be empty and unoccupied.

                                       -7-

<PAGE>

16.  Lessor's Rights
    
    Lessee covenants and agrees that Lessor shall have the right to do the 
following things and matters in and about the demised premises:

    (a)       Inspection of Premises
    
         At all reasonable times by himself or his duly authorized agents to 
go upon and inspect the demised premises and every part thereof, and/or at 
his option to make repairs, alterations and additions to the demised premises 
or the building of which the demised premises is a part.

<#>
    (b)       Rules and Regulations

         At any time or times and from time to time to make such rules and 
regulations as in his judgment may from time to time be necessary for the 
safety, care and cleanliness of the premises, and for the preservation of 
good order therein. Such rules and regulations shall, when noticed thereof is 
given to Lessee, form a part of this lease.
</#>

    (c)       Sale or Rent Sign - Prospective Purchasers or Tenants

         To display a "For Sale" sign at any time, and also, after notice 
from either party of intention to determine this lease, or at any time within 
three months prior to the expiration of this lease, a "For Rent" sign, or 
both "For Rent" and "For Sale" signs; and all of said signs shall be placed 
upon such part of the premises as Lessor may elect and may contain such 
matter as Lessor shall require.  Persons authorized by Lessor may inspect the 
premises at reasonable hours during the said periods.

    (d)       Discontinue Facilities and Service

         The Lessor may discontinue all facilities furnished and services 
rendered, or any of them, by Lessor, not expressly covenanted for herein, it 
being understood that they constitute no part of the consideration for this 
lease.

17.  Responsibility of Lessee

    (a)       Lessee agrees to be responsible for and to relieve and hereby 
relieves the Lessor from all liability by reason of any injury or damage to 
any person or property in the demised premises, whether belonging to the 
Lessee or any other person, caused by any fire, breakage or leakage in any 
part or portion of the demised premises, or any part or portion of the 
building of which the demised premises is a part, or from water, rain or snow 
that may leak into, issue or flow from any part of the said premises, or of 
the building of which the demised premises is a part, or from the drains, 
pipes, or plumbing work of the same, or from any place or quarter, whether 
such


                                       -8-

<PAGE>

breakage, leakage, injury or damage be caused by or result from the 
negligence of Lessor or his servants or agents.

    (b)       Lessee also agrees to be responsible for and to relieve and 
hereby relieves Lessor from all liability by reason of any damage or injury 
to any person or thing which may arise from or be due to the use, misuse or 
abuse of all or any of the elevators, hatches, openings, stairways, hallways, 
or any kind whatsoever, which may exist or hereafter be erected or 
constructed on the said premises, or from any kind of injury which may arise 
from any other cause whatsoever on the said premises or the building of which 
the demised premises is a part, whether such damage, injury, use, misuse or 
abuse be caused by or result from the negligence of Lessor, his servants or 
agents.

18.  Responsibility of Lessor

    (a)     Total Destruction of Premises

         In the event that the demised premises is totally destroyed or so 
damaged by fire or other casualty not occurring through fault or negligence 
of the Lessee or those employed by or acting for him, that the same cannot be 
repaired or restored within a reasonable time, this lease shall absolutely 
cease and determine, and the rent shall abate for the balance of the term.

    (b)    Partial Destruction of Premises

         If the damage caused as above be only partial and such that the 
premises can be restored to their then condition within a reasonable time, 
the Lessor may, at his option, restore the same with reasonable promptness, 
reserving the right to enter upon the demised premises for that purpose.  The 
Lessor also reserves the right to enter upon the demised premises whenever 
necessary to repair damage caused by fire or other casualty to the building 
of which the demised premises is a part, even though the effect of such entry 
be to render the demised premises or a part thereof untenantable.  In either 
event the rent shall be apportioned and suspended during the time the Lessor 
is in possession, taking into account the proportion of the demised premises 
rendered untenantable and the duration of the Lessor's possession.  If a 
dispute arises as to the amount of rent due under this clause, Lessee agrees 
to pay the full amount claimed by Lessor. Lessee shall, however, have the 
right to proceed by law to recover the excess payment, if any.

    (c)       Repairs by Lessor

         Lessor shall make such election to repair the premises or terminate 
this lease by giving notice thereof to Lessee at the leased premises within 
thirty days from the day Lessor received notice that the demised premises had 
been destroyed or damaged by fire or other casualty.

    (d)       Damage for Interruption of Use


                                       -9-

<PAGE>

         Lessor shall not be liable for any damage, compensation or claim by 
reason of inconvenience or annoyance arising from the necessity of repairing 
any portion of the building, the interruption in the use of the premises, or 
the termination of this lease by reason of the destruction of the premises.

    (e)       Representation of Condition of Premises

         The Lessor has let the demised premises in their present "as is" 
condition and without any representations on the part of the Lessor is under 
no duty to make repairs or alterations, or decorations at the inception of 
this lease or at any time thereafter unless such duty of Lessor shall be set 
forth in writing endorsed hereon.

    (f)       Zoning

         It is understood and agreed that the Lessor hereof does not warrant 
or undertake that the Lessee shall be able to obtain a permit under any 
Zoning Ordinance or Regulation for such use as Lessee intends to make of the 
said premises, and nothing in this lease contained shall obligate the Lessor 
to assist Lessee in obtaining said permits; the Lessee further agrees that in 
the event a permit cannot be obtained by Lessee under any Zoning Ordinance or 
Regulation, this lease shall not terminate without Lessor's consent, and the 
Lessee shall use the premises only in a manner permitted under such Zoning 
Ordinance or Regulation.

19.  Miscellaneous Agreements and Conditions

    (a)       Effect of Repairs on Rental

         No contract entered into or that may be subsequently entered into by 
Lessor with Lessee, relative to any alterations, additions, improvements or 
repairs, nor the failure of Lessor to make such alterations, additions, 
improvements or repairs as required by any such contract, nor the making by 
Lessor or his agent or contractors of such alterations, additions, 
improvements or repairs shall in any way affect the payment of the rent or 
said other charges at the time specified in this lease, except to the extent 
and in the manner hereinbefore provided.

    (b)       Waiver of Custom

         It is hereby covenanted and agreed, any law, usage or custom to the 
contrary notwithstanding, that Lessor shall have the right at all times to 
enforce the covenants and provisions of this lease in strict accordance with 
the terms hereof, notwithstanding any conduct or custom on the part of the 
Lessor in refraining from so doing at any time or times; and, further, that 
the failure of Lessor at any time or times to enforce his rights under said 
covenants and provisions strictly in accordance with the same shall not be 
construed as having created a custom in any way or manner contrary to the 
specific terms, provisions and covenants of this lease or as having in any 
way or manner modified the same.

                                       -10-

<PAGE>

    (c)       Conduct of Lessee 

         This lease is granted upon the express condition that Lessee and/or 
the occupants of the premises herein leased, shall not conduct themselves in 
a manner which the Lessor in his sole opinion may deem improper or 
objectionable, and that if at any time during the term of this lease or any 
extension or continuation thereof, Lessee or any occupier of the said 
premises shall have conducted himself, herself or themselves in a manner 
which Lessor in his sole opinion deems improper or objectionable, Lessee 
shall be taken to have broken the covenants and conditions of this lease, and 
Lessor will be entitled to all of the rights and remedies granted and 
reserved herein for the Lessee's failure to observe any of the covenants and 
conditions of this lease.

    (d)       Failure of Lessee to Repair

         In the event of the failure of Lessee promptly to perform the 
covenants of Section 14(b) hereof, Lessor may go upon the demised premises 
and perform such covenants, the cost thereof, at the sole option of Lessor, 
to be charged to Lessee as additional and delinquent rent.

    (e)  Waiver of  Subrogation

         Lessor and Lessee hereby agree that all insurance policies which 
each of them shall carry to insure the demised premises and the contents 
therein against casualty loss, and all liability policies which they shall 
carry pertaining to the use and occupancy of the demised premises shall 
contain waivers of the right of subrogation against Lessor and Lessee herein, 
their heirs, administrators, successors, and assigns.

    (f)  Security Interest.

         Lessee hereby grants to Lessor a security interest under the Uniform 
Commercial Code in all of Lessee's goods and property in, on or about the 
demised premises.  Said security interest shall secure unto Lessor the 
payment of all rent (and charges collectible or reserved as rent) hereunder 
which shall be required under the provisions of the said Uniform Commercial 
Code to perfect a security interest in Lessee's said goods and property.

20.  Remedies of Lessor - If the Lessee

    (a)  Does not pay in full when due any and all installments of rent 
and/or any other charge or payment herein reserved, included, or agreed to be 
treated or collected as rent and/or any other charge, expense, or cost herein 
agreed to be paid by the Lessee; or

    (b)  Violates or fails to perform or otherwise breaks any covenant or 
agreement herein contained; or  

    (c)  Vacates the demised premises or removes or attempts to remove or 
manifests an

                                       -11-

<PAGE>

intention to remove any goods or property therefrom otherwise than in the 
ordinary and usual course of business without having first paid and satisfied 
the Lessor in full for all rent and other charges then due or that may 
thereafter become due until the expiration of the then current term, above 
mentioned; or

    (d)  Becomes embarrassed or insolvent, or makes an assignment for the 
benefit of creditors, or if a petition in bankruptcy is filed by or against 
the Lessee, or a bill in equity or other proceeding for the appointment of a 
receiver for the Lessee is filed, or if proceedings for reorganization or for 
composition with creditors under any State or Federal law be instituted by or 
against Lessee, or if the real or personal property of the Lessee shall be 
levied upon or be sold, or if for any other reason Lessor shall, in good 
faith believe that Lessee's ability to comply with the covenants of this 
lease, including the prompt payment of rent hereunder, is or may become 
impaired, thereupon:

         (1)  The whole balance of rent and other charges, payments, costs, 
and expenses herein agreed to be paid by Lessee, or any part thereof, and 
also all costs and officers' commissions including watchmen's wages shall be 
taken to be due and payable and in arrears as if by the terms and provisions 
of this lease said balance of rent and other charges, payments, taxes, costs 
and expenses were on that date, payable in advance.  Further, provisions of 
this lease or any part thereof is assigned, or if the premises, or any part 
thereof is sub-let, Lessee hereby irrevocably constitutes and appoints Lessor 
as agent to collect the rents due from such assignee or sub-lessee and apply 
the same to the rent due hereunder without in any way affecting Lessee's 
obligation to pay any unpaid balance of rent due hereunder; or 

               (2) At the option of the Lessor, this lease and the terms 
hereby created shall determine and become absolutely void without any right 
on part of the Lessee to reinstate this Lease by payment of any sum due or by 
other performance of any condition, term, or covenant broken upon Lessor 
shall be entitled to recover damages for such breach in an amount equal to 
the amount of rent reserved for the balance of this lease, less the fair 
market rental value of the said demised premises for the remainder of the 
lease term.

21.  Further Remedies of Lessor

    In the event of any default as above set forth in Section 14, the Lessor, 
or anyone acting on Lessor's behalf. at Lessor's option:

    (a)  may without notice or demand enter the demised premises, breaking 
open locked doors if necessary to effect entrance, without liability to 
action for prosecution or damages for such entry or for the manner thereof, 
for the purpose of distraining or levying and for any other purposes, and 
take possession of and sell all goods and chattels at auction, on three days' 
notice served in person on the Lessee or left on the premises, and pay the 
said Lessor out of the proceeds, and even if the rent be not due and unpaid, 
should the Lessee at any time remove or attempt to remove goods and chattels 
from the premises without leaving enough thereon to meet

                                       -12-

<PAGE>

the next periodical payment, Lessee authorizes the Lessor to follow for a 
period of ninety days after such removal; take possession of and sell at 
auction, upon like notice, sufficient of such goods to meet the proportion of 
rent accrued at the time of such removal; and the Lessee hereby releases and 
discharges the Lessor, and his agents, from all claims, actions, suits, 
damages, and penalties, for or by reason or on account of any entry, 
distraint, levy, appraisement or sale; and/or

    (b)  may enter the premises, and without demand proceed by distress and 
sale of the goods there found to levy the rent and/or other charges herein 
payable as rent, and all costs and officers' commissions, including 
watchmen's wages and sums chargeable to Lessor, and further including a sum 
equal to 5% of the amount of the levy as commissions to the constable or 
other person making the levy, shall be paid by the Lessee, and in such case 
all costs, officers' commission and other charges shall immediately attach 
and become part of the claim of Lessor for rent, and any tender of rent 
without said costs, commission and charges made after the issue of a warrant 
of distress shall not be sufficient to satisfy the claim of the Lessor. 
Lessee hereby expressly waives in favor of Lessor the benefit of all laws now 
made or which may hereafter be made regarding any limitation as to the goods 
upon which, or the time within which, distress is to be made after removal of 
goods, and further relieves the Lessor of the obligations of proving or 
identifying such goods, it being the purpose and intent of this provision 
that all goods of Lessee, whether upon the demised premises or not, shall be 
liable to distress for rent.  Lessee waives in favor of Lessor all rights 
under the Act of Assembly of April 6, 1951, P.L. 69, and all supplements and 
amendments thereto that have been or may hereafter be passed, and authorizes 
the sale of any goods distrained for rent at any time after five days from 
said distraint without any appraisement and/or condemnation thereof.

    (c)  The Lessee further waives the right to issue a Writ of Replevin 
under the Pennsylvania Rules of Civil Procedure, No. 1071 &c. and Laws of the 
Commonwealth of Pennsylvania, or under any other law previously enacted and 
now in force, or which may be hereafter enacted, for the recovery of any 
articles, household goods, furniture, etc., seized under a distress for rent 
or levy upon an execution for rent, damages or otherwise; all waivers 
hereinbefore mentioned are hereby extended to apply to any such action; and/or

    (d)  May lease said premises or any part or parts thereof to such person 
or persons as may in Lessor's discretion seem best and the Lessee shall be 
liable for any loss of rent for the balance of the then current term.

22.  Confession of Judgment for Money

    Lessor covenants and agrees that if the rent and/or charges reserved in 
this lease as rent (including all accelerations of rent by and under the 
provisions of this lease) shall remain unpaid five (5) days after the same is 
required to be paid, then and in that event.  Lessor shall cause Judgment to 
be entered against Lessee, and for that purpose Lessee hereby authorizes and 
empowers Lessor or any Prothonotary of Court or Attorney of any Court of 
Record to appear for and confess judgment against Lessee and agrees that 
Lessor may commence pursuant to the Rule 

                                       -13-

<PAGE>

of Civil Procedure No. 2950 et. seq. for the recovery from Lessee of all rent 
hereunder (including all        of rent permissible under the provisions of 
this lease) and/or for all charges reserved hereunder as rent, as well as for 
interest and Attorney's commission, for which authorization to confess 
judgment, this lease, or a true and correct copy thereof, shall be 
sufficient.  Such Judgment may be confessed against Lessee for the amount of 
rent in arrears (including all accelerations of rent permissible   provisions 
of this lease) and/or for all charges reserved hereunder as rent, as well as 
interest and costs; together with an        commission of five percent (5%) 
of the full amount of Lessor's claim against Lessee.  Neither the right to 
institute an action      Pennsylvania Rules of Civil Procedure No. 2950 et. 
seq. nor the authority to confess judgment granted herein shall be exhausted 
by      exercises thereof but successive complaints may be filed and 
successive judgments may be entered for the aforedescribed sums five days 
after they become due as well as after the expiration of the original term 
and/or during or after the expiration of any extension or renewal             
           .

23.  Confession of Judgment for Possession of Real Property

    Lessee covenants and agrees that if this lease shall be terminated 
(either because of condition broken during the term of this lease, renewal or 
extension thereof and/or when the term hereby created or any extension 
thereof shall have expired) then and in that event may cause a judgement in 
ejectment to be entered against Lessee for possession of the demised 
premises, and for that purpose Lessee authorizes and empowers any 
Prothonotary, Clerk of Court or Attorney of any Court of Records to appear 
for Lessee and to confess against Lessee in Ejectment for possession of the 
herein demised premises and agrees that Lessor may commence any action 
pursuant to the Rule of Civil Procedure No. 2970 et. seq. for the entry of a 
an order in Ejectment for the possession of real property, and Lessee agrees 
that a Writ of Possession pursuant thereto may issue forthwith, for which 
authorization to confess judgment and for the issued writ or writ of 
possession pursuant thereto this lease, or a true and correct copy thereof, 
shall be sufficient warrant.  Lessee further             and agrees, that if 
for any reason whatsoever, after said action shall have commenced the action 
shall be terminated and the                premises demised hereunder shall 
remain in or be restored to Lessee.  Lessor shall have the right upon any 
subsequent default or defaults the termination of this lease as above set 
forth to commence successive actions for possession of real property and to 
cause the entry of such judgments by confession in Ejectment for possession 
of the premises demised hereunder.

24.  Affidavit of Default

    In any amicable action of ejectment and/or for rent in arrears, Lessor 
shall first cause to be filed in such action an affidavit made by him or 
someone acting for him setting forth the facts necessary to authorize the 
entry of judgment, of which facts such affidavit shall be conclusive evidence 
and of a true copy of this lease (and of the truth of the copy such affidavit 
shall be sufficient evidence) be filed in such action, it shall not be 
necessary to file the original as a warrant of attorney, any rule of Court, 
custom or practice to the contrary notwithstanding.

                                       -14-

<PAGE>

25.  Waivers by Lessee of Errors, Right of Appeal, Stay, Exemption, 
Inquisition

    Lessee hereby releases to Lessor and to any and all attorneys who may 
appear for Lessee all errors in any procedure or action Judgment by 
Confession by virtue of the warrants of attorney contained in this lease, and 
all liability therefor.  Lessee further authorizes the Prothonotary or Clerk 
of Court to issue a Writ of Execution or other process, and further agrees 
that real estate sold on a Writ of Execution or other process.  If 
proceedings shall be commenced to recover possession of the demised premises 
either at the end of the term or sooner termination of this lease, or for 
nonpayment of rent or any other reason Lessee specifically waives the right 
to the three (3) months' notice and/or the fifteen (15) or thirty (30) days' 
notice required by the Act of April 6, 1951, P.L. 69, and agrees that five 
(5) days' notice shall be sufficient in either or any such case.

26.  Right of Assignee of Lessor

    The right to enter judgment against Lessee by confession and to enforce 
all of the other provisions of this lease herein provided for the option of 
any assignee of this lease, be exercised by any assignee of the Lessor's 
right, title and interest in this lease in his, her or its name, any statute, 
rule of court, custom, or practice to the contrary notwithstanding.

27.  Remedies Cumulative 

    All of the remedies hereinbefore given to Lessor and all rights and 
remedies given to him by law and equity shall be cumulative and concurrent.  
No determination of this lease or the taking or recovering of the premises 
shall deprive Lessor of any of his remedies or actions against the Lessee for 
rent due at the time or which, under the terms hereof, would in the future 
become due as if there has been no determination, or for any and all sums due 
at the time or which, under the terms hereof, would in the future become due 
as if there had been no determination, nor shall the bringing of any action 
for rent or breach of covenant, or the resort to any other remedy herein 
provided for the recovery of rent be construed as a waiver of the right to 
obtain possession of the premises.

28.  Condemnation

    In the event that the premises demised or any part thereof is taken or 
condemned for a public or quasi-public use, this lease shall, as to the part 
so taken, terminate as of the date title shall vest in the condemnor, and 
rent shall abate in proportion to the square feet of leased space taken or 
condemned or shall cease if the entire premises be so taken. In either event 
the Lessee waives all claims against the Lessor by reason of the complete or 
partial taking of the demised premises.

29.  Subordination

                                       -15-

<PAGE>

    This Agreement of Lease and all its terms, covenants and provisions are 
and each of them is subject and subordinate to any lease or other arrangement 
or right to possession, under which the Lessor is in control of the demised 
premises, to the rights of the owner or owner's of the demised premises and 
of the land or buildings of which the demised premises are a part, to all 
rights of the Lessor's landlord and to any and all mortgages and other 
encumbrances now or hereafter placed upon the demised premises or upon the 
land and/or the buildings containing the same; and Lessee expressly agrees 
that if Lessor's tenancy, control, or right to possession shall terminate 
either by expiration, forfeiture or otherwise, then this lease shall 
thereupon immediately terminate and the Lessee shall, thereupon, give 
immediate possession; and Lessee hereby waives any and all claims for damages 
or otherwise by reason of such termination of the aforesaid.

30.  Notices

    All notices must be given by registered mail return receipt requested.

31.  Lease Contains All Agreements

    It is expressly understood and agreed by and between the parties hereto 
that this lease and the riders attached hereto and forming a part hereof set 
forth all the promises, agreements, conditions and understandings between 
Lessor or his Agents and Lessee relative to the demised premises, and that 
there are no promises, agreements, conditions or understandings, either oral 
or written, between them other than are herein set forth.  It is further 
understood and agreed that, except as herein otherwise provided, no 
subsequent alteration, amendment, change or addition to this lease shall be 
binding upon Lessor or Lessee unless reduced to writing and signed by them.

32.  Heirs and Assignees

    All rights and liabilities herein given to, or imposed upon, the 
respective parties hereto shall extend to and bind the several and respective 
heirs, executors, administrators, successors and assigns of said parties; and 
if there shall be more than one Lessee, they shall all be bound jointly and 
severally by the terms, covenants and agreements, herein, and the word 
"Lessee" shall be deemed and taken to mean each and every person or party 
mentioned as a Lessee herein, be the same one or more; and if there shall be 
more than one Lessee, any notice required or permitted by the terms of this 
lease may be given by or to any one thereof, and shall have the same force 
and effect as if given by or to all thereof.  The words "his" and "him" 
wherever stated herein shall be deemed to refer to the "Lessor" and "Lessee" 
whether such Lessor or Lessee be singular or plural and irrespective of 
gender.  No rights, however, shall inure to the benefit of any assignee of 
Lessee unless the assignment to such assignee has been approved by Lessor in 
writing as aforesaid.

33.  Headings No Part of Lease

    Any headings preceding the text of the several paragraphs and 
sub-paragraphs hereof are

                                       -16-

<PAGE>

inserted solely for convenience of reference and shall not constitute a part 
of this lease, nor shall they affect its meaning, construction or effect.

    IN WITNESS WHEREOF, the parties hereto have executed these presents the 
day and year first above written, and intend to be legally bound thereby.

SEALED AND DELIVERED IN THE
PRESENCE OF:


                                       /s/  RE/MAX PROPERTIES     (AGENT)
- --------------------------------    ------------------------------


                                                                   (SEAL)
- --------------------------------    ------------------------------


                                      /s/ Richard C. Birkmeyer     (SEAL)
- --------------------------------    ------------------------------


                                                                   (SEAL)
- --------------------------------    ------------------------------


                                     /s/  Lang Associates          (SEAL)
- --------------------------------    ------------------------------




                                       -17-

<PAGE>

                             ADDENDUM TO LEASE AGREEMENT

34.  The parties intend that the rent payable hereunder shall be an 
absolutely net return to Lessor for the term of the Lease, undiminished by 
the taxes, or any other carrying charges, maintenance charges, repairs or any 
other charges of any kind whatsoever except Lessor's income taxes, and Lessor 
shall not be required to furnish any utilities or perform any services of any 
kind or nature whatsoever, except as specified in this lease or in this 
Addendum thereto.

35.  a.   Lessee agrees to pay as rent in addition to the minimum rental 
herein reserved:

     (1)  All taxes (including but not limited to real estate 
          taxes) ("taxes") assessed or imposed upon the demised 
          premises during the term of this lease or any renewal or 
          extension thereof.
     
     (2)  All premiums for insurance, obtained by Lessor, 
          against loss by fire and such other hazards, casualties 
          and contingencies as are usually covered by the broadest 
          form of extended coverage policy available in the area of 
          the county in which the demised premises is located, and 
          such other insurance as specified by Lessor from time to 
          time in connection with the demised premises.  The fire 
          insurance and extended coverage insurance, together with 
          such other insurance as Lessor shall obtain in connection 
          with the demised premises shall be in such amounts as 
          Lessor shall determine.
     
     (3)  All premiums or comprehensive general liability 
          insurance, obtained by Lessor, protecting Lessor against 
          any injury or damage to any person or property occurring 
          in, or about the demised premises, or any sidewalks, 
          driveways, or other areas appurtenant to the demised 
          premises, said insurance to be in such amounts as Lessor 
          shall determine-
     
     (4)  All premiums for full rental value insurance 
          covering One Hundred Percent (100%) of the minimum and 
          additional rent payable hereunder.
     
     b.   Lessee's aforementioned payment of taxes and insurance premiums 
shall be a proportionate share of the entire taxes and insurance premium 
payable for Lot 53 of Newtown Industrial Commons (for both land and 
improvements) The sum payable by Lessee, or Lessee's proportionate share, 
shall be calculated by multiplying the total annual taxes and insurance 
premiums by a fraction, the numerator of which is the number of square feet 
in the demised premise and the denominator of which is the total square feet 
of the buildings of Lot 53.  The parties agree that the term "proportionate 
share shall be equal to

   Fifty Three and Twenty Eight Hundredths Percent (53.28%) for July, 1996 only

   Forty Two and Eighty Eight Hundredths Percent (42.88%) from August 1, 1996 

                                       -18-

<PAGE>

   through June 30, 1998

of the said taxes and insurance premium costs; provided, however, that said 
proportion of insurance premiums payable by Lessee shall be adjusted to 
reflect any disproportionate increase thereof which shall be as a result of 
Lessee's use or occupancy of the demised premises.

    c.   Lessee shall pay the taxes and insurance premiums for each year of 
the Lease monthly, initially on the basis of the prior year's tax bill and 
insurance premiums.  Thus, Lessee shall pay one-twelfth (1/12) of the 
estimated total sum for taxes and insurance premiums each month at the same 
time Lessee pays the minimum rental, subject to the following adjustment: 
After a current bill is available to Lessor for either taxes or any insurance 
premium, Lessor shall notify Lessee of any adjustment to be made to the 
estimated annual taxes or insurance premium and Lessee shall pay with its 
next monthly rental payment any adjustments necessary to cover its 
proportionate share of the entire current year's actual taxes or insurance 
premium from the beginning of said Lease year to the date of payment with 
monthly payments thereafter based on the actual tax bill or insurance premium 
for the current Lease year, as the case may be. To facilitate this, Lessee 
will pay $1.30 sq. ft into an escrow account.  Said amount to be escrowed 
monthly and will be adjusted periodically. copies of actual bills to be 
furnished to Lessee at no expense with each adjustment.  This amount shall be 
deemed as additional rent.

    d.   Anything herein contrary notwithstanding, Lessee shall be 
responsible for all taxes imposed on the demised premises arising from or 
related to the Lessee's use, occupancy, employment and/or business at the 
demised premises.

     (5) Insurance coverages specified under clauses 35 (a)    
         2-4) above shall be reasonable for the risk factors 
         involved and the premiums charged therefor competitive 
         with prevailing market rate structures.

36.  Lessee shall obtain all utility services, at Lessee's own cost and 
expense, from the utility or municipality supplying same.  Lessee 
acknowledges that Lessor is not supplying any utility service to the demised 
premises and that it shall have all invoices for utility service billed 
directly to Lessee.  Lessee agrees that in the event Lessee fails to pay for 
utility services as provided for herein, Lessor shall bill Lessee directly 
for same within ten (10) days after Lessor receives bill, and Lessee shall 
promptly pay the same.

37.  a.   Lessee agrees to accept the demised premises in the physical order 
and condition existing on the date of commencement of the term of this Lease. 
 Except as specified hereinafter, Lessee shall, throughout the term hereof, 
at Lessee's sole expense, make all necessary or appropriate repairs, 
replacements, and renewals, interior or exterior, non-structural, ordinary 
and extraordinary, foreseen and unforeseen, required to keep and maintain the 
demised premises and all systems, equipment and apparatus appurtenant thereto 
or used in connection therewith, in good order and condition.  The Lessee 
shall also provide to the Lessor, a statement from a reputable contractor 
that the heating and air conditioning systems (if any) have been serviced and 

                                       -19-

<PAGE>

checked over at least once in the period of a year.

    b.   Upon receipt of written notice from the Lessee, Lessor agrees to 
proceed with due diligence to repair, at its own cost and expense, any leaks 
in the roof or make any repairs, to the structural walls of the herein 
demised premises, provided such repairs are not made necessary by the Lessee, 
its servants, workmen, employees or any agents, or contractors employed by 
it.  In no event, however, shall Lessor be liable to Lessee, Its servants, 
invitees, licensees, agents or contractors for any loss or damage due to, or 
alleged to be due to, any leaks from the said roof and/or damage caused by 
failure to make repairs necessary to the structural wall of the demised 
premises during the term of this Lease or any renewals thereof.

    c.   Lessee shall be responsible and pay an amount equal to its 
proportionate share, or

         *    Fifty Three and Twenty Eight Hundredths Percent (53.28%)

         *    Forty Two and Eighty Eight Hundredths Percent (42.88%)

         *    SEE NUMBER 35

of Lessor's cost of snow removal, maintenance Of pavement and parking area, 
and landscaping (including grass cutting and shrubbery trimming) for said Lot 
53. Payments covering snow removal, maintenance of paving and parking area 
and landscaping are to be made from escrow account referred to in Paragraph 
35c.  Said account to -be adjusted periodically.

    d.   Lessor shall paint the outside trim on the buildings on Lot 53 once 
in every four (4) year period.  Lessee shall pay its proportionate share, or

         *    Fifty Three and Twenty Eight Hundredths Percent (53.28%)

         *    Forty Two and Eight Eight Hundredths Percent (42.88%)

         *    SEE NUMBER 35

for all costs incurred for such painting.  Lessee's proportionate share for 
the painting shall be limited, however, by a cap on the total expenditure for 
painting in any given year of Two Thousand Five Hundred Dollars ($2,500.00), 
the cap to he adjusted in accordance with any increase in the cost of living.

    e.   Lessee shall pay its proportionate share for any repaving of the 
parking area of Lot 53.  Lessee's proportionate share for the parking lot 
repaving shall be limited, however, by a cap on total expenditures for such 
repaving of Three Thousand Dollars ($3,000.00), the cap to be adjusted in 
accordance with any increase in the cost of living in the same manner as set 
forth in Subparagraph 37d. above.

                                       -20-

<PAGE>

    f.   At the expiration of this Lease, or any earlier termination thereof, 
Lessee covenants and agrees to return the demised premises, and all systems, 
equipment, and apparatus appurtenant hereto or used in connection therewith 
in the same condition required to be maintained by Lessee under this Lease, 
normal wear and tear accepted. If, at the expiration of this Lease, Lessee 
fails to return the demised premises, including air-conditioning units, 
exhaust fans and other apparatus, in the same condition as required 
hereunder, any expense incurred by Lessor to repair or replace same shall be 
deducted from the sum deposited by Lessee as collateral security pursuant to 
Clause 42, normal wear and tear excepted.;

    g.   Any repairs, replacements and renewals and/or any labor or materials 
performed and/or furnished in or about the demised premises by Lessee during 
the term of the Lease shall be performed and furnished in strict compliance 
with all applicable laws, regulations, ordinances, and requirement of all 
duly constituted municipal authorities or other governmental bodies having 
jurisdiction, and the requirements of any board of fire underwriters having 
jurisdiction.

38.  Notwithstanding anything elsewhere herein contained to the contrary, 
Lessee shall, at Lessee's sole risk and expense, have the privilege of 
erecting a sign or signs upon the demised premises subject to and in 
compliance with any and all laws, statutes, ordinances, rules, regulations 
and requirements of the municipal and other duly constituted authorities and 
insurance organizations; provided, however, the plans and specifications 
therefor shall first be submitted to Lessor and Newtown Industrial Commons, 
Inc. for written approval as to size, character and location, which approval 
shall not be unreasonably withheld; and further provided that upon 
termination of the Lease term, or any sooner determination of this Lease, or 
any extension or renewal thereof, Lessee shall, at its sole risk and expense, 
remove such sign or signs and restore the premises to its condition prior to 
the erection thereof, ordinary wear and tear excepted.  Lessee shall defend, 
protect and save harmless Lessor of and from any and all claims for injuries 
to persons or damage to property caused by the erection, maintenance, repair 
or removal of said sign or signs.

39.  Lessor hereby grants Lessee, its invitees and licensees, the right to 
park automobiles in the parking area in front of the demised premises; 
provided, however, that parking of automobiles shall be limited to continuous 
periods no longer than twenty-four (24) hours, Lessee hereby agrees that it 
shall not park, nor permit any of its invitees or licensees to park, any 
automobile, in the said parking area for longer than a continuous twenty-four 
(24) hour period.

40.  Lessor hereby grants Lessee, its invitees and licensees, the right to 
park tractor-trailer(s) in the parking area of the demised premises.  Such 
right to park, however, shall be limited to continuous periods no longer than 
forty-eight (48) hours. if Lessee parks, or permits any of its invitees or 
licensees to park, a tractor-trailer in the aforementioned area for longer 
than any continuous forty-eight (48) hour period, Lessee shall pay to Lessor, 
as additional rent Thirty Dollars ($30.00) per day for each day said 
tractor-trailer is parked beyond the forty-eight (48) hour period up to Nine 
Hundred Dollars ($900.00) per month.  Failure to pay the aforementioned rent 
shall be considered a default under this Lease.

                                       -21-

<PAGE>

41.  Lessee hereby agrees to use no exterior portion of the demised premises 
or any exterior portion of Lot 53 for storage.  In the event there is 
exterior storage, Lessor shall have the right to remove any items stored 
externally.  Lessee hereby agrees to reimburse Lessor for the cost of 
removing said goods and said invoice shall be paid within ten (10) days of 
invoice presentation.

42.  In the event the Lessee should default hereunder, security deposit shall 
be forthwith applicable on account of sums which may be due to Lessor by 
reason of such default. Such application of security deposit shall be in 
addition to all other rights and remedies accruing to Lessor hereunder.  At 
the termination of Lessee's tenancy and upon surrender of the demised 
premises as provided for in this Lease, the security sum shall be returned to 
Lessee, only if Lessee is not in default hereunder.

43.  It is agreed that if the rent is not paid by the tenth (10th) day of 
each month, there will be automatically assessed a penalty of ten percent 
(10%) of any rentals due which will be deemed as additional rent hereunder 
and due for the current month.

         IN WITNESS WHEREOF, and intending to be legally bound, these 
presents have been duly executed under seal by a duly authorized officer of 
each of the parties hereto.

WITNESSED;                   LESSOR; LANG ASSOCIATES


                             /s/  Lang Associates
- --------------------------   -----------------------------------


WITNESSED;                   LESSEE; STRATEGIC DIAGNOSTICS, INC.


                             /s/  Richard C. Birkmeyer
- --------------------------   ------------------------------------


                             AGENT; RE/MAX PROPERTIES, LTD.


                             /s/  RE/MAX PROPERTIES                         
                             -------------------------------------
 


                                       -22-

<PAGE>

               CONTINUANCES TO PART TWO OF LEASE AGREEMENT
          BETWEEN LANG ASSOCIATES AND STRATEGIC DIAGNOSTICS, INC.


    14B. Unless provided for by insurance.

    17B. Unless provided for by insurance.

    20.  Except for Lessee's obligation to pay rent under 
         Paragraph Four hereunder. Lessor agrees to give Lessee 
         notice of a default with 15 days notice to cure such 
         default. if Lessee does not correct such default within 
         15 days, then Lessor can proceed with remedies hereunder.


         IN WITNESS WHEREOF, and intending to be legally bound, these 
presents have been duly executed under seal by a duly authorized officer of 
each of the parties hereto.

WITNESSED;                   LESSOR; LANG ASSOCIATES


                             /s/  Lang Associates
- -------------------------    ------------------------------------


WITNESSED;                   LESSEE; STRATEGIC DIAGNOSTICS, INC.


                             /s/  Richard C. Birkmeyer
- -------------------------    ------------------------------------


                             AGENT; RE/MAX PROPERTIES, LTD.


                             /s/  RE/MAX PROPERTIES                         
                             ------------------------------------

                                       -23-




<PAGE>

                                                                  Exhibit 10.18
                                   INDUSTRIAL LEASE

     1. Parties.  This Lease, dated, for reference purposes only October 26, 
1993, is made by and between TOBER & AGNEW PROPERTIES, INC., a Delaware 
corporation (herein called "Lessor") and Strategic Diagnostic Industries 
Incorporated, a Delaware corporation (herein called "Lessee").

     2. Premises.  Lessor hereby leases to Lessee and Lessee leases from 
Lessor for the Term (as hereinafter defined)at the rental, and upon all of 
the conditions set forth herein, all that certain space (the "premises") 
which is the portion of the building erected on lots 32 and 33, at 128 Sandy 
Drive, Newark, Delaware as more fully shown on the plan attached hereto as 
Exhibit "A", consisting of Ten Thousand Three Hundred (10,300) square feet, 
more or less.  The Premises includes all fixtures, improvements, additions 
and other property installed therein at the commencement Date (as hereinafter 
defined) or at any time during the time of this lease (other than Tenant's 
movable personal property and trade fixtures) together with the right to use, 
in common with others, any entrances, lobbies, hallways parking lot, 
walkways, elevators and other public portions of the building in which the 
Premises is located (the "Building") . The Building contains 25,600 square 
feet.

     3. Term.

          3.1. Term.  The term of this lease and Lessee's obligation to pay 
rent hereunder shall commence upon the date when the premises is ready for 
occupancy and a certificate of occupancy or equivalent certificate has been 
issued by the appropriate governmental agency (the "Commencement Date") The 
premises shall be deemed ready for occupancy when Lessor has substantially 
completed the work depicted or described on the plans and specifications 
listed in Exhibit "B" attached hereto (the "Tenant Improvement Work") . The 
parties agree to execute an Addendum contemporaneously with the execution of 
this lease which sets forth the parties' rights and duties with respect to 
the Tenant Improvement Work.  "Substantial Completion" shall mean such 
completion as shall enable Lessee to reasonably and conveniently use and 
occupy the premises for the conduct of its business.  The term ("Term") of 
this lease shall end five (5) years after the Commencement Date.  The parties 
agree to confirm the Commencement Date in writing.

          3.2.  Delay in-Possession. If for any reason Lessor cannot deliver 
possession of the premises to Lessee on the Commencement Date, Lessee shall 
not be obligated to pay rent until possession of the premises is tendered to 
Lessee.

     4. Use.

<PAGE>

          4.1. Use.  The premises shall be used and occupied for the 
following: office and laboratory uses and the manufacturing of immunological 
reagents and ascites and any uses accessory thereto or any other use which is 
reasonably comparable and for no other purpose.

     5. Base Rent.

          (a)  Lessee shall pay to Lessor as rent for the premises, (the "Base 
Rent"), in advance, in fixed monthly payments on the first day of each month 
of the Term.

          (b)  From the Commencement Date until the first anniversary of the 
commencement Date, the Base Rent shall be an amount to be computed at the 
rate of $4.27 annually per square foot.

          (c)  Rent for any period during the Term hereof which is for less than
one month shall be a pro rata portion of the monthly installment.

          (d)  Rent shall be payable in lawful money of the United States to 
Lessor at the address stated herein or to such other persons or at such other 
places as Lessor may designate in writing.

          (e)  commencing on the first anniversary of the Commencement Date, 
and on each anniversary of the Commencement Date thereafter through the end 
of the Term and any renewal thereof, the Base Rent shall be computed in 
accordance with the provisions of this subparagraph.  In the event the 
Consumer Price Index for Urban Wage Earners and clerical Workers in the city 
of Philadelphia (1967 = 100) (hereinafter called the "Price Index") or a 
successor or substitute index appropriately adjusted, reflects an increase in 
the cost of living for the month immediately preceding such anniversary date 
("Adjustment Month") over and above such cost of living as reflected by the 
Price Index as it existed for the month immediately preceding the prior 
anniversary date (hereinafter called the "Base Index"), the Base Rent during 
such lease year shall equal to the number of square feet in the Premises, 
multiplied by $4.27 plus the product of (i) $4.27 (as adjusted in the prior 
year in accordance with this subparagraph) multiplied by (ii) the lesser of 
(A) five percent 5% or (B) a fraction, the numerator of which is the Price 
Index for the Adjustment Month and the denominator of which is the Base Index 
(but in no event shall such increase be less than 4%).  In the event that 
such determination cannot be made until after any anniversary of the 
Commencement Date, the increase in the monthly rental payments due for the 
months prior to such determination shall be paid to Lessee upon the date the 
next payment of rent is due following such determination.

     6. Operating Expenses.  In addition to the Base Rent, Lessee will pay to 
Lessor as additional rent Lessee's operating Expense Share of the amount of 
operating Expenses paid, payable or incurred by Lessor in each year of the 
Term and Lessee's Tax Share of the real property taxes payable by Lessor in 
each year of the Term, and Lessee's share of the premiums

                                       2

<PAGE>

for required insurance payable by Lessor.  As used in this lease the 
following terms shall be defined as hereinafter provided:

          (a)  Lessee's Operating Expense Share  shall be forty-one percent 
(41%);

          (b)  "Operating Expenses" shall mean the following:

               (i)  Costs of cleaning, repairing and maintaining the Common 
     Areas of the Building (including the costs for snow removal).  As used in 
     this lease, the term "common areas" means, without limitation, the
     entrances, lobbies, trash facilities, driveways, walkways, landscaping and
     all other areas and facilities, including the plumbing, electrical, and
     sprinkler systems, ductwork, roof and exterior wall and windows, in the
     Building which are provided for and designated from time to time by Lessor
     for the general non-exclusive use and convenience of Lessee and its
     employees, invitees, licensees or other visitors.  Lessor grants Lessee,
     its employees, invitees, licensees and other visitors a non-exclusive
     license for the Term to use the common Areas; and

               (ii)  The cost of premiums for the insurance required under
     paragraphs 9. 1 and 9. 3 (provided that Lessee shall pay loot of any
     increase in or component of any such premiums directly attributable to 
     the construction of the Tenant Improvement Work and the specialty
     equipment installed);

               (iii)  Notwithstanding anything else contained in this
     paragraph, "Operating Expenses" shall not include: (i) any capital
     additions made to the Building; (ii) repairs or other work occasioned by
     fire, windstorm, or other insured casualty or hazard; (iii) leasing
     commissions and advertising expenses incurred in procuring new tenants;
     (iv) repairs or rebuilding necessitated by condemnation to the extent that
     Lessor has received condemnation proceeds for such repairs or rebuilding;
     (v) any depreciation and amortization of the Building; (vi) principal or
     interest payments on any indebtedness applicable to the Building or the
     Premises, including any mortgage debt or ground rents payable under any
     ground lease for the Building.

          (c)  Lessee's Tax Share shall be 41% of the real property taxes 
assessed on the date hereof, plus 100% of any increase in such taxes directly 
attributable to the construction of the Tenant Improvement Work;

          (d)  As used herein the term "real property tax" shall include any 
form of real estate tax or assessment, general, special, ordinary or 
extraordinary, and any license fee, commercial rental tax, improvement bond 
or bonds, levy or tax (other than inheritance, personal income or estate 
taxes) imposed on the Premises by any authority having the direct or indirect 
power to tax, including any city, state or federal government, or any school, 
agricultural, sanitary,

                                       3

<PAGE>

fire, street, drainage or other improvement district thereof, as against any 
legal or equitable interest of Lessor in the Premises or in the real property 
of which the Premises is a part, as against Lessor's right to rent or other 
income therefrom, and as against Lessor's business of leasing the Premises.  
The term "real property tax" shall also include any tax, fee, levy, 
assessment or charge in substitution of, partially or totally, any tax, fee, 
levy, assessment for charge hereinabove included within the definition of 
"real property tax."

     All payments of additional rent for operating Expenses payable by Lessee 
shall be paid within ten days of receipt by Lessee of Lessor's statement of 
amounts due, which statement shall include at Lessee's request copies of 
relevant invoices and receipts.  All payments of additional rent for real 
property taxes payable by Lessee shall be paid within the period prescribed 
by law for the payment thereof without penalty or interest; provided that 
Lessor has sent to Lessee copies of such tax bills when received from the 
taxing authority.

7. Compliance with Law; Environmental Matters.

          7.1. Compliance With Law.

              (a)  Lessor warrants to Lessee that the Premises, in its state 
existing on the Commencement Date, and the above described uses do not 
violate any covenants or restrictions of record, or any applicable zoning or 
building code, regulation or ordinance in effect on said date.  In the event 
it is determined that this warranty has been violated, then it shall be the 
obligation of the Lessor to promptly, at Lessor's sole cost and expense, 
rectify any such violation.

              (b)  Except as provided in paragraph 7.2(a), Lessee shall, at 
Lessee's expense, comply promptly with all applicable statutes, ordinances, 
rules, regulations, orders, covenants and restrictions of record, and 
requirements in effect during the Term or any part of the term hereof, 
regulating the use by Lessee of the Premises.

          7.2. Environmental Matters.  Lessor represents and warrants that 
all activities at the Premises since Lessor's acquisition or Premises have 
been and are being conducted in compliance with all statutes, ordinances, 
regulations, orders, and requirements of common law concerning (i) those 
activities, (ii) repairs or construction of any improvements, (iii) handling 
of any materials, (iv) discharges to the air, soil, surface, or groundwater, 
and (v) storage, treatment, or disposal of any waste at or connected with any 
activity at the Premises ("Environmental Statutes").

          Lessor represents and warrants that no Contamination is present at 
the Premises.  The term "Contamination" means the uncontained presence of 
Hazardous Substances at the Premises, or arising from the Premises which may 
require remediation under any applicable law.  The term "Hazardous 
Substances" means "hazardous substances" as defined pursuant to the 
comprehensive Environmental Response, compensation and Liability Act, as 
amended, "regulated substances" within the meaning of Subtitle I of the 
Resource Conservation

                                       4

<PAGE>

Recovery Act, as amended, "hazardous wastes", as defined pursuant to the 
Delaware Hazardous Waste Management Act, or "regulated substances" as defined 
pursuant to the Del aware Underground Storage Tank Act.

          Lessor represents and warrants that no portion of the Premises 
constitutes any of the following "Environmentally Sensitive Areas":

               (i)  a wetland or other "water of the United States" for purposes
     of section 404 of the federal clean Water Act or any similar area regulated
     under any state law;

               (ii) a portion of the coastal zone for purposes of the Federal
     Coastal Zone Management Act and the Delaware Coastal Zone Act; or

               (iii) any other area, including but not limited to a floodplain
     or other flood hazard area, the development of which is specially
     restricted under any applicable law by reason of its physical
     characteristics or prior use.

          Lessor represents and warrants that no tanks for the storage of any 
liquid or gas are present on the Premises except for two underground 500 
gallon liquid propane tanks.

          Lessor represents and warrants that (i) at no point in any 
structure at the Premises will air radiation levels exceed 4 
picocuries/liter, (ii) Lessor does not know or have reason to know of any 
investigation of the Premises for the presence of radon gas or the presence 
of the radioactive decay products of radon (collectively "Radon") and (iii) 
Lessor has provided to Lessee a report of each investigation relevant to the 
presence of Radon at the Premises of which Lessor has any knowledge.

          The parties hereby agree that if any of the representations or 
warranties contained in this paragraph 7.2 shall prove to be incorrect, or if 
Lessor breaches any covenant contained in this paragraph 7.2, Lessor shall be 
afforded an opportunity to cure such default provided that (i) such breach or 
condition is susceptible of remediation within a reasonable amount of time as 
determined by Lessee; and (ii) Lessor begins promptly after the discovery of 
such breach or condition diligently to remedy same and continues such 
diligent efforts until satisfactory remediation has been achieved.

          Lessor shall indemnify and hold Lessee harmless of, from, and 
against any and all expense, loss or liability suffered by Lessee by reason 
of the Lessor's breach of any provision of this Section including, but not 
limited to, (i) costs to comply with any Environmental Statutes; (ii) costs 
to study or to remedy contamination of the Premises or arising from the 
Premises; (iii) costs incident to the study or removal of tanks, their 
contents or associated Contamination; (iv) cost to prevent air radiation 
levels in any structure hereafter erected in the Premises from exceeding 4 
picocuries/liter or to reduce air radiation levels in any structure on the 
Premises to 4

                                       5

<PAGE>

picocuries/liter or less; (v) fines, penalties, or other sanctions assessed 
due to Lessor's failure to have complied with Environmental Statutes; (vi) 
loss of value of the Property by reason of a failure to comply with 
Environmental Statutes or the presence on the Property of any Hazardous 
Substance, tank, Environmentally Sensitive Feature or Radon; and (vii) legal 
and professional fees and costs in connection with the foregoing.  For 
purposes of this subparagraph, the term "Lessee" shall mean Lessee, its 
successors and assigns.  Nothing herein shall be construed to include (i) any 
condition or occurrence arising out of Lessee's activities in or on the 
Premises, or (ii) any consequential damages or losses sustained by Lessee as 
a result of interruption of Lessee's business activities or the dislocation 
of Lessee's facilities as a result of a default pursuant to this paragraph 
7.2.

          7.3. Condition of Premises.

               (a)  Lessor shall deliver the Premises to Lessee clean and 
free of debris on the Commencement Date and Lessor further warrants to Lessee 
that the Tenant Improvement Work in the Premises shall be in good operating 
condition on the Commencement Date.  In the event that it is determined that 
this warranty has been violated, then it shall be the obligation of Lessor, 
after receipt of written notice from Lessee setting forth with specificity 
the nature of the violation, to promptly, at Lessor's sole cost, rectify such 
violation.

          Within thirty (30) days after the Commencement Date, Lessee shall 
give Lessor a written list (the "Punch List") of all contended defects in 
Lessor's construction work and of all contained variances in Lessor's work as 
described in Exhibit "HI' attached hereto.  Lessor shall correct all items on 
the Punch List within thirty (30) days after Lessor's receipt of the Punch 
List, unless the nature of the defect or variance is such that a longer 
period of time is required to repair or correct the same, in which case 
Lessor shall exercise due diligence in correcting such defect or variance at 
the earliest possible date and with a minimum of interference with Lessee's 
operations.  Nothing in this subparagraph shall be deemed a waiver by Lessee 
of Lessor's warranty contained in paragraph 7.3(a) for violations discovered 
after delivery of the Punch List.

     8. Repairs, Alterations and Building Services.

          8.1. Lessor's Obligations.

               (a)  Lessor shall keep in good order, condition and repair the 
Common Areas of the Building.

               (b)  If Lessor fails to perform Lessor's obligations under 
this paragraph 8.1 or under any other paragraph of this lease, Lessee may at 
Lessee's option and upon 10 days' prior written notice to Lessor (except in 
the case of emergency, in which case no notice shall be required), perform 
such obligations on Lessor's behalf and put the Common Areas and HVAC in good 
order, condition and repair, and the cost thereof shall be offset against the 
installment rent next due.

                                       6

<PAGE>

          8.2. Lessee's Obligations.  Lessee, at its expense, shall maintain 
and keep in good order, condition and repair the plumbing, electric, HVAC, 
lighting, fixtures, interior walls, ceilings, floors, windows, doors and 
plate glass located in, on, or within the Premises or any part thereof, and 
which are for the exclusive use of the Premises or Lessee.  Lessee shall 
procure and maintain at Lessee's expense an HVAC maintenance agreement, which 
shall be in form and substance reasonably satisfactory to Lessor. On the last 
day of the Term hereof, or on any sooner termination, Lessee shall surrender 
the Premises to Lessor in the same condition as received, ordinary wear and 
tear excepted, clean and free of debris.

          8.3. Alterations and Additions.

               (a)  Lessee shall not, without Lessor's prior written consent, 
which consent shall not be unreasonably withheld or delayed, make any 
alterations, improvements, additions, or Utility Installations in, on or 
about the Premises, except for nonstructural alterations not exceeding 
$7,500.  In any event, whether or not in excess of $7,500 in cost, Lessee 
shall make no change or alteration to the exterior of the Premises nor the 
exterior of the Building without Lessor's prior written consent.  As used in 
this paragraph 8.3 the term "Utility Installation" shall mean air lines, 
power panels, electrical distribution systems, lighting fixtures, space 
heaters, air conditioning, plumbing, and fencing.  Should Lessee make any 
alterations,, improvements, additions or Utility Installations without the 
prior approval of Lessor, Lessor may require that Lessee remove any or all of 
the same.

               (b)  Any alterations, improvements, additions or Utility 
Installations in or about the Premises that Lessee shall desire to make and 
which requires the consent of the Lessor shall be presented to Lessor in 
written form, with proposed detailed plans.  If Lessor shall give its 
consent, the consent shall be deemed conditioned upon Lessee acquiring a 
permit to do so from appropriate government agencies, the furnishing of a 
copy thereof to Lessor prior to the commencement of the work and the 
compliance by Lessee of all conditions of said permit in a prompt and 
expeditious manner.

               (c)  Lessee shall pay, when due, all claims for labor or 
materials furnished to or for Lessee at or for use in the Premises, which 
claims are or may be secured by any mechanics' or materialmen's lien against 
the Premises or any interest therein.  Lessee shall give Lessor not less than 
ten (10) days' notice prior to the commencement of any work in the Premises, 
and Lessor shall have the right to post notices of non-responsibility in or 
on the Premises as provided by law.  If Lessee shall, in good faith, contest 
the validity of any such lien, claim or demand, then Lessee shall, at its 
sole expense defend itself and Lessor against the same and shall pay and 
satisfy any such adverse judgment that may be rendered thereon before the 
endorsement thereof against the Lessor or the Premises, upon the condition 
that if Lessor shall require, Lessee shall furnish to Lessor a surety bond 
satisfactory to Lessor in an amount equal to such contested lien claim or 
demand indemnifying Lessor against liability for the same and holding the 
Premises free from the effect of such lien or claim and shall obtain release 
of such lien by substitution of such surety bond as security therefor.  In 
addition, Lessor may require

                                       7

<PAGE>

Lessee to pay Lessor's attorneys fees and costs in participating in such 
action if Lessor shall decide it is to its best interest to do so.

               (d)  Unless Lessor requires their removal, as set forth in 
paragraph 8.3(a), all alterations, improvements, additions and Utility 
Installations, which may be made on the Premises, shall become the property 
of Lessor and remain upon and be surrendered with the Premises at the 
expiration of the Term.

     9. Insurance; Indemnity.

          9.1. Liability Insurance - Lessor.  Lessor shall obtain and keep in 
force during the Term of this lease a policy of Combined Single Limit Bodily 
Injury and Property Damage Insurance, insuring Lessor and Lessee against any 
liability arising out of the ownership, use or occupancy maintenance of the 
Premises and all areas appurtenant thereto in an amount not less than 
$500,000 per occurrence.

          9.2. Liability Insurance - Lessee.. Lessee shall obtain and keep in 
force during the Term of this lease a policy of combined Single Limit Bodily 
Injury and Property Damage Insurance, insuring Lessor and Lessee against any 
liability arising out of the use or occupancy of the Premises and all areas 
appurtenant thereto in an amount not less than $500,000 per occurrence.

          9.3. Property Insurance.  Lessor shall obtain and keep in force 
during the Term of this lease a policy or policies of insurance covering loss 
or damage to the Building, including Lessee's fixtures, equipment or tenant 
improvements in an amount not to exceed the full replacement value thereof as 
the same may exist from time to time, providing protection against all perils 
included within the classification of fire, extended coverage, vandalism, 
malicious mischief, flood (in the event same is required by a lender having a 
lien on the Premises), special extended perils ("all risk", as such term is 
used in the insurance industry).

          9.4. Insurance Policies.  Insurance required hereunder shall be in 
companies holding a "General Policyholders Rating" of at least B plus, or 
such other rating as may be required by a lender having a lien on the 
Premises, as set forth in the most current issue of "Best Insurance Guide".  
Lessor and Lessee shall deliver to each other copies of policies of all 
insurance required under paragraph 8 or certificates evidencing the existence 
and amounts of such insurance.  No such policy shall be cancellable or 
subject to reduction of coverage or other modification except after thirty 
(30) days' prior written notice to the other.  Each party shall, at least 
thirty (30) days prior to the expiration of such policies, furnish the other 
with renewals thereof.  Lessee shall not do or permit to be done anything 
which shall invalidate the insurance policies referred to in paragraph 9.3.

          9.5. Waiver of Subrogation.  Lessee and Lessor each hereby release 
and relieve the other, and waive their entire right of recovery against the 
other for loss or damage arising out

                                       8

<PAGE>

of or incident to the perils insured against under paragraph 9.3, which 
perils occur in, on or about the Premises, whether due to the negligence of 
Lessor or Lessee or their agents, employees, contractors and/or invitees.  
Lessee and Lessor shall, upon obtaining the policies of insurance required 
hereunder, give notice to the insurance carrier or carriers that the 
foregoing mutual waiver of subrogation is contained in this lease.

          9.6. Indemnity.  Lessee shall indemnify and hold harmless Lessor 
from and against any and all claims arising from Lessee's use of the 
Premises, or from the conduct of Lessee's business or from any activity, work 
or things done, permitted or suffered by Lessee in or about the Premises or 
elsewhere and shall further indemnify and hold harmless Lessor from and 
against any and all claims arising from any breach or default in the 
performance of any obligation on Lessee's part to be performed under the 
terms of this lease, or arising from any negligence of the Lessee, or any of 
Lessee's agents, contractors, or employees, and from and against all costs, 
attorneys' fees, expenses and liabilities incurred in the defense of any such 
claim or any action or proceeding brought thereon; and in case any action or 
proceeding be brought against Lessor by reason of any such claim.  Lessee 
upon notice from Lessor shall defend the same at Lessee's expense by counsel 
satisfactory to Lessor.

               Lessor shall indemnify and hold harmless Lessee from and 
against any and all claims arising from any breach or default in the 
performance of any obligation on Lessor's part to be performed under the 
terms of this lease, or arising from any negligence of the Lessor, or any of 
Lessor's agents, contractors, or employees, and from and against all costs, 
attorneys' fees, expenses and liabilities incurred in the defense of any such 
claim or any action or proceeding brought thereon; and in case any action or 
proceeding be brought against Lessee by reason of any such claim.  Lessor 
upon notice from Lessee shall defend the same at Lessor's expense by counsel 
satisfactory to Lessee.

     10. Destruction.

          10.1 Definitions.

               (a)  "Premises Partial Damage" shall herein mean damage or 
destruction to the Premises to the extent that the cost of repair is less 
than 50% of the fair market value of the Premises immediately prior to such 
damage or destruction. "Premises Building Partial Damage" shall herein mean 
damage or destruction to the Building of which the Premises are a part to the 
extent that the cost of repair is less that 50% of the fair market value of 
the Building as a whole immediately prior to such damage or destruction.

               (b)  "Premises Total Destruction" shall herein mean damage or 
destruction to the Premises to the extent that the cost of repair is 50% or 
more of the fair market value of the Premises immediately prior to such 
damage or destruction.

                                       9

<PAGE>

               (c)  "Insured Loss" shall herein mean damage or destruction 
which was caused by an event required to be covered by the insurance 
described in paragraph 10.

          10.2. Partial Damage - Insured Loss.  Subject to the provisions of 
paragraph 10.4, 10.5 and 10.6, if at any time during the Term of this lease 
there is damage which is an Insured loss and which falls into the 
classification of Premises Partial Damage or Premises Building Partial 
Damage, then Lessor shall, at Lessor's sole cost, repair such damage, 
including Lessee's fixtures, equipment or tenant improvements as soon as 
reasonably possible and this lease shall continue in full force and effect.

          10.3. Partial Damage - Uninsured Loss.  Subject to the provisions 
of paragraphs 10.4, 10.5 and 10.6, if at any time during the Term of this 
lease there is damage which is not an Insured loss and which fails within the 
classification of Premises Partial Damage or Premises Building Partial 
Damage, unless caused by a willful act of Lessee (in which event Lessee shall 
make the repairs at Lessee's expense), Lessor may at Lessor's option either 
(i) repair such damage as soon as reasonably possible at Lessor's expense, in 
which event this lease shall continue in full force and effect, or (ii) give 
written notice to Lessee within fifteen (15) days after the date of the 
occurrence of such damage of Lessor's intention to cancel and terminate this 
lease. In the event Lessor shall give such notice of Lessor's intention to 
cancel and terminate this lease, Lessee shall have the right within fifteen 
(15) days after the receipt of such notice to give written notice to Lessor 
of Lessee's intention to repair such damage at Lessee's expense, in which 
event this lease shall continue in full force and effect, and Lessee shall 
proceed to make such repairs as soon as reasonably possible.  If Lessee does 
not give such notice within such 15-day period this lease shall be cancelled 
and terminated and Lessee shall have no further obligations or duties 
thereunder including the payment of rent as of the date of the occurrence of 
such damage.

          10.4. Total Destruction.  If at any time during the term of this 
lease there is damage, whether or not an Insured loss, (including destruction 
required by any authorized public authority), which falls into the 
classification of Premises Total Destruction or Premises Building Total 
Destruction, this lease shall automatically terminate and Lessee shall have 
no further obligations or duties thereunder including the payment of rent as 
of the date of such total destruction.

          10.5. Damage Near End of Term.

               (a)  If at any time during the last six months of the Term of 
this lease there is damage, whether or not an Insured loss, which falls 
within the classification of Premises Partial Damage, Lessor and Lessee each 
has the option to cancel and terminate this lease as of the date of 
occurrence of such damage by giving written notice to the other of its 
election to do so within 30 days after the date of occurrence of such damage.

               (b)  Notwithstanding paragraph 10. 5 (a) , in the event that 
Lessee has an option to extend or renew this lease, and the time within which 
said option may be exercised has not yet expired, Lessee shall exercise such 
option, if it is to be exercised at all, no later that 25 days after

                                      10

<PAGE>

the occurrence of an Insured loss falling within the classification of 
Premises Partial Damage during the last six months of the Term of this lease. 
 If Lessee duly exercises such option during said 25 day period, Lessor 
shall, at Lessor's expense, repair such damage as soon as reasonably possible 
and this lease shall continue in full force and effect.  If Lessee fails to 
exercise such option during said 25 day period, then Lessor may at Lessor's 
option terminate and cancel this lease as of the expiration of said 25 day 
period by giving written notice to Lessee of Lessor's election to do so 
within 5 days after the expiration of said 25 day period, notwithstanding any 
term or provision in the grant of option to the contrary.

          10.6. Abatement of Rent; Lessee's Remedies.

               (a)  In the event of damage described in paragraphs 10.2 or 
10.3 and Lessor or Lessee repairs or restores the Premises pursuant to the 
provisions of this paragraph 10, the rent payable hereunder for the period 
during which such damage, repair or restoration continues shall be abated in 
proportion to the degree to which Lessee's use of the Premises is impaired.  
Except for abatement of rent Lessee shall have no claim against Lessor for 
any damage suffered by reason of any such damage, destruction, repair or 
restoration.

               (b)  If Lessor shall be obligated to repair or restore the 
Premises under the provisions of this paragraph 10 and shall not commence 
meaningful repair or restoration within 30 days after such obligations shall 
accrue, Lessee may at Lessee's option cancel and terminate his lease by 
giving Lessor written notice of Lessee's election to do so at any time prior 
to Lessor's meaningful commencement of such repair or restoration.  In such 
event this lease shall terminate as of the date of such notice and Lessee 
shall have no further obligations or duties thereunder, including the payment 
of rent, as of the date of the occurrence of the damage.

          10.7. Termination - Advance Payments.  Upon termination of this 
lease pursuant to this paragraph 10, an equitable adjustment shall be made 
concerning any advance rent and any advance payments made by Lessee to Lessor.

          10.8. Waiver.  Lessor and Lessee waive the provisions of any 
statutes which relate to termination of leases when leased property is 
destroyed and agree that such event shall be governed by the terms of this 
lease.

     11. Utilities, Lessee shall pay for all water, gas, heat, light, power, 
telephone and other-utilities and services supplied to the Premises, together 
with any taxes thereon.  Such services are to be separately metered to Lessee.

     12. Assignment and Subletting

          12.1. Lessor's Consent Required, Lessee shall not voluntarily or by 
operation of law assign, transfer, mortgage, sublet, or otherwise transfer or 
encumber all of any part of Lessee's interest in this lease or in the 
Premises, without Lessor's prior written consent, which Lessor shall

                                      11

<PAGE>

not unreasonably withhold or delay.  Lessor shall respond in writing to 
Lessee's request for consent hereunder in a timely manner and any attempted 
assignment, transfer, mortgage, encumbrance or subletting without such 
consent shall be void and shall constitute a breach of this lease.

          12.2. Lessee Affiliate.  Notwithstanding the provisions of 
paragraph 12.1 hereof, Lessee may assign or sublet the Premises, or any 
portion thereof, without Lessor's consent, to any corporation which controls, 
is controlled by or is under common control with Lessee, or to any 
corporation resulting from the merger or consolidation with Lessee, or to any 
person or entity, which acquires all or substantially all of the assets of 
Lessee as a going concern of the business that is being conducted on the 
Premises, provided that said assignee assumes, in full, the obligations of 
Lessee under this lease.  Any such assignment shall not, in any way, affect 
or limit the liability of Lessee under the terms of this lease even if after 
such assignment or subletting the terms of this lease are changed or altered, 
provided, however, that any material change to the terms of this lease 
(including, but not limited to, the Term or Rent) after such an assignment or 
subletting, shall require the prior consent of Lessor and any such change 
made without Lessor's prior consent shall not be binding on Lessor.

          12.3. No Release of Lessee.  Regardless of Lessor's consent, no 
subletting or assignment shall release Lessee of Lessee's obligation or alter 
the primary liability of Lessee to pay the Rent and to perform all other 
obligations to be performed by Lessee hereunder.  The acceptance of Rent by 
Lessor from any other person shall not be deemed to be a waiver by Lessor or 
any provision hereof.  Consent to one assignment or subletting shall not be 
deemed consent to any subsequent assignment or subletting. In the event of 
default by any assignee of Lessee or any successor of Lessee, in the 
performance of any of the terms thereof, Lessor may proceed directly against 
Lessee without the necessity of exhausting remedies against said assignee.  
Lessor may consent to subsequent assignments or subletting of this Lease or 
amendments or modifications to this Lease with assignees of Lessee or any 
successor of Lessee, and without obtaining its or their consent thereto and 
such action shall not relieve Lessee of liability under this Lease.

          12.4. Assignment Fees.  In the event Lessee shall assign or sublet 
the Premises then Lessee shall pay an assignment processing fee equal to 
$200.00 for each such request.

     13. Defaults; Remedies.

          13.1. Defaults.  The occurrence of any one or more of the following 
events shall constitute a material default and breach of this Lease by Lessee:

               (a)  The failure by Lessee to make any payment of rent as and 
when due, where such failure shall continue for a period of five days after 
Lessee's receipt of written notice from Lessor.  In the event that Lessor 
serves Lessee with a Notice to Pay Rent or Quit pursuant to applicable 
Unlawful Detainer statutes, such Notice to Pay Rent or Quit shall also 
constitute the notice required by this subparagraph;

                                      12

<PAGE>

               (b)  The failure by Lessee to observe or perform any of the 
covenants, conditions or provisions of this Lease to be observed or performed 
by Lessee, other than described in paragraph (a) above, where such failure 
shall continue for a period of 30 days after written notice hereof from 
Lessor to Lessee; provided, however, that if the nature of Lessee's default 
is such that more than 30 days are reasonably required for its cure, then 
Lessee shall not be deemed to be in default if Lessee commenced such cure 
within said 30-day period and thereafter diligently prosecutes such cure to 
completion;

               (c)  (i) The making by Lessee of any general arrangement or 
assignment for the benefit of creditors; (ii) Lessee becomes a "debtor" as 
defined in 11 U.S.C. Section 101 or any successor statute thereto (unless, in 
the case of a petition filed against Lessee, the same is dismissed within 60 
days); (iii) the appointment of a trustee or receiver to take possession of 
substantially all of Lessee's assets located at the Premises or of Lessee's 
interest in this lease, where possession is not restored to Lessee within 30 
days; or (iv) the attachment, execution or other judicial seizure of 
substantially all of Lessee's assets located at the Premises or of Lessee's 
interest in this lease, where such seizure is not discharged within 30 days.  
Provided, however, in the event that any provision of this paragraph 13.1(c) 
is contrary to any applicable law, such provision shall be of no force or 
effect;

               (d)  The discovery by Lessor that any financial statement 
given to Lessor by Lessee, any assignee of Lessee, any subtenant of Lessee, 
any successor in interest of Lessee or any guarantor of Lessee's obligation 
hereunder, and any of them, was materially false.

          13.2. Remedies.  In the event of any such material default or 
breach by Lessee, Lessor may at any time after providing Lessee with written 
notice, but without limiting Lessor in the exercise of any right or remedy 
which Lessor may have by reason of such default or breach:

               (a)  Terminate Lessee's right to possession of the Premises by 
any lawful means, in which case this lease shall terminate and Lessee shall 
immediately surrender possession of the Premises to Lessor.  In such event 
Lessor shall be entitled to recover from Lessee all damages incurred by 
Lessor by reason of Lessee's default including, but not limited to, the cost 
of recovering possession of the Premises; expenses of reletting, including 
necessary renovation and alteration of the premises, reasonable attorneys' 
fees, and any real estate commission actually paid; the worth at the time of 
award by the court having jurisdiction thereof of the amount by which the 
unpaid rent for the balance of the term after the time of such award exceeds 
the amount of such rental loss for the same period that Lessee proves could 
be reasonably avoided.

               (b)  Maintain Lessee's right to possession in which case this 
lease shall continue in effect whether or not Lessee shall have abandoned the 
Premises.  In such event Lessor shall be entitled to enforce all of Lessor's 
rights and remedies under this lease, including the right to recover the rent 
as it becomes due hereunder;

                                      13

<PAGE>

               (c)  Pursue any other remedy now or hereafter available to 
Lessor under the laws or judicial decisions of the State of Delaware.  Unpaid 
installments of rent and other unpaid monetary obligations of Lessee under 
the terms of this lease shall bear interest from the date due at the maximum 
rate then allowable by law.

          13.3. Default by Lessor.  Lessor shall not be in default unless 
Lessor fails to perform obligations required of Lessor within a reasonable 
time, but in no event later than ten (10) days after written notice by Lessee 
to Lessor and to the holder of any first mortgage or deed of trust covering 
the Premises whose name and address shall have theretofore been furnished to 
Lessee in writing, specifying wherein Lessor has failed to perform such 
obligation; provided, however, that if the nature of Lessor's obligation is 
such that more than ten (10) days are required for performance then Lessor 
shall not be in default if Lessor commences meaningful performance within 
such lo-day period and thereafter diligently prosecutes the same to 
completion.

          13.4. Late Charges.  Lessee hereby acknowledges that late payment 
by Lessee to Lessor of rent and other sums due hereunder will cause Lessor to 
incur costs not contemplated by this lease, the exact amount of which will be 
extremely difficult to ascertain. Such costs include, but are not limited to, 
processing and accounting charges, and late charges which may be imposed on 
Lessor by the terms of any mortgage or trust deed covering the Premises.  
Accordingly, if any installment of rent shall not be received by Lessor or 
Lessor's designee within fifteen (15) days after such amount shall be due, 
then, without any requirement for notice to Lessee, Lessee shall pay to 
Lessor a late charge equal to 3% of such overdue amount.  The parties hereby 
agree that such late charge represents a fair and reasonable estimate of 
costs Lessor will incur by reason of late payment by Lessee.  Acceptance of 
such late charge by Lessor shall in no event constitute a waiver of Lessee's 
default with respect to such overdue amount, nor prevent Lessor from 
exercising any of the other rights and remedies granted hereunder.

          14. Condemnation.  If the Premises or any portion thereof are taken 
under the power of eminent domain, or sold under the threat of the exercise 
of said power (all of which are herein called "condemnation"), this lease 
shall terminate as to the part so taken as of the date the condemning 
authority takes title or possession, whichever first occurs.  If more than 
10% of the floor area of the Building, or more than 25% of the area of the 
Premises is taken by condemnation, Lessee may, at Lessee's option, to be 
exercised in writing within fifteen (15) days after Lessor shall have given 
Lessee written notice of such taking (or in the absence of such notice, 
within fifteen (15) days after the condemning authority shall have taken 
possession) terminate this lease as of the date the condemning authority 
takes such possession.  If Lessee opts to terminate this lease as described 
in the foregoing, Lessee's obligations and duties under this lease shall 
cease as of the date of condemning authority take such possession.  If Lessee 
does not terminate this lease in accordance with the foregoing, this lease 
shall remain in full force and effect as to the portion of the Premises 
remaining, except that the rent shall be reduced in the proportion that the 
floor area of the Building taken bears to the total floor area of the 
Building situated on the Premises.  No reduction of rent shall occur if the 
only area taken is that which does not have a building located thereon.  Any 
award for the taking of all or any part of the Premises under the power of 
eminent domain or any payment

                                      14

<PAGE>

made under threat of the exercise of such power shall be the property of 
Lessor, whether such award shall be made as compensation for diminution in 
value of the leasehold or for the taking of the fee, or as severance damages; 
provided, however, that Lessee shall be entitled to any award for loss of or 
damage to Lessee's equipment, trade fixtures and removable personal property. 
 In the event that this lease is not terminated by reason of such 
condemnation, Lessor shall to the extent of severance damages received by 
Lessor in connection with such condemnation, repair any damage to the 
Premises caused by such condemnation except to the extent that Lessee has 
been reimbursed therefor by the condemning authority.

     15. Brokers' Fees.

          Lessor shall be responsible for all brokers,, commissions or 
finder's fees charged by Stoltz Realty and warrants to Lessee that no 
brokers' commissions, finders, fees or similar payments shall be claimed 
through Lessee in connection with the execution of this lease, and agrees to 
indemnify and hold Lessee harmless from any liability that may arise from 
such claims, including reasonable attorney's fees.

     16. Estoppel Certificate.

               (a)  Lessee shall at any time upon not less than 10 days' 
prior written notice from Lessor execute,, acknowledge and deliver to Lessor 
a statement in writing (i) certifying that this lease is unmodified and in 
full force and effect (or, if modified, stating the nature of such 
modification and certifying that this lease, as so modified,, is in full 
force and effect) and the date to which the rent is paid and (ii) 
acknowledging that there are not, to Lessee's knowledge, any uncured 
defaults, or events which with the passage of time would be defaults, on the 
part of Lessor hereunder, or specifying such defaults if any are claimed.  
Any such statement may be conclusively relied upon by any prospective 
purchaser or encumbrancer of the Premises.

               (b)  At Lessor's option, Lessee's failure to deliver such 
statement within such time shall be a material breach of this lease or shall 
be conclusive upon Lessee (i) that this lease is in full force and effect, 
without modification except as may be represented by Lessor, (ii) that there 
are no uncured defaults in Lessor's performance, and (iii) that not more than 
one month's rent has been paid in advance or such failure may be considered 
by Lessor as a default by Lessee under this lease.

              (c)  If Lessor desires to finance, refinance, or sell the 
Premises, or any part thereof, Lessee hereby agrees to deliver to any lender 
or purchaser designated by Lessor such financial statements of Lessee as may 
be reasonable required by such lender or purchaser.  Such statements shall 
include to the extent available the past three years' financial statements of 
Lessee.  All such financial statements shall be received by Lessor and such 
lender or purchaser in confidence and shall be used only for the purposes 
herein set forth.

                                      15

<PAGE>

     17. Lessor's Liability.  The term "Lessor" as used herein shall mean 
only the owner and owners at the time in question of the fee title or a 
lessee's interest in a ground lease of the Premises.  In the event of any 
transfer of such title or interest, Lessor herein name (and in case of any 
subsequent transfers then the grantor) shall be relieved from and after the 
date of such transfer of all liability as respects Lessor's obligations 
thereafter to be performed, provided that any funds in the hands of Lessor of 
the then grantor at the time of such transfer, in which Lessee has an 
interest, shall be delivered to the grantee.  The obligations contained in 
this Lease to be performed by Lessor shall, subject as aforesaid, be binding 
on Lessor's successors and assigns, only during their respective periods of 
ownership.

     18. Severability.  The invalidity of any provisions of this Lease as 
determined by a court of competent jurisdiction, shall in no way affect the 
validity of any other provision hereof.

     19. Time--of Essence. Time is of the essence.

     20. Incorporation of  Prior Agreements; Amendments.

     This Lease contains all agreements of the parties with respect to any 
matter mentioned herein.  No prior agreement or understanding pertaining to 
any such matter shall be effective.  This Lease may be modified in writing 
only, signed by the parties in interest at the time of the modification.  
Except as otherwise stated in this Lease, Lessee hereby acknowledges that 
neither the real estate brokers listed in paragraph 15 hereof nor any 
cooperating broker on this transaction nor the Lessor or any employees or 
agents of any of said persons has made any oral or written warranties or 
representations to Lessee relative to the condition or use by Lessees of said 
Premises and Leases acknowledges that Lessee assumes all responsibility 
regarding the Occupational Safety Health Act, the legal use and adaptability 
of the Premises and the compliance thereof with all applicable laws and 
regulations in effect during the term of this Lease except as otherwise 
specifically stated in this Lease.

     21. Notices.  Any notice required or permitted to be given hereunder 
shall be in writing and may be given personal delivery or by certified mail, 
and if given personally or by mail, shall be deemed sufficiently given if 
addressed to Lessee or to Lessor at the address noted below the signature of 
the respective parties, as the case may be. Each such notice shall be deemed 
given upon personal delivery or, if by certified mail, upon mailing.  Either 
party may by notice to the other specify a different address for notice 
purposes except that upon Lessee's taking possession of the Premises, the 
Premises shall constitute Lessee's address for notice purposes.  A copy of 
all notices required or permitted to be given to Lessor hereunder shall be 
concurrently transmitted to such party or parties at such addresses as Lessor 
may from time to time hereafter designate by notice to Lessee.

     22. Waivers.  No waiver by Lessor or any provision hereof shall be 
deemed a waiver of any other provision hereof or of any subsequent breach by 
Lessee of the same or any other provision.  Lessor's consent to, or approval 
of any act, shall not be deemed to render unnecessary the obtaining of 
Lessor's consent to or approval of any subsequent act by Lessee.  The 
acceptance of rent

                                      16

<PAGE>

hereunder by Lessor shall not be a waiver of any preceding breach by Lessee 
of any provision hereof, other than the failure of Lessee to pay the 
particular rent so accepted, regardless of Lessor's knowledge of such 
preceding breach at the time of acceptance of such rent.

     23. Recording.  Either Lessor or Lessee shall, upon request of the 
other, execute, acknowledge and deliver to the other a "short form" 
memorandum of this lease for recording purposes.

     24. Holding Over.  If Lessee, with Lessor's consent, remains in 
possession of the Premises or any part thereof after the expiration of the 
term hereof, such occupancy shall be a tenancy from month to month upon all 
the provisions of this lease pertaining to the obligations of Lessee, but all 
options and rights of first refusal, if any, granted under the terms of this 
lease shall be deemed terminated and be of no further effect during said 
month to month tenancy.

     25. Cumulative Remedies.  No remedy or election hereunder shall be 
deemed exclusive but shall, wherever possible, be cumulative with all other 
remedies at law or in equity.

     26. Covenants and Conditions.  Each provision of this lease performable 
by Lessee shall be deemed both a covenant and a condition.

     27. Binding Effect; Choice of Law.  Subject to any provisions hereof 
restricting assignment or subletting by Lessee, this lease shall bind the 
parties, their personal representatives, successors and assigns.  This lease 
shall be governed by the laws of the State of Delaware.

     28. Subordination.

               (a)  This lease, at Lessor's option, shall be subordinate to 
any ground lease, mortgage, deed of trust, or any other hypothecation or 
security now or hereafter placed upon the real property of which the Premises 
are a part and to any and all advances made on the security thereof and to 
all renewals, modifications, consolidations, replacements and extensions 
thereof.  Notwithstanding such subordination, Lessee's right to quiet 
possession of the Premises shall not be disturbed if Lessee is not in default 
and so long as Lessee shall pay the Rent and observe and perform all of the 
provisions of this lease, unless this lease is otherwise terminated pursuant 
to its terms.  If any mortgagee, trustee or ground Lessor shall elect to have 
this lease prior to the lien of its mortgage, deed of trust or ground lease, 
and shall give written notice thereof to Lessee, this lease shall be deemed 
prior to such mortgage, deed of trust, or ground lease, whether this lease is 
dated prior or subsequent to the date of said mortgage, deed of trust or 
ground lease or the date of recording thereof.

               (b)  Lessee agrees to execute any documents required to 
effectuate an attornment, a subordination or to make this lease prior to the 
lien of any mortgage, deed of trust or ground lease, as the case may be.  If 
Lessee fails to execute such documents within 10 days after written demand, 
Lessor may execute such documents on behalf of Lessee as Lessee's 
attorney-in-

                                      17

<PAGE>

fact.  Lessee does hereby make, constitute and irrevocably appoint Lessor as 
Lessee's attorney-in-fact and in Lessee's name, place and stead, to execute 
such documents in accordance with this paragraph 28(b).

     29. Intentionally Omitted.

     30. Lessor's Access.  Lessor and Lessor's agents, upon prior written 
notice to Lessee, shall have the right to enter the Premises at reasonable 
times for the purpose of inspecting the same, showing the same to prospective 
purchasers, lenders, or lessees, and making such alterations, repairs, 
improvements or additions to the Premises or to the Building of which they 
are a part as Lessor may deem necessary or desirable; provided, however that 
upon such entry Lessor and/or Lessor's agents (except in the case of 
emergency) shall be required to be accompanied by a representative of Lessee 
for purposes of protecting and preserving the confidentiality of Lessee's 
work on the Premises.  Lessor may not at any time place on or about the 
Premises any ordinary "For Sale" signs.  Lessor may at any time during the 
last 120 days of the Term hereof place on or about the Premises on the 
Building any ordinary "For Lease" signs, all without rebate of rent or 
liability to Lessee; provided that Lessor shall not permitted to place "For 
Lease" signs on or about the Premises until any options or rights available 
to Lessee to extend the term of this lease or to renew this lease or any 
options or rights of first refusal to lease the Premises or rights of first 
offer to purchase the Premises have lapsed.

     31. Signs.  Lessee shall not place any sign upon the Premises without 
Lessor's prior written consent, which shall not be unreasonably withheld, 
except that Lessee shall have the right, without the prior permission of 
Lessor, to place ordinary and usual for rent or sublet signs thereon.

     32. Merger.  The voluntary or other surrender of this lease by Lessee, 
or a mutual cancellation thereof, or a termination by Lessor, shall not work 
a merger, and shall, at the option of Lessor, terminate all or any existing 
subtenancies or may, at the option of Lessor, operate as an assignment to 
Lessor of any or all of such subtenancies.

     33. Consents.  Wherever in this lease the consent of one party is 
required to an act of the other party, such consent shall not be unreasonably 
withheld.

     34. Quiet Possession.. Upon Lessee paying the rent for the Premises and 
observing and performing all of the covenants, conditions and provisions on 
Lessee's part to be observed and performed hereunder, Lessee shall have quiet 
possession of the Premises for the entire Term hereof subject to all of the 
provisions of this lease.  The individuals executing this lease on behalf of 
Lessor  represent and warrant to Lessee that they are fully authorized and 
legally capable of executing this lease on behalf of Lessor and that such 
execution is binding upon all parties holding an ownership interest in the 
Premises.

     35. Options: Right of First Refusal.

                                      18

<PAGE>

          35.1. Definition.  As used in this paragraph the word "Options" 
means the right or option to extend the term of this lease or to renew this 
lease.

          35.2. Options Personal.  Each Option granted to Lessee in this 
lease is personal to Lessee and may not be exercised or be assigned, 
voluntarily or involuntarily, by or to any person or entity other than 
Lessee, provided, however, the Option may be exercised by or assigned to any 
Lessee Affiliate as defined in paragraph 12 of this lease.  The Options 
herein granted to Lessee are not assignable separate and apart from this 
lease.

          35.3. Effect of Default on Options.

               (a)  Lessee shall have no right to exercise an Option, 
notwithstanding any provision in the grant of Option to the contrary, (i) 
during the time commencing from the date Lessor gives to Lessee a notice of 
default pursuant to paragraph 13.1(a) or 13.1(b) and continuing until the 
default alleged in said notice of default is cured, or (ii) at any time after 
an event of default described in paragraphs 13.1(c) or 13.1(d) (without any 
necessity of Lessor to give notice of such default to Lessee).

               (b)  The period of time within which an option may be 
exercised shall not be extended or enlarged by reason of Lessee's inability 
to exercise an option because of the provisions of paragraph 36.3.

          35.4. Option to Renew.  Lessee shall have the right, at its sole 
option, to renew this lease for an additional period of five (5), years 
following the term hereof, upon the same terms and conditions in effect at 
the expiration of the prior term, including provision for the escalation of 
rent and including this option to renew; provided-that the ceiling and floor 
limitations for the escalation of rent in Section 5(e) (ii) herein shall not 
apply following the fifteenth anniversary of the Commencement Date; provided 
further that Lessee shall have given Lessor no more than six and no less than 
three months written notice in advance at the end of the prior term of its 
intention to renew this lease.  Lessee hereby guarantees that it will 
exercise the first five (5) year renewal option under this Lease and that TSD 
Biosciences will exercise the first five (5) year renewal option under its 
lease with Lessor for a portion of the Building.  In the event TSD 
Biosciences fails to exercise its first five (5) year option as provided 
above then Lessee will lease such space on the terms made available to TSD 
Biosciences.

     36. Multiple Tenant Building.. Lessee agrees that it will abide by, keep 
and observe all reasonable rules and regulations which Lessor may make from 
time to time for the management, safety, care, and cleanliness of the 
building and grounds, the parking of vehicles and the preservation of good 
order therein as well as for the convenience of other occupants and tenants 
of the building.  The violations of any such rules and regulations shall be 
deemed a material breach of this Lease by Lessee.

                                      19

<PAGE>

     37. Security Measures.  Lessee hereby acknowledges that the rent payable 
to Lessor hereunder does not include the cost of guard service or other 
security measures, and that Lessor shall have no obligation whatsoever to 
provide same.  Lessee assumes all responsibility for the protection of 
Lessee, its agents and invitees from acts of third parties.

     38. Easements.  Lessor reserves to itself the right, from time to time, 
to grant such easements, rights and dedications that Lessor deems necessary 
or desirable, and to cause the recordation of Parcel Maps and restrictions, 
so long as such easements rights, dedications, Maps and restrictions do not 
interfere' with the use of the Premises by Lessee.  Lessee shall sign any of 
the aforementioned documents upon request of Lessor and failure to do so 
shall constitute a material breach of this lease.

     39. Performance Under Protest.  If at any time a dispute shall arise as 
to any amount or sum of money to be paid by one party to the other under the 
provisions hereof the party against whom the obligation to pay the money is 
asserted shall have the right to make payment "under protest" and such 
payment shall not be regarded as a voluntary payment, and there shall survive 
the right on the part of said party to institute suit for recovery of such 
SUM.  If it shall be adjudged that there was no legal obligation on the part 
of said party to pay such sum or any part thereof, said party shall be 
entitled to recover such sum or so much thereof as it was not legally 
required to pay under the provisions of this lease.

     40. Authority.  If either Lessor or Lessee is a corporation, trust, or 
general or limited partnership, each individual executing this lease on 
behalf of such entity represents and warrants that he or she is duly 
authorized to execute and deliver this Lease on behalf of said entity.

LESSOR AND LESSEE HAVE CAREFULLY READ AND REVIEWED THIS LEASE AND EACH TERM 
AND PROVISION CONTAINED HEREIN AND, BY EXECUTION OF THIS LEASE, SHOW THEIR 
INFORMED AND VOLUNTARY CONSENT THERETO, THE PARTIES HEREBY AGREE THAT, AT THE 
TIME THIS LEASE IS EXECUTED, THE TERMS OF THIS LEASE ARE COMMERCIALLY 
REASONABLE AND EFFECTUATE THE INTENT AND PURPOSE OF LESSOR AND LESSEE WITH 
RESPECT TO THE PREMISES.

The parties hereto have executed this Lease at the Place and on the dates 
specified immediately adjacent to their respective signatures.

Executed at Strategic Diagnostics Industries, Inc., 128 Sandy Drive, Newark, 
DE 19713 on Oct. 26, 1993.

                             LESSOR: TOBER & AGNEW PROPERTIES, INC. 

                             By:    /s/ ROBERT C. TOBER
                                 ------------------------------------
                                    (Seal)
                             Title:      PRES. 
                                    ---------------------------------

                                      20

<PAGE>

Executed at Strategic Diagnostics Industries, Inc., 128 Sandy Drive, Newark, 
DE 19713 on Oct. 26, 1993.

                             LESSEE: STRATEGIC DIAGNOSTICS INDUSTRIES  
                                     INCORPORATED 
               
                             By:  /s/ ANNE CAVANAUGH  
                                  --------------------------------
                                      (Seal)

                             Title:      VICE PRES.  
                                    ------------------------------

                                      21

<PAGE>

                          ADDENDUM TO INDUSTRIAL LEASE

     This Addendum to the Industrial Lease (the "Industrial Lease"), dated, 
for reference purposes only October 26, 1993, is made by and between TOBER & 
AGNEW PROPERTIES, INC., a Delaware corporation (herein called " Lessor") and 
Strategic Diagnostics Industries, Inc. a Delaware corporation (herein called 
"Lessee").  The "Industrial Lease" is that lease agreement dated as of this 
same date made by and between the Lessor and the Lessee.  All capitalized 
terms used herein and not defined herein shall have the same meaning as set 
forth in the Industrial Lease.

     1. Lessor's Obligations to Construct Tenant Improvement Work.

          (a)  Lessor hereby covenants and agrees to commence the Tenant 
Improvement Work immediately upon execution of the lease and to complete the 
Tenant Improvement Work in as expeditious a manner as possible in accordance 
with all applicable standards of care and diligence.

          (b)  Lessor represents and warrants that it has available to it the 
financial resources and personnel and that it possesses the expertise to 
commence construction of the Tenant Improvement Work and to complete it in 
accordance with the covenants made in subparagraph (a).

          (c)  Any breach of the representations, warranties and covenants 
contained in this Addendum to the Industrial Lease shall constitute a 
material breach of the Industrial Lease.  In the event of such breach, Lessee 
may terminate the Industrial Lease.

     2. Payment for Tenant Improvement Work.

          (a)  All costs (up to a maximum of $350,000 in the aggregate for 
those items described in Sections 2(b)(i) and 2(b)(iii) herein) for Tenant 
Improvement Work ("Tenant Improvement Costs"), as defined by Section 2(b) 
herein, shall be financed by the Lessor and paid for by the Lessee.  All 
Tenant Improvement Costs shall be paid in full by the Lessee in monthly 
installments over the five (5) year period immediately following the 
Commencement Date.

          (b)  Tenant Improvement Costs shall be the following costs directly 
associated with the work depicted or described in Exhibit B of the industrial 
Lease:

               (i)  supplier and subcontractor costs, professional fees
     including, but not limited to,, architectural fees, permits and
     inspection costs incurred after February 22, 1991;

               (ii)  a ten percent (10%) surcharge on those costs described in
     the foregoing Section 2(b)(i);

               (iii) the following costs relating to the acquisition of
     financing for the Tenant Improvement Work:

                                      22

<PAGE>

                        A. loan origination fees;

                        B. other loan costs, including, but not limited to,
          legal and recording costs and document preparation fees;

                        C. bank appraisal fees; and

                        D. interest on all loans undertaken by the Lessor
          prior to the Commencement Date to finance the Tenant Improvement Work.

          (c)  Interest of nine percent (9%) per annum shall be charged on 
all costs associated with the items described in the foregoing Sections 
2(b)(i) - (iii).

          (d)  Beginning with the first year following the tenth anniversary 
of the Commencement Date, and on each anniversary of the Commencement Date 
thereafter through the end of the term and any renewal thereof, the Base 
Rent, as defined in section 5 of the Industrial Lease and as adjusted 
therein, as it is applied to that portion of the Premises subject to the 
Tenant Improvement Work (the "Improvement Work Base Rent"), shall be 
increased by $1.50 per square foot plus the product of (i) $1.50 (as adjusted 
in each year beginning with the first anniversary of the Commencement Date 
through the tenth anniversary in accordance with this subparagraph) 
multiplied by (ii) the lesser of (A) five percent 5% or (B) a fraction, the 
numerator of which is the Price Index for the Adjustment Month and the 
denominator of which is the Base Index from the Prior Year (but in no event 
shall such increase be less than 4%); provided that the ceiling and floor 
limitations for the escalation of the Improvement Work Base Rent in this 
Section 2(e) (ii) shall not apply following the fifteenth anniversary of the 
Commencement Date.

The parties hereto have executed this Addendum to the Industrial Lease at the 
Place and on the dates specified immediately adjacent to their respective 
signatures.

Executed at Strategic Diagnostics Industries, Inc., 128 Sandy Drive, Newark, 
DE 19713 on Oct. 26, 1993.

                             LESSOR: TOBER & AGNEW PROPERTIES, INC. 

                             By:  /s/ ROBERT C. TOBER 
                                 ----------------------------- 
                                      (Seal)
                             Title:      PRES.  
                                    -------------------------- 

                                      23

<PAGE>

Executed at Strategic Diagnostics Industries, Inc., 128 Sandy Drive, Newark, 
DE 19713 on Oct. 26, 1993.

                             LESSEE: STRATEGIC DIAGNOSTICS INDUSTRIES   
                                     INCORPORATED 

                             By:  /s/ ANNE CAVANAUGH  
                                 ----------------------------
                                      (Seal)

                             Title:      VICE PRES. 
                                    --------------------------

                                      24


<PAGE>

                                                                   Exhibit 10.19

                                   INDUSTRIAL LEASE
                                           
    1.    Parties.  This Lease, dated, for reference purposes only August 9,
1990, is made by and between TOBER & AGNEW PROPERTIES, INC., a Delaware
corporation (herein called "Lessor") and STRATEGIC DIAGNOSTICS INCORPORATED, a
Delaware Corporation (herein called "Lessee").

    2.    Promises.  Lessor hereby leases to Lessee and Lessee leases from
Lessor for the Term (as hereinafter defined) at the rental, and upon all of the
conditions set forth herein, all that certain space (the "Premises") which is
the portion of the building erected on Lots 32 and 33, at 128 Sandy Drive,
Newark, Delaware as more fully shown on the plan attached hereto as Exhibit "A",
consisting of Seven Thousand Five Hundred Ten (7,510) square feet, more or less.
The Premises includes all fixtures, improvements, additions and other property 
installed therein at the Commencement Date (as hereinafter defined), or at any
time during the time of this Lease (other than Tenant's movable personal
property and trade fixtures), together with the right to use, in common with
others, any entrances, lobbies, hallways parking lot, walkways, elevators and
other public portions of the building in which the Premises is located (the
"Building").  The Building contains 25,600 square feet.

    3.    Term.   Tenant Improvement Work.

          3.1.   Term.  The term of this Lease and Lessee's obligation to pay 
rent hereunder shall commence upon the date when the Premises is ready for
occupancy and a certificate of occupancy or equivalent certificate has been
issued by the appropriate governmental agency (the "Commencement Date").  The
Premises shall be deemed ready for occupancy when Lessor has substantially
completed the work depicted or described on the plans and specifications listed
in Exhibit "B" attached hereto (the "Tenant Improvement Work").  "Substantial
Completion" shall mean such completion as shall enable Lessee to reasonably and
conveniently use and occupy the Premises for the conduct of its business.  The
term ("Term") of this Lease shall end ten (10) years after the Commencement
Date.  The parties agree to confirm the Commencement Date in writing.  

          3.2    Delay in Possession.  If for any reason Lessor cannot deliver 
possession of the Premises to Lessee on the Commencement Date, Lessee shall not
be obligated to pay rent until possession of the Premises is tendered to Lessee.

          3.3    Lessor's Obligation to Construct Tenant Improvement Work.

                (a)    Lessor hereby covenants and agrees to commence the Tenant
Improvement Work immediately upon execution of the Lease and to complete the
Tenant 
                                       -1-

<PAGE>

Improvement Work in as expeditious a manner as possible in accordance
with all applicable standards of care and diligence.

                (b)    Lessor represents and warrants that it has available to
it the financial resources and personnel and that it possesses the expertise to
commence construction of the Tenant Improvement Work and to complete it in
accordance with the covenants made in subparagraph (a).

                (c)    Any breach of the representations, warranties and
covenants contained in this paragraph 3.3 shall constitute a material breach of
this Lease.  In the event of such breach, Lessee may terminate this Lease.

    4.    Use.

          4.1.  Use.   The Premises shall be used and occupied for the
following: office and laboratory uses and the manufacturing of immunological
reagents and test kits and any uses accessory thereto or any other use which is
reasonably comparable and for no other purpose.

    5.    Base Rent.

                (a)    Lessee shall pay to Lessor as rent for the Premises, 
(the "Base Rent"), in advance, in fixed monthly payments on the first day of
each month of the Term.

                (b)    From the Commencement Date until the first anniversary of
the Commencement Date, the Base Rent shall be an amount to be computed as the
sum of the following components:

                       (i)    $3.45 annually per square foot;

                       (ii)   $3.75 annually per square foot (attributable to
the cost of the Tenant Improvement Work amortized over the entire Term);

                       (iii)  an additional component to be calculated as the
(i) sum of (1) specialty equipment and materials costs plus (2) subcontractor
installation charges, (ii) multiplied by 1.12,  (iii) amortized at the rate of 
11.5% per annum over the first three years of the Term, and (iv) divided by the
number of square feet in the Premises. (All such costs and charges must be
approved by Lessee prior to commencement of work.)

                On the Commencement Date, Lessor and Lessee shall execute an
addendum to this Lease setting forth the amount of the monthly rent to be paid
by Lessee to Lessor and the components thereof.

                                       -2-

<PAGE>

                (c)    Rent for any period during the Term hereof which is for
less than one month shall be a pro rata portion of the monthly installment.

                (d)    Rent shall be payable in lawful money of the United 
States to Lessor at the address stated herein or to such other persons or at 
such other places as Lessor may designate in writing.

                (e)    Commencing on the first anniversary of the Commencement
Date, and on each anniversary of the Commencement Date thereafter through the 
end of the Term and any renewal thereof, the Base Rent shall be computed in 
accordance with the provisions of this subparagraph.  In the event the Consumer
Price Index for Urban Wage Earners and Clerical Workers in the City of 
Philadelphia (1967 = 100) (hereinafter called the "Price Index") or a successor
or substitute index appropriately adjusted, reflects an increase in the cost of
living for the month immediately preceding such anniversary date ("Adjustment 
Month") over and above such cost of living as reflected by the Price Index as it
existed for the month immediately preceding the prior anniversary date
(hereinafter called the "Base Index"), the Base Rent during such lease year
shall equal (i) the number of square feet in the Premises, multiplied by the sum
of the components referenced in subparagraphs 5(b)(ii) and (iii), plus (ii) the
number of square feet in the Premises multiplied by $3.45 (as adjusted in the
prior year in accordance with this subparagraph) plus (iii) the number of square
feet in the Premises, multiplied by the product of (A) $3.45 (as adjusted in the
prior year in accordance with this subparagraph) multiplied by (B) the lesser of
(x) five percent 5% or (y) a fraction, the numerator of which is the Price Index
for the Adjustment Month and the denominator of which is the Base Index (but in
no event shall such increase be less than 4%).  In the event that such 
determination cannot be made until after any anniversary of the Commencement
Date, the increase in the monthly rental payments due for the months prior to
such determination shall be paid to Lessee upon the date the next payment of 
rent is due following such determination.  Commencing on the fourth anniversary
of the Commencement Date, the computation of Base Rent shall no longer include
the component referenced in subparagraph 5(b)(iii), which costs shall have been
reimbursed in full to Landlord by such date.

    6.    Operating Expenses.  In addition to the Base Rent, Lessee will pay to 
Lessor as additional rent Lessee's Operating Expense Share of the amount of 
Operating Expenses paid, payable or incurred by Lessor in each year of the Term
and Lessee's Tax Share of the real property taxes payable by Lessor in each year
of the Term, and Lessee's share of the premiums for required insurance payable
by Lessor.  As used in this Lease the following terms shall be defined as 
hereinafter provided: 

                (i)    Lessee's Operating Expense Share shall be twenty-nine 
percent (29%);

                (ii)   "Operating Expenses" shall mean the following:

                                       -3-

<PAGE>

                       (a)   Costs of cleaning, repairing and maintaining the
Common Areas of the Building (including the costs for snow removal).  As used in
this Lease, the term "common areas" means, without limitation, the entrances, 
lobbies, trash facilities, driveways, walkways, landscaping and all other areas
and facilities, including the plumbing, electrical, and sprinkler systems,  
ductwork, roof and exterior wall and windows, in the Building which are provided
for and designated from time to time by Lessor for the general non-exclusive use
and convenience of Lessee and its employees, invitees, licenses or other 
visitors.  Lessor grants Lessee, its employees, invitees, licensees and other
visitors a non-exclusive license for the Term to use the Common Areas; and

                       (b)   The cost of premiums for the insurance required 
under paragraphs 9.1 and 9.3 (provided that Lessee shall pay 100% of any 
increase in or component of any such premiums directly attributable to the 
construction of the Tenant Improvement Work and the specialty equipment 
installed);

                       (c)   Notwithstanding anything else contained in this 
paragraph, "Operating Expenses" shall not include: (i) any capital additions 
made to the Building; (ii) repairs or other work occasioned by fire, windstorm,
or other insured casualty or hazard; (iii) leasing commissions and advertising
expenses incurred in procuring new tenants; (iv) repairs or rebuilding 
necessitated by condemnation to the extent that Lessor has received condemnation
proceeds for such repairs or rebuilding; (v) any depreciation and amortization
of the Building; (vi) principal or interest payments on any indebtedness 
applicable to the Building or the Premises, including any mortgage debt or 
ground rents payable under any ground lease for the Building.

                (iii)   Lessee's Tax Share shall be 29% of the real property 
taxes assessed on the date hereof, plus 100% of any increase in such taxes 
directly attributable to the construction of the Tenant Improvement Work;

                (iv)    As used herein the term "real property tax" shall 
include any form of real estate tax or assessment, general, special, ordinary 
or extraordinary, and any license fee, commercial rental tax, improvement 
bond or bonds, levy or tax (other than inheritance, personal income or estate 
taxes) imposed on the Premises by any authority having the direct or indirect 
power to tax, including any city, state or federal government, or any school, 
agricultural, sanitary, fire, street, drainage or other improvement district 
thereof, as against any legal or equitable interest of Lessor in the Premises 
or in the real property of which the Premises is a part, as against Lessor's 
right to rent or other income therefrom, and as against Lessor's business of 
leasing the Premises.  The term "real property tax" shall also include any 
tax, fee, levy, assessment or charge in substitution of, partially or 
totally, any tax, fee, levy, assessment for charge hereinabove included 
within the definition of "real property tax."

                 All payments of additional rent for operating Expenses payable 
by Lessee shall be paid within ten days of receipt by Lessee of Lessor's 
statement of amounts due, which 

                                       -4-

<PAGE>

statement shall include at Lessee's request copies of relevant invoices and 
receipts.  All payments of additional rent for real property taxes payable by 
Lessee shall be paid within the period prescribed by law for the payment 
thereof without penalty or interest; provided that Lessor has sent to Lessee 
copies of such tax bills when received from the taxing authority.

    7.    Compliance with Law; Environmental Matters.

          7.1    Compliance with Law.  (a) Lessor warrants to Lessee that the 
Premises, in its state existing on the Commencement Date, and the 
above-described uses do not violate any covenants or restrictions of record, 
or any applicable zoning or building code, regulation or ordinance in effect 
on said date.  In the event it is determined that this warranty has been 
violated, then it shall be the obligation of the Lessor to promptly, at 
Lessor's sole cost and expense, rectify any such violation.

                (b)    Except as provided in paragraph 7.2(a), Lessee shall, 
at Lessee's expense, comply promptly with all applicable statutes, 
ordinances, rules, regulations, orders, covenants and restrictions of record, 
and requirements in effect during the Term or any part of the term hereof, 
regulating the use by Lessee of the Premises.

          7.2    Environmental Matters.  Lessor represents and warrants that 
all activities at the Premises since Lessor's acquisition of the Premises 
have been and are being conducted in compliance with all statutes, 
ordinances, regulations, orders, and requirements of common law concerning 
(i) those activities, (ii) repairs or construction of any improvements, (iii) 
handling of any materials, (iv) discharges to the air, soil, surface, or 
groundwater, and (v) storage, treatment, or disposal of any waste at or 
connected with any activity at the Premises ("Environmental Statutes").

          Lessor represents and warrants that no Contamination is present at 
the Premises.  The term "Contamination" means the uncontained presence of 
Hazardous Substances at the Premises, or arising from the Premises which may 
require remediation under any applicable law.  The term "Hazardous 
Substances" means "hazardous substances" as defined pursuant to the 
Comprehensive Environmental Response, Compensation and Liability Act, as 
amended, "regulated substances" within the meaning of Subtitle I of the 
Resource Conservation Recovery Act, as amended, "hazardous wastes". as 
defined pursuant to the Delaware Hazardous Waste Management Act, or 
"regulated substances" as defined pursuant to the Delaware Underground 
Storage Tank Act.

         Lessor represents and warrants that no portion of the Premises 
constitutes any of the following "Environmentally Sensitive Areas":

                       (i)    a wetland or other "water of the United states" 
for purposes of section 404 of the federal Clean Water Act or any similar 
area regulated under any state law;

                                       -5-

<PAGE>

                       (ii)   a portion of the coastal zone for purposes of 
the Federal Coastal Zone Management Act and the Delaware Coastal Zone Act; or

                       (iii)  any other area, including but not limited to a 
floodplain or other flood hazard area, the development of which is specially 
restricted under any applicable law by reason of its physical characteristics 
or prior use.

         Lessor represents and warrants that no tanks for the storage of any 
liquid or gas are present on the Premises except for two underground 500 
gallon liquid propane tanks.

         Lessor represents and warrants that (i) at no point in any structure 
at the Premises will air radiation levels exceed 4 picocuries/liter, (ii) 
Lessor does not know or have reason to know of any investigation of the 
Premises for the presence of radon gas or the presence of the radioactive 
decay products of radon (collectively "Radon") and (iii) Lessor has provided 
to Lessee a report of each investigation relevant to the presence of Radon at 
the Premises of which Lessor has any knowledge.

         The parties hereby agree that if any of the representations or 
warranties contained in this paragraph 7.2 shall prove to be incorrect, or if 
Lessor breaches any covenant contained in this paragraph 7.2, Lessor shall be 
afforded an opportunity to cure such default provided that (i) such breach or 
condition is susceptible of remediation within a reasonable amount of time as 
determined by Lessee; and (ii) Lessor begins promptly after the discovery of 
such breach or condition diligently to remedy same and continues such 
diligent efforts until satisfactory remediation has been achieved.

         Lessor shall indemnify and hold Lessee harmless of, from, and 
against any and all expense, loss or liability suffered by Lessee by reason 
of the Lessor's breach of any provision of this Section including, but not 
limited to, (i) costs to comply with any Environmental Statutes; (ii) costs 
to study or to remedy Contamination of the Premises or arising from the 
Premises; (iii) costs incident to the study or removal of tanks, their 
contents or associated Contamination; (iv) cost to prevent air radiation 
levels in any structure hereafter erected in the Premises from exceeding 4 
picocuries/liter or to reduce air radiation levels in any structure on the 
Premises to 4 picocuries/liter or less; (v) fines, penalties, or other 
sanctions assessed due to Lessor's failure to have complied with 
Environmental Statutes; (vi) loss of value of the Property by reason of a 
failure to comply with Environmental Statutes or the presence on the Property 
of any Hazardous Substance, tank, Environmentally Sensitive Feature or Radon; 
and (vii) legal and professional fees and costs in connection with the 
foregoing.  For purposes of this subparagraph, the term "Lessee" shall mean 
Lessee, its successors and assigns.  Nothing herein shall be construed to 
include (i) any condition or occurrence arising out of Lessee's activities in 
or on the Premises, or (ii) any consequential damages or losses sustained by 
Lessee as a result of interruption of Lessee's business activities or the 
dislocation of Lessee's facilities as a result of a default pursuant to this 
paragraph 7.2.


                                       -6-

<PAGE>

          7.3    Condition of Premises.

                (a)  Lessor shall deliver the Premises to Lessee clean and 
free of debris on the Commencement Date and Lessor further warrants to Lessee 
that the Tenant Improvement Work in the Premises shall be in good operating 
condition on the Commencement Date.  In the event that it is determined that 
this warranty has been violated, then it shall be the obligation of Lessor, 
after receipt of written notice from Lessee setting forth with specificity 
the nature of the violation, to promptly, at Lessor's sole cost, rectify such 
violation.

                (b)  Within thirty (30) days after the Commencement Date, 
Lessee shall give Lessor a written list (the "Punch List") of all contended 
defects in Lessor's construction work and of all contained variances in 
Lessor's work as described in Exhibit "HI' attached hereto.  Lessor shall 
correct all items on the Punch List within thirty (30) days after Lessor's 
receipt of the Punch List, unless the nature of the defect or variance is 
such that a longer period of time is required to repair or correct the same, 
in which case Lessor shall exercise due diligence in correcting such defect 
or variance at the earliest possible date and with a minimum of interference 
with Lessee's operations.  Nothing in this subparagraph shall be deemed a 
waiver by Lessee of Lessor's warranty contained in paragraph 7.3(a) for 
violations discovered after delivery of the Punch List.

    8.    Maintenance, Repairs, Alterations and Building Services.

          8.1    Lessor's Obligations

                 (a)   Lessor shall keep in good order, condition and repair 
the Common Areas of the Building, and the heating, ventilation and air 
conditioning system installed for the use of the Premises (the "HVAC").

              (b)  If Lessor fails to perform Lessor's obligations under this 
paragraph 8.1 or under any other paragraph of this Lease, Lessee may at 
Lessee's option and upon 10 days' prior written notice to Lessor (except in 
the case of emergency, in which case no notice shall be required), perform 
such obligations on Lessor's behalf and put the Common Areas and HVAC in good 
order, condition and repair, and the cost thereof shall be offset against the 
installment rent next due.

          8.2    Lessee's Obligations.  Lessee, at its expense, shall 
maintain and keep in good order, condition and repair the plumbing, electric, 
HVAC, lighting, fixtures, interior walls, ceilings, floors, windows, doors 
and plate glass located in, on, or within the Premises or any part thereof, 
and which are for the exclusive use of the Premises or Lessee.  Lessor shall 
procure and maintain at Lessee's expense an HVAC maintenance agreement, which 
shall be in form and substance reasonably satisfactory to Lessee. On the last 
day of the Term hereof, or on any sooner termination, Lessee shall surrender 
the Premises to Lessor in the same condition as received, ordinary wear and 
tear excepted, clean and free of debris.

                                       -7-

<PAGE>


          8.3    Alterations and Additions.

                 (a)   Lessee shall not, without Lessor's prior written 
consent, which consent shall not be unreasonably withheld or delayed, make 
any alterations, improvements, additions, or Utility Installations in, on or 
about the Premises, except for nonstructural alterations not exceeding 
$7,500.  In any event, whether or not in excess of $7,500 in cost, Lessee 
shall make no change or alteration to the exterior of the Premises nor the 
exterior of the Building without Lessor's prior written consent.  As used in 
this paragraph 8.3 the term "Utility Installation" shall mean air lines, 
power panels, electrical distribution systems, lighting fixtures, space 
heaters, air conditioning, plumbing, and fencing.  Should Lessee make any 
alterations, improvements, additions or Utility Installations without the 
prior approval of Lessor, Lessor may require that Lessee remove any or all of 
the same.

                 (b)   Any alterations, improvements, additions or Utility 
Installations in or about the Premises that Lessee shall desire to make and 
which requires the consent of the Lessor shall be presented to Lessor in 
written form, with proposed detailed plans.  If Lessor shall give its 
consent, the consent shall be deemed conditioned upon Lessee acquiring a 
permit to do so from appropriate government agencies, the furnishing of a 
copy thereof to Lessor prior to the commencement of the work and the 
compliance by Lessee of all conditions of said permit in a prompt and 
expeditious manner.

                (c)    Lessee shall pay, when due, all claims for labor or 
materials furnished to or for Lessee at or for use in the Premises, which 
claims are or may be secured by any mechanics' or materialmen's lien against 
the Premises or any interest therein.  Lessee shall give Lessor not less than 
ten (10) days' notice prior to the commencement of any work in the Premises, 
and Lessor shall have the right to post notices of non-responsibility in or 
on the Premises as provided by law.  If Lessee shall, in good faith, contest 
the validity of any such lien, claim or demand, then Lessee shall, at its 
sole expense defend itself and Lessor against the same and shall pay and 
satisfy any such adverse judgment that may be rendered thereon before the 
endorsement thereof against the Lessor or the Premises, upon the condition 
that if Lessor shall require, Lessee shall furnish to Lessor a surety bond 
satisfactory to Lessor in an amount equal to such contested lien claim or 
demand indemnifying Lessor against liability for the same and holding the 
Premises free from the effect of such lien or claim and shall obtain release 
of such lien by substitution of such surety bond as security therefor.  In 
addition, Lessor may require Lessee to pay Lessor's attorneys fees and costs 
in participating in such action if Lessor shall decide it is to its best 
interest to do so.

                (d)   Unless Lessor requires their removal, as set forth in 
paragraph 8.3(a), all alterations, improvements, additions and Utility 
Installations, which may be made on the Premises, shall become the property 
of Lessor and remain upon and be surrendered with the Premises at the 
expiration of the Term.

                                       -8-

<PAGE>

    9.    Insurance; Indemnity.

          9.1    Liability Insurance - Lessor.  Lessor shall obtain and keep 
in force during the Term of this Lease a policy of Combined Single Limit 
Bodily Injury and Property Damage Insurance, insuring Lessor and Lessee 
against any liability arising out of the ownership, use or occupancy 
maintenance of the Premises and all areas appurtenant thereto in an amount 
not less than $500,000 per occurrence.

          9.2    Liability Insurance - Losses.  Lessee shall obtain and keep 
in force during the Term of this Lease a policy of Combined Single Limit 
Bodily Injury and Property Damage Insurance, insuring Lessor and Lessee 
against any liability arising out of the use or occupancy of the Premises and 
all areas appurtenant thereto in an amount not less than $500,000 per 
occurrence.

          9.3    Property Insurance.  Lessor shall obtain and keep in force 
during the Term of this Lease a policy or policies of insurance covering loss 
or damage to the Building, including Lessee's fixtures, equipment or tenant 
improvements in an amount not to exceed the full replacement value thereof as 
the same may exist from time to time, providing protection against all perils 
included within the classification of fire, extended coverage, vandalism, 
malicious mischief, flood (in the event same is required by a lender having a 
lien on the Premises), special extended perils ("all risk", as such term is 
used in the insurance industry).

          9.4    Insurance Policies.  Insurance required hereunder shall be 
in companies holding a "General Policyholders Rating" of at least B plus, or 
such other rating as may be required by a lender having a lien on the 
Premises, as set forth in the most current issue of "Best Insurance Guide".  
Lessor and Lessee shall deliver to each other copies of policies of all 
insurance required under paragraph 8 or certificates evidencing the existence 
and amounts of such insurance.  No such policy shall be cancellable or 
subject to reduction of coverage or other modification except after thirty 
(30) days' prior written notice to the other.  Each party shall, at least 
thirty (30) days prior to the expiration of such policies, furnish the other 
with renewals thereof.  Lessee shall not do or permit to be done anything 
which shall invalidate the insurance policies referred to in paragraph 9.3.

          9.5    Waiver of Subrogation.  Lessee and Lessor each hereby 
release and relieve the other, and waive their entire right of recovery 
against the other for loss or damage arising out of or incident to the perils 
insured against under paragraph 9.3, which perils occur in, on or about the 
Premises, whether due to the negligence of Lessor or Lessee or their agents, 
employees, contractors and/or invitees.  Lessee and Lessor shall, upon 
obtaining the policies of insurance required hereunder, give notice to the 
insurance carrier or carriers that the foregoing mutual waiver of subrogation 
is contained in this Lease.

          9.6    Indemnity.  Lessee shall indemnify and hold harmless Lessor 
from and against any and all claims arising from Lessee's use of the 
Premises, or from the conduct of 

                                       -9-

<PAGE>

Lessee's business or from any activity, work or things done, permitted or 
suffered by Lessee in or about the Premises or elsewhere and shall further 
indemnify and hold harmless Lessor from and against any and all claims 
arising from any breach or default in the performance of any obligation on 
Lessee's part to be performed under the terms of this Lease, or arising from 
any negligence of the Lessee, or any of Lessee's agents, contractors, or 
employees, and from and against all costs, attorneys' fees, expenses and 
liabilities incurred in the defense of any such claim or any action or 
proceeding brought thereon; and in case any action or proceeding be brought 
against Lessor by reason of any such claim.  Lessee upon notice from Lessor 
shall defend the same at Lessee's expense by counsel satisfactory to Lessor.

          Lessor shall indemnify and hold harmless Lessee from and against 
any and all claims arising from any breach or default in the performance of 
any obligation on Lessor's part to be performed under the terms of this 
Lease, or arising from any negligence of the Lessor, or any of Lessor's 
agents, contractors, or employees, and from and against all costs, attorneys' 
fees, expenses and liabilities incurred in the defense of any such claim or 
any action or proceeding brought thereon; and in case any action or 
proceeding be brought against Lessee by reason of any such claim. Lessor upon 
notice from Lessee shall defend the same at Lessor's expense by counsel 
satisfactory to Lessee.

    10.    Damage or Destruction.

           10.1    Definitions.

                   (a)   "Premises Partial Damage" shall herein mean damage 
or destruction to the Premises to the extent that the cost of repair is less 
than 50% of the fair market value of the Premises immediately prior to such 
damage or destruction. "Premises Building Partial Damage" shall herein mean 
damage or destruction to the Building of which the Premises are a part to the 
extent that the cost of repair is less that 50% of the fair market value of 
the Building as a whole immediately prior to such damage or destruction.

                   (b)   "Premises Total Destruction" shall herein mean 
damage or destruction to the Premises to the extent that the cost of repair 
is 50% or more of the fair market value of the Premises immediately prior to 
such damage or destruction.

                   (c)   "Insured Loss" shall herein mean damage or 
destruction which was caused by an event required to be covered by the 
insurance described in paragraph 10.

           10.2    Partial Damage - Insured Loss.  Subject to the provisions 
of paragraph 10.4, 10.5 and 10.6, if at any time during the Term of this 
Lease there is damage which is an Insured Loss and which falls into the 
classification of Premises Partial Damage or Premises Building Partial 
Damage, then Lessor shall, at Lessor's sole cost, repair such damage, 
including Lessee's fixtures, equipment or tenant improvements as soon as 
reasonably possible and this Lease shall continue in full force and effect.

                                       -10-

<PAGE>

           10.3    Partial Damage - Uninsured Loss.  Subject to the 
provisions of paragraphs 10.4, 10.5 and 10.6, if at any time during the Term 
of this Lease there is damage which is not an Insured Loss and which fails 
within the classification of Premises Partial Damage or Premises Building 
Partial Damage, unless caused by a willful act of Lessee (in which event 
Lessee shall make the repairs at Lessee's expense), Lessor may at Lessor's 
option either (i) repair such damage as soon as reasonably possible at 
Lessor's expense, in which event this Lease shall continue in full force and 
effect, or (ii) give written notice to Lessee within fifteen (15) days after 
the date of the occurrence of such damage of Lessor's intention to cancel and 
terminate this Lease. In the event Lessor shall give such notice of Lessor's 
intention to cancel and terminate this Lease, Lessee shall have the right 
within fifteen (15) days after the receipt of such notice to give written 
notice to Lessor of Lessee's intention to repair such damage at Lessee's 
expense, in which event this Lease shall continue in full force and effect, 
and Lessee shall proceed to make such repairs as soon as reasonably possible. 
 If Lessee does not give such notice within such 15-day period this Lease 
shall be cancelled and terminated and Lessee shall have no further 
obligations or duties thereunder including the payment of rent as of the date 
of the occurrence of such damage.

           10.4     Total Destruction.  If at any time during the term of 
this Lease there is damage, whether or not an Insured Loss, (including 
destruction required by any authorized public authority), which falls into 
the classification of Premises Total Destruction or Premises Building Total 
Destruction, this Lease shall automatically terminate and Lessee shall have 
no further obligations or duties thereunder including the payment of rent as 
of the date of such total destruction.

           10.5    Damage Near End of Term.

                   (a)   If at any time during the last six months of the 
Term of this Lease there is damage, whether or not an Insured Loss, which 
falls within the classification of Premises Partial Damage, Lessor and Lessee 
each has the option to cancel and terminate this Lease as of the date of 
occurrence of such damage by giving written notice to the other of its 
election to do so within 30 days after the date of occurrence of such damage.

                   (b)   Notwithstanding paragraph 10.5(a), in the event that 
Lessee has an option to extend or renew this Lease, and the time within which 
said option may be exercised has not yet expired, Lessee shall exercise such 
option, if it is to be exercised at all, no later that 25 days after the 
occurrence of an Insured Loss falling within the classification of Premises 
Partial Damage during the last six months of the Term of this Lease.  If 
Lessee duly exercises such option during said 25 day period, Lessor shall, at 
Lessor's expense, repair such damage as soon as reasonably possible and this 
Lease shall continue in full force and effect.  If Lessee fails to exercise 
such option during said 25 day period, then Less may at Lessee's option 
terminate and cancel this Lease as of the expiration of said 25 day period by 
giving written notice to Lessee of 

                                       -11-

<PAGE>

Lessor's election to do so within 5 days after the expiration of said 25 day 
period, notwithstanding any term or provision in the grant of option to the 
contrary.

           10.6    Abatement of Rent; Lessee's Remedies.

                   (a)   In the event of damage described in paragraphs 10.2 
or 10.3 and Lessor or Lessee repairs or restores the Premises pursuant to the 
provisions of this paragraph 10, the rent payable hereunder for the period 
during which such damage, repair or restoration continues shall be abated in 
proportion to the degree to which Lessee's use of the Premises is impaired.  
Except for abatement of rent Lessee shall have no claim against Lessor for 
any damage suffered by reason of any such damage, destruction, repair or 
restoration.

                   (b)   If Lessor shall be obligated to repair or restore 
the Premises under the provisions of this paragraph 10 and shall not commence 
meaningful repair or restoration within 30 days after such obligations shall 
accrue, Lessee may at Lessee's option cancel and terminate his Lease by 
giving Lessor written notice of Lessee's election to do so at any time prior 
to Lessor's meaningful commencement of such repair or restoration.  In such 
event this Lease shall terminate as of the date of such notice and Lessee 
shall have no further obligations or duties thereunder, including the payment 
of rent, as of the date of the occurrence of the damage.

           10.7    Termination - Advance Payments.  Upon termination of this 
Lease pursuant to this paragraph 10, an equitable adjustment shall be made 
concerning any advance rent and any advance payments made by Lessee to Lessor.

           10.8    Waiver.  Lessor and Lessee waive the provisions of any 
statutes which relate to termination of leases when leased property is 
destroyed and agree that such event shall be governed by the terms of this 
Lease.

    11.    Utilities.  Lessee shall pay for all water, gas, heat, light, 
power, telephone and other utilities and services supplied to the Premises, 
together with any taxes thereon.  Such services are to be separately metered 
to Lessee.

    12.    Assignment and Subletting.

           12.1    Lessor's Consent Required.  Lessee shall not voluntarily 
or by operation of law assign, transfer, mortgage, sublet, or otherwise 
transfer or encumber all of any part of Lessee's interest in this Lease or in 
the Premises, without Lessor's prior written consent, which Lessor shall not 
unreasonably withhold or delay.  Lessor shall respond in writing to Lessee's 
request for consent hereunder in a timely manner and any attempted 
assignment, transfer, mortgage, encumbrance or subletting without such 
consent shall be void and shall constitute a breach of this Lease.

                                       -12-

<PAGE>

           12.2    Lessee Affiliate.  Notwithstanding the provisions of 
paragraph 12.1 hereof, Lessee may assign or sublet the Premises, or any 
portion thereof, without Lessor's consent, to any corporation which controls, 
is controlled by or is under common control with Lessee, or to any 
corporation resulting from the merger or consolidation with Lessee, or to any 
person or entity, which acquires all or substantially all of the assets of 
Lessee as a going concern of the business that is being conducted on the 
Premises, provided that said assignee assumes, in full, the obligations of 
Lessee under this Lease.  Any such assignment shall not, in any way, affect 
or limit the liability of Lessee under the terms of this Lease even if after 
such assignment or subletting the terms of this Lease are changed or altered, 
provided, however, that any material change to the terms of this Lease 
(including, but not limited to, the Term or Rent) after such an assignment or 
subletting, shall require the prior consent of Lessor and any such change 
made without Lessor's prior consent shall not be binding on Lessor.

           12.3    No Release of Losses.  Regardless of Lessor's consent, no 
subletting or assignment shall release Lessee of Lessee's obligation or alter 
the primary liability of Lessee to pay the Rent and to perform all other 
obligations to be performed by Lessee hereunder.  The acceptance of Rent by 
Lessor from any other person shall not be deemed to be a waiver by Lessor of 
any provision hereof.  Consent to one assignment or subletting shall not be 
deemed consent to any subsequent assignment or subletting. In the event of 
default by any assignee of Lessee or any successor of Lessee, in the 
performance of any of the terms thereof, Lessor may proceed directly against 
Lessee without the necessity of exhausting remedies against said assignee.  
Lessor may consent to subsequent assignments or subletting of this Lease or 
amendments or modifications to this Lease with assignees of Lessee or any 
successor of Lessee, and without obtaining its or their consent thereto and 
such action shall not relieve Lessee of liability under this Lease.

           12.4    Assignment Fees.  In the event Lessee shall assign or 
sublet the Premises then Lessee shall an assignment processing fee equal to 
$200.00 for each such request.

    13.    Defaults; Remedies.

           13.1    Defaults.  The occurrence of any one or more of the 
following events shall constitute a material default and breach of this Lease 
by Lessee:

                   (a)   The failure by Lessee to make any payment of rent as 
and when due, where such failure shall continue for a period of five days 
after Lessee's receipt of written notice from Lessor.  In the event that 
Lessor serves Lessee with a Notice to Pay Rent or Quit pursuant to applicable 
Unlawful Detainer statutes, such Notice to Pay Rent or Quit shall also 
constitute the notice required by this subparagraph;

                   (b)   The failure by Lessee to observe or perform any of 
the covenants, conditions or provisions of this Lease to be observed or 
performed by Lessee, other than described in paragraph (a) above, where such 
failure shall continue for a period of 30 days after written notice hereof 
from Lessor to Lessee; provided, however, that if the nature of Lessee's 

                                       -13-

<PAGE>

default is such that more than 30 days are reasonably required for its cure, 
then Lessee shall not be deemed to be in default if Lessee commenced such 
cure within said 30-day period and thereafter diligently prosecutes such cure 
to completion;

                   (c)   (i) The making by Lessee of any general arrangement 
or assignment for the benefit of creditors; (ii) Lessee becomes a "debtor" as 
defined in 11 U.S.C. Section 101 or any successor statute thereto (unless, in 
the case of a petition field against Lessee, the same is dismissed within 60 
days); (iii) the appointment of a trustee or receiver to take possession of 
substantially all of Lessee's assets located at the Premises or of Lessee's 
interest in this Lease, where possession is not restored to Lessee within 30 
days; or (iv) the attachment, execution or other judicial seizure of 
substantially all of Lessee's assets located at the Premises or of Lessee's 
interest in this Lease, where such seizure is not discharged within 30 days.  
Provided, however, in the event that any provision of this paragraph 13.1(c) 
is contrary to any applicable law, such provision shall be of no force or 
effect;

                   (d)   The discovery by Lessor that any financial statement 
given to Lessor by Lessee, any assignee of Lessee, any subtenant of Lessee, 
any successor in interest of Lessee or any guarantor of Lessee's obligation 
hereunder, and any of them, was materially false.

           13.2    Remedies.  In the event of any such material default or 
breach by Lessee, Lessor may at any time after providing Lessee with written 
notice, but without limiting Lessor in the exercise of any right or remedy 
which Lessor may have by reason of such default or breach:

                   (a)   Terminate Lessee's right to possession of the 
Premises by any lawful means, in which case this Lease shall terminate and 
Lessee shall immediately surrender possession of the Premises to Lessor.  In 
such event Lessor shall be entitled to recover from Lessee all damages 
incurred by Lessor by reason of Lessee's default including, but not limited 
to, the cost of recovering possession of the Premises; expenses of reletting, 
including necessary renovation and alteration of the premises, reasonable 
attorneys' fees, and any real estate commission actually paid; the worth at 
the time of award by the court having jurisdiction thereof of the amount by 
which the unpaid rent for the balance of the term after the time of such 
award exceeds the amount of such rental loss for the same period that Lessee 
proves could be reasonably avoided.

                   (b)   Maintain Lessee's right to possession in which case 
this Lease shall continue in effect whether or not Lessee shall have 
abandoned the Premises.  In such event Lessor shall be entitled to enforce 
all of Lessor's rights and remedies under this Lease, including the right to 
recover the rent as it becomes due hereunder;

                   (c)   Pursue any other remedy now or hereafter available 
to Lessor under the laws or judicial decisions of the State of Delaware.  
Unpaid installments of rent and other unpaid monetary obligations of Lessee 
under the terms of this Lease shall bear interest from the date due at the 
maximum rate then allowable by law.

                                       -14-

<PAGE>

           13.3    Default by Lessor.  Lessor shall not be in default unless 
Lessor fails to perform obligations required of Lessor within a reasonable 
time, but in no event later than ten (10) days after written notice by Lessee 
to Lessor and to the holder of any first mortgage or deed of trust covering 
the Premises whose name and address shall have theretofore been furnished to 
Lessee in writing, specifying wherein Lessor has failed to perform such 
obligation; provided, however, that if the nature of Lessor's obligation is 
such that more than ten (10) days are required for performance then Lessor 
shall not be in default if Lessor commences meaningful performance within 
such lo-day period and thereafter diligently prosecutes the same to 
completion.

           13.4    Late Charges.  Lessee hereby acknowledges that late 
payment by Lessee to Lessor of rent and other sums due hereunder will cause 
Lessor to incur costs not contemplated by this Lease, the exact amount of 
which will be extremely difficult to ascertain. Such costs include, but are 
not limited to, processing and accounting charges, and late charges which may 
be imposed on Lessor by the terms of any mortgage or trust deed covering the 
Premises.  Accordingly, if any installment of rent shall not be received by 
Lessor or Lessor's designee within fifteen (15) days after such amount shall 
be due, then, without any requirement for notice to Lessee, Lessee shall pay 
to Lessor a late charge equal to 3% of such overdue amount.  The parties 
hereby agree that such late charge represents a fair and reasonable estimate 
of costs Lessor will incur by reason of late payment by Lessee.  Acceptance 
of such late charge by Lessor shall in no event constitute a waiver of 
Lessee's default with respect to such overdue amount, nor prevent Lessor from 
exercising any of the other rights and remedies granted hereunder.

    14.    Condemnation.  If the Premises or any portion thereof are taken 
under the power of eminent domain, or sold under the threat of the exercise 
of said power (all of which are herein called "condemnation"), this Lease 
shall terminate as to the part so taken as of the date the condemning 
authority takes title or possession, whichever first occurs.  If more than 
10% of the floor area of the Building, or more than 25% of the area of the 
Premises is taken by condemnation, Lessee may, at Lessee's option, to be 
exercised in writing within fifteen (15) days after Lessor shall have given 
Lessee written notice of such taking (or in the absence of such notice, 
within fifteen (15) days after the condemning authority shall have taken 
possession) terminate this Lease as of the date the condemning authority 
takes such possession.  If Lessee opts to terminate this Lease as described 
in the foregoing, Lessee's obligations and duties under this Lease shall 
cease as of the date of condemning authority take such possession.  If Lessee 
does not terminate this Lease in accordance with the foregoing, this Lease 
shall remain in full force and effect as to the portion of the Premises 
remaining, except that the rent shall be reduced in the proportion that the 
floor area of the Building taken bears to the total floor area of the 
Building situated on the Premises.  No reduction of rent shall occur if the 
only area taken is that which does not have a building located thereon.  Any 
award for the taking of all or any part of the Premises under the power of 
eminent domain or any payment made under threat of the exercise of such power 
shall be the property of Lessor, whether such award shall be made as 
compensation for diminution in value of the leasehold or for the taking of 
the fee, or as severance damages; provided, however, that Lessee shall be 
entitled to any award for loss of or damage to Lessee's equipment, trade 
fixtures and removable personal property.  In the event that this Lease 

                                       -15-

<PAGE>

is not terminated by reason of such condemnation, Lessor shall to the extent 
of severance damages received by Lessor in connection with such condemnation, 
repair any damage to the Premises caused by such condemnation except to the 
extent that Lessee has been reimbursed therefor by the condemning authority.

    15.    Brokers' Fees.

           Lessor shall be responsible for all brokers, commissions or 
finder's fees charged by Stoltz Realty and Dunn Associates, and warrants to 
Lessee that no brokers' commissions, finders' fees or similar payments shall 
be claimed through Lessee in connection with the execution of this Lease, and 
agrees to indemnify and hold Lessee harmless from any liability that may 
arise from such claims, including reasonable attorney's fees.

    16.    Estoppel Certificate.

           (a)   Lessee shall at any time upon not less than 10 days I prior 
written notice from Lessor execute, acknowledge and deliver to Lessor a 
statement in writing (i) certifying that this Lease is unmodified and in full 
force and effect (or, if modified, stating the nature of such modification 
and certifying that this Lease, as so modified, is in full force and effect) 
and the date to which the rent is paid and (ii) acknowledging that there are 
not, to Lessee's knowledge, any uncured defaults, or events which with the 
passage of time would be defaults, on the part of Lessor hereunder, or 
specifying such defaults if any are claimed.  Any such statement may be 
conclusively relied upon by any prospective purchaser or encumbrancer of the 
Premises.

           (b)   At Lessor's option, Lessee's failure to deliver such 
statement within such time shall be a material breach of this Lease or shall 
be conclusive upon Lessee (i) that this Lease is in full force and effect, 
without modification except as may be represented by Lessor, (ii) that there 
are no uncured defaults in Lessor's performance, and (iii) that not more than 
one month's rent has been paid in advance or such failure may be considered 
by Lessor as a default by Lessee under this Lease.

           (c)   If Lessor desires to finance, refinance, or sell the 
Premises, or any part thereof, Lessee hereby agrees to deliver to any lender 
or purchaser designated by Lessor such financial statements of Lessee as may 
be reasonably required by such lender or purchaser.  Such statements shall 
include to the extent available the past three years' financial statements of 
Lessee.  All such financial statements shall be received by Lessor and such 
lender or purchaser in confidence and shall be used only for the purposes 
herein set forth.

    17.    Lessor's Liability.  The term "Lessor" as used herein shall mean 
only the owner or owners at the time in question of the fee title or a 
lessee's interest in a ground lease of the Premises.  In the event of any 
transfer of such title or interest, Lessor herein named (and in case of any 
subsequent transfers then the grantor) shall be relieved from and after the 
date of such transfer of all liability as respects Lessor's obligations 
thereafter to be performed, provided that 

                                       -16-

<PAGE>

any funds in the hands of Lessor or the then grantor at the time of such 
transfer, in which Lessee has an interest, shall be delivered to the grantee. 
 The obligations contained in this Lease to be performed by Lessor shall, 
subject as aforesaid, be binding on Lessor's successors and assigns, only 
during their respective periods of ownership.

    18.    Severability.  The invalidity of any provisions of this Lease as 
determined by a court of competent jurisdiction, shall in no way affect the 
validity of any other provision hereof.

    19.    Time of Essence.  Time is of the essence.

    20.    Incorporation of Prior Agreements; Amendments.  This Lease 
contains all agreements of the parties with respect to any matter mentioned 
herein.  No prior agreement or understanding pertaining to any such matter 
shall be effective.  This Lease may be modified in writing only, signed by 
the parties in interest at the time of the modification.  Except as otherwise 
stated in this Lease, Lessee hereby acknowledges that neither the real estate 
brokers listed in paragraph 15 hereof nor any cooperating broker on this 
transaction nor the Lessor or any employees or agents of any of said persons 
has made any oral or written warranties or representations to Lessee relative 
to the condition or use by Lessee of said Premises and Lessee acknowledges 
that Lessee assumes all responsibility regarding the Occupational Safety 
Health Act, the legal use and adaptability of the Premises and the compliance 
thereof with all applicable laws and regulations in effect during the term of 
this Lease except as otherwise specifically stated in this Lease.

    21.    Notices.  Any notice required or permitted to be given hereunder 
shall be in writing and may be given by personal delivery or by certified 
mail, and if given personally or by mail, shall be deemed sufficiently given 
if addressed to Lessee or to Lessor at the address noted below the signature 
of the respective parties, as the case may be. Each such notice shall be 
deemed given upon personal delivery or, if by certified mail, upon mailing.  
Either party may by notice to the other specify a different address for 
notice purposes except that upon Lessee's taking possession of the Premises, 
the Premises shall constitute Lessee's address for notice purposes.  A copy 
of all notices required or permitted to be given to Lessor hereunder shall be 
concurrently transmitted to such party or parties at such addresses as Lessor 
may from time to time hereafter designate by notice to Lessee.

    22.    Waivers.  No waiver by Lessor or any provision hereof shall be 
deemed a waiver of any other provision hereof or of any subsequent breach by 
Lessee of the same or any other provision.  Lessor's consent to, or approval 
of any act, shall not be deemed to render unnecessary the obtaining of 
Lessor's consent to or approval of any subsequent act by Lessee.  The 
acceptance of rent hereunder by Lessor shall not be a waiver of any preceding 
breach by Lessee of any provision hereof, other than the failure of Lessee to 
pay the particular rent so accepted, regardless of Lessor's knowledge of such 
preceding breach at the time of acceptance of such rent.

                                       -17-

<PAGE>

    23.    Recording.  Either Lessor or Lessee shall, upon request of the 
other, execute, acknowledge and deliver to the other a "short form" 
memorandum of this Lease for recording purposes.

    24.    Holding Over.  If Lessee, with Lessor's consent, remains in 
possession of the Premises or any part thereof after the expiration of the 
term hereof, such occupancy shall be a tenancy from month to month upon all 
the provisions of this Lease pertaining to the obligations of Lessee, but all 
options and rights of first refusal, if any, granted under the terms of this 
Lease shall be deemed terminated and be of no further effect during said 
month to month tenancy.

    25.    Cumulative Remedies.  No remedy or election hereunder shall be 
deemed exclusive but shall, wherever possible, be cumulative with all other 
remedies at law or in equity.

    26.    Covenants and Conditions.  Each provision of this Lease 
performable by Lessee shall be deemed both a covenant and a condition.

    27.    Binding Effect; Choice of Law.  Subject to any provisions hereof 
restricting assignment or subletting by Lessee, this Lease shall bind the 
parties, their personal representatives, successors and assigns.  This Lease 
shall be governed by the laws of the State of Delaware.

    28.    Subordination.

                 (a)   This Lease, at Lessor's option, shall be subordinate 
to any ground lease, mortgage, deed of trust, or any other hypothecation or 
security now or hereafter placed upon the real property of which the Premises 
are a part and to any and all advances made on the security thereof and to 
all renewals, modifications, consolidations, replacements and extensions 
thereof.  Notwithstanding such subordination, Lessee's right to quiet 
possession of the Premises shall not be disturbed if Lessee is not in default 
and so long as Lessee shall pay the Rent and observe and perform all of the 
provisions of this Lease, unless this Lease is otherwise terminated pursuant 
to its terms.  If any mortgagee, trustee or ground lessor shall elect to have 
this Lease prior to the lien of its mortgage, deed of trust or ground lease, 
and shall give written notice thereof to Lessee, this Lease shall be deemed 
prior to such mortgage, deed of trust, or ground lease, whether this Lease is 
dated prior or subsequent to the date of said mortgage, deed of trust or 
ground lease or the date of recording thereof.

                 (b)   Lessee agrees to execute any documents required to 
effectuate an attornment, a subordination or to make this Lease prior to the 
lien of any mortgage, deed of trust or ground lease, as the case may be.  If 
Lessee fails to execute such documents within 10 days after written demand, 
Lessor may execute such documents on behalf of Lessee as Lessee's 
attorney-in-fact.  Lessee does hereby make, constitute and irrevocably 
appoint Lessor as Lessee's attorney-in-fact and in Lessee's name, place and 
stead, to execute such documents in accordance with this paragraph 28(b).

                                       -18-

<PAGE>

    29.    Intentionally Omitted

    30.    Lessor's Access.  Lessor and Lessor's agents, upon prior written 
notice to Lessee, shall have the right to enter the Premises at reasonable 
times for the purpose of inspecting the same, showing the same to prospective 
purchasers, lenders, or lessees, and making such alterations, repairs, 
improvements or additions to the Premises or to the Building of which they 
are a part as Lessor may deem necessary or desirable; provided, however that 
upon such entry Lessor and/or Lessor's agents (except in the case of 
emergency) shall be required to be accompanied by a representative of Lessee 
for purposes of protecting and preserving the confidentiality of Lessee's 
work on the Premises.  Lessor may not at any time place on or about the 
Premises any ordinary "For Sale" signs.  Lessor may at any time during the 
last 120 days of the Term hereof place on or about the Premises on the 
Building any ordinary "For Lease" signs, all without rebate of rent or 
liability to Lessee; provided that Lessor shall not permitted to place "For 
Lease" signs on or about the Premises until any options or rights available 
to Lessee to extend the term of this Lease or to renew this Lease or any 
options or rights of first refusal to lease the Premises or rights of first 
offer to purchase the Premises have lapsed.

    31.    Signs.  Lessee shall not place any sign upon the Premises without 
Lessor's prior written consent, which shall not be unreasonably withheld, 
except that Lessee shall have the right, without the prior permission of 
Lessor, to place ordinary and usual for rent or sublet signs thereon.

    32.    Merger.  The voluntary or other surrender of this Lease by Lessee, 
or a mutual cancellation thereof, or a termination by Lessor, shall not work 
a merger, and shall, at the option of Lessor, terminate all or any existing 
subtenancies or may, at the option of Lessor, operate as an assignment to 
lessor of any or all of such subtenancies.

    33.    Consents.  Wherever in this Lease the consent of one party is 
required to an act of the other party, such consent shall not be unreasonably 
withheld.

    34.    Quiet Possession.  Upon Lessee paying the rent for the Premises 
and observing and performing all of the covenants, conditions and provisions 
on Lessee's part to be observed and performed hereunder, Lessee shall have 
quiet possession of the Premises for the entire Term hereof subject to all of 
the provisions of this Lease.  The individuals executing this Lease on behalf 
of Lessor represent and warrant to Lessee that they are fully authorized and 
legally capable of executing this Lease on behalf of Lessor and that such 
execution is binding upon all parties holding an ownership interest in the 
Premises.

    36.    Options; Right of First Refusal.

           36.1    Definition.  As used in this paragraph the word "Options" 
has the following meaning: (1) the right or option to extend the term of this 
Lease or to renew this Lease; (2) the option or right of first refusal to 
lease any space contiguous to the Premises.

                                       -19-

<PAGE>

           36.2    Options Personal.  Each Option granted to Lessee in this 
Lease is personal to Lessee and may not be exercised or be assigned, 
voluntarily or involuntarily, by or to any person or entity other than 
Lessee, provided, however, the Option may be exercised by or assigned to any 
Lessee Affiliate as defined in paragraph 12 of this Lease.  The Options 
herein granted to Lessee are not assignable separate and apart from this 
Lease.

           36.3    Effect of Default on Options.

                   (a)   Lessee shall have no right to exercise an option, 
notwithstanding any provision in the grant of Option to the contrary, (i) 
during the time commencing from the date Lessor gives to Lessee a notice of 
default pursuant to paragraph 13.1(a) or 13.1(b) and continuing until the 
default alleged in said notice of default is cured, or (ii) at any time after 
an event of default described in paragraphs 13.1(c) or 13.1(d) (without any 
necessity of Lessor to give notice of such default to Lessee).

                   (b)   The period of time within which an option may be 
exercised shall not be extended or enlarged by reason of Lessee's inability 
to exercise an option because of the provisions of paragraph 36.3.

           36.4    Option to Renew.  Lessee shall have the right, at its sole 
option, to renew this Lease for an additional period of three (3) years 
following the term hereof, upon the same terms and conditions in effect at 
the expiration of the prior term (including provision for the escalation of 
rent and including this option to renew); provided Lessee shall have given 
Lessor no more than six and no less than three months written notice in 
advance at the end of the prior term.

           36.5    Option to Extend Promises.  Lessor hereby grants to Lessee 
the right at any time and from time to time to lease any or all of the 
unleased space adjacent to the Premises for a term concurrent with the 
remaining Term of this Lease, at a Base Rent (prior to the inclusion of 
reimbursement for Lessor's "tenant finish work" in such space) of $3.95 per 
square foot (as escalated beginning on the first anniversary of the 
Commencement Date to reflect any increase in the Price Index between the date 
of this Lease and the date of the exercise of this option), on all the other 
terms and conditions set forth in this Lease.  For purposes of this paragraph 
36.5, "tenant finish work" shall mean improvements to such space made by 
Lessor comparable in quality and type to the Tenant Improvement Work 
described in Exhibit C, for which Lessor shall be reimbursed an amount equal 
to $30.15 per square foot (as escalated beginning on the first anniversary of 
the Commencement Date to reflect any increase in the Price Index between the 
date of this Lease and the date of the exercise of this option) plus interest 
thereon calculated at 1 1/2% over the prime rate then in effect at Wilmington 
Trust Company.

           36.6    Right of First Refusal.  If, at any time during the term 
of this Lease or any extension thereof, Lessor or its successors or assigns 
shall receive a bona fide offer from any 

                                       -20-

<PAGE>

third party to lease all or any portion of the space adjacent to the 
Premises, Lessor shall offer such space to Lessee upon same financial terms 
as set forth in such offer.  Lessor's offer to Lessee shall be in writing, 
and Lessee shall have a period of fourteen days within which Lessee may 
elect, by written notice to Lessor, to rent such space on the same terms as 
set forth in such offer.  If Lessee shall refuse any such offer and if Lessor 
shall nevertheless fail to complete the leasing of such space under the terms 
of such offer, Lessor shall not thereafter lease such space except by 
preceding in accordance of the terms of this paragraph as though any 
subsequent offer were a new offer made under the terms hereof.

    37.    Multiple Tenant Building.  Lessee agrees that it will abide by, 
keep and observe all reasonable rules and regulations which Lessor may make 
from time to time for the management, safety, care, and cleanliness of the 
Building and grounds, the parking of vehicles and the preservation of good 
order therein as well as for the convenience of other occupants and tenants 
of the Building.  The violations of any such rules and regulations shall be 
deemed a material breach of this Lease by Lessee.

    38.    Security Measures.  Lessee hereby acknowledges that the rent 
payable to Lessor hereunder does not include the cost of guard service or 
other security measures, and that Lessor shall have no obligation whatsoever 
to provide same.  Lessee assumes all responsibility for the protection of 
Lessee, its agents and invitees from acts of third parties.

    39.    Easements.  Lessor reserves to itself the right, from time to 
time, to grant such easements, rights and dedications that Lessor deems 
necessary or desirable, and to cause the recordation of Parcel Maps and 
restrictions, so long as such easements, rights, dedications, Maps and 
restrictions do not interfere with the use of the Premises by Lessee.  Lessee 
shall sign any of the aforementioned documents upon request of Lessor and 
failure to do so shall constitute a material breach of this Lease.

    40.    Performance Under Protest.  If at any time a dispute shall arise 
as to any amount or sum of money to be paid by one party to the other under 
the provisions hereof, the party against whom the obligation to pay the money 
is asserted shall have the right to make payment "under protest" and such 
payment shall not be regarded as a voluntary payment, and there shall survive 
the right on the part of said party to institute suit for recovery of such 
sum.  If it shall be adjudged that there was no legal obligation on the part 
of said party to pay such sum or any part thereof, said party shall be 
entitled to recover such sum or so much thereof as it was not legally 
required to pay under the provisions of this Lease.

    41.    Authority.  If either Lessor or Lessee is a corporation, trust, or 
general or limited partnership, each individual executing this Lease on 
behalf of such entity represents and warrants that he or she is duly 
authorized to execute and deliver this Lease on behalf of said entity.

                                       -21-

<PAGE>

LESSOR AND LESSEE HAVE CAREFULLY READ AND REVIEWED THIS LEASE AND EACH TERM 
AND PROVISION CONTAINED HEREIN AND, BY EXECUTION OF THIS LEASE, SHOW THEIR 
INFORMED AND VOLUNTARY CONSENT THERETO, THE PARTIES HEREBY AGREE THAT, AT THE 
TIME THIS LEASE IS EXECUTED, THE TERMS OF THIS LEASE ARE COMMERCIALLY 
REASONABLE AND EFFECTUATE THE INTENT AND PURPOSE OF LESSOR AND LESSEE WITH 
RESPECT TO THE PREMISES.

The parties hereto have executed this Lease at the place and on the dates 
specified immediately adjacent to their respective signatures.

Executed at Strategic Diagnostics Industries, Inc., 128 Sandy Drive, Newark, DE 
19713 on Oct. 26, 1993.

                        LESSOR: TOBER & AGNEW PROPERTIES, INC. 

                        By:    /s/ ROBERT C. TOBER              
                           -------------------------------------
                                   (Seal)

                        Title:      PRES. 
                              ----------------------------------


Executed at Strategic Diagnostics Industries, Inc., 128 Sandy Drive, Newark, DE
19713 on Oct. 26, 1993.

                        LESSEE: STRATEGIC DIAGNOSTICS INDUSTRIES               
                                INCORPORATED 

                        By:  /s/ ANNE CAVANAUGH                  
                           -------------------------------------
                                 (Seal)

                        Title:      VICE PRES.
                              ----------------------------------



                                       -22-


        

<PAGE>


                                                                   Exhibit 10.20

                                   INDUSTRIAL LEASE
                                           
1.     Parties.   This Lease, dated, for reference purposes only June 7, 1991, 
is made by and between TOBER & AGNEW PROPERTIES, INC., a Delaware corporation
(herein called "Lessor") and TSD BioServices, a Delaware general partnership
(herein called "Lessee").

2.     Premises.  Lessor hereby leases to Lessee and Lessee leases from Lessor
for the Term (as hereinafter defined)at the rental, and upon all of the
conditions set forth herein, all that certain space (the "premises") which is
the portion of the building erected on lots 32 and 33, at 128 Sandy Drive,
Newark, Delaware as more fully shown on the plan attached hereto as Exhibit
"A", consisting of Seven Thousand Six Hundred Fifty (7,650) square feet, more
or less.  The Premises includes all fixtures,improvements, additions and other
property installed therein at the commencement Date (as hereinafter defined) or
at any time during the time of this lease (other than Tenant's movable personal
property and trade fixtures) together with the right to use, in common with
others, any entrances, lobbies, hallways parking lot, walkways, elevators and
other public portions of the building in which the Premises is located
(the "Building") The Building contains 25,600 square feet.

3.     Term.

       3.1. Term.  The term of this lease and Lessee's obligation to pay rent
hereundershall commence upon the date when the premises is ready for occupancy
and a certificate of occupancy or equivalent certificate has been issued by the
appropriate governmental agency (the "Commencement Date") The premises shall be
deemed ready for occupancy when Lessor has substantially completed the work
depicted or described on the plans and specifications listed in Exhibit "B" 
attached hereto (the "Tenant Improvement Work").  The parties agree to execute 
an Addendum contemporaneously with the execution of this lease which sets forth
the parties, rights and duties with respect to the Tenant Improvement Work.  
"Substantial Completion" shall mean such completion as shall enable Lessee to 
reasonably and conveniently use and occupy the premises for the conduct of its
business.  The term ("Term") of this lease shall end five (5) years after the
commencement Date.  The parties agree to confirm the commencement Date in
writing.

       3.2. Delay in Possession.  If for any reason Lessor cannot deliver
possession of the premises to Lessee on the commencement Date, Lessee shall
not be obligated to pay rent until possession of the premises is tendered to
Lessee.

4.     Use.

       4.1. Use.  The premises shall be used and occupied for the following: 
office and laboratory uses and the manufacturing of immunological reagents 
and ascites and any uses accessory thereto or any other use which is reasonably
comparable and for no other purpose.

                                       1


<PAGE>

5.     Base Rent.

               (a)  Lessee shall pay to Lessor as rent for the premises, (the
"Base Rent"), in advance, in fixed monthly payments on the first day of each
month of the Term.

               (b)  From the Commencement Date until the first anniversary of
the commencement Date, the Base Rent shall be an amount to be computed at the
rate of $3.95 annually per square foot.

               (c)  Rent for any period during the Term hereof which is for less
than one month shall be a pro rata portion of the monthly installment.

               (d)  Rent shall be payable in lawful money of the United States
to Lessor at the address stated herein or to such other persons or at such 
other places as Lessor may designate in writing.

               (e)  commencing on the first anniversary of the Commencement
Date, and on each anniversary of the commencement Date thereafter through the
end of the Term and any renewal thereof, the Base Rent shall be computed in
accordance with the provisions of this subparagraph.  In the event the Consumer
Price Index for Urban Wage Earners and clerical Workers in the city of 
Philadelphia (1967 = 100) (hereinafter called the "Price Index") or a successor
or substitute index appropriately adjusted, reflects an increase in the cost of
living for the month immediately preceding such anniversary date ("Adjustment
Month") over and above such cost of living as reflected by the Price Index as
it existed for the month immediately preceding the prior anniversary date 
(hereinafter called the "Base Index"), the Base Rent during such lease year 
shall equal to the number of square feet in the Premises, multiplied by $3.95
plus the product of (i) $3.95 (as adjusted in the prior year in accordance 
with this subparagraph) multiplied by (ii) the lesser of (A) five percent 5% or
(B) a fraction, the numerator of which is the Price Index for the Adjustment 
Month and the denominator of which is the Base Index (but in no event shall 
such increase be less than 4%).  In the event that such determination cannot 
be made until after any anniversary of the commencement Date, the increase in
the monthly rental payments due for the months prior to such determination 
shall bepaid to Lessee upon the date the next payment of rent is due following
such determination.

6.     Operating Expenses.  In addition to the Base Rent, Lessee will pay to 
Lessor as additional rent Lessee's operating Expense Share of the amount of 
Operating Expenses paid, payable or incurred by Lessor in each year of the Term
and Lessee's Tax Share of the real property taxes payable by Lessor in each 
year of the Term, and Lessee's share of the premiums for required insurance 
payable by Lessor.  As used in this lease the following terms shall be defined
as hereinafter provided:

          (a)  Lessee's operating Expense Share shall be thirty percent (30%);

                                       2

<PAGE>

          (b)  "Operating Expenses" shall mean the following:

                    (i) Costs of cleaning, repairing and maintaining the 
Common Areas of the Building (including the costs for snow removal).  As used 
in this lease, the term "common areas" means, without limitation, the 
entrances, lobbies, trash facilities, driveways, walkways, landscaping and all 
other areas and facilities, including the plumbing, electrical, and sprinkler
systems, ductwork, roof and exterior wall and windows, in the Building which 
are provided for and designated from time to time by Lessor for the general 
non-exclusive use and convenience of Lessee and its employees, invitees, 
licensees or other visitors.  Lessor grants Lessee, its employees,invitees, 
licensees and other visitors a non-exclusive license for the Term to use the 
common Areas; and 

                   (ii) The cost of premiums for the insurance required under 
paragraphs 9.1 and 9.3 (provided that Lessee shall pay 100% of any increase in 
or component of any such premiums directly attributable to the construction of 
the Tenant Improvement Work and the specialty equipment installed);

                  (iii) Notwithstanding anything else contained in this 
paragraph, "Operating Expenses" shall not include: (i)      any capital 
additions made to the Building; (ii)repairs or other work occasioned by fire, 
windstorm, or other insured casualty or hazard; (iii) leasing commissions and 
advertising expenses incurred inprocuring new tenants; (iv) repairs or 
rebuilding necessitated by condemnation to the extent that Lessor has received 
condemnation proceeds for such repairs or rebuilding; (v)any depreciation and 
amortization of the Building; (vi) principal or interest payments on any 
indebtedness applicable to the Building or the Premises, including any mortgage
debt or ground rents payable under any ground lease for the Building.

               (c)  Lessee's Tax Share shall be 30% of the real property taxes 
assessed on the date hereof, plus 100% of any increase in such taxes directly 
attributable to the construction of the Tenant Improvement Work;

               (d)  As used herein the term "real property tax" shall include 
any form of real estate tax or assessment, general, special, ordinary or 
extraordinary, and any license fee, commercial rental tax, improvement bond or 
bonds, levy or tax (other than inheritance, personal income or estate taxes) 
imposed on the Premises by any authority having the direct or indirect power to
tax, including any city, state or federal government, or any school, 
agricultural, sanitary, fire, street, drainage or other improvement district 
thereof, as against any legal or equitable interest of Lessor in the Premises 
or in the real property of which the Premises is a part, as against Lessor's 
right to rent or other income therefrom, and as against Lessor's business of 
leasing the Premises.  The term "real property tax" shall also include any tax,
fee, levy, assessment or charge in substitution of, partially or totally, any 
tax, fee, levy, assessment for charge hereinabove included within the definition
of "real property tax."

                                       3

<PAGE>

                    All payments of additional rent for Operating Expenses 
payable by Lessee shall be paid within ten days of receipt by Lessee of 
Lessor's statement of amounts due, which statement shall include at Lessee's 
request copies of relevant invoices and receipts.  All payments of additional 
rent for real property taxes payable by Lessee shall be paid within the period 
prescribed by law for the payment thereof without penalty or interest; provided
that Lessor has sent to Lessee copies of such tax bills when received from the 
taxing authority.

7.      Compliance with Law; Environmental Matters.

        7.1. Compliance With Law.

               (a)  Lessor warrants to Lessee that the Premises, in its state 
existing on the commencement Date, and the above described uses do not violate 
any covenants or restrictions of record, or any applicable zoning or building 
code, regulation or ordinance in effect on said date.  In the event it is 
determined that this warranty has been violated, then it shall be the 
obligation of the Lessor to promptly, at Lessor's sole cost and expense, 
rectify any such violation.

               (b)  Except as provided in paragraph 7.2(a), Lessee shall, at 
Lessee's expense, comply promptly with all applicable statutes, ordinances, 
rules, regulations, orders, covenants and restrictions of record, and 
requirements in effect during the Term or any part of the term hereof, 
regulating the use by Lessee of the Premises.

          7.2. Environmental Matters.  Lessor represents and warrants that all 
activities at the Premises since Lessor's acquisition or Premises have been and
are being conducted in compliance with all statutes, ordinances, regulations, 
orders, and requirements of common law concerning (i) those activities, (ii) 
repairs or construction of any improvements, (iii) handling of any materials, 
(iv) discharges to the air, soil, surface, or groundwater, and (v) storage, 
treatment, or disposal of any waste at or connected with any activity at the 
Premises ("Environmental Statutes").

               Lessor represents and warrants that no contamination is present 
at the Premises.  The term "Contamination" means the uncontained presence of 
Hazardous Substances at the Premises, or arising from the Premises which may 
require remediation under any applicable law.  The term Hazardous Substances" 
means "hazardous substances" as defined pursuant to the comprehensive 
Environmental Response, compensation and Liability Act, as amended, "regulated 
substances" within the meaning of Subtitle I of the Resource Conservation 
Recovery Act, as amended, "hazardous wastes", as defined pursuant to the 
Delaware Hazardous Waste Management Act, or "regulated substances" as defined 
pursuant to the Del aware Underground Storage Tank Act.

               Lessor represents and warrants that no portion of the Premises 
constitutes any of the following "Environmentally Sensitive Areas":

                                       4

<PAGE>

                    (i)     a wetland or other "water of the United States"   
         for purposes of section 404 of the federal clean Water Act or any 
         similar area regulated under any state law;

                    (ii)    a portion of the coastal zone for purposes of the 
          Federal Coastal Zone Management Act and the Delaware Coastal Zone 
          Act; or

                    (iii)   any other area, including but not limited to a 
          floodplain or other flood hazard area, the development of which is 
          specially restricted under any applicable law by reason of its 
          physical characteristics or prior use.

          Lessor represents and warrants that no tanks for the storage of any 
liquid or gas are present on the Premises except for two underground 500 
gallon liquid propane tanks.

          Lessor represents and warrants that (i) at no point in any 
structure at the Premises will air radiation levels exceed 4 
picocuries/liter, (ii) Lessor does not know or have reason to know of any 
investigation of the Premises for the presence of radon gas or the presence 
of the radioactive decay products of radon (collectively "radon") and (iii) 
Lessor has provided to Lessee a report of each investigation relevant to the 
presence of Radon at the Premises of which Lessor has any knowledge.

          The parties hereby agree that if any of the representations or 
warranties contained in this paragraph 7.2 shall prove to be incorrect, or if 
Lessor breaches any covenant contained in this paragraph 7.2, Lessor shall be 
afforded an opportunity to cure such default provided that (i) such breach or 
condition is susceptible of remediation within a reasonable amount of time as 
determined by Lessee; and (ii) Lessor begins promptly after the discovery of 
such breach or condition diligently to remedy same and continues such 
diligent efforts until satisfactory remediation has been achieved.

          Lessor shall indemnify and hold Lessee harmless of, from, and 
against any and all expense, loss or liability suffered by Lessee by reason 
of the Lessor's breach of any provision of this Section including, but not 
limited to, (i) costs to comply with any Environmental Statutes; (ii) costs 
to study or to remedy contamination of the Premises or arising from the 
Premises; (iii) costs incident to the study or removal of tanks, their 
contents or associated Contamination; (iv) cost to prevent air radiation 
levels in any structure hereafter erected in the Premises from exceeding 4 
picocuries/liter or to reduce air radiation levels in any structure on the 
Premises to 4 picocuries/liter or less; (v) fines, penalties, or other 
sanctions assessed due to Lessor's failure to have complied with 
Environmental Statutes; (vi) loss of value of the Property by reason of a 
failure to comply with Environmental Statutes or the presence on the Property 
of any Hazardous Substance, tank, Environmentally Sensitive Feature or Radon; 
and (vii) legal and professional fees and costs in connection with the 
foregoing.  For purposes of this subparagraph, the term "lessee" shall mean 
Lessee, its successors and assigns.  Nothing herein shall be construed to 
include (i) any condition or occurrence arising out of Lessee's activities in 
or on the Premises, or (ii) any consequential damages or losses sustained by 
Lessee as a result of interruption of 

                                       5

<PAGE>

Lessee's business activities or the dislocation of Lessee's facilities as a 
result of a default pursuant to this paragraph 7.2.

     7.3. Condition of Premises.

          (a)  Lessor shall deliver the Premises to Lessee clean and free of 
debris on the Commencement Date and Lessor further warrants to Lessee that 
the Tenant Improvement Work in the Premises shall be in good operating 
condition on the Commencement Date.  In the event that it is determined that 
this warranty has been violated, then it shall be the obligation of Lessor, 
after receipt of written notice from Lessee setting forth with specificity 
the nature of the violation, to promptly, at Lessor's sole cost, rectify such 
violation.

          Within thirty (30) days after the commencement Date, Lessee shall 
give Lessor a written list (the "Punch List") of all contended defects in 
Lessor's construction work and of all contained variances in Lessor's work as 
described in Exhibit "HO attached hereto.  Lessor shall correct all items on 
the Punch List within thirty (30) days after Lessor's receipt of the Punch 
List, unless the nature of the defect or variance is such that a longer 
period of time is required to repair or correct the same, in which case 
Lessor shall exercise due diligence in correcting such defect or variance at 
the earliest possible date and with a minimum of interference with Lessee's 
operations.  Nothing in this subparagraph shall be deemed a waiver by Lessee 
of Lessor's warranty contained in paragraph 7.3(a) for violations discovered 
after delivery of the Punch List.

8.        Maintenance, Repairs, Alterations and Building Services.

          8.1. Lessor's Obligations.

          (a)  Lessor shall keep in good order, condition and repair the 
Common Areas of the Building, and the heating, ventilation and air 
conditioning system installed for the use of the Premises (the "HVAC").

          (b)  If Lessor fails to perform Lessor's obligations under this 
paragraph 8.1 or under any other paragraph of this lease, Lessee may at 
Lessee's option and upon 10 days' prior written notice to Lessor (except in 
the case of emergency, in which case no notice shall be required), perform 
such obligations on Lessor's behalf and put the Common Areas and HVAC in good 
order, condition and repair, and the cost thereof shall be offset against the 
installment rent next due.

          8.2. Lessee's Obligations.  Lessee, at its expense, shall maintain 
and keep inood order, condition and repair the plumbing, electric, HVAC, 
lighting, fixtures, interior walls, ceilings, floors, windows, doors and 
plate glass located in, on, or within the Premises or any part thereof, and 
which are for the exclusive use of the Premises or Lessee.  Lessor shall 
procure and maintain at Lessee's expense an HVAC maintenance agreement, which 
shall be in form and substance reasonably satisfactory to Lessee.  On the 
last day of the Term hereof, or on any sooner 

                                       6

<PAGE>

termination, Lessee shall surrender the Premises to Lessor in the same 
condition as received, ordinary wear and tear excepted, clean and free fo 
debris.

          8.3. Alterations and Additions.

          (a)  Lessee shall not, without Lessor's prior written consent, 
which consent shall not be unreasonably withheld or delayed, make any 
alterations, improvements, additions, or Utility Installations in, on or 
about the Premises, except for nonstructural alterations not exceeding 
$7,500.  In any event, whether or not in excess of $7,500 in cost, Lessee 
shall make no change or alteration to the exterior of the Premises nor the 
exterior of the Building without Lessor's prior written consent.  As used in 
this paragraph 8.3 the term "Utility Installation" shall mean air lines, 
power panels, electrical distribution systems, lighting fixtures, space 
heaters, air conditioning, plumbing, and fencing.  Should Lessee make any 
alterations, improvements, additions or Utility Installations without the 
prior approval of Lessor, Lessor may require that Lessee remove any or all of 
the same.

          (b)  Any alterations, improvements, additions or Utility 
Installations in or about the Premises that Lessee shall desire to make and 
which requires the consent of the Lessor shall be presented to Lessor in 
written form, with proposed detailed plans.  If Lessor shall give its 
consent, the consent shall be deemed conditioned upon Lessee acquiring a 
permit to do so from appropriate government agencies, the furnishing of a 
copy thereof to Lessor prior to the commencement of the work and the 
compliance by Lessee of all conditions of said permit in a prompt and 
expeditious manner.

          (c)  Lessee shall pay, when due, all claims for labor or materials 
furnished to or for Lessee at or for use in the Premises, which claims are or 
may be secured by any mechanics, or materialmen's lien against the Premises 
or any interest therein.  Lessee shall give Lessor not less than ten (10) 
days' notice prior to the commencement of any work in the Premises, and 
Lessor shall have the right to post notices of nonresponsibility in or on the 
Premises as provided by law.  If Lessee shall, in good faith, contest the 
validity of any such lien, claim or demand, then Lessee shall, at its sole 
expense defend itself and Lessor against the same and shall pay and satisfy 
any such adverse judgment that may be rendered thereon before the endorsement 
thereof against the Lessor or the Premises, upon the condition that if Lessor 
shall require, Lessee shall furnish to Lessor a surety bond satisfactory to 
Lessor in an amount equal to such contested lien claim or demand indemnifying 
Lessor against liability for the same and holding the Premises free from the 
effect of such lien or claim and shall obtain release of such lien by 
substitution of such surety bond as security therefor.  In addition, Lessor 
may require Lessee to pay Lessor's attorneys fees and costs in participating 
in such action if Lessor shall decide it is to its best interest to do SO.

          (d)  Unless Lessor requires their removal, as set forth in 
paragraph 8.3(a), all alterations, improvements, additions and Utility 
Installations, which may be made on the

                                       7

<PAGE>

Premises, shall become the property of Lessor and remain upon and be 
surrendered with the Premises at the expiration of the Term.

9.        Insurance; Indemnity.

          9.1. Liability Insurance - Lessor.  Lessor shall obtain and keep in 
force during the Term of this lease a policy of Combined Single Limit Bodily 
Injury and Property Damage Insurance, insuring Lessor and Lessee against any 
liability arising out of the ownership, use or occupancy maintenance of the 
Premises and all areas appurtenant thereto in an amount not less than 
$500,000 per occurrence.

          9.2. Liability Insurance - Lessee.  Lessee shall obtain and keep in 
force during the Term of this lease a policy of combined Single Limit Bodily 
Injury and Property Damage Insurance, insuring Lessor and Lessee against any 
liability arising out of the use or occupancy of the Premises and all areas 
appurtenant thereto in an amount not less than $500,000 per occurrence.

          9.3. Property Insurance.  Lessor shall obtain and keep in force 
during the Term of this lease a policy or policies of insurance covering loss 
or damage to the Building, including Lessee's fixtures, equipment or tenant 
improvements in an amount not to exceed the full replacement value thereof as 
the same may exist from time to time, providing protection against all perils 
included within the classification of fire, extended coverage, vandalism, 
malicious mischief, flood (in the event same is required by a lender having a 
lien on the Premises), special extended perils ("all risk", as such term is 
used in the insurance industry).

          9.4. Insurance Policies.  Insurance required hereunder shall be in 
companies holding a "General Policyholders Rating" of at least B plus, or 
such other rating as may be required by a lender having a lien on the 
Premises, as set forth in the most current issue of "Best Insurance Guide".  
Lessor and Lessee shall deliver to each other copies of policies of all 
insurance required under paragraph 8 or certificates evidencing the existence 
and amounts of such insurance.  No such policy shall be cancellable or 
subject to reduction of coverage or other modification except after thirty 
(30) days, prior written notice to the other.  Each party shall, at least 
thirty (30) days prior to the expiration of such policies, furnish the other 
with renewals thereof.  Lessee shall not do or permit to be done anything 
which shall invalidate the insurance policies referred to in paragraph 9.3.

          9.5. Waiver or Subrogation.  Lessee and Lessor each hereby release 
and relievehe other, and waive their entire right of recovery against the 
other for loss or damage arising out of or incident to the perils insured 
against under paragraph 9.3, which perils occur in, on or about the Premises, 
whether due to the negligence of Lessor or Lessee or their agents, employees, 
contractors and/or invitees.  Lessee and Lessor shall, upon obtaining the 
policies of insurance required hereunder, give notice to the insurance 
carrier or carriers that the foregoing mutual waiver of subrogation is 
contained in this lease.

                                       8

<PAGE>

          9.6. Indemnity.  Lessee shall indemnify and hold harmless Lessor 
from and against any and all claims arising from Lessee's use of the 
Premises, or from the conduct of Lessee's business or from any activity,  
work or things done, permitted or suffered by Lessee in or about the Premises 
or elsewhere and shall further indemnify and hold harmless Lessor from and 
against any and all claims arising from any breach or default in the 
performance of any obligation on Lessee's part to be performed under the 
terms of this lease, or arising from any negligence of the Lessee, or any of 
Lessee's agents, contractors, or employees, and from and against all costs, 
attorneys' fees, expenses and liabilities incurred in the defense of any such 
claim or any action or proceeding brought thereon; and in case any action or 
proceeding be brought against Lessor by reason of any such claim.  Lessee 
upon notice from Lessor shall defend the same at Lessee's expense by counsel 
satisfactory to Lessor.

               Lessor shall indemnify and hold harmless Lessee from and 
against any and all claims arising from any breach or default in the 
performance of any obligation on Lessor's part to be performed under the 
terms of this lease, or arising from any negligence of the Lessor, or any of 
Lessor's agents, contractors, or employees, and from and against all costs, 
attorneys' fees, expenses and liabilities incurred in the defense of any such 
claim or any action or proceeding brought thereon; and in case any action or 
proceeding be brought against Lessee by reason of any such claim. Lessor upon 
notice from Lessee shall defend the same at Lessor's expense by counsel 
satisfactory to Lessee.

10.       Damage or Destruction.

          10.1.     Definitions.

                    (a)  "Premises Partial Damage" shall herein mean damage 
or destruction to the Premises to the extent that the cost of repair is less 
than 50% of the fair market value of the Premises immediately prior to such 
damage or destruction. "Premises Building Partial Damage" shall herein mean 
damage or destruction to the Building of which the Premises are a part to the 
extent that the cost of repair is less that 50% of the fair market value of 
the Building as a whole immediately prior to such damage or destruction.

                    (b)  "Premises Total Destruction" shall herein mean 
damage or destruction to the Premises to the extent that the cost of repair 
is 50% or more of the fair market value of the Premises immediately prior to 
such damage or destruction.

                    (c)  "Insured Loss" shall herein mean damage or 
destruction which was caused by an event required to be covered by the 
insurance described in paragraph 10.

          10.2.     Partial Damage - Insured Loss.  Subject to the provisions 
of paragraph 10.4, 10.5 and 10.6, if at any time during the Term of this 
lease there is damage which is an Insured loss and which falls into the 
classification of Premises Partial Damage or Premises Building Partial 
Damage, then Lessor shall, at Lessor's sole cost, repair such damage, 
including Lessee's fixtures, 

                                       9

<PAGE>

equipment or tenant improvements as soon as reasonably possible and this 
lease shall continue in full force and effect.

          10.3.     Partial Damage - Uninsured Loss.  Subject to the 
provisions of paragraphs 10.4, 10.5 and 10.6, if at any time during the Term 
of this lease there is damage which is not an Insured loss and which fails 
within the classification of Premises Partial Damage or Premises Building 
Partial Damage, unless caused by a willful act of Lessee (in which event 
Lessee shall make the repairs at Lessee's expense), Lessor may at Lessor's 
option either (i) repair such damage as soon as reasonably possible at 
Lessor's expense, in which event this lease shall continue in full force and 
effect, or (ii) give written notice to Lessee within fifteen (15) days after 
the date of the occurrence of such damage of Lessor's intention to cancel and 
terminate this lease.  In the event Lessor shall give such notice of Lessor's 
intention to cancel and terminate this lease, Lessee shall have the right 
within fifteen (15) days after the receipt of such notice to give written 
notice to Lessor of Lessee's intention to repair such damage at Lessee's 
expense, in which event this lease shall continue in full force and effect, 
and Lessee shall proceed to make such repairs as soon as reasonably possible. 
 If Lessee does not give such notice within such 15-day period this lease 
shall be cancelled and terminated and Lessee shall have no further 
obligations or duties thereunder including the payment of rent as of the date 
of the occurrence of such damage.

          10.4.     Total Destruction.  If at any time during the term of 
this lease there is damage, whether or not an Insured loss, (including 
destruction required by any authorized public authority), which falls into 
the classification of Premises Total Destruction or Premises Building Total 
Destruction, this lease shall automatically terminate and Lessee shall have 
no further obligations or duties thereunder including the payment of rent as 
of the date of such total destruction.

          10.5      Damage Year End of Term.

                    (a)  If at any time during the last six months of the 
Term of this lease there is damage, whether or not an Insured loss, which 
falls within the classification of Premises Partial Damage, Lessor and Lessee 
each has the option to cancel and terminate this lease as of the date of 
occurrence of such damage by giving written notice to the other of its 
election to do so within 30 days after the date of occurrence of such damage.

                    (b)  Notwithstanding paragraph 10.5(a), in the event that 
Lessee has an option to extend or renew this lease, and the time within which 
said option may be exercised has not yet expired, Lessee shall exercise such 
option, if it is to be exercised at all, no later that 25 days after the 
occurrence of an Insured loss falling within the classification of Premises 
Partial Damage during the last six months of the Term of this lease.  If 
Lessee duly exercises such option during said 25 day period, Lessor shall, at 
Lessor's expense, repair such damage as soon as reasonably possible and this 
lease shall continue in full force and effect.  If Lessee fails to exercise 
such option during said 25 day period, then less may at Lessee's option 
terminate and cancel this lease 

                                       10

<PAGE>

as of the expiration of said 25 day period by giving written notice to Lessee 
of Lessor's election to do so within 5 days after the expiration of said 25 
day period, notwithstanding any term or provision in the grant of option to 
the contrary.

          10.6.     Abatement of Rent; Lessee's Remedies.

                    (a)  In the event of damage described in paragraphs 10.2 
or 10.3 and Lessor or Lessee repairs or restores the Premises pursuant to the 
provisions of this paragraph 10, the rent payable hereunder for the period 
during which such damage, repair or restoration continues shall be abated in 
proportion to the degree to which Lessee's use of the Premises is impaired.  
Except for abatement of rent Lessee shall have no claim against Lessor for 
any damage suffered by reason of any such damage, destruction, repair or 
restoration.

                    (b)  If Lessor shall be obligated to repair or restore 
the Premises under the provisions of this paragraph 10 and shall not commence 
meaningful repair or restoration within 30 days after such obligations shall 
accrue, Lessee may at Lessee's option cancel and terminate his lease by 
giving Lessor written notice of Lessee's election to do so at any time prior 
to Lessor's meaningful commencement of such repair or restoration.  In such 
event this lease shall terminate as of the date of such notice and Lessee 
shall have no further obligations or duties thereunder, including the payment 
of rent, as of the date of the occurrence of the damage.

          10.7.     Termination Advance Payments.  Upon termination of this 
lease pursuant to this paragraph 10, an equitable adjustment shall be made 
concerning any advance rent and any advance payments made by Lessee to Lessor.

          10.8.     Waiver.  Lessor and Lessee waive the provisions of any 
statutes which relate to termination of leases when leased property is 
destroyed and agree that such event shall be governed by the terms of this 
lease.

11.       Utilities.  Lessee shall pay for all water, gas, heat, light, 
power, telephone and other utilities and services supplied to the Premises, 
together with any taxes thereon.  Such services are to be separately metered 
to Lessee.

12.       Assignment and Subletting.

          12.1      Lessor's Consent Required.  Lessee shall not voluntarily 
or by operation of law assign, transfer, mortgage, sublet, or otherwise 
transfer or encumber all of any part of Lessee's interest in this lease or in 
the Premises, without Lessor's prior written consent, which Lessor shall not 
unreasonably withhold or delay.  Lessor shall respond in writing to Lessee's 
request for consent hereunder in a timely manner and any attempted 
assignment, transfer, mortgage, encumbrance or subletting without such 
consent shall be void and shall constitute a breach of this lease.

                                       11

<PAGE>

          12.2      Lessee Affiliate.  Notwithstanding the provisions of 
paragraph 12.1 hereof, Lessee may assign or sublet the Premises, or any 
portion thereof, without Lessor's consent, to any corporation which controls, 
is controlled by or is under common control with Lessee, or to any 
corporation resulting from the merger or consolidation with Lessee, or to any 
person or entity, which acquires all or substantially all of the assets of 
Lessee as a going concern of the business that is being conducted on the 
Premises, provided that said assignee assumes, in full, the obligations of 
Lessee under this lease.  Any such assignment shall not, in any way, affect 
or limit the liability of Lessee under the terms of this lease even if after 
such assignment or subletting the terms of this lease are changed or altered, 
provided, however, that any material change to the terms of this lease 
(including, but not limited to, the Term or Rent) after such an assignment or 
subletting, shall require the prior consent of Lessor and any such change 
made without Lessor's prior consent shall not be binding on Lessor.

          12.3      No Release of Lessee.  Regardless of Lessor's consent, no 
subletting or assignment shall release Lessee of  Lessee's obligation or 
alter the primary liability of Lessee to pay the Rent and to perform all 
other obligations to be performed by Lessee hereunder.  The acceptance of 
Rent by Lessor from any other person shall not be deemed to be a waiver by 
Lessor or any provision hereof.  Consent to one assignment or subletting 
shall not be deemed consent to any subsequent assignment or subletting. In 
the event of default by any assignee of Lessee or any successor of Lessee, in 
the performance of any of the terms thereof, Lessor may proceed directly 
against Lessee without the necessity of exhausting remedies against said 
assignee.  Lessor may consent to subsequent assignments or subletting of this 
Lease or amendments or modifications to this Lease with assignees of Lessee 
or any successor of Lessee, and without obtaining its or their consent 
thereto and such action shall not relieve Lessee of liability under this 
Lease.

          12.4      Assignment Fees.  In the event Lessee shall assign or 
sublet the Premises then Lessee shall pay an assignment processing fee equal 
to $200.00 for each such request.

13.       Defaults; Remedies.

          13.1      Defaults.  The occurrence of any one or more of the 
following events shall constitute a material default and breach of this Lease 
by Lessee:

                    (a)  The failure by Lessee to make any payment of rent as 
and when due, where such failure shall continue for a period of five days 
after Lessee's receipt of written notice from Lessor.  In the event that 
Lessor serves Lessee with a Notice to Pay Rent or Quit pursuant to applicable 
Unlawful Detainer statutes, such Notice to Pay Rent or Quit shall also 
constitute the notice required by this subparagraph;

                    (b)  The failure by Lessee to observe or perform any of 
the covenants, conditions or provisions of this Lease to be observed or 
performed by Lessee, other than described in paragraph (a) above, where such 
failure shall continue for a period of 30 days after written notice hereof 
from Lessor to Lessee; provided, however, that if the nature of Lessee's 

                                       12

<PAGE>

default is such that more than 30 days are reasonably required for its cure, 
then Lessee shall not be deemed to be in default if Lessee commenced such 
cure within said 30-day period and thereafter diligently prosecutes such cure 
to completion;

                    (c)  (i) The making by Lessee of any general arrangement 
or assignment for the benefit of creditors; (ii) Lessee becomes a "debtor" as 
defined in 11 U.S.C. Section 101 or any successor statute thereto (unless, in 
the case of a petition filed against Lessee, the same is dismissed within 60 
days); (iii) the appointment of a trustee or receiver to take possession of 
substantially all of Lessee's assets located at the Premises or of Lessee's 
interest in this lease, where possession is not restored to Lessee within 30 
days; or (iv) the attachment, execution or other judicial seizure of 
substantially all of Lessee's assets located at the Premises or of Lessee's 
interest in this lease, where such seizure is not discharged within 30 days.  
Provided, however, in the event that any provision of this paragraph 13.1(c) 
is contrary to any applicable law, such provision shall be of no force or 
effect;

                    (d)  The discovery by Lessor that any financial statement 
given to Lessor by Lessee, any assignee of Lessee, any subtenant of Lessee, 
any successor in interest of Lessee or any guarantor of Lessee's obligation 
hereunder, and any of them, was materially false.

          13.2      Remedies.  In the event of any such material default or 
breach by Lessee, Lessor may at any time after providing Lessee with written 
notice, but without limiting Lessor in the exercise of any right or remedy 
which Lessor may have by reason of such default or breach:

                    (a)  Terminate Lessee's right to possession of the 
Premises by any lawful means, in which case this lease shall terminate and 
Lessee shall immediately surrender possession of the Premises to Lessor.  In 
such event Lessor shall be entitled to recover from Lessee all damages 
incurred by Lessor by reason of Lessee's default including, but not limited 
to, the cost of recovering possession of the Premises; expenses of reletting, 
including necessary renovation and alteration of the premises, reasonable 
attorneys' fees, and any real estate commission actually paid; the worth at 
the time of award by the court having jurisdiction thereof of the amount by 
which the unpaid rent for the balance of the term after the time of such 
award exceeds the amount of such rental loss for the same period that Lessee 
proves could be reasonably avoided.

                    (b)  Maintain Lessee's right to possession in which case 
this lease shall continue in effect whether or not Lessee shall have 
abandoned the Premises.  In such event Lessor shall be entitled to enforce 
all of Lessor's rights and remedies under this lease, including the right to 
recover the rent as it becomes due hereunder;

                    (c)  Pursue any other remedy now or hereafter available 
to Lessor under the laws or judicial decisions of the State of Delaware.  
Unpaid installments of rent and other unpaid monetary obligations of Lessee 
under the terms of this lease shall bear interest from the date due at the 
maximum rate then allowable by law.

                                       13

<PAGE>

          13.3.     Default by Lessor.  Lessor shall not be in default unless 
Lessor fails to perform obligations required of  Lessor within a reasonable 
time, but in no event later than ten (10) days after written notice by Lessee
to Lessor and to the holder of any first mortgage or deed of trust covering
the Premises whose name and address shall have theretofore been furnished to
Lessee in writing, specifying wherein Lessor has failed to perform such 
obligation; provided, however, that if the nature of Lessor's obligation is 
such that more than ten (10) days are required for performance then Lessor 
shall not be in default if Lessor commences meaningful performance within such
10-day period and thereafter diligently prosecutes the same to completion.

          13.4.     Late Charges.  Lessee hereby acknowledges that late 
payment by Lessee to Lessor of rent and other sums due hereunder will cause 
Lessor to incur costs not contemplated by this lease, the exact amount of 
which will be extremely difficult to ascertain.  Such costs include, but are 
not limited to, processing and accounting charges, and late charges which may 
be imposed on Lessor by the terms of any mortgage or trust deed covering the 
Premises.  Accordingly, if any installment of rent shall not be received by 
Lessor or Lessor's designee within fifteen (15) days after such amount shall 
be due, then, without any requirement for notice to Lessee, Lessee shall pay 
to Lessor a late charge equal to 3% of such overdue amount.  The parties 
hereby agree that such late charge represents a fair and reasonable estimate 
of costs Lessor will incur by reason of late payment by Lessee.  Acceptance 
of such late charge by Lessor shall in no event constitute a waiver of 
Lessee's default with respect to such overdue amount, nor prevent Lessor from 
exercising any of the other rights and remedies granted hereunder.

14.       Condemnation.

          If the Premises or any portion thereof are taken under the power of 
eminent domain, or sold under the threat of the exercise of said power (all 
of which are herein called "condemnation"), this lease shall terminate as to 
the part so taken as of the date the condemning authority takes title or 
possession, whichever first occurs.  If more than 10% of the floor area of 
the Building, or more than 25% of the area of the Premises is taken by 
condemnation, Lessee may, at Lessee's option, to be exercised in writing 
within fifteen (IS) days after Lessor shall have given Lessee written notice 
of such taking (or in the absence of such notice, within fifteen (15) days 
after the condemning authority shall have taken possession) terminate this 
lease as of the date the condemning authority takes such possession.  If 
Lessee opts to terminate this lease as described in the foregoing, Lessee's 
obligations and duties under this lease shall cease as of the date of 
condemning authority take such possession.  If Lessee does not terminate this 
lease in accordance with the foregoing, this lease shall remain in full force 
and effect as to the portion of the Premises remaining, except that the rent 
shall be reduced in the proportion that the floor area of the Building taken 
bears to the total floor area of the Building situated on the Premises.  No 
reduction of rent shall occur if the only area taken is that which does not 
have a building located thereon.  Any award for the taking of all or any part 
of the Premises under the power of eminent domain or any payment made under 
threat of the exercise of such power shall be the property of Lessor, whether 
such award shall be made as compensation for diminution in value of the 
leasehold or for the taking of the' fee, or as severance damages; 

                                       14

<PAGE>

provided, however, that Lessee shall be entitled to any award for loss of or 
damage to Lessee's equipment, trade fixtures and removable personal property. 
In the event that this lease is not terminated by reason of such 
condemnation, Lessor shall to the extent of severance damages received by 
Lessor in connection with such condemnation, repair any damage to the 
Premises caused by such condemnation except to the extent that Lessee has 
been reimbursed therefor by the condemning authority.

15.       Brokers' Fees.

          Lessor shall be responsible for all brokers, commissions or 
finder's fees charged by Stoltz Realty and warrants to Lessee that no 
brokers' commissions, finders, fees or similar payments shall be claimed 
through Lessee in connection with the execution of this lease, and agrees to 
indemnify and hold Lessee harmless from any liability that may arise from 
such claims, including reasonable attorney's fees.

16.       Estoppel Certificate.

          (a)  Lessee shall at any time upon not less than 10 days, prior 
written notice from Lessor execute, acknowledge and deliver to Lessor a 
statement in writing (i) certifying that this lease is unmodified and in full 
force and effect (or, if modified, stating the nature of such modification 
and certifying that this lease, as so modified, is in full force and effect) 
and the date to which the rent is paid and (ii) acknowledging that there are 
not, to Lessee's knowledge, any uncured defaults, or events which with the 
passage of time would be defaults, on the part of Lessor hereunder, or 
specifying such defaults if any are claimed.  Any such statement may be 
conclusively relied upon by any prospective purchaser or encumbrancer of the 
Premises.

          (b)  At Lessor's option, Lessee's failure to deliver such statement 
within such time shall be a material breach of this lease or shall be 
conclusive upon Lessee (i) that this lease is in full force and effect, 
without modification except as may be represented by Lessor, (ii) that there 
are no uncured defaults in Lessor's performance, and (iii) that not more than 
one month's rent has been paid in advance or such failure may be considered 
by Lessor as a default by Lessee under this lease.

          (c)  If Lessor desires to finance, refinance, or sell the Premises, 
or any part thereof, Lessee hereby agrees to deliver to any lender or 
purchaser designated by Lessor such financial statements of Lessee as may be 
reasonable required by such lender or purchaser.  Such statements shall 
include to the extent available the past three years' financial statements of 
Lessee.  All such financial statements shall be received by Lessor and such 
lender or purchaser in confidence and shall be used only for the purposes 
herein set forth.

17.       Lessor's Liability.  The term "Lessor" as used herein shall mean 
only the owner and owners at the time in question of the fee title or a 
lessee's interest in a ground lease of the Premises.  In the event of any 
transfer of such title or interest, Lessor herein name (and in case of any 
subsequent transfers then the grantor) shall be relieved from and after the 
date of such 

                                       15

<PAGE>

transfer of all liability as respects Lessor's obligations thereafter to be 
performed, provided that any funds in the hands of Lessor of the then grantor 
at the time of such transfer, in which Lessee has an interest, shall be 
delivered to the grantee.  The obligations contained in this Lease to be 
performed by Lessor shall, subject as aforesaid, be binding on Lessor's 
successors and assigns, only during their respective periods of ownership.

18.       Severability.  The invalidity of any provisions of this Lease as 
determined by a court of competent jurisdiction, shall in no way affect the 
validity of any other provision hereof.

19.       Time--of Essence.   Time is of the essence.

20.       Incorporation of  Prior Agreements; Amendments.  This Lease 
contains all agreements of the parties with respect to any matter mentioned 
herein.  No prior agreement or understanding pertaining to any such matter 
shall be effective.  This Lease may be modified in writing only, signed by 
the parties in interest at the time of the modification.  Except as otherwise 
stated in this Lease, Lessee hereby acknowledges that neither the real estate 
brokers listed in paragraph 15 hereof nor any cooperating broker on this 
transaction nor the Lessor or any employees or agents of any of said persons 
has made any oral or written warranties or representations to Lessee relative 
to the condition or use by Lessees of said Premises and Leases acknowledges 
that Lessee assumes all responsibility regarding the Occupational Safety 
Health Act, the legal use and adaptability of the Premises and the compliance 
thereof with all applicable laws and regulations in effect during the term of 
this Lease except as otherwise specifically stated in this Lease.

21.       Notices.  Any notice required or permitted to be given hereunder 
shall be in writing and may be given personal delivery or by certified mail, 
and if given personally or by mail, shall be deemed sufficiently given if 
addressed to Lessee or to Lessor at the address noted below the signature of 
the respective parties, as the case may be. Each such notice shall be deemed 
given upon personal delivery or, if by certified mail, upon mailing.  Either 
party may by notice to the other specify a different address for notice 
purposes except that upon Lessee's taking possession of the Premises, the 
Premises shall constitute Lessee's address for notice purposes.  A copy of 
all notices required or permitted to be given to Lessor hereunder shall be 
concurrently transmitted to such party or parties at such addresses as Lessor 
may from time to time hereafter designate by notice to Lessee.

22.       Waivers.  No waiver by Lessor or any provision hereof shall be 
deemed a waiver of any other provision hereof or of any subsequent breach by 
Lessee of the same or any other provision.  Lessor's consent to, or approval 
of any act, shall not be deemed to render unnecessary the obtaining of 
Lessor's consent to or approval of any subsequent act by Lessee.  The 
acceptance of rent hereunder by Lessor shall not be a waiver of any preceding 
breach by Lessee of any provision hereof, other than the failure of Lessee to 
pay the particular rent so accepted, regardless of Lessor's knowledge of such 
preceding breach at the time of acceptance of such rent.

                                       16

<PAGE>

23.       Recording.  Either Lessor or Lessee shall, upon request of the 
other, execute, acknowledge and deliver to the other a "short form" 
memorandum of this lease for recording purposes.

24.       Holding Over.  If Lessee, with Lessor's consent, remains in 
possession of the Premises or any part thereof after the expiration of the 
term hereof, such occupancy shall be a tenancy from month to month upon all 
the provisions of this lease pertaining to the obligations of Lessee, but all 
options and rights of first refusal, if any, granted under the terms of this 
lease shall be deemed terminated and be of no further effect during said 
month to month tenancy.

25.       Cumulative Remedies.  No remedy or election hereunder shall be 
deemed exclusive but shall, wherever possible, be cumulative with all other 
remedies at law or in equity.

26.       Covenants and Conditions.  Each provision of this lease performable 
by Lessee shall be deemed both a covenant and a condition.

27.       Binding Effect; Choice of Law.  Subject to any provisions hereof 
restricting assignment or subletting by Lessee, this lease shall bind the 
parties, their personal representatives, successors and assigns.  This lease 
shall be governed by the laws of the State of Delaware.

28.       Subordination.

          (a)  This lease, at Lessor's option, shall be subordinate to any 
ground lease, mortgage, deed of trust, or any other hypothecation or security 
now or hereafter placed upon the real property of which the Premises are a 
part and to any and all advances made on the security thereof and to all 
renewals, modifications, consolidations, replacements and extensions thereof. 
 Notwithstanding such subordination, Lessee's right to quiet possession of 
the Premises shall not be disturbed if Lessee is not in default and so long 
as Lessee shall pay the Rent and observe and perform all of the provisions of 
this lease, unless this lease is otherwise terminated pursuant to its terms.  
If any mortgagee, trustee or ground Lessor shall elect to have this lease 
prior to the lien of its mortgage, deed of trust or ground lease, and shall 
give written notice thereof to Lessee, this lease shall be deemed prior to 
such mortgage, deed of trust, or ground lease, whether this lease is dated 
prior or subsequent to the date of said mortgage, deed of trust or ground 
lease or the date of recording thereof.

          (b)  Lessee agrees to execute any documents required to effectuate 
an attornment, a subordination or to make this lease prior to the lien of any 
mortgage, deed of trust or ground lease, as the case may be.  If Lessee fails 
to execute such documents within 10 days after written demand, Lessor may 
execute such documents on behalf of Lessee as Lessee's attorney-in-fact.  
Lessee does hereby make, constitute and irrevocably appoint Lessor as 
Lessee's attorney-in-fact and in Lessee's name, place and stead, to execute 
such documents in accordance with this paragraph 28(b).

                                       17

<PAGE>

29.       Intentionally omitted.

30.       Lessor's Access.  Lessor and Lessor's agents, upon prior written 
notice to Lessee, shall have the right to enter the Premises at reasonable 
times for the purpose of inspecting the same, showing the same to prospective 
purchasers, lenders, or lessees, and making such alterations, repairs, 
improvements or additions to the Premises or to the Building of which they 
are a part as Lessor may deem necessary or desirable; provided, however that 
upon such entry Lessor and/or Lessor's agents (except in the case of 
emergency) shall be required to be accompanied by a representative of Lessee 
for purposes of protecting and preserving the confidentiality of Lessee's 
work on the Premises.  Lessor may not at any time place on or about the 
Premises any ordinary "For Sale" signs.  Lessor may at any time during the 
last 120 days of the Term hereof place on or about the Premises on the 
Building any ordinary "For Lease" signs, all without rebate of rent or 
liability to Lessee; provided that Lessor shall not permitted to place "For 
lease" signs on or about the Premises until any options or rights available 
to Lessee to extend the term of this lease or to renew this lease or any 
options or rights of first refusal to lease the Premises or rights of first 
offer to purchase the Premises have lapsed.

31.       Signs.  Lessee shall not place any sign upon the Premises without 
Lessor's prior written consent, which shall not be unreasonably withheld, 
except that Lessee shall have the right, without the prior permission of 
Lessor, to place ordinary and usual for rent or sublet signs thereon.

32.       Merger.  The voluntary or other surrender of this lease by Lessee, 
or a mutual cancellation thereof, or a termination by Lessor, shall not work 
a merger, and shall, at the option of Lessor, terminate all or any existing 
subtenancies or may, at the option of Lessor, operate as an assignment to 
Lessor of any or all of such subtenancies.

33.       Consents.  Wherever in this lease the consent of one party is 
required to an act of the other party, such consent shall not be unreasonably 
withheld.

34.       Quiet Possession.  Upon Lessee paying the rent for the Premises and 
observing and performing all of the covenants, conditions and provisions on 
Lessee's part to be observed and performed hereunder, Lessee shall have quiet 
possession of the Premises for the entire Term hereof subject to all of the 
provisions of this lease.  The individuals executing this lease on behalf of 
Lessor represent and warrant to Lessee that they are fully authorized and 
legally capable of executing this lease on behalf of Lessor and that such 
execution is binding upon all parties holding an ownership interest in the 
Premises.

35.       Options; Right of First Refusal.

          35.1.     Definition.  As used in this paragraph the word "0ptions" 
means the right or option to extend the term of this lease or to renew this 
lease.

                                       18

<PAGE>

          35.2.     Options Personal.  Each Option granted to Lessee in this 
lease is personal to Lessee and may not be exercised or be assigned, 
voluntarily or involuntarily, by or to any person or entity other than 
Lessee, provided, however, the Option may be exercised by or assigned to any 
Lessee Affiliate as defined in paragraph 12 of this lease.  The Options 
herein granted to Lessee are not assignable separate and apart from this 
lease.

          35.3.     Efect of Default on Options.

          (a)  Lessee shall have no right to exercise an option, 
notwithstanding any provision in the grant of Option to the contrary, (i) 
during the time commencing from the date Lessor gives to Lessee a notice of 
default pursuant to paragraph 13.1(a) or 13.1(b) and continuing until the 
default alleged in said notice of default is cured, or (ii) at any time after 
an event of default described in paragraphs 13.1(c) or 13.1(d) (without any 
necessity of Lessor to give notice of such default to Lessee).

          (b)  The period of time within which an Option may be exercised 
shall not be extended or enlarged by reason of Lessee's inability to exercise 
an option because of the provisions of paragraph 36.3.

          35.4.     Option to Renew.  Lessee shall have the right, at its 
sole option, to renew this lease for an additional period of five (5) years 
following the term hereof, upon the same terms and conditions in effect at 
the expiration of the prior term, including provision for the escalation of 
rent and including this option to renew,* provided---that the ceiling and 
floor limitations for the escalation of rent in Section 5(a)(ii) herein shall 
not apply following the fifteenth anniversary of the Commencement Date; 
provided further that Lessee shall have given Lessor no more than six and no 
less than three months written notice in advance at the end of the prior term 
of its intention to renew this lease,

36.       Multiple Tenant Building.  Lessee agrees that it will abide by, 
keep and observe all reasonable rules and regulations which Lessor may make 
from time to time for the management, safety, care, and cleanliness of the 
building and grounds, the parking of vehicles and the preservation of good 
order therein as well as for the convenience of other occupants and tenants 
of the building.  The violations of any such rules and regulations shall be 
deemed a material breach of this Lease by Lessee.

37.       Security Measures.  Lessee hereby acknowledges that the rent 
payable to Lessor hereunder does not include the cost of guard service or 
other security measures, and that Lessor shall have no obligation whatsoever 
to provide same.  Losses assumes all responsibility for the protection of 
Lessee, its agents and invitees from acts of third parties.

38.       Easements.  Lessor reserves to itself the right, from time to time, 
to grant such easements, rights and dedications that Lessor deems necessary 
or desirable, and to cause the recordation of Parcel Maps and restrictions, 
so long as such easements rights, dedications, Maps and restrictions 

                                       19

<PAGE>

do not interfere' with the use of the Premises by Lessee.  Lessee shall sign 
any of the aforementioned documents upon request of Lessor and failure to do 
so shall constitute a material breach of this lease.

39.       Performance Under Protest.  If at any time a dispute shall arise as 
to-any amount or sum of money to be paid by one part to the other under the 
revisions hereof the party against whom the obligation to pay the money is 
asserted shall have the right to make payment "under protest" and such 
payment shall not be regarded as a voluntary payment, and there shall survive 
the right on the part of said party to institute suit for recovery of such 
sum.  If it shall be adjudged that there was no legal obligation on the part 
of said party to pay such sum or any part thereof, said party shall be 
entitled to recover such sum or so much thereof as it was not legally 
required to pay under the provisions of this lease.

40.       Authority.  If either Lessor or Lessee is a corporation, trust, or 
general or limited partnership, each individual executing this lease on 
behalf of such entity represents and warrants that he or she is duly 
authorized to execute and deliver this Lease on behalf of said entity.

LESSOR AND LESSEE HAVE CAREFULLY READ AND REVIEWED THIS LEASE AND EACH TERM 
AND PROVISION CONTAINED HEREIN AND, BY EXECUTION OF THIS LEASE, SHOW THEIR 
INFORMED AND VOLUNTARY CONSENT THERETO, THE PARTIES HEREBY AGREE THAT, AT THE 
TIME THIS LEASE IS EXECUTED, THE TERMS OF THIS LEASE ARE COMMERCIALLY 
REASONABLE AND EFFECTUATE THE INTENT AND PURPOSE OF LESSOR AND LESSEE WITH 
RESPECT TO THE PREMISES.

The parties hereto have executed this Lease at the Place and on the dates 
specified immediately adjacent to their respective signatures.

Executed at 128 Sandy Bank Drive, Newark, DE 19713 on June 7, 1991.

                        LESSOR: TOBER & AGNEW PROPERTIES, INC.

                        By:         /s/  R. TOBER               
                           ------------------------------------- (Seal)
                        Title:            PRESIDENT                             
                              ---------------------------------- (Seal)


Executed at 128 Sandy Bank Drive, Newark, DE 19713 on June 7, 1991.


[CORPORATE SEAL]        LESSEE:  /s/  TSD BioServices                         
                               --------------------------------- (Seal)
                                 a Delaware general partnership,
                                 its general partners

                                       20

<PAGE>

                        STRATEGIC DIAGNOSTICS VENTURES, INC. 

                        By:   /s/   MARTHA C. REIDER                     (Seal)
                           ------------------------------------- (Seal)
                        Title:        Vice President                           
                              ---------------------------------- (Seal)

                        TACONIC VENTURES, INC.

                        By:   /s/  RICHARD S. PHALEN                     (Seal)
                           ------------------------------------- (Seal)
                        Title:        President                             
                              ---------------------------------- (Seal)

                        STRATEGIC DIAGNOSTICS INCORPORATED

                        By:   /s/   MARTHA C. REIDER                     (Seal)
                           ------------------------------------- (Seal)
                        Title:         Vice President                      
                              ---------------------------------- (Seal)

                        TACONIC FARMS, INC.

                        By:   /s/    RICHARD S. PHELAN                   (Seal)
                           ------------------------------------- (Seal)
                        Title:        President                             
                              ---------------------------------- (Seal)

                                       21


<PAGE>

                             ADDENDUM TO INDUSTRIAL LEASE

         This Addendum to the Industrial Lease (the "Industrial Lease") , 
dated, for reference purposes only June 7, 1991, is made by and between TOBER 
& AGNEW PROPERTIES, INC. , a Delaware corporation (herein called "Lessor") 
and TSD BioServices, a Delaware general partnership (herein called "Lessee") 
, Strategic Diagnostics Incorporated (herein called "SDI") and Taconic Farms 
Inc. (herein called "Taconic") . The "Industrial Lease" is that lease 
agreement dated as of this same date made by and between the Lessor and the 
Lessee.  All capitalized terms used herein and not defined herein shall have 
the same meaning as set forth in the Industrial Lease.

    1.   Lessor's Obligation to Construct Tenant Improvement Work.

         (a)  Lessor hereby covenants and agrees to commence the Tenant 
improvement work immediately upon execution of the lease and to complete the 
Tenant improvement Work in as expeditious a manner as possible in accordance 
with all applicable standards of care and diligence.

         (b)  Lessor represents and warrants that it has available to it the 
financial resources and personnel and that it possesses the expertise to 
commence construction of the Tenant Improvement Work and to complete it in 
accordance with the covenants made in subparagraph (a),

         (c)  Any breach of the representations, warranties and covenants 
contained in this Addendum to the Industrial Lease shall constitute a 
material breach of the Industrial Lease.  In the event of such breach, Lessee 
may terminate the Industrial Lease.

    2.   Payment for Tenant Improvement work

         (a)  All costs (up to a maximum of $300,000 in the Aggregate for 
those items described in Sections 2(b)(i) and 2(b)(iii) herein) for Tenant 
Improvement Work (#Tenant Improvement Costs"), as defined by Section 2(b) 
herein, shall be financed by the Lessor and paid for by the Lessee.  All 
Tenant Improvement Costs shall be paid in full by the Lessee in monthly 
installments over the five (5) year period immediately following the 
Commencement Date.

         (b)  Tenant Improvement Costs shall be the following costs directly 
associated with the work depicted or described in Exhibit B of the Industrial 
Lease:

              (i)  supplier and subcontractor costs,  professional fees 
including, but not limited to, architectural fees, permits and inspection 
costs incurred after February 22, 1991;

              (ii) a ten percent (10%) surcharge on those costs described in 
the foregoing Section 2(b)(i);


                                       22

<PAGE>

              (iii)     the following costs relating to the acquisition of 
financing for the Tenant Improvement Work:

                   A.   loan origination fees;

                   B.   other loan costs, including, but not limited to, 
legal and recording costs and document preparation fees;

                   C.   bank appraisal fees; and 

                   D.   interest on all loans undertaken by the Lessor prior 
to the Commencement Date to finance the Tenant Improvement Work.

         (c)  Interest of eleven percent (11%) per annum shall be charged on 
all costs associated with the items described in the foregoing Sections 
2(b)(i) - (iii).

         (d)  SDI and Taconic hereby guarantee, jointly and severally, the 
payments due from the Lessee for all Tenant Improvement Costs required by 
this Addendum to the Industrial Lease.

         (e)  Beginning with the first year following the tenth anniversary 
of the Commencement Date, the Base Rent, as defined in Section 5 of the 
Industrial Lease and as adjusted therein, as it is applied to that portion of 
the Premises subject to the Tenant Improvement Work (the "Improvement Work 
Base Rent"), shall be increased by $1.50 per square foot plus the product of 
(i) $1.50 (as adjusted in the prior year in accordance with this 
subparagraph) multiplied by (ii) the lesser of (A) five percent 5% or (B) a 
fraction, the numerator of which is the Price Index -for the Adjustment Month 
and the denominator of which is the Base Index (but in no event shall such 
increase be less than 4%); provided that the ceiling and floor limitations 
for the escalation of the Improvement Work Base Rent in this Section 2(e)(ii) 
shall not apply following the fifteenth anniversary of the Commencement Date.

The parties hereto have executed this Lease at the Place and on the dates 
specified immediately adjacent to their respective signatures.

Executed at 128 Sandy Bank Drive, Newark, DE 19713 on June 7, 1991.

                        LESSOR: TOBER & AGNEW PROPERTIES, INC.

                        By:         /s/  R. TOBER                        (Seal)
                           ------------------------------------- (Seal)

                        Title:            PRESIDENT                         
                              ---------------------------------- (Seal)


                                       23



<PAGE>

Executed at 128 Sandy Bank Drive, Newark, DE 19713 on June 7, 1991.


[CORPORATE SEAL]        LESSEE:   /s/  TSD BioServices                      
                               --------------------------------- (Seal)
                                 a Delaware general partnership,
                                 its general partners


                        STRATEGIC DIAGNOSTICS VENTURES, INC. 

                        By:   /s/   MARTHA C. REIDER                     (Seal)
                           ------------------------------------- (Seal)
                        Title:           Vice President                      
                              ---------------------------------- (Seal)


                        TACONIC VENTURES, INC.

                        By:    /s/  RICHARD                              (Seal)
                           ------------------------------------- (Seal)
                        Title:           President                       
                              ---------------------------------- (Seal)


                        STRATEGIC DIAGNOSTICS INCORPORATED

                        By:   /s/   MARTHA C. REIDER             (Seal)
                           ------------------------------------- (Seal)
                        Title:            Vice President                       
                              ---------------------------------- (Seal)


                        TACONIC FARMS, INC.

                        By:   /s/    RICHARD W. PHELAN           (Seal)
                           ------------------------------------- (Seal)
                        Title:           President                            
                              ---------------------------------- (Seal)
     

                                       24






<PAGE>


Exhibit 21.1  Subsidiaries of the Registrant


    Name of Subsidiary        Jurisdiction of Organization    Year of Formation
    -----------------         ----------------------------    -----------------

    EnSys (Europe) Limited    United Kingdom                  1993

    TSD BioServices, Inc.     Delaware                        1996

<PAGE>

Exhibit 24     Consent of Arthur Andersen LLP

As independent public accountants, we hereby consent to the incorporation of 
our report included in this Form 10-K, into the Company's previously filed 
Registration Statements on Form S-8 (No. 333-20421) and on Form S-8 
(No. 333-21211) of Strategic Diagnostics Inc. (formerly EnSyS Enviromental 
Products, Inc.).

                                                 Arthur Andersen LLP


Philadelphia, Pa.,
 April 10, 1997  

<TABLE> <S> <C>

<PAGE>
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<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1996
<PERIOD-START>                             JAN-01-1996
<PERIOD-END>                               DEC-31-1996
<CASH>                                             917
<SECURITIES>                                     5,710
<RECEIVABLES>                                    2,514
<ALLOWANCES>                                       180
<INVENTORY>                                      1,557
<CURRENT-ASSETS>                                11,028
<PP&E>                                           1,266
<DEPRECIATION>                                     538
<TOTAL-ASSETS>                                  14,581
<CURRENT-LIABILITIES>                            3,858
<BONDS>                                              0
                                0
                                         22
<COMMON>                                           131
<OTHER-SE>                                           0
<TOTAL-LIABILITY-AND-EQUITY>                    14,581
<SALES>                                          3,402
<TOTAL-REVENUES>                                 5,837
<CGS>                                                0
<TOTAL-COSTS>                                   14,411
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                    81
<INTEREST-EXPENSE>                                   3
<INCOME-PRETAX>                                (8,388)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                            (8,388)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   (8,388)
<EPS-PRIMARY>                                   (2.12)
<EPS-DILUTED>                                        0
        

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