<PAGE>

                          SECURITIES AND EXCHANGE COMMISSION
                                Washington, D.C. 20549
                             -----------------------------
                                      FORM 10-Q


(Mark One)
    [X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
EXCHANGE ACT OF 1934    For the Quarterly Period Ended June 30, 1997

    [  ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
EXCHANGE ACT OF 1934    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

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


                 Former Name, Former Address and Former Fiscal Year,
                         if Changed Since Last Report:  None


    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
                                               ---       ---
    As of June 30, 1997 there were 13,089,949  outstanding shares of the
Registrant's common stock, par value $.01 per share. 

<PAGE>
                           STRATEGIC DIAGNOSTICS INC.
                                     INDEX
 
<TABLE>
<CAPTION>
ITEM                                                                                                            PAGE
-----------------------------------------------------------------------------------------------------------     -----
<S>                                                                                                          <C>
PART I.....................................................................................................           1
    ITEM 1. Financial Statements (Unaudited)...............................................................           1
        Consolidated Balance Sheets--December 31, 1996 and June 30, 1997...................................           1
        Consolidated Statements of Operations--Three months and six months ended June 30, 1996 and 1997....           2
        Consolidated Statements of Cash Flows--Six months ended June 30, 1996 and 1997.....................           3
        Notes to Consolidated Interim Financial Statements.................................................           4
    ITEM 2. Management's Discussion and Analysis of Financial Condition and Results of Operations..........          10
PART II....................................................................................................          18
    ITEM 4. Submission of Matters to a Vote of Securities Holders..........................................          18
    ITEM 6. Exhibits and Reports on Form 8-K...............................................................          18
SIGNATURES.................................................................................................          19
</TABLE>
 
<PAGE>
                                     PART I
 
ITEM 1. FINANCIAL STATEMENTS
 
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
                          CONSOLIDATED BALANCE SHEETS
                       (IN THOUSANDS, EXCEPT SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                             DECEMBER
                                                                                                31,       JUNE 30,
                                                                                               1996         1997
                                                                                            -----------  -----------
<S>                                                                                         <C>          <C>
                                                                                                         (UNAUDITED)
ASSETS
CURRENT ASSETS:
  Cash and cash equivalents...............................................................   $     917    $     803
  Short-term investments..................................................................       5,710        3,690
  Receivables, less allowance for doubtful accounts of $180...............................       2,334        3,434
  Inventories.............................................................................       1,557        1,779
  Other current assets....................................................................         510          274
      Total current assets................................................................      11,028        9,980
PROPERTY AND EQUIPMENT:
  Equipment...............................................................................       1,002        1,024
  Furniture and fixtures..................................................................          66           66
  Leasehold improvements..................................................................         198          221
                                                                                                 1,266        1,311
  Less Accumulated depreciation and amortization..........................................        (538)        (764)
      Net property and equipment..........................................................         728          547
OTHER ASSETS:
  Note receivable and other assets........................................................         715          716
  Intangible assets.......................................................................       2,110        1,971
      Total other assets..................................................................       2,825        2,687
                                                                                             $  14,581    $  13,214
LIABILITIES AND STOCKHOLDERS' EQUITY CURRENT LIABILITIES:
  Accounts payable........................................................................   $   1,566    $     697
  Accrued expenses........................................................................       2,066        1,178
  Deferred revenue........................................................................         141          114
  Current portion of capital lease obligations............................................          85           42
      Total current liabilities...........................................................       3,858        2,031
CAPITAL LEASE OBLIGATIONS.................................................................          50           50
COMMITMENTS AND CONTINGENCIES STOCKHOLDERS' EQUITY:
  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           22
  Common stock, $.01 par value, 35,000,000 shares authorized, 13,055,170 and 13,089,949
    issued and outstanding at December 31, 1996 and June 30, 1997 (unaudited),
    respectively..........................................................................         131          131
  Additional paid-in capital..............................................................      23,905       23,905
  Accumulated deficit.....................................................................     (13,379)     (12,919)
  Deferred compensation...................................................................          (6)          (6)
      Total stockholders' equity..........................................................      10,673       11,133
                                                                                             $  14,581    $  13,214
</TABLE>
 
        The accompanying notes are an integral part of these statements.

                                     1

<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
                     CONSOLIDATED STATEMENTS OF OPERATIONS
                (IN THOUSANDS, EXCEPT SHARE AND PER SHARE DATA)
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                                    THREE MONTHS               SIX MONTHS
                                                                   ENDED JUNE 30             ENDED JUNE 30,
                                                              ------------------------  ------------------------
<S>                                                           <C>         <C>           <C>         <C>
                                                                 1996         1997         1996         1997
                                                              ----------  ------------  ----------  ------------
NET REVENUES:
  Product Related...........................................  $      625  $      3,103  $    1,225  $      5,506
  Contract and other........................................         525           395       1,094           766
      Total net revenues....................................       1,150         3,498       2,319         6,272
OPERATING EXPENSES:
  Manufacturing.............................................         511         1,440         928         2,250
  Research and development..................................         374           409         782           903
  Selling, general and administrative.......................         248         1,358         452         2,788
      Total operating expenses..............................       1,133         3,207       2,162         5,941
      Operating income......................................          17           291         157           331
INTEREST INCOME, NET........................................           4            60           8           129
EQUITY INCOME OF TSD BIOSERVICES............................          90       --              163       --
NET INCOME (LOSS)...........................................         111           351         328           460
ACCRETION OF REDEEMABLE CONVERTIBLE PREFERRED STOCK
  LIQUIDATION VALUE.........................................        (159)      --             (318)      --
NET INCOME APPLICABLE TO COMMON STOCKHOLDERS................  $      (48) $        351  $       10  $        460
NET INCOME PER SHARE APPLICABLE TO COMMON STOCKHOLDERS......  $     (.01) $        .02  $        0  $        .03
SHARES USED IN COMPUTING NET INCOME (LOSS) PER SHARE
  APPLICABLE TO COMMON STOCKHOLDERS.........................   3,464,000    15,520,000   3,464,000    15,553,000
</TABLE>
 
        The accompanying notes are an integral part of these statements.

                                     2

<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                                                                     SIX MONTHS ENDED
                                                                                                         JUNE 30,
                                                                                                   --------------------
<S>                                                                                                <C>        <C>
                                                                                                     1996       1997
                                                                                                   ---------  ---------
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income.......................................................................................  $     328  $     460
Adjustments to reconcile net income to cash used in operating
Depreciation and amortization....................................................................         92        365
Amortization of deferred compensation............................................................         33     --
(Increase) decrease in-
  Receivables....................................................................................       (295)    (1,100)
  Inventories....................................................................................        (75)      (222)
  Other current assets...........................................................................        (17)       236
  Note receivable and other assets...............................................................       (233)        (1)
Increase (decrease) in-
  Accounts payable...............................................................................         67       (869)
  Accrued expenses...............................................................................        115       (888)
  Deferred revenue...............................................................................       (201)       (27)
  Net cash used in operating activities..........................................................       (186)    (2,046)
CASH FLOWS FROM INVESTING ACTIVITIES:
  Purchases of property and equipment............................................................        (28)       (45)
  Short-term investment activity, net............................................................     --           2020
  Net cash provided by investing activities......................................................        (28)     1,975
CASH FLOWS FROM FINANCING ACTIVITIES:
  Proceeds from sale of redeemable convertible preferred stock, net..............................        473     --
  Repayments on capital lease obligations........................................................     --            (43)
  Net cash provided by (used in) financing activities............................................        473        (43)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS.............................................        259       (114)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD...................................................         35        917
CASH AND CASH EQUIVALENTS, END OF PERIOD.........................................................  $     294  $     803
SUPPLEMENTAL CASH FLOW DISCLOSURE:
Cash paid for interest...........................................................................  $       2  $      21
</TABLE>
 
        The accompanying notes are an integral part of these statements.

                                     3

<PAGE>
                  STRATEGIC DIAGNOSTICS INC. AND SUBSIDIARIES
 
               NOTES TO CONSOLIDATED INTERIM FINANCIAL STATEMENTS
          (IN THOUSANDS, EXCEPT SHARE AND PER SHARE DATA) (UNAUDITED)
 
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 for at least the next 18 months.
 
BASIS OF PRESENTATION AND INTERIM FINANCIAL STATEMENTS
 
    The accompanying balance sheets at December 31, 1996 and June 30, 1997, and
the statements of operations for the three months and six months ended June 30,
1996 and 1997 and cash flows for the six months ended June 30, 1996 and 1997
include the consolidated financial statements of the Company. All intercompany
balances and transactions have been eliminated in consolidation. For comparative
purposes, the statements of operations for the three months and six months ended
June 30, 1996 and 1997 and cash flows for the six months ended June 30, 1996 and
1997 include Strategic Diagnostics Inc. ("SDI") prior to its acquisition of
Ohmicron Corporation ("Ohmicron"), which occurred on August 30, 1996 (Note 3),
the dissolution of TSD BioServices which occurred on October 15, 1996 (Note 3)
and its merger with EnSys Environmental Products, Inc. ("EnSys") which occurred
on December 30, 1996 (Note 3). Also presented where indicated, is selected pro
forma information for the three months and six months ended June 30, 1996, which
includes SDI, Ohmicron and EnSys as if the EnSys and Ohmicron transactions had
occurred on January 1, 1996.
 
    The accompanying unaudited consolidated interim financial statements of the
Company have been prepared by the Company pursuant to the rules and regulations
of the Securities and Exchange Commission regarding financial reporting.
Accordingly, they do not include all the information and footnotes required by
generally accepted accounting principles for complete financial statements and
should be read in conjunction with the Company's Annual Report on Form 10-K for
the fiscal year ended December 31, 1996. In the opinion of management, the
accompanying financial statements include all adjustments (all of which are of a
normal recurring nature) necessary for a fair presentation. 

                                     4

<PAGE>

The results of operations for the three months and six months ended June 30, 
1997 are not necessarily indicative of the results expected for the full year.
 
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. NET INCOME PER SHARE APPLICABLE TO COMMON STOCKHOLDERS:
 
    Net income per share applicable to common stockholders for all periods
presented is calculated by dividing net income 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 EnSys Merger discussed in Note
3. This retroactive adjustment is reflected in the net income per share
calculations and the Notes to the Consolidated Interim Financial Statements.
 
    Net income applicable to common stockholders is the sum of the net income
less 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 6). No additional accretion will be recorded.
 
3. MERGERS AND ACQUISITIONS
 
MERGER WITH ENSYS ENVIRONMENTAL PRODUCTS, INC.
--------------------------------------------------
 
    On December 30, 1996, SDI 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, 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.

                                     5

<PAGE> 

    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 acquiror 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 "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, ("Accounting for Research and
Development Costs," "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 are being amortized on a straight-line basis over
7-10 years. Amortization expense included in selling, general and administrative
in the accompanying consolidated statement of operations, for the six months
ended June 30, 1997 is approximately $68 related to the merger.
 
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 

                                     6

<PAGE>

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. 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 are being amortized on a 
straight-line basis over 7-10 years. Amortization expense included in 
selling, general and administrative in the accompanying consolidated 
statement of operations for the six months ended June 30, 1997 is 
approximately $38. 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.
 
    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 was treated as a purchase, with the consideration
provided being SDI's investment of $338 which approximated the fair market value
of the assets received.

                                     7

<PAGE>
 
UNAUDITED PRO FORMA COMBINED RESULTS OF OPERATIONS
-----------------------------------------------------
 
    The following table summarizes the unaudited pro forma combined results of
operations for the three months and six months ended June 30, 1996, assuming
that the Merger, the Ohmicron acquisition and the TSD BioServices dissolution
had occurred on January 1, 1996:
 
<TABLE>
<CAPTION>
                                                                           THREE MONTHS ENDED   SIX MONTHS ENDED
                                                                              JUNE 30, 1996       JUNE 30, 1996
                                                                           -------------------  -----------------
<S>                                                                        <C>                  <C>
Net Revenues.............................................................       $   3,770           $   6,626
Net loss.................................................................       $    (532)          $  (2,134)
Net loss per share.......................................................       $    (.04)          $    (.16)
</TABLE>
 
    The above pro forma information excludes the $1,700 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).
 
4. SHORT-TERM INVESTMENTS:
 
<TABLE>
<CAPTION>
                                                                                  DECEMBER 31, 1996  JUNE 30, 1997
                                                                                  -----------------  -------------
<S>                                                                               <C>                <C>
Cash equivalents................................................................      $   3,502        $   2,210
Securities of agencies of the U.S. Government...................................            686           --
Commercial paper................................................................          1,522            1,480
                                                                                         ------           ------
                                                                                      $   5,710        $   3,690
                                                                                         ------           ------
                                                                                         ------           ------
</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.
 
5. NOTES PAYABLE:
 
    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.

                                     8

<PAGE>
 
    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 6).
 
6. 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 6) 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.
 
    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.
 
                                       9

<PAGE>

ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
  RESULTS OF OPERATIONS
 
FORWARD LOOKING STATEMENTS
 
    The information included in this report on Form 10-Q contains forward
looking statements reflecting the current expectations of Strategic Diagnostics
Inc. and its subsidiaries (the "Company"). Investors are cautioned that all
forward looking statements involve risks and uncertainties, that 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 to integrate
the acquired businesses and achieve anticipated synergies, and competition.
 
BACKGROUND
 
    The Company is the entity resulting from the combination of EnSys
Environmental Products, Inc. ("EnSys"), Ohmicron Corporation ("Ohmicron"), TSD
BioServices ("TSD") and Strategic Diagnostics Inc. ("SDI"). On August 30, 1996
Ohmicron was acquired by SDI, with certain Ohmicron shareholders and note
holders receiving shares of SDI common stock. On October 1, 1996 SDI entered
into an agreement to dissolve TSD BioServices, a partnership, between Taconic
Farms, Inc. and SDI and to liquidate its assets, in connection with which
certain rights and assets formerly owned by the partnership were distributed to
SDI and placed in a wholly owned subsidiary of SDI. On December 30, 1996 SDI was
merged with and into EnSys. The surviving entity was then renamed Strategic
Diagnostics Inc. Each of the 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 unaudited historical
financial information presented herein includes the results of SDI for all
periods and the results of Ohmicron from August 30, 1996, TSD from October 1,
1996, and EnSys from December 30, 1996, (the "Historical Financial Statements").
 
    EnSys was formed in 1984 to develop proprietary biotechnology based test
systems designed for 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 US. 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, Inc. 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 million and 1,100,000 shares of EnSys common
stock.

                                     10

<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 contact with a corporate
partner (a large integrated chemical company) 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, Inc. (an affiliate of Merck KGaA, Darmstadt,
Germany) 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, Inc. In
September 1996, EM Industries, Inc. and SDI reached an agreement whereby the
February 1992 agreement was terminated, together with EM Industries, Inc.'s
marketing rights thereunder, in exchange for certain specified royalty payments
to EM Industries, Inc. and shares of SDI common stock. The marketing activities
with respect to such products are now the responsibility of the Company.
 
    Since 1992, the Company 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 that it has developed or
acquired.
 
RESULTS OF OPERATIONS
 
    As described above, the Historical Financial Statements presented herein
include the results of SDI for all periods and the results of Ohmicron from
August 30, 1996, TSD from October 1, 1996 and EnSys from December 30, 1996.
 
    For comparative purposes, the following table sets forth the pro forma
results of operations for the periods indicated. The 1996 unaudited pro forma
information presents the combined results as if the acquisition of Ohmicron,
dissolution of TSD and the EnSys merger had been completed at January 1, 1996
(the "Pro Forma Financial Information").

                                     11

<PAGE>
 
<TABLE>
<CAPTION>
                                                               SELECTED PRO FORMA AND HISTORICAL COMBINED INFORMATION
                                                 -----------------------------------------------------------------------------------
                                                                    THREE MONTHS ENDED                          SIX MONTHS ENDED
                                                 ---------------------------------------------------------  ------------------------
                                                                                           HISTORICAL                    HISTORICAL
                                                             PRO FORMA                --------------------   PRO FORMA   -----------
                                                  JUN.96    SEPT.96 (1)  DEC.96 (2)    MAR.97     JUN.97     JUN.96(3)     JUN.97
                                                 ---------  -----------  -----------  ---------  ---------  -----------  -----------
<S>                                              <C>        <C>          <C>          <C>        <C>        <C>          <C>
NET REVENUES:
  Product related..............................  $   3,247   $   3,049    $   2,310   $   2,402  $   3,103   $   5,575    $   5,506
  Contract and other...........................        523         422          293         371        395       1,051          766
                                                 ---------  -----------  -----------  ---------  ---------  -----------  -----------
    Total net revenues.........................      3,770       3,471        2,603       2,773      3,498       6,626        6,272
OPERATING EXPENSES:
  Manufacturing................................      1,413       1,590        1,652         809      1,440       2,705        2,250
  Research & Development.......................        920         657          591         494        409       2,084          903
Selling, general and administrative............      2,107       1,682        2,320       1,430      1,358       4,280        2,788
                                                 ---------  -----------  -----------  ---------  ---------  -----------  -----------
  Total operating expenses.....................      4,440       3,929        4,563       2,733      3,207       9,069        5,941
                                                 ---------  -----------  -----------  ---------  ---------  -----------  -----------
  Operating income.............................       (670)       (458)      (1,960)         40        291      (2,443)         331
INTEREST INCOME NET............................        139         158          122          69         60         309          129
                                                 ---------  -----------  -----------  ---------  ---------  -----------  -----------
    NET INCOME.................................  ($    531)  ($    300)   ($  1,838)  $     109  $     351   ($  2,134)   $     460
                                                 ---------  -----------  -----------  ---------  ---------  -----------  -----------
                                                 ---------  -----------  -----------  ---------  ---------  -----------  -----------
</TABLE>
 
------------------------
 
(1) Pro forma data excludes $3.9 million of acquired research and development
    expenses incurred in connection with the acquisition of Ohmicron.
 
(2) Pro forma data excludes $4.4 million of acquired research and development
    expenses incurred in connection with the acquisition of EnSys.
 
(3) Pro forma data results excludes $1.7 million of acquired research and
    development expenses incurred in connection with the acquisition of the
    EnviroGard product line from Millipore, Inc. in March 1996. See the
    Historical Financial Information for 1996 actual results.
 
COMPARISON WITH PRO FORMA FINANCIAL INFORMATION
 
THREE MONTHS ENDED JUNE 30, 1997 VS. 1996
 
    Product related revenues from the Company's emerging markets for genetic
testing of agricultural products and water quality tests (referred to herein as
"Emerging Markets") increased during the three month period ended June 30, 1997
by more than 25%, combined, over the comparable period in 1996. This increase
reflects that sales of selected products in these categories are beginning to
reach commercial scale. These increases were offset by a small decrease in the
Company's industrial testing business. This decrease was primarily due to the
consolidation of duplicative and low-volume product lines previously sold by
each of the separate companies prior to the merger. Overall, product related
revenues decreased in the period by $144,000 (4%) to $3.1 million. During the
1997 second quarter, the Company entered into a development and supply agreement
for a large seed manufacturer to purchase more than one million test strips
primarily in the second half of 1997. The Company expects product related
revenues to increase in 1997 as Emerging Markets continue to develop and as
other customer need driven sales and marketing initiatives reach the market
place.

                                     12

<PAGE>
 
    Approximately 45% of the Company's product related revenues in 1997 is, and
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.
 
    Contract and other revenues decreased by $128,000 (24%) to $395,000 during
the quarter reflecting the Company's emphasis to increase revenues by marketing
developed products over additional research and development projects. Research
and development contracts continue to be integral to the Company's operations,
however, the proportion of these activities to the Company's total is expected
to decline. Contract and other revenues are expected to remain at approximately
the second quarter 1997 levels. These contracts historically have been large and
long-term in nature. Accordingly, such revenues tend to fluctuate from
quarter-to-quarter.
 
    Total operating expenses decreased $1.2 million (28%) from the prior period
to $3.2 million. This decrease results primarily from lower costs associated
with more efficient operations of the combined companies after the mergers. The
combined Company has a lower level of personnel costs compared with each of the
separate companies combined. At June 30, 1997, the Company had approximately 100
employees versus 200 employees on a combined basis at June 30, 1996.
Efficiencies were also achieved as duplicate facilities were closed. The
operations in North Carolina and portions of the Pennsylvania operation have
been consolidated into the Company's Delaware facility.
 
    Manufacturing expenses include the costs of products sold and increased
$27,000 (2%) in 1997 to $1.4 million. This increase is due to the inclusion of
approximately $100,000 of certain overhead expenses previously reported in
selling, general and administrative expenses to conform to current
classifications. Gross margins as a percent of revenue were approximately equal
to the prior year before this reclassification. The Company expects gross profit
margins to increase in 1997 due to an increase in the sales of its products,
efficiencies gained through consolidation and the elimination of product sales
at cost to EM Industries, Inc. that occurred in 1996.
 
    Research and development expenses decreased $511,000 (56%) to $409,000. 
This decrease is attributable to the consolidation of research and 
development projects under way during the first half of 1996 as well as the 
factors noted above. These expenses are expected to increase over the second 
quarter 1997 levels to approximately the amounts expended during the first 
quarter of 1997.
 
    Selling, general and administrative expenses decreased $749,000 (36%) to
$1.4 million. The decrease is due to the items noted above. These expenses are
expected to increase to slightly more than the amounts expended during the first
quarter of 1997.
 
    Net interest income decreased $79,000 (57%) to $60,000. This decrease is
attributable primarily to a lower average balance of investments at June 30,
1997. Net interest income is expected to be about the same as the second quarter
amount for the balance of 1997.

                                     13

<PAGE>
 
    The net income for the three month period ended June 30, 1997 was $351,000
compared to the net loss of $531,000 for the three month period ended June 30,
1996. Net income was primarily a result of sharply lower costs and expenses on
approximately the same volume of revenue, all as described above.
 
SIX MONTHS ENDED JUNE 30, 1997 VS. 1996
 
    Overall, product related revenues decreased in the six-month period ended
June 30, 1997 by $69,000 (1%) to $5.5 million compared to the comparable period
in the prior year. Product related revenues from the Company's Emerging Markets
for genetic testing of agricultural products and water quality tests increased
by approximately 36% during the period over 1996 as the Company's products in
these categories began to reach commercial scale and for the reasons previously
discussed. These increases were offset by a small decrease in the Company's
industrial testing business. This decrease was primarily due to the
consolidation of duplicative and low-volume product lines previously sold by
each of the separate companies prior to the merger. The Company expects product
related revenues to increase further in 1997 as Emerging Markets continue to
develop and as other customer need driven sales and marketing initiatives reach
the marketplace.
 
    Contract and other revenues decreased by $285,000 (27%) to $766,000 during
the period reflecting the Company's emphasis to increase revenues by marketing
developed products over additional research and development projects as
previously discussed. Contract and other revenues are expected to remain at
approximately the second quarter 1997 levels. These contracts historically have
been large and long-term in nature. Accordingly, such revenues tend to fluctuate
from period-to-period.
 
    Total operating expenses decreased $3.1 million (35%) from the prior period
to $5.9 million. This decrease results primarily from lower costs associated
with more efficient operations of the combined companies after the mergers as
previously discussed.
 
    Manufacturing costs decreased $455,000 (17%) from the prior period to $2.3
million. This decrease results primarily from lower costs associated with more
efficient operations of the combined companies after the mergers as previously
discussed. Gross margins increased $386,000 (13%) to $3.3 million. These margins
for the first half of 1997 were approximately 59% of revenues. The increase in
gross margins for the first half of 1997 result primarily from the efficiencies
and other factors described above. Margins, as a percent of revenue, for the
second half of 1997 are expected to be approximately equal to those in the first
half.
 
    Research and development costs decreased $1.2 million (57%) from the prior
period to $903,000. This decrease is attributable to the consolidation of an
EnSys research and development project underway during the first half of 1996 as
well as other factors noted above.

    Selling, general and administrative costs decreased $1.5 million (35%) from
the prior period to $2.8 million. These decreases are attributable to increased
efficiencies from the mergers as described above.

                                     14

<PAGE>
 
    Net interest income decreased $180,000 (58%) to $129,000. This decrease is
attributable primarily to a lower average balance of investments at June 30,
1997. Net interest income is expected to be slightly lower for the balance of
1997.
 
    The net income for the six month period ended June 30, 1997 was $460,000
compared to the net loss of $2.1 million for the six month period ended June 30,
1996. The net income was primarily a result of the decrease in total operating
expenses due to the combined companies after the mergers as discussed above.
 
HISTORICAL FINANCIAL STATEMENTS
 
    As described above, the Historical Financial Statements presented herein
include the results of SDI for all periods and the results of Ohmicron from
August 30, 1996, TSD from October 1, 1996 and EnSys from December 30, 1996.
 
THREE MONTHS ENDED JUNE 30, 1997 VS. MARCH 31, 1997
 
    Total net revenues increased during the three month period ended June 30,
1997 over the three month period ended March 31, 1997 by $725,000 (26%). Product
related sales increased $701,000 (29%). This increase reflects the favorable
effects of the efforts the Company made during the quarter to stabilize and
further develop customer relationships after the mergers. This increase also was
achieved as demand for the Company's immunoassay based test kits increased
during the second quarter of 1997 due to seasonal factors. Historically, the
second quarter is a strong selling period of the year. Additionally, sales of
the Company's products to the agricultural and water quality market segments
(segments that are less seasonal) continued to be strong.
 
    Total operating expenses increased $474,000 (17%) from the prior period to
$3.2 million. Included in this total, manufacturing costs increased $631,000
(78%) from the prior period to $1.4 million. This increase in manufacturing
costs is due primarily to the higher costs of products sold associated with the
higher sales volume in the second quarter of 1997 and the reclassification of
$100,000 of certain expenses to conform to current classifications. The Company
expects gross profit margins to increase in 1997 due to an increase in the sales
of its products and efficiencies gained through consolidation. Research and
development costs decreased $85,000 (17%) from the prior period to $409,000 due
to a decreased level of activity in the second quarter in comparison to the
first quarter. Selling, general and administrative costs decreased $72,000 (5%)
from the prior period to $1.4 million. The decrease of selling, general and
administrative costs is due to the realization of continued efficiencies from
the combination of SDI, Ohmicron, TSD and EnSys.
 
    Net interest income decreased $9,000 (13%). This decrease is attributable
primarily to a lower average balance of investments at June 30, 1997.

                                     15

<PAGE>
 
    Net income increased $242,000 (122%) to $351,000 in 1997. This increase in
net income results from the higher sales volume and lower expenses, all as
described above.
 
THREE MONTHS ENDED JUNE 30, 1997 VS 1996
 
    Revenues for the period increased by $2.3 million (204%) to $3.5 million
during the three month period ended June 30, 1997 compared to the comparable
period of 1996. Of this total, product related revenues increased $2.5 million
(396%) to $3.1 million and contract and other revenues decreased $130,000 (25%)
to $395,000. The increase in total net revenue and product related revenue is
attributable to the additional products and customers arising from the merger of
SDI, Ohmicron and EnSys. The decrease in contract and other revenue reflects the
decreased emphasis by the Company on research and development contract revenues
in favor of the marketing of developed products as described above.
 
    Total operating expenses increased $2.1 million (183%) to $3.2 million. Of
this total, manufacturing costs increased $929,000 (182%) to $1.4 million,
research and development expenses increased $35,000 (9%) to $409,000 and
selling, general and administrative expenses increased $1.1 million (448%) to
$1.4 million. All of these increases are due to the combination of SDI,
Ohmicron, TSD and EnSys.
 
    Net interest income increased $54,000 to $60,000 during the period. This
increase is due to the investments acquired in the combinations.
 
    Equity in the income of TSD BioServices, a partnership in which SDI was a
general partner, was eliminated in 1997 as TSD was dissolved in 1996 and certain
assets of the partnership were transferred into a wholly owned subsidiary of the
Company.
 
    The net income for the three month period ended June 30, 1997 was $351,000
compared to the net loss of $48,000 for the three month period ended June 30,
1996. The net income was primarily a result of the increase in revenue and
decrease in total operating expenses due to the combined companies after the
mergers as discussed above.
 
SIX MONTHS ENDED JUNE 30, 1997 VS. 1996
 
    Revenues for the period increased by $4 million (170%) to $6.3 million
during the six months ended June 30, 1997 as compared to the comparable period
of 1997. Of this total, product related revenues increased $4.3 million (349%)
to $5.5 million and contract and other revenues decreased $328,000 (30%) to
$766,000. The increase in total net revenue and product related revenue is
attributable to the additional products and customers arising from the merger of
SDI, Ohmicron and EnSys. The decrease in contract and other revenue reflects the
decreased emphasis by the Company on research and development contract revenues
in favor of the marketing of developed products as described above.

                                     16

<PAGE>
 
    Total operating expenses increased $3.8 million (175%) to $5.9 million. Of
this total, manufacturing costs increased $1.3 million (142%) to $2.3 million,
research and development expenses increased $121,000 (15%) to $903,000 and
selling, general and administrative expenses increased $2.3 million (517%) to
$2.8 million. All of these increases are due to the combination of SDI,
Ohmicron, TSD and EnSys.
 
    Net interest income increased $121,000 to $129,000 during the period. This
increase is due to the investments acquired in the mergers.
 
    Equity in income of TSD BioServices (a partnership) was eliminated in 1997
as TSD was dissolved in 1996 and became a wholly owned subsidiary.
 
    The net income for the six month period ended June 30, 1997 was $460,000
compared to the net income $10,000 for the six month period ended June 30, 1996.
The net income was primarily a result of the increase in revenue and decrease in
total operating expenses due to the combined companies after the mergers as
discussed above.
 
LIQUIDITY AND CAPITAL RESOURCES
 
    The Company's working capital which consists principally of cash, cash
equivalents and marketable investments, increased $779,000 from December 31,
1996 to $8 million at June 30, 1997. Cash, cash equivalents and short-term
investments decreased $2.5 million to $4.5 million. This decrease was used to
reduce accounts payable and accrued expenses by $1.8 million and finance
increases in accounts receivable and inventories of $1.3 million and was net of
increases attributable to changes in other current assets and liabilities of
$208,000 and net income of $460,000.
 
    The Company believes that its current cash, cash equivalents and marketable
securities will be sufficient to meet its working capital and 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 its long-term requirements.
 
                                       17

<PAGE>
                                    PART II
 
ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITIES HOLDERS
 
    The Company held its annual meeting of shareholders on May 20, 1997. At the
meeting, the following Class I Directors were elected:
 
<TABLE>
<CAPTION>
DIRECTORS                                                    SHARES VOTED FOR  SHARES WITHHELD
-----------------------------------------------------------  ----------------  ---------------
<S>                                                          <C>               <C>
Grover C. Wrenn............................................       7,856,818          23,051
Richard C. Birkmeyer.......................................       7,856,818          23,051
Kathleen E. Lamb...........................................       7,807,953          71,916
Curtis Lee Smith, Jr.......................................       7,831,818          48,051
</TABLE>
 
ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K
 
(a) Exhibits:
 
    27 Financial Data Schedule (in electronic format only).
 
(b) Reports on Form 8-K
 
    No reports on Form 8-K were filed by the registrant during the quarter
    covered by this report.
 
                                       18

<PAGE>

                                      SIGNATURES

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



                                       STRATEGIC DIAGNOSTICS INC.
                                       --------------------------
                                              (Registrant)   

 

Signature                                  Title                        Date
---------                                  -----                        ----

/s/ RICHARD C. BIRKMEYER
------------------------
    Richard C. Birkmeyer    President and Chief Executive 
                                Officer                          August 12, 1997
                             (Principal Executive Officer)
/s/ ARTHUR A. KOCH, JR.
-----------------------
    Arthur A. Koch, Jr.     Vice President and Chief 
                                Financial Officer                August 12, 1997
                             (Principal Financial Officer)


                                     19