<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 March 31, 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)
                            ------------------------
 
<TABLE>
<S>                                                 <C>
                     DELAWARE                                           56-1581761
         (State or other jurisdiction of                             (I.R.S. employer
          incorporation or organization)                           identification no.)

                 128 SANDY DRIVE                                          19713
                 NEWARK, DELAWARE                                       (Zip Code)
     (Address of principal executive offices)
</TABLE>
 
       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 March 31, 1997 there were 13,057,672 outstanding shares of the
Registrant's common stock, par value $.01 per share.

<PAGE>
                           STRATEGIC DIAGNOSTICS INC.
                                     INDEX
 
<TABLE>
<CAPTION>
       ITEM                                                         PAGE
------------------------------------------------------------------  ----
<S>      <C>    <C>                                                 <C>
PART I............................................................    1
         ITEM 1. Financial Statements (unaudited)..................   1
                Consolidated Balance Sheets.......................    1
                Consolidated Statements of Operations.............    2
                Consolidated Statements of Cash Flows.............    3
                Notes to Consolidated Interim Financial               4
                Statements........................................
         ITEM 2. Management's Discussion and Analysis of Financial   12
                Condition and Results of Operations...............
PART II...........................................................   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>
                                                                                                                  MARCH 31,
                                                                                                 DECEMBER 31,        1997
                                                                                                     1996        (UNAUDITED)
<S>                                                                                             <C>             <C>
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
ASSETS
------------------------------------------------------------------------------------------------------------------------------
CURRENT ASSETS:
  Cash and cash equivalents...................................................................  $          917  $          644
  Short-term investments......................................................................           5,710           4,031
  Receivables, less allowance for doubtful accounts of $180 at December 31, 1996 and March 31,
    1997 (unaudited)..........................................................................           2,334           3,344
  Inventories.................................................................................           1,557           1,674
  Other current assets........................................................................             510             433
------------------------------------------------------------------------------------------------------------------------------
      Total current assets....................................................................          11,028          10,126
------------------------------------------------------------------------------------------------------------------------------
PROPERTY AND EQUIPMENT:
  Equipment...................................................................................           1,002           1,015
  Furniture and fixtures......................................................................              66              66
  Leasehold improvements......................................................................             198             200
------------------------------------------------------------------------------------------------------------------------------
                                                                                                         1,266           1,281
      Less Accumulated depreciation and amortization..........................................            (538)           (651)
------------------------------------------------------------------------------------------------------------------------------
      Net property and equipment..............................................................             728             630
------------------------------------------------------------------------------------------------------------------------------
OTHER ASSETS:
  Note receivable and other assets............................................................             715             717
  Intangible assets, net......................................................................           2,110           2,041
------------------------------------------------------------------------------------------------------------------------------
      Total other assets......................................................................           2,825           2,758
------------------------------------------------------------------------------------------------------------------------------
                                                                                                $       14,581  $       13,514
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
LIABILITIES AND STOCKHOLDERS' EQUITY
------------------------------------------------------------------------------------------------------------------------------
CURRENT LIABILITIES:
  Accounts payable............................................................................  $        1,566  $        1,115
  Accrued expenses............................................................................           2,066           1,369
  Deferred revenue............................................................................             141             133
  Current portion of capital lease obligations................................................              85              65
------------------------------------------------------------------------------------------------------------------------------
      Total current liabilities...............................................................           3,858           2,682
------------------------------------------------------------------------------------------------------------------------------
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 13,057,672 issued
    and outstanding at December 31, 1996 and March 31, 1997 (unaudited), respectively.........             131             131
  Additional paid-in capital..................................................................          23,905          23,905
  Accumulated deficit.........................................................................         (13,379)        (13,270)
  Deferred compensation.......................................................................              (6)             (6)
------------------------------------------------------------------------------------------------------------------------------
      Total stockholders' equity..............................................................          10,673          10,782
------------------------------------------------------------------------------------------------------------------------------
      Total liabilities and stockholders' equity..............................................  $       14,581  $       13,514
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
</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 ENDED MARCH 31,
-------------------------------------------------------------------------------------------------------------------------
                                                                                                   1996          1997
<S>                                                                                             <C>          <C>
-------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------
NET REVENUES:
  Product Related.............................................................................   $     600   $      2,402
  Contract and other..........................................................................         569            371
-------------------------------------------------------------------------------------------------------------------------
      Total net revenues......................................................................       1,169          2,773
-------------------------------------------------------------------------------------------------------------------------
OPERATING EXPENSES:
  Manufacturing...............................................................................         417            809
  Research and development....................................................................         408            494
  Selling, general and administrative.........................................................         204          1,430
-------------------------------------------------------------------------------------------------------------------------
      Total operating expenses................................................................       1,029          2,733
-------------------------------------------------------------------------------------------------------------------------
      Operating income........................................................................         140             40
INTEREST INCOME, NET..........................................................................           4             69
EQUITY IN INCOME OF TSD BIOSERVICES...........................................................          73        --
-------------------------------------------------------------------------------------------------------------------------
NET INCOME....................................................................................         217            109
ACCRETION OF REDEEMABLE CONVERTIBLE PREFERRED STOCK LIQUIDATION VALUE.........................        (159)       --
-------------------------------------------------------------------------------------------------------------------------
NET INCOME APPLICABLE TO COMMON STOCKHOLDERS..................................................   $      58   $        109
-------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------
NET INCOME PER SHARE APPLICABLE TO COMMON STOCKHOLDERS........................................   $     .02   $        .01
-------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------
SHARES USED IN COMPUTING NET INCOME PER SHARE APPLICABLE TO COMMON STOCKHOLDERS...............   3,464,000     15,585,000
-------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------
</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>
                                                                                                THREE MONTHS ENDED MARCH 31,
---------------------------------------------------------------------------------------------------------------------------
                                                                                                     1996          1997
<S>                                                                                              <C>            <C>
---------------------------------------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------------------------------------
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net income...................................................................................    $     217     $     109
  Adjustments to reconcile net income to cash used in operating activities-
    Depreciation and amortization..............................................................           45           182
    Amortization of deferred compensation......................................................           16        --
    (Increase) decrease in-
      Receivables..............................................................................         (157)       (1,010)
      Inventories..............................................................................          (18)         (117)
      Other current assets.....................................................................           (8)           77
      Note receivable and other assets.........................................................           (6)           (2)
    Increase (decrease) in-
      Accounts payable.........................................................................          (21)         (451)
      Accrued expenses.........................................................................          (84)         (697)
      Deferred revenue.........................................................................           32            (8)
---------------------------------------------------------------------------------------------------------------------------
      Net cash provided by (used in) operating activities......................................           16        (1,917)
---------------------------------------------------------------------------------------------------------------------------
CASH FLOWS FROM INVESTING ACTIVITIES:
  Purchases of property and equipment..........................................................       --               (15)
  Short-term investment activity, net..........................................................       --             1,679
---------------------------------------------------------------------------------------------------------------------------
  Net cash provided by investing activities....................................................       --             1,664
---------------------------------------------------------------------------------------------------------------------------
CASH FLOWS FROM FINANCING ACTIVITIES:
  Proceeds from sale of redeemable convertible preferred stock, net............................          473        --
  Repayments on capital lease obligations......................................................       --               (20)
---------------------------------------------------------------------------------------------------------------------------
  Net cash provided by (used in) financing activities..........................................          473           (20)
---------------------------------------------------------------------------------------------------------------------------
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS...........................................          489          (273)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD.................................................           35           917
---------------------------------------------------------------------------------------------------------------------------
CASH AND CASH EQUIVALENTS, END OF PERIOD.......................................................    $     524     $     644
---------------------------------------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------------------------------------
SUPPLEMENTAL CASH FLOW DISCLOSURE:
  Cash paid for interest.......................................................................    $       1     $       8
</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)
 
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 March 31, 1997, 
and the statements of operations and cash flows for the three months ended 
March 31, 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 and 
cash flows for the three months ended March 31, 1996 include Strategic 
Diagnostics Inc. ("SDI") prior to its acquisition of Ohmicron Corporation 
("Ohmicron"), which occurred on August 30, 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 ended March 31, 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. The results of
operations for the three months ended March 31, 1997 are not necessarily
indicative of the results expected for the full year.
 
                                       4
<PAGE>
    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 7). No additional accretion will be recorded.
 
   
                                       5
<PAGE>
 
 
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,
 
                                       6
<PAGE>
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 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. 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 three months ended March 31, 1997 is
approximately $34.
 
                                       7
<PAGE>
    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 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 three months
ended March 31, 1997 is approximately $19. 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. Recent equity
transactions included the January 2, 1996 sale of 897,154 shares of redeemable
convertible preferred stock at $2.37 per share.
 
    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
 
                                       8
<PAGE>
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.
 
    UNAUDITED PRO FORMA COMBINED RESULTS OF OPERATIONS
 
    The following table summarizes the unaudited pro forma combined results of
operations for the three months ended March 31, 1996, assuming that the Merger,
the Ohmicron acquisition and the TSD BioServices dissolution had occurred on
January 1, 1996:
 
<TABLE>
<S>                                                                            <C>
Revenues.....................................................................  $   2,856
Net loss.....................................................................  $  (1,603)
Net loss per share...........................................................  $    (.12)
</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         March 31,
                                                                                                     1996              1997
                                                                                                 -------------    -------------
                                                                                                                   (UNAUDITED)
<S>                                                                                               <C>             <C>
Cash equivalents................................................................................  $   3,502          $   2,347 
Securities of agencies of the U.S. Government...................................................        686                 79 
Commercial paper................................................................................      1,522              1,605 
                                                                                                  ---------        ------------
                                                                                                  $   5,710          $   4,031 
                                                                                                  ---------        ------------
                                                                                                  ---------        ------------
</TABLE>
 
                                       9
<PAGE>
    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.
 
    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 7).
 
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).
 
                                       10
<PAGE>
    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.
 
                                       11

<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"), and
Strategic Diagnostics Inc. ("SDI"). On August 30, 1996 Ohmicron was merged with
and into SDI, with certain Ohmicron shareholders 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
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 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.
 
    Ohmicron was founded in 1984 and began marketing its RaPID
Assay-Registered -TM- products in 1991 to the same general market and in
the same fashion as previously described for EnSys.
 
                                       12
<PAGE>
    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 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 mergers with EnSys and
Ohmicron had been completed at January 1, 1996 and includes the results of
operations of SDI prior to the mergers, Ohmicron and EnSys, (the "Pro Forma
Financial Information").
 
                                       13
<PAGE>
           SELECTED FINANCIAL DATA AND PRO FORMA COMBINED INFORMATION
 
<TABLE>
<CAPTION>
                                                                         THREE MONTHS ENDED
                                                    ------------------------------------------------------------
<S>                                                 <C>            <C>       <C>           <C>          <C>
                                                                         PRO FORMA                      ACTUAL
                                                    -------------------------------------------------   --------
                                                    MARCH-96 (1)   JUNE-96   SEPT-96 (2)   DEC-96 (3)   MARCH-97
                                                    ------------   -------   -----------   ----------   --------
NET REVENUES:
Product related...................................     2,328        3,247       3,049         2,310      2,402
Contract and other................................       528          523         422           293        371
                                                      ------       -------      -----      ----------   --------
      Total net revenues..........................     2,856        3,770       3,471         2,603      2,773
                                                      ------       -------      -----      ----------   --------
OPERATING EXPENSES:
Manufacturing.....................................     1,292        1,413       1,590         1,652        809
Research & development............................     1,164          920         657           591        494
Selling, general and administrative...............     2,173        2,107       1,682         2,320      1,430
                                                      ------       -------      -----      ----------   --------
      Total Operating expenses....................     4,629        4,440       3,929         4,563      2,733 
                                                      ------       -------      -----      ----------   --------
Operating income..................................    (1,773)        (670)       (458)       (1,960)        40
INTEREST INCOME, NET..............................       170          139         158           122         69
                                                      ------       -------      -----      ----------   --------
NET INCOME........................................    (1,603)        (531)       (300)       (1,838)       109
                                                      ------       -------      -----      ----------   --------
                                                      ------       -------      -----      ----------   --------
</TABLE>
 
------------------------
 
(1) Pro forma data excludes $1.7 million of acquired research and development
    expenses incurred in connection with the acquisition of the EnviroGard-TM-
    product line from Millipore, Inc. in March 1996. See the Historical
    Financial Information for 1996 actual results.
 
(2) Pro forma data excludes $3.9 million of acquired research and development
    expenses incurred in connection with the acquisition of Ohmicron.
 
(3) Pro forma data excludes $4.4 million of acquired research and
    development expenses incurred in connection with the acquisition of EnSys.
 
PRO FORMA FINANCIAL INFORMATION
 
    THREE MONTHS ENDED MARCH 31, 1997 VS 1996
 
    Product related revenues increased in the period by $74,000 (3%) to
approximately $2.4 million while contract and other revenues decreased by
$157,000 (30%) to $371,000. These changes result from the Company's increased
emphasis on increasing revenues by marketing developed products over additional
research and development projects. The increase in product related revenues was
achieved while the Company continued the integration activities associated with
the mergers of EnSys and Ohmicron during 1997. These activities will continue in
1997, however, the Company's sales efforts became more productive during the
quarter ended March 31, 1997 as efforts to inform customers of the breadth and
scope of the Company's integrated product lines began to produce favorable
results. The Company expects product related revenues to increase further in
1997 as these and other customer driven initiatives reach the market place.
Research and development contracts continue to be integral to the Company's
operations, however, the proportion of these activities to the Company's total
operations is expected to decline. Contract and other revenues are expected to
increase slightly over the first quarter 1997 levels. These contracts
historically have been large and long-term in nature, accordingly such revenues
tend to fluctuate from quarter-to-quarter.
 
                                       14
<PAGE>
    A significant portion of the Company's 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, SDI's sales in a particular quarter
in 1997 may not be indicative of its revenues for any subsequent quarter during
the year.
 
    Total operating expenses decreased $1.9 million from the prior period to
$2.7 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 March 31, 1997, the Company had approximately
100 employees versus 230 employees on a combined basis at March 31, 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 decreased
$483,000 in 1997 to $809,000 (37%). This decrease is due to the items referred
to above. 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 $670,000 to $494,000 (58%). This
decrease is attributable to the consolidation of EnSys 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 slightly over the first quarter
1997 levels.
 
    Selling, general and administrative expenses decreased $743,000 to $1.4
million (34%). The decrease is due to the items noted above. These expenses are
expected to increase slightly over the first quarter of 1997 levels.
 
    Net interest income decreased $101,000 to $69,000. This decrease is
attributable primarily to a lower average balance of investments at March 31,
1997. Net interest income is expected to be slightly lower for the balance of
1997.
 
    THREE MONTHS ENDED MARCH 31, 1997 VS DECEMBER 31, 1996
 
    Total net revenues increased over the three month period ended December 31,
1996 by $170,000 (7%). Product related sales increased $92,000 (4%). 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 remained strong during the first quarter of 1997 despite
seasonal factors, such as cold weather, that historically have made the first
quarter the slowest 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 in 1997. Contract and
other revenues increased
 
                                       15

<PAGE>

$78,000 (27%). This increase is due to the initiation of a research and 
development project during the first quarter. Product related and contract 
revenues are expected to increase over the first quarter 1997 levels for the 
reasons noted above.
 
    Total operating expenses declined $1.8 million (40%). Included in this
total, manufacturing costs decreased $843,000 (51%), research and development
costs decreased $97,000 (16%) and selling, general and administrative costs
decreased $890,000 (38%). These decreases are attributable to increased
efficiencies arising from the mergers as described above.
 
    Net interest income decreased $53,000 (43%). This decrease is attributable
primarily to a lower average balance of investments at March 31, 1997.
 
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 and EnSys from December 30, 1996.
 
    THREE MONTHS ENDED MARCH 31, 1997 VS 1996
 
    Revenues for the period increased by $1.6 million to $2.8 million (137%)
from 1996 to 1997. Of this total, product related revenues increased $1.8
million to $2.4 million (300%) and contract and other revenues decreased
$198,000 to $371,000 (35%). 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 $1.7 million to $2.7 million (166%). Of
this total, manufacturing costs increased $392,000 to $809,000 (94%), research
and development expenses increased $86,000 to $494,000 (21%) and selling,
general and administrative expenses increased $1.2 million to $1.4 million
(601%). All of these increases are due to the combination of SDI, Ohmicron and
EnSys.
 
    Net interest income increased $65,000 to $69,000 during the period. This
increase is due to the investments acquired in the combinations.
 
    Equity in income of TSD BioServices (a partnership) was eliminated in 1997
as TSD was dissolved in 1996 and became a wholly owned subsidiary.
 
                                       16
<PAGE>
LIQUIDITY AND CAPITAL RESOURCES
 
    The Company's working capital which consists principally of cash, cash
equivalents and marketable investments, increased $274,000 from December 31,
1996 to $7.4 million at March 31, 1997. Cash, cash equivalents and short-term
investments decreased $2.0 million to $4.7 million. This decrease was used to
reduce accounts payable and accrued expenses by $1.1 million and finance
increases in accounts receivable and inventories of $1.1 million and was net of
increases attributable to changes in other current assets and liabilities of
$49,000 and net income of $109,000.
 
    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 6. EXHIBITS AND REPORTS ON FORM 8-K
 
    (a) Exhibits:
 
    27 Financial Data Schedule (in electronic format only)
 
    (b) Reports on Form 8-K: The Company filed the following 3 reports on Form
8-K for the quarter ended March 31, 1997.
 
    On January 14, 1997, the Company filed a report on Form 8-K responding to
Item 2 of that Form reporting upon the merger between Strategic Diagnostics Inc.
and EnSys Environmental Products, Inc. which occurred on December 30, 1996.
Historical financial statements of the constituent corporations and pro forma
financial statements were incorporated by reference into the Form 8-K from the
Company's Form S-4 (File No. 333-17505).
 
    On February 5, 1997 and February 12, 1997 the Company filed a Form 8-K and
Form 8-K/A, respectively responding to Item 4 of Form 8-K reporting upon a
change in the Company's accountants that occurred on January 29, 1997.
 
                                       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)
 
<TABLE>
<CAPTION>
SIGNATURE                                                                      TITLE                               DATE
-----------------------------------------------------  -----------------------------------------------------  ---------------
<S>                                                    <C>                                                    <C>
 
/s/ RICHARD C. BIRKMEYER                               President and Chief Executive Officer                  May 15, 1997
---------------------------                            (Principal Executive Officer)
Richard C. Birkmeyer                                   
 
/s/ ARTHUR A. KOCH, JR.                                Vice President and Chief Financial Officer             May 15, 1997
---------------------------                            (Principal Financial Officer)
Arthur A. Koch, Jr.                                    
</TABLE>
 
                                       19