<PAGE>


THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE 
SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR UNDER THE SECURITIES LAWS 
OF ANY STATE. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY 
AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS PERMITTED UNDER THE 
ACT AND THE APPLICABLE STATE SECURITIES LAWS, PURSUANT TO REGISTRATION OR 
EXEMPTION THEREFROM.  THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION 
OF COUNSEL IN FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER TO THE EFFECT 
THAT ANY PROPOSED TRANSFER OR RESALE IS IN COMPLIANCE WITH THE ACT AND ANY 
APPLICABLE STATE SECURITIES LAWS.

                               BIOCIRCUITS CORPORATION

                  WARRANT FOR THE PURCHASE OF SHARES OF COMMON STOCK


No. 1997-K2                                                  50,000 Shares


    FOR VALUE RECEIVED, BIOCIRCUITS CORPORATION, a Delaware corporation (the
"Company"), with its principal office at 1324 Chesapeake Terrace, Sunnyvale,
California 94089, hereby certifies that KMC Systems, Inc. ("Kollsman" or
alternatively, "Holder"), or its assigns, in consideration for Kollsman's
commitment to shut down all IOS activity other than the shipment of instruments
through the end of April 1997, is entitled, subject to the provisions of this
Warrant, to purchase from the Company, at any time before 5:00 p.m. (Pacific
Daylight Standard Time) June 30, 1998 (the "Expiration Date"), the number of
fully paid and nonassessable shares of Common Stock of the Company set forth
above, subject to adjustment as hereinafter provided.  The term "Common Stock"
shall mean the aforementioned Common Stock of the Company, together with any
other equity securities that may be issued by the Company in addition thereto or
in substitution therefor as provided herein.  The shares of Common Stock
deliverable upon such exercise, as adjusted from time to time, are hereinafter
referred to as "Warrant Shares."

    SECTION 1.  EXERCISE OF WARRANT.  Holder may purchase said number of 
Warrant Shares at a purchase price per share of one cent ($0.01) per share 
(the "Exercise Price").  This Warrant may be exercised in whole or in part on 
any business day prior to the Expiration Date by presentation and surrender 
hereof to the Company at its principal office at the address set forth in the 
initial paragraph hereof (or at such other address as the Company may 
hereafter notify Holder in writing) with the Purchase Form annexed hereto 
duly executed and accompanied by proper payment of the Exercise Price in 
lawful money of the United States of America in the form of a check, subject 
to collection, for the number of Warrant Shares specified in the Purchase 
Form.  


                                      1.

<PAGE>

    If this Warrant should be exercised in part only, the Company shall, upon
surrender of this Warrant, execute and deliver a new warrant evidencing the
rights of Holder thereof to purchase the balance of the Warrant Shares
purchasable hereunder.  Upon receipt by the Company of this Warrant and such
Purchase Form, together with proper payment of the Exercise Price, at such
office, Holder shall be deemed to be the holder of record of the Warrant Shares,
notwithstanding that the stock transfer books of the Company shall then be
closed or that certificates representing such Warrant Shares shall not then be
actually delivered to Holder.  The Company shall pay any and all documentary
stamp or similar issue or transfer taxes payable in respect of the issue or
delivery of the Warrant Shares.

    SECTION 2.  RESERVATION OF SHARES.  The Company hereby agrees that at all 
times there shall be reserved for issuance and delivery upon exercise of this 
Warrant all shares of its Common Stock or other shares of capital stock of 
the Company from time to time issuable upon exercise of this Warrant.  All 
such shares shall be duly authorized and, when issued upon such exercise in 
accordance with the terms of this Warrant, shall be validly issued, fully 
paid and nonassessable, free and clear of all liens, security interests, 
charges and other encumbrances or restrictions on sale (other than as 
provided in the Company's certificate of incorporation and any restrictions 
on sale set forth herein or pursuant to applicable federal and state 
securities laws) and free and clear of all preemptive rights.

    SECTION 3.  FRACTIONAL INTEREST.  The Company will not issue a fractional 
share of Common Stock upon exercise of a Warrant.  Instead, the Company will 
deliver its check for the current market value of the fractional share.  The 
current market value of a fraction of a share is determined as follows: 
multiply the current market price of a full share by the fraction of a share 
and round the result to the nearest cent.  The current market price of a 
share of Common Stock for purposes of this Section 3 is the Quoted Price (as 
defined in Section 6(b)) of the Common Stock on the last trading day prior to 
the exercise date.

    SECTION 4.  ASSIGNMENT OR LOSS OF WARRANT.

         (a)  Subject to the provisions of Section 8, Holder shall be 
entitled, without obtaining the consent of the Company, to assign its 
interest in this Warrant in whole or in part to any person or persons.  
Subject to the provisions of Section 8, upon surrender of this Warrant to the 
Company or at the office of its stock transfer agent or warrant agent, with 
the Assignment Form annexed hereto duly executed and funds sufficient to pay 
any transfer tax, the Company shall, without charge, execute and deliver a 
new Warrant or Warrants in the name of the assignee or assignees named in 
such instrument of assignment (any such assignee will also be a "Holder" for 
purposes of this Warrant) and, if Holder's entire interest is not being 
assigned, in the name of Holder, and this Warrant shall promptly be canceled.

         (b)  Upon receipt of evidence satisfactory to the Company of the 
loss, theft, destruction or mutilation of this Warrant, and (in the case of 
loss, theft or destruction) of indemnification satisfactory to the Company, 
and upon surrender and cancellation of this Warrant, if mutilated, the 
Company shall execute and deliver a new Warrant of like tenor and date.


                                    2.

<PAGE>

    SECTION 5.  RIGHTS OF HOLDER.  Holder shall not, by virtue hereof, be
entitled to any rights of a stockholder in the Company, either at law or equity,
and the rights of Holder are limited to those expressed in this Warrant. 
Nothing contained in this Warrant shall be construed as conferring upon Holder
hereof the right to vote or to consent or to receive notice as a stockholder of
the Company on any matters or with respect to any rights whatsoever as a
stockholder of the Company.  No dividends or interest shall be payable or
accrued in respect of this Warrant or the interest represented hereby or the
Warrant Shares purchasable hereunder until, and only to the extent that, this
Warrant shall have been exercised in accordance with its terms.

    SECTION 6.  ADJUSTMENT OF NUMBER OF SHARES.  The number and kind of
securities purchasable upon the exercise of this Warrant shall be subject to
adjustment from time to time upon the occurrence of certain events, as follows:

         (a) ADJUSTMENT FOR CHANGE IN CAPITAL STOCK.  If at any time after the
date hereof, the Company:

              (i)   pays a dividend or makes a distribution on its Common Stock
                    in shares of its Common Stock;

              (ii)  subdivides its outstanding shares of Common Stock into a
                    greater number of shares;

              (iii) combines its outstanding shares of Common Stock into a
                    smaller number of shares;

              (iv)  makes a distribution on its Common Stock in shares of its
                    capital stock other than Common Stock; or

              (v)   issues by reclassification of its Common Stock any shares 
                    of its capital stock;

then the Exercise Price in effect immediately prior to such action shall be 
adjusted so that Holder may receive upon exercise of this Warrant and payment 
of the same aggregate consideration the number of shares of capital stock of 
the Company which Holder would have owned immediately following such action 
if Holder had exercised this Warrant immediately prior to such action; 
PROVIDED, HOWEVER, that in no event shall the Exercise Price be reduced to 
less than the par value per share of Common Stock.

    The adjustment shall become effective immediately after the record date 
in the case of a dividend or distribution and immediately after the effective 
date in the case of a subdivision, combination or reclassification.

         (b)  QUOTED PRICE OF THE COMMON STOCK.  The "Quoted Price" of the
Common Stock is the last reported sales price of the Common Stock as reported by
the Nasdaq National 


                                    3.

<PAGE>

Market, or the primary national securities exchange on which the Common Stock 
is then quoted; provided, however, that if the Common Stock is neither traded 
on the Nasdaq National Market nor on a national securities exchange, the 
price referred to above shall be the price reflected on the Nasdaq National 
Market, or if the Common Stock is not then traded on the Nasdaq National 
Market, the price reflected in the over-the counter market as reported by the 
National Quotation Bureau, Inc. or any organization performing a similar 
function.

         (c)  NOTICE OF CERTAIN ACTIONS.  In the event that:

              (i)  the Company shall authorize the issuance to all holders of
its Common Stock of rights, warrants, options or convertible securities to
subscribe for or purchase shares of its Common Stock or of any other
subscription rights, warrants, options or convertible securities; or

              (ii) the Company shall authorize the distribution to all holders
of its Common Stock of evidence of its indebtedness or assets (other than cash
dividends or cash distributions payable out of consolidated current or retained
earnings as shown on the books of the Company and paid in the ordinary course of
business); or

              (iii) the Company shall authorize any capital reorganization
or reclassification of the Common Stock (other than a subdivision or combination
of the outstanding Common Stock and other than a change in par value of the
Common Stock) or of any consolidation or merger to which the Company is a party
and for which approval of any stockholders of the Company is required (other
than a consolidation or merger in which the Company is the continuing
corporation and that does not result in any reclassification or change of the
Common Stock outstanding), or of the conveyance or transfer of the properties
and assets of the Company as an entirety or substantially as an entirety; or

              (iv) the Company is the subject of a voluntary or involuntary
dissolution, liquidation or winding-up procedure; or

              (v)  the Company proposes to take any action that would require
an adjustment of the Exercise Price;

then the Company shall cause to be mailed by first-class mail to Holder, at 
least twenty (20) days prior to the applicable record or effective date 
hereinafter specified, a notice stating (x) the date as of which the holders 
of Common Stock of record to be entitled to receive any such rights, warrants 
or distributions are to be determined, or (y) the date on which any such 
consolidation, merger, conveyance, transfer, dissolution, liquidation or 
winding-up is expected to become effective, and the date as of which it is 
expected that holders of Common Stock of record shall be entitled to exchange 
their shares of Common Stock for securities or other property, if any, 
deliverable upon such reorganization, reclassification, consolidation, 
merger, conveyance, transfer, dissolution, liquidation or winding-up.


                                    4.

<PAGE>

         (d)  NO ADJUSTMENT UPON EXERCISE OF WARRANT.  No adjustments shall be
made under any Section herein in connection with the issuance of Warrant Shares
upon exercise of this Warrant.

    SECTION 7.  RECLASSIFICATION, REORGANIZATION, CONSOLIDATION OR MERGER.  
In the event of any reclassification, capital reorganization or other change 
of outstanding shares of Common Stock of the Company (other than a 
subdivision or combination of the outstanding Common Stock and other than a 
change in the par value of the Common Stock) or in the event of any 
consolidation or merger of the Company with or into another corporation 
(other than a merger in which the Company is the continuing corporation and 
that does not result in any reclassification, capital reorganization or other 
change of outstanding shares of Common Stock of the class issuable upon 
exercise of this Warrant) or in the event of any sale, lease, transfer or 
conveyance to another corporation of the property and assets of the Company 
as an entirety or substantially as an entirety, the Company shall, as a 
condition precedent to such transaction, cause effective provisions to be 
made so that Holder shall have the right thereafter, by exercising this 
Warrant, to purchase the kind and amount of shares of stock and other 
securities and property (including cash) receivable upon such 
reclassification, capital reorganization and other change, consolidation, 
merger, sale or conveyance by a holder of the number of shares of Common 
Stock that might have been received upon exercise of this Warrant immediately 
prior to such reclassification, capital reorganization, change, 
consolidation, merger, sale or conveyance. Any such provision shall include 
provisions for adjustments in respect of such shares of stock and other 
securities and property that shall be as nearly equivalent as may be 
practicable to the adjustments provided for in this Warrant.  The foregoing 
provisions of this Section 7 shall similarly apply to successive 
reclassifications, capital reorganizations and changes of shares of Common 
Stock and to successive consolidations, mergers, sales or conveyances. 

    SECTION 8.  TRANSFER TO COMPLY WITH THE SECURITIES ACT OF 1933.  This 
Warrant may not be exercised and neither this Warrant nor any of the Warrant 
Shares, nor any interest in either, may be offered, sold, assigned, pledged, 
hypothecated, encumbered or in any other manner transferred or disposed of, 
in whole or in part, except in compliance with applicable United States 
federal and state securities or Blue Sky laws and the terms and conditions 
hereof.  Each subsequent Warrant shall bear a legend in substantially the 
same form as the legend set forth on the first page of this Warrant.  Each 
certificate for Warrant Shares issued upon exercise of this Warrant and 
subsequent Warrants, unless at the time of exercise such Warrant Shares are 
acquired pursuant to a registration statement that has been declared 
effective under the Act, and applicable Blue Sky laws shall bear a legend 
substantially in the following form:

    THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
    SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR UNDER THE
    SECURITIES LAWS OF ANY STATE.  THESE SECURITIES ARE SUBJECT TO
    RESTRICTIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED
    OR RESOLD EXCEPT AS PERMITTED UNDER THE ACT AND THE APPLICABLE STATE
    SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM.  THE
    ISSUER OF THESE SECURITIES 



                                    5.

<PAGE>

    MAY REQUIRE AN OPINION OF COUNSEL IN FORM AND SUBSTANCE SATISFACTORY 
    TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED TRANSFER OR RESALE IS 
    IN COMPLIANCE WITH THE ACT AND ANY APPLICABLE STATE SECURITIES LAWS.

Any certificate for any Warrant Shares issued at any time in exchange or
substitution for any certificate for any Warrant Shares bearing such legend
(except a new certificate for any Warrant Shares issued after the acquisition of
such Warrant Shares pursuant to a registration statement that has been declared
effective under the Act) shall also bear such legend unless, in the opinion of
counsel for the Company, the Warrant Shares represented thereby need no longer
be subject to the restriction contained herein.  The provision of this Section 8
shall be binding upon all subsequent holders of certificates for Warrant Shares
bearing the above legend and all subsequent Holders of this Warrant and new
warrants (as provided in Section 1), if any.

    SECTION 9.  REGISTRATION RIGHTS.

         (a)  If at any time after the date hereof and prior to the Expiration
Date, the Company shall determine to register any of its Common Stock, for its
own account or for the account of others on a registration statement on Form S-1
or Form S-3, the Company shall:

              (i)  promptly give Holder written notice thereof (which shall
include a list of the jurisdictions in which the Company intends to attempt to
qualify such securities under the applicable blue sky or other state
securities); and

              (ii) include in such registration (and any related qualification
under blue sky laws or other compliance), and in any underwriting involved
therein, all shares of Common Stock of the Company obtained upon exercise of
this Warrant (the "Registrable Securities") specified in a written request or
requests by Holder, received by the Company within twenty (20) days after such
written notice is given, requesting inclusions in such registration.

         (b)  UNDERWRITING.  If the registration of which the Company gives
notice is for a registered public offering involving an underwriting, the
Company shall so advise Holder as a part of the written notice given pursuant to
Paragraph 9(a)(i).  In such event, the right of Holder to registration pursuant
to this Section 9 shall be conditioned upon Holder's participation in such
underwriting and the inclusion of Holder's Registrable Securities in the
underwriting to the extent provided herein.

         Holder shall (together with the Company and the other holders
distributing their securities through such underwriting) enter into an
underwriting agreement in customary form with the underwriter or underwriters
selected for such underwriting by the Company.  Notwithstanding any other
provision of this Section 9, if the underwriter determines that marketing
factors require a limitation of the number of shares to be underwritten, the
underwriter may exclude some or all of the Registrable Securities from such
registration and underwriting.


                                    6.

<PAGE>

         If Holder disapproves of the terms of any such underwriting, Holder
may select to withdraw therefrom by written notice to the Company and the
underwriter.  Any Registrable Securities so withdrawn from such underwriting
shall also be withdrawn from such registration.

         (c)  The Company shall bear registration expenses (exclusive of
underwriting discounts and commissions) for the Form S-1 or Form S-3
registration.

         (d)  If requested by the underwriters, Holder, or any assignee of
Holder, shall not sell or otherwise transfer or dispose of any securities of the
Company held by Holder for a period of up to 180 days following a public
offering by the Company of its capital stock.

         (e)  (i) The Company will indemnify Holder, each of Holder's officers,
directors, partners and agents, and each person controlling Holder, with respect
to such registration, qualification or compliance that has been effected
pursuant to this Section 9, and each underwriter, if any, and each person who
controls any underwriter against all claims, losses, damages and liabilities (or
actions in respect thereof) including any of the foregoing incurred in
settlement of any litigation commenced or threatened arising out of or based on
(x) any untrue statement (or alleged untrue statement) of a material fact
contained in any prospectus, offering circular or other similar document
(including any related registration statement, notification or the like)
incident to any such registration, qualification or compliance, or based on any
omission (or alleged omission) to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading in the
light of the circumstances under which they were made, or (y) any violation (or
alleged violation) by the Company of any federal, state or common law rule or
regulation applicable to the Company in connection with any such registration,
qualification or compliance, and will reimburse Holder, each of its officers,
directors, partners and agents, and each person controlling Holder, each such
underwriter and each person who controls any such underwriter, for any legal and
any other expenses reasonably incurred in connection with investigating or
defending any such claim, loss, damage, liability or action, as incurred,
provided that the Company will not be liable in any such case to the extent that
any such claim, loss, damage, liability or expense arises out of or is based on
any untrue statement (or alleged untrue statement) or omission (or alleged
omission) based upon written information furnished to the Company by an
instrument duly executed by Holder or such underwriter and stated to be
specifically for use therein.

              (ii) Holder shall, if Registrable Securities held by Holder are
included in the securities as to which such registration, qualification or
compliance is being effected, indemnify the Company, each of its directors and
officers, each legal counsel and independent accountant of the Company, each
underwriter, if any, of the Company's securities covered by such a registration
statement, each person who controls the Company or such underwriter within the
meaning of the Securities Act, and each other such holder, each of its
directors, officers, and partners and agents and each person controlling such
other holder, against all claims, losses, damages and liabilities (or actions in
respect thereof) including any of the foregoing incurred in settlement of any
litigation commenced or threatened arising out of or based on any untrue
statement (or alleged untrue statement) of a material fact contained in any such
registration statement, prospectus, offering circular or other similar document
(including any related 



                                    7.

<PAGE>

registration statement, notification or the like) incident to any such 
registration, qualification or compliance, or any omission (or alleged 
omission) to state therein a material fact required to be stated therein or 
necessary to make the statements therein not misleading in the light of the 
circumstances under which they were made, and shall reimburse the Company, 
its directors, officers, legal counsel, accountants, underwriters, control 
persons and such other holders and each such holder's directors, officers, 
partners, agents and control persons for any legal and any other expenses 
reasonably incurred in connection with investigating or defending any such 
claim, loss, damage, liability or action, as incurred, in each case to the 
extent, but only to the extent, that such untrue statement (or alleged untrue 
statement) or omission (or alleged omission) is made in such registration 
statement, prospectus, offering circular or other document in reliance upon 
and in conformity with written information furnished to the Company by an 
instrument duly executed by Holder and stated to be specifically for use 
therein; provided, however, that the obligations of Holder hereunder shall be 
limited to an amount equal to the proceeds to Holder for Registrable 
Securities sold as contemplated herein.

              (iii)  Each party entitled to indemnification under this
Subsection 9(e) (the "Indemnified Party") shall give notice to the party
required to provide indemnification (the "Indemnifying Party") promptly after
such Indemnified Party has received written notice of any claim as to which
indemnity may be sought, and shall permit the Indemnifying Party to assume the
defense of any such claim or any litigation resulting therefrom, provided that
counsel for the Indemnifying Party, who shall conduct the defense of such claim
or litigation, shall be approved by the Indemnified Party (whose approval shall
not unreasonably be withheld).  The Indemnified Party may participate in such
defense at the Indemnified Party's expense; provided, however, that the
Indemnifying Party shall bear the expense of such defense of the Indemnified
Party if representation of both parties by the same counsel would be
inappropriate due to actual or potential conflicts of interest.  The failure of
any Indemnified Party to give notice as provided herein shall relieve the
Indemnifying Party of its obligations under this Subsection 9(e) only to the
extent that such failure to give notice shall materially adversely prejudice the
Indemnifying Party in the defense of any such claim or any such litigation.  No
Indemnifying Party, in the defense of any such claim or litigation, shall,
except with the consent of each Indemnified Party, consent to entry of any
judgment or enter into any settlement which does not include as an unconditional
term thereof the giving by the claimant or plaintiff to such Indemnified Party
of a release from all liability in respect to such claim or litigation.

    SECTION 10.  MODIFICATION AND WAIVER.  Neither this Warrant nor any term 
hereof may be changed, waived, discharged or terminated other than by an 
instrument in writing signed by the Company and by Holder.

    SECTION 11.  NOTICES.  Any notice, request or other document required or 
permitted to be given or delivered to Holder or the Company shall be 
delivered or shall be sent by certified mail, postage prepaid, to Holder at 
its address as shown on the books of the Company or to the Company at the 
address indicated therefor in the first paragraph of this Warrant.

    SECTION 12.  DESCRIPTIVE HEADINGS AND GOVERNING LAW.  The description 
headings of the several Sections, Subsections and Paragraphs of this Warrant 
are inserted for convenience 


                                    8.

<PAGE>

only and do not constitute a part of this Warrant. This Warrant shall be 
construed and enforced in accordance with, and the rights of the parties 
shall be governed by, the laws of the State of California, without regard to 
its conflicts of laws principles.

    IN WITNESS WHEREOF, the Company has duly caused this Warrant to be signed
by its duly authorized officer and to be dated as of __________, 1997.



                        BIOCIRCUITS CORPORATION


                        By:                                
                           --------------------------------------
                             John Kaiser
                             Chief Executive Officer



                                    9.

<PAGE>

                              PURCHASE FORM


                                                  Dated ___________, 19____


    The undersigned hereby irrevocably elects to exercise the within Warrant 
No. 1997-K2 to purchase ________ shares of Common Stock of Biocircuits 
Corporation and hereby makes payment of $_____________ in payment of the 
exercise price thereof.

                                  KMC SYSTEMS, INC.


                                  By:
                                     ----------------------------------

                                  Print Name:
                                             --------------------------

                                  Title:
                                         ------------------------------

<PAGE>


                             ASSIGNMENT FORM


                                                 Dated _________, 19____



    FOR VALUE RECEIVED, KMC Systems, Inc. hereby sells, assigns and transfers
unto __________________________________________________ (the "Assignee"), 
          (please type or print in block letters)

___________________________________________________________________________
                               (insert address)
its right to purchase up to _______ shares of Common Stock of Biocircuits 
Corporation represented by Biocircuits Corporation Warrant No. 1997-K2 and 
does hereby irrevocably constitute and appoint ____________________________ 
attorney, to transfer the same on the books of Biocircuits Corporation, with 
full power of substitution in the premises.

                                  KMC SYSTEMS, INC.


                                  By:
                                     ----------------------------------

                                  Print Name:
                                             --------------------------

                                  Title:
                                         ------------------------------