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                                                                   EXHIBIT 10.77

                                WARRANT AGREEMENT

               AGREEMENT, dated as of this 19th day of March, 1998, between
ACCUMED INTERNATIONAL, INC., a Delaware corporation (the "Company"), and
COMMONWEALTH ASSOCIATES, a New York corporation ("Commonwealth").

                               W I T N E S S E T H

               WHEREAS, in connection with a private placement (the "Private
Placement") of a minimum of forty (40) and a maximum of sixty (60) units
("Units"), each Unit consisting of shares of the Company's Common Stock, $.01
par value per share ("Common Stock") and Common Stock purchase warrants
("Warrants"), each Warrant exercisable to purchase one share of the Company's
Common Stock, the Company will issue up to 8,000,000 Warrants; and

               NOW THEREFORE, in consideration of the premises and the mutual
agreements hereinafter set forth and for the purpose of defining the terms and
provisions of the Warrants and the certificates representing the Warrants and
the respective rights and obligations thereunder of the Company, and the holders
of certificates representing the Warrants, the parties hereto agree as follows:

               SECTION 1. Definitions. As used herein, the following terms shall
have the following meanings, unless the context shall otherwise require:

               (a) "Common Stock" shall mean stock of the Company of any class,
whether now or hereafter authorized, which has the right to participate in the
distributions of earnings and assets of the Company without limit as to amount
or percentage, which at the date hereof consists of 50,000,000 authorized shares
of Common Stock, $.01 par value per share.

               (b) "Corporate Office" shall mean the office of the Company (or
its successor) at which at any particular time its principal business shall be
administered, which office is located at the date hereof at 900 North Franklin
Street, Suite 401, Chicago, Illinois 60610.

               (c) "Exercise Date" shall mean, as to any Warrant, the date on
which the Company shall have received both (a) the Warrant Certificate
representing such Warrant, with the exercise form thereon properly completed and
duly executed by the Registered Holder thereof or his attorney duly authorized
in writing, and (b) payment in cash, or by official bank or certified check made
payable to the Company, of an amount in lawful money of the United States of
America equal to the applicable Purchase Price.

               (d) "Initial Warrant Exercise Date" shall mean (i) March 19, 1998
with 



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respect to Warrants to purchase up to 3,183,200 shares (39.79%) of Common
Stock issuable pursuant to this Warrant Agreement and (ii) the date in which the
Company has a sufficient number of authorized shares of Common Stock reserved
for issuance (after taking into account all shares reserved for issuance on the
conversion of convertible securities and the exercise of outstanding options and
warrants) to permit the issuance of the shares of Common Stock to be issued
pursuant to the exercise of the Warrants ("Authorized Share Date") with respect
to Warrants to purchase up to 4,816,800 shares (60.21%) of Common Stock issuable
pursuant to this Warrant Agreement.

               (e) "Market Price" shall mean (i) the average closing bid price
of the Common Stock, for twenty (20) consecutive trading days ending on the
Calculation Date as reported by Nasdaq, if the Common Stock is traded on the
SmallCap Market, or (ii) the average last reported sales price of the Common
Stock, for twenty (20) consecutive trading days ending on the Calculation Date,
as reported by the primary exchange on which the Common Stock is traded, if the
Common Stock is traded on a national securities exchange, or by Nasdaq, if the
Common Stock is traded on the Nasdaq National Market.

               (f) "Purchase Price" shall mean the purchase price to be paid
upon exercise of each Warrant in accordance with the terms hereof, which price
shall be $0.75 per share subject to adjustment from time to time pursuant to the
provisions of Section 8 hereof and subject to the Company's right to reduce the
Purchase Price upon notice to all warrantholders.

               (g) "Redemption Price" shall mean the price at which the Company
may, at its option in accordance with the terms hereof, redeem the Warrants
which price shall be $0.25 per Warrant.

               (h) "Registered Holder" shall mean the person in whose name any
certificate representing Warrants shall be registered on the books maintained by
the Company.

               (i) "Warrant Expiration Date" shall mean 5:00 P.M. (New York
time) on March 19, 2005, or such earlier date as the Warrants shall be redeemed,
provided that if such date shall in the State of New York be a holiday or a day
on which banks are authorized to close, then 5:00 P.M. (New York time) on the
next following day which in the State of New York is not a holiday or a day on
which banks are authorized to close. Upon notice to all warrantholders the
Company shall have the right to extend the Warrant Expiration Date.

               SECTION 2.    Warrants and Issuance of Warrant Certificates.

               (a) A Warrant shall initially entitle the Registered Holder of
the Warrant Certificate representing such Warrant to purchase one share of
Common Stock upon the exercise thereof, in accordance with the terms hereof,
subject to modification and adjustment as provided in Section 8.



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               (b) From time to time, up to the Warrant Expiration Date, the
Company shall execute and deliver stock certificates in required whole number
denominations representing up to an aggregate of 8,000,000 shares of Common
Stock, subject to adjustment as described herein, upon the exercise of Warrants
in accordance with this Agreement.

               (c) From time to time, up to the Warrant Expiration Date, the
Company shall execute and deliver Warrant Certificates in required whole number
denominations to the persons entitled thereto in connection with any transfer or
exchange permitted under this Agreement; provided that no Warrant Certificates
shall be issued except (i) those initially issued hereunder, (ii) those issued
on or after the Initial Warrant Exercise Date, upon the exercise of fewer than
all Warrants represented by any Warrant Certificate, to evidence any unexercised
Warrants held by the exercising Registered Holder, (iii) those issued upon any
transfer or exchange pursuant to Section 6; (iv) those issued in replacement of
lost, stolen, destroyed or mutilated Warrant Certificates pursuant to Section 7;
and (v) at the option of the Company, in such form as may be approved by the its
Board of Directors, to reflect (a) any adjustment or change in the Purchase
Price or Target Price (as defined in Section 9) or the number of shares of
Common Stock purchasable upon exercise of the Warrants, made pursuant to Section
8 hereof and (b) other modifications approved by Warrantholders in accordance
with Section 16 hereof.

               SECTION 3. Form and Execution of Warrant Certificates. (a) The
Warrant Certificates shall be substantially in the form annexed hereto as
Exhibit A (the provisions of which are hereby incorporated herein) and may have
such letters, numbers or other marks of identification or designation and such
legends, summaries or endorsements printed, lithographed, engraved or typed
thereon as the Company may deem appropriate and as are not inconsistent with the
provisions of this Agreement, or as may be required to comply with any law or
with any rule or regulation made pursuant thereto or with any rule or regulation
of any stock exchange on which the Warrants may be listed, or to conform to
usage. The Warrant Certificates shall be dated the date of issuance thereof
(whether upon initial issuance, transfer, exchange or in lieu of mutilated,
lost, stolen, or destroyed Warrant Certificates) and issued in registered form.
Warrants shall be numbered serially with the letter W.

               (b) Warrant Certificates shall be executed on behalf of the
Company by its Chairman of the Board, Chief Executive Officer or Chief Financial
Officer and by its Secretary or an Assistant Secretary, by manual signatures or
by facsimile signatures printed thereon, and shall have imprinted thereon a
facsimile of the Company's seal. In case any officer of the Company who shall
have signed any of the Warrant Certificates shall cease to be such officer of
the Company before the date of issuance of the Warrant Certificates and issue
and delivery thereof, such Warrant Certificates may nevertheless be issued and
delivered with the same force and effect as though the person who signed such
Warrant Certificates had not ceased to be such officer of the Company. After
execution by the Company, Warrant Certificates shall be delivered by the Company
to the Registered Holder.



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               SECTION 4.    Exercise.

               (a) Each Warrant may be exercised by the Registered Holder
thereof at any time on or after the Initial Exercise Date, but not after the
Warrant Expiration Date, upon the terms and subject to the conditions set forth
herein and in the applicable Warrant Certificate. A Warrant shall be deemed to
have been exercised immediately prior to the close of business on the Exercise
Date and the person entitled to receive the securities deliverable upon such
exercise shall be treated for all purposes as the holder upon exercise thereof
as of the close of business on the Exercise Date. As soon as practicable on or
after the Exercise Date the Company shall deposit the proceeds received from the
exercise of a Warrant, and promptly after clearance of checks received in
payment of the Purchase Price pursuant to such Warrants, cause to be issued and
delivered by the Transfer Agent, to the person or persons entitled to receive
the same, a certificate or certificates for the securities deliverable upon such
exercise, (plus a certificate for any remaining unexercised Warrants of the
Registered Holder). Notwithstanding the foregoing, in the case of payment made
in the form of a check drawn on an account of Commonwealth or such other
investment banks and brokerage houses as the Company shall approve, certificates
shall promptly be issued without any delay.

               SECTION 5. Reservation of Shares; Listing; Payment of Taxes; etc.
(a) The Company covenants that it will at all times reserve and keep available
out of its authorized Common Stock, solely for the purpose of issue upon
exercise of Warrants, such number of shares of Common Stock as shall then be
issuable upon the exercise of all outstanding Warrants. The Company covenants
that all shares of Common Stock which shall be issuable upon exercise of the
Warrants and payment of the Purchase Price pursuant to the terms hereof shall,
at the time of delivery, be duly and validly issued, fully paid, nonassessable
and free from all taxes, liens and charges with respect to the issue thereof
(other than those which the Company shall promptly pay or discharge).

               (b) The Company will use reasonable efforts to obtain appropriate
approvals or registrations (in such states as requested in writing by or on
behalf of any Warrantholders) under state "blue sky" securities laws or
compliance with exemption requirements (if such exemptions are not self
executing) with respect to the exercise of the Warrants; provided, however, that
the Company shall not be obligated to file any general consent to service of
process or qualify as a foreign corporation in any jurisdiction. With respect to
any such securities laws, however, Warrants may not be exercised by, or shares
of Common Stock issued to, any Registered Holder in any state in which such
exercise would be unlawful.

               (c) The Company shall pay all documentary, stamp or similar taxes
and other governmental charges that may be imposed with respect to the issuance
of Warrants, or the issuance, or delivery of any shares upon exercise of the
Warrants; provided, however, that if the shares of Common Stock are to be
delivered in a name other than the name of the Registered Holder of the Warrant
Certificate representing any Warrant being exercised, then 



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no such delivery shall be made unless (i) the person requesting the same has
paid to the Company the amount of transfer taxes or charges incident thereto, if
any and (ii) the Registered Holder has provided documentation satisfactory to
the Company's counsel that such issuance is not in violation of applicable
Federal and state securities laws.

               SECTION 6.    Exchange and Registration of Transfer.

               Subject to the restrictions on transfer contained in the Warrant
Certificates and the Subscription Agreements and Registration Rights Agreements
(the "Subscription Agreements") between the Company and the purchasers of Units:

               (a) Warrant Certificates may be exchanged for other Warrant
Certificates representing an equal aggregate number of Warrants of the same
class or may be transferred in whole or in part. Warrant Certificates to be
exchanged shall be surrendered to the Company at its Corporate Office, and upon
satisfaction of the terms and provisions hereof, the Company shall execute, and
the Company shall countersign, issue and deliver in exchange therefor the
Warrant Certificate or Certificates which the Registered Holder making the
exchange shall be entitled to receive.

               (b) The Company shall keep at its office books in which, subject
to such reasonable regulations as it may prescribe, it shall register Warrant
Certificates and the transfer thereof in accordance with its regular practice.
Upon due presentment for registration of transfer of any Warrant Certificate at
its Corporate Office, the Company shall execute and the Company shall issue and
deliver to the transferee or transferees a new Warrant Certificate or
Certificates representing an equal aggregate number of Warrants.

               (c) With respect to all Warrant Certificates presented for
registration of transfer, or for exchange or exercise, the subscription form on
the reverse thereof shall be duly endorsed, or be accompanied by a written
instrument or instruments of transfer and subscription, in form satisfactory to
the Company, duly executed by the Registered Holder or his attorney-in-fact duly
authorized in writing provided to the Company.

               (d) The Company may require payment by such Registered Holder of
a sum sufficient to cover any tax or other governmental charge that may be
imposed in connection therewith.

               (e) All Warrant Certificates surrendered for exercise or for
exchange in case of mutilated Warrant Certificates shall be promptly cancelled
by the Company and thereafter retained by the Company until termination of this
Agreement or resignation of the Company or, with the prior written consent of
Commonwealth, disposed of or destroyed.

               (f) Prior to due presentment for registration of transfer
thereof, the Company may deem and treat the Registered Holder of any Warrant
Certificate as the absolute 



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owner thereof and of each Warrant represented thereby (notwithstanding any
notations of ownership or writing thereon made by anyone other than a duly
authorized officer of the Company) for all purposes and shall not be affected by
any notice to the contrary.

               SECTION 7. Loss or Mutilation. Upon receipt by the Company of
evidence satisfactory to it of the ownership of and loss, theft, destruction or
mutilation of any Warrant Certificate and (in case of loss, theft or
destruction) of indemnity satisfactory to it, and (in the case of mutilation)
upon surrender and cancellation thereof, the Company shall execute and (in the
absence of notice to the Company that the Warrant Certificate has been acquired
by a bonafide purchaser) countersign and deliver to the Registered Holder in
lieu thereof a new Warrant Certificate of like tenor representing an equal
aggregate number of Warrants. Applicants for a substitute Warrant Certificate
shall comply with such other reasonable regulations and pay such other
reasonable charges as the Company may prescribe.

               SECTION 8.    Adjustment of Exercise Price and Number of Shares
                             of Common Stock or Warrants.

               (a) Subject to the exceptions referred to in Section 8(g) below,
in the event the Company shall, at any time or from time to time after the date
hereof, sell any shares of Common Stock for a consideration per share less than
the current fair market value per share of the Common Stock on the date of the
sale or issue any shares of Common Stock as a stock dividend to the holders of
Common Stock, or subdivide or combine the outstanding shares of Common Stock
into a greater or lesser number of shares (any such sale, issuance, subdivision
or combination being herein called a "Change of Shares"), then, and thereafter
upon each further Change of Shares, the Purchase Price in effect immediately
prior to such Change of Shares shall be changed to a price (including any
applicable fraction of a cent) determined by multiplying the Purchase Price in
effect immediately prior thereto by a fraction, the numerator of which shall be
the sum of the number of shares of Common Stock outstanding immediately prior to
the issuance of such additional shares and the number of shares of Common Stock
which the aggregate consideration received (determined as provided in subsection
8(f)(F) below), if any, for the issuance of such additional shares would
purchase at such current market price per share of Common Stock, and the
denominator of which shall be the sum of the number of shares of Common Stock
outstanding immediately after the issuance of such additional shares. Such
adjustment shall be made successively whenever such an issuance is made.

                      Upon each adjustment of the Purchase Price pursuant to
this Section 8, the total number of shares of Common Stock purchasable upon the
exercise of each Warrant shall (subject to the provisions contained in Section
8(b) hereof) be such number of shares (calculated to the nearest tenth)
purchasable at the Purchase Price immediately prior to such adjustment
multiplied by a fraction, the numerator of which shall be the Purchase Price in
effect immediately prior to such adjustment and the denominator of which shall
be the Purchase Price in effect immediately after such adjustment.



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               (b) The Company may elect, upon any adjustment of the Purchase
Price hereunder, to adjust the number of Warrants outstanding, in lieu of the
adjustment in the number of shares of Common Stock purchasable upon the exercise
of each Warrant as hereinabove provided, so that each Warrant outstanding after
such adjustment shall represent the right to purchase one share of Common Stock.
Each Warrant held of record prior to such adjustment of the number of Warrants
shall become that number of Warrants (calculated to the nearest tenth)
determined by multiplying the number one by a fraction, the numerator of which
shall be the Purchase Price in effect immediately prior to such adjustment and
the denominator of which shall be the Purchase Price in effect immediately after
such adjustment. Upon each adjustment of the number of Warrants pursuant to this
Section 8, the Company shall, as promptly as practicable, cause to be
distributed to each Registered Holder of Warrant Certificates on the date of
such adjustment Warrant Certificates evidencing, subject to Section 11 hereof,
the number of additional Warrants to which such Registered Holder shall be
entitled as a result of such adjustment or, at the option of the Company, cause
to be distributed to such Registered Holder in substitution and replacement for
the Warrant Certificates held by it prior to the date of adjustment (and upon
surrender thereof, if required by the Company) new Warrant Certificates
evidencing the number of Warrants to which such Registered Holder shall be
entitled after such adjustment.

               (c) In case of any reclassification, capital reorganization or
other change of outstanding shares of Common Stock, or in case of any
consolidation or merger of the Company with or into another corporation (other
than a consolidation or merger in which the Company is the continuing
corporation and which does not result in any reclassification, capital
reorganization or other change of outstanding shares of Common Stock), or in
case of any sale or conveyance to another corporation of the property of the
Company as, or substantially as, an entirety (other than a sale/leaseback,
mortgage or other financing transaction), the Company shall cause effective
provision to be made so that each holder of a Warrant then outstanding shall
have the right thereafter, by exercising such Warrant, to purchase the kind and
number of shares of stock or other securities or property (including cash)
receivable upon such reclassification, capital reorganization or other change,
consolidation, merger, sale or conveyance by a holder of the number of shares of
Common Stock that might have been purchased upon exercise of such Warrant
immediately prior to such reclassification, capital reorganization or other
change, consolidation, merger, sale or conveyance. Any such provision shall
include provision for adjustments that shall be as nearly equivalent as may be
practicable to the adjustments provided for in this Section 8. The foregoing
provisions shall similarly apply to successive reclassifications, capital
reorganizations and other changes of outstanding shares of Common Stock and to
successive consolidations, mergers, sales or conveyances.

               (d) Irrespective of any adjustments or changes in the Purchase
Price or the number of shares of Common Stock purchasable upon exercise of the
Warrants, the Warrant Certificates theretofore and thereafter issued shall,
unless the Company shall exercise its option 



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to issue new Warrant Certificates pursuant to Section 2(c) hereof, continue to
express the Purchase Price per share and the number of shares purchasable
thereunder as the Purchase Price per share, and the number of shares purchasable
were expressed in the Warrant Certificates when the same were originally issued.

               (e) After each adjustment of the Purchase Price pursuant to this
Section 8, the Company will promptly prepare a certificate signed by the
Chairman, Chief Executive Officer or Chief Financial Officer, and by the
Treasurer or an Assistant Treasurer or the Secretary or an Assistant Secretary,
of the Company setting forth: (i) the Purchase Price as so adjusted, (ii) the
number of shares of Common Stock purchasable upon exercise of each Warrant after
such adjustment, and, if the Company shall have elected to adjust the number of
Warrants, the number of Warrants to which the registered holder of each Warrant
shall then be entitled, and (iii) a brief statement of the facts accounting for
such adjustment. The Company will promptly cause a brief summary thereof to be
sent by ordinary first class mail to Commonwealth and to each Registered Holder
of Warrants at his last address as it shall appear on the registry books of the
Company. No failure to mail such notice nor any defect therein or in the mailing
thereof shall affect the validity thereof except as to the holder to whom the
Company failed to mail such notice, or except as to the holder whose notice was
defective. The affidavit of an officer of the Secretary or an Assistant
Secretary of the Company that such notice has been mailed shall, in the absence
of fraud, be prima facie evidence of the facts stated therein.

               (f) For purposes of Section 8(a) and 8(b) hereof, the following
provisions (A) to (F) shall also be applicable:

                      (A) The number of shares of Common Stock outstanding at
               any given time shall include shares of Common Stock owned or held
               by or for the account of the Company and the sale or issuance of
               such treasury shares or the distribution of any such treasury
               shares shall not be considered a Change of Shares for purposes of
               said sections.

                      (B) No adjustment of the Purchase Price shall be made
               unless such adjustment would require an increase or decrease of
               at least $.10 in such price; provided that any adjustments which
               by reason of this clause (B) are not required to be made shall be
               carried forward and shall be made at the time of and together
               with the next subsequent adjustment which, together with any
               adjustment(s) so carried forward, shall require an increase or
               decrease of at least $.10 in the Purchase Price then in effect
               hereunder.

                      (C) In case of (1) the sale by the Company for cash of any
               rights or warrants to subscribe for or purchase, or any options
               for the purchase of, Common Stock or any securities convertible
               into or exchangeable for Common Stock without the payment of any
               further consideration other than cash, if any



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               (such convertible or exchangeable securities being herein called
               "Convertible Securities"), or (2) the issuance by the Company,
               without the receipt by the Company of any consideration therefor,
               of any rights or warrants to subscribe for or purchase, or any
               options for the purchase of, Common Stock or Convertible
               Securities, in each case, if (and only if) the consideration
               payable to the Company upon the exercise of such rights, warrants
               or options shall consist of cash, whether or not such rights,
               warrants or options, or the right to convert or exchange such
               Convertible Securities, are immediately exercisable, and the
               price per share for which Common Stock is issuable upon the
               exercise of such rights, warrants or options or upon the
               conversion or exchange of such Convertible Securities (determined
               by dividing (x) the minimum aggregate consideration payable to
               the Company upon the exercise of such rights, warrants or
               options, plus the consideration received by the Company for the
               issuance or sale of such rights, warrants or options, plus, in
               the case of such Convertible Securities, the minimum aggregate
               amount of additional consideration, if any, other than such
               Convertible Securities, payable upon the conversion or exchange
               thereof, by (y) the total maximum number of shares of Common
               Stock issuable upon the exercise of such rights, warrants or
               options or upon the conversion or exchange of such Convertible
               Securities issuable upon the exercise of such rights, warrants or
               options) is less than the Market Price of the Common Stock on the
               date of the issuance or sale of such rights, warrants or options,
               then the total maximum number of shares of Common Stock issuable
               upon the exercise of such rights, warrants or options or upon the
               conversion or exchange of such Convertible Securities (as of the
               date of the issuance or sale of such rights, warrants or options)
               shall be deemed to be outstanding shares of Common Stock for
               purposes of Sections 8(a) and 8(b) hereof and shall be deemed to
               have been sold for cash in an amount equal to such price per
               share.

                      (D) In case of the sale by the Company for cash of any
               Convertible Securities, whether or not the right of conversion or
               exchange thereunder is immediately exercisable, and the price per
               share for which Common Stock is issuable upon the conversion or
               exchange of such Convertible Securities (determined by dividing
               (x) the total amount of consideration received by the Company for
               the sale of such Convertible Securities, plus the minimum
               aggregate amount of additional consideration, if any, other than
               such Convertible Securities, payable upon the conversion or
               exchange thereof, by (y) the total maximum number of shares of
               Common Stock issuable upon the conversion or exchange of such
               convertible Securities) is less than the Market Price of the
               Common Stock on the date of the sale of such Convertible
               Securities, then the total maximum number of shares of Common
               Stock issuable upon the conversion or exchange of such
               Convertible Securities (as of the date of the sale of such
               Convertible Securities) shall be deemed to be outstanding shares
               of Common Stock for purposes of Sections 8(a) and 8(b)
               hereof and shall 



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               be deemed to have been sold for cash in an amount equal to such
               price per share.

                      (E) If the exercise or purchase price provided for in any
               right, warrant or option referred to in (C) above, or the rate at
               which any Convertible Securities referred to in (C) or (D) above
               are convertible into or exchangeable for Common Stock, shall
               change at any time (other than under or by reason of provisions
               designed to protect against dilution), the Purchase Price then in
               effect hereunder shall forthwith be readjusted to such Purchase
               Price as would have obtained (1) had the adjustments made upon
               the issuance or sale of such rights, warrants, options or
               Convertible Securities been made upon the basis of the issuance
               of only the number of shares of Common Stock theretofore actually
               delivered (and the total consideration received therefor) upon
               the exercise of such rights, warrants or options or upon the
               conversion or exchange of such Convertible Securities, (2) had
               adjustments been made on the basis of the Purchase Price as
               adjusted under clause (1) for all transactions (which would have
               affected such adjusted Purchase Price) made after the issuance or
               sale of such rights, warrants, options or Convertible Securities,
               and (3) had any such rights, warrants, options or Convertible
               Securities then still outstanding been originally issued or sold
               at the time of such change. On the expiration of any such right,
               warrant or option or the termination of any such right to convert
               or exchange any such Convertible Securities, the Purchase Price
               then in effect hereunder shall forthwith be readjusted to such
               Purchase Price as would have obtained (a) had the adjustments
               made upon the issuance or sale of such rights, warrants, options
               or Convertible Securities been made upon the basis of the
               issuance of only the number of shares of Common Stock theretofore
               actually delivered (and the total consideration received
               therefor) upon the exercise of such rights, warrants or options
               or upon the conversion or exchange of such Convertible Securities
               and (b) had adjustments been made on the basis of the Purchase
               Price as adjusted under clause (a) for all transactions (which
               would have affected such adjusted Purchase Price) made after the
               issuance or sale of such rights, warrants, options or Convertible
               Securities.

                      (F) In case of the sale for cash of any shares of Common
               Stock, any Convertible Securities, any rights or warrants to
               subscribe for or purchase, or any options for the purchase of,
               Common Stock or Convertible Securities, the consideration
               received by the Company therefore shall be deemed to be the gross
               sales price therefor without deducting therefrom any expense paid
               or incurred by the Company or any underwriting discounts or
               commissions or concessions paid or allowed by the Company in
               connection therewith.

               (g) No adjustment to the Purchase Price of the Warrants or to the
number of shares of Common Stock purchasable upon the exercise of each Warrant
will be made, 



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however,

                    (i) upon the exercise of any of the options presently
               outstanding under the Company's Stock Option Plans (the "Plans")
               for officers, directors and certain other key personnel of and
               consultants to, the Company; or

                   (ii) upon the grant or exercise of any other options which
               may hereafter be granted or exercised under the Plans or under
               any other employee benefit plan of the Company; or

                  (iii) upon the sale or exercise of the Warrants or any other
               Warrants issued by the Company, including the warrants to be
               issued to Commonwealth in connection with the Private Placement;
               or

                   (iv) upon the issuance or sale of Common Stock or Convertible
               Securities upon the exercise of any rights or warrants to
               subscribe for or purchase, or any options for the purchase of,
               Common Stock or Convertible Securities, whether or not such
               rights, warrants or options were outstanding on the date of the
               original sale of the Warrants or were thereafter issued or sold;
               or

                    (v) upon the issuance or sale of Common Stock upon
               conversion or exchange of any Convertible Securities, whether or
               not any adjustment in the Purchase Price was made or required to
               be made upon the issuance or sale of such Convertible Securities
               and whether or not such Convertible Securities were outstanding
               on the date of the original sale of the Warrants or were
               thereafter issued or sold; or

                   (vi) upon any amendment to or change in the terms of any
               rights or warrants to subscribe for or purchase, or options for
               the purchase of, Common Stock or Convertible Securities or in the
               terms of any Convertible Securities, including, but not limited
               to, any extension of any expiration date of any such right,
               warrant or option, any change in any exercise or purchase price
               provided for in any such right, warrant or option, any extension
               of any date through which any Convertible Securities are
               convertible into or exchangeable for Common Stock or any change
               in the rate at which any Convertible Securities are convertible
               into or exchangeable for Common Stock (other than rights,
               warrants, options or Convertible Securities issued or sold after
               the close of business on the date of the original issuance of the
               Warrants (i) for which an adjustment in the Purchase Price then
               in effect was theretofore made or required to be made, upon the
               issuance or sale thereof, or (ii) for which such an adjustment
               would have been required had the exercise or purchase price of
               such rights, warrants or options at the time of the issuance or
               sale thereof or the rate of conversion or exchange of such
               Convertible Securities, at the time of the sale



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               of such Convertible Securities, or the issuance or sale of rights
               or warrants to subscribe for or purchase, or options for the
               purchase of, such Convertible Securities, been the price or rate
               as changed, in which case the provisions of Section 8(f)(E)
               hereof shall be applicable if, but only if, the exercise or
               purchase price thereof, as changed, or the rate of conversion or
               exchange thereof, as changed, consists of cash or requires the
               payment of additional consideration, if any, consisting of cash
               and the Company did not receive any consideration other than
               cash, if any, in connection with such change).

               (h) As used in this Section 8, the term "Common Stock" shall mean
and include the Company's Common Stock authorized on the date of the original
issue of the Units and shall also include any capital stock of any class of the
Company thereafter authorized which shall not be limited to a fixed sum or
percentage in respect of the rights of the holders thereof to participate in
dividends and in the distribution of assets upon the voluntary liquidation,
dissolution or winding up of the Company; provided, however, that the shares
issuable upon exercise of the Warrants shall include only shares of such class
designated in the Company's Certificate of Incorporation, as amended, as Common
Stock on the date of the original issue of the Units or (i), in the case of any
reclassification, change, consolidation, merger, sale or conveyance of the
character referred to in Section 8(c) hereof, the stock, securities or property
provided for in such section or (ii), in the case of any reclassification or
change in the outstanding shares of Common Stock issuable upon exercise of the
Warrants as a result of a subdivision or combination or consisting of a change
in par value, or from par value to no par value, or from no par value to par
value, such shares of Common Stock as so reclassified or changed.

               (i) Any determination as to whether an adjustment in the Purchase
Price in effect hereunder is required pursuant to Section 8, or as to the amount
of any such adjustment, if required, shall be binding upon the holders of the
Warrants and the Company if made in good faith by the Board of Directors of the
Company.

               (j) If and whenever the Company shall declare any dividends or
distributions or grant to the holders of Common Stock, as such, rights or
warrants to subscribe for or to purchase, or any options for the purchase of,
Common Stock or securities convertible into or exchangeable for or carrying a
right, warrant or option to purchase Common Stock, the Company shall notify each
of the then Registered Holders of the Warrants of such event prior to its
occurrence to enable such Registered Holders to exercise their Warrants and
participate as holders of Common Stock in such event.

               SECTION 9.    Redemption.

               (a) On not less than thirty (30) days' notice given at any time
after the date hereof (the "Redemption Notice"), to Registered Holders of the
Warrants being redeemed, the Warrants may be redeemed, at the option of the
Company, at a redemption price of $0.25 per 



                                      -12-

<PAGE>   13

Warrant, provided (i) the Market Price of the Common Stock shall equal or exceed
$4.50 per share (the "Target Price"), subject to adjustment as set forth in
Section 9(f), below and (ii) there is an effective registration statement
covering the shares of Common Stock issuable upon exercise of the Warrants. All
Warrants must be redeemed if any are redeemed. For purposes of this Section 9,
the Calculation Date shall mean a date within 15 days of the mailing of the
Redemption Notice. The date fixed for redemption of the Warrants is referred to
herein as the "Redemption Date".

               (b) If the conditions set forth in Section 9(a) are met, and the
Company desires to exercise its right to redeem the Warrants, it shall mail a
Redemption Notice to each of the Registered Holders of the Warrants to be
redeemed, first class, postage prepaid, not later than the thirtieth day before
the date fixed for redemption, at their last address as shall appear on the
records maintained pursuant to Section 6(b). Any notice mailed in the manner
provided herein shall be conclusively presumed to have been duly given whether
or not the Registered Holder receives such notice.

               (c) The Redemption Notice shall specify (i) the redemption price,
(ii) the Redemption Date, (iii) the place where the Warrant Certificates shall
be delivered and the redemption price paid, (iv) that the right to exercise the
Warrant shall terminate at 5:00 P.M. (New York time) on the business day
immediately preceding the Redemption Date. No failure to mail such notice nor
any defect therein or in the mailing thereof shall affect the validity of the
proceedings for such redemption except as to a Registered Holder (a) to whom
notice was not mailed or (b) whose notice was defective. An affidavit of the
Company that notice of redemption has been mailed shall, in the absence of
fraud, be prima facie evidence of the facts stated therein.

               (d) Any right to exercise a Warrant shall terminate at 5:00 P.M.
(New York time) on the business day immediately preceding the Redemption Date.
On and after the Redemption Date, Registered Holders of the Warrants shall have
no further rights except to receive, upon surrender of the Warrant, payment of
the Redemption Price.

               (e) From and after the Redemption Date, the Company shall, at the
place specified in the Redemption Notice, upon presentation and surrender to the
Company by or on behalf of the Registered Holder thereof of one or more Warrant
Certificates evidencing Warrants to be redeemed, deliver or cause to be
delivered to or upon the written order of such Registered Holder a sum in cash
equal to the Redemption Price of each such Warrant. From and after the
Redemption Date and upon the deposit or setting aside by the Company of a sum
sufficient to redeem all the Warrants called for redemption, such Warrants shall
expire and become void and all rights hereunder and under the Warrant
Certificates, except the right to receive payment of the Redemption Price, shall
cease.

               (f) If the shares of Common Stock are subdivided or combined into
a greater or smaller number of shares of Common Stock, the Target Price shall be
proportionally



                                      -13-

<PAGE>   14

adjusted by the ratio which the total number of shares of Common Stock
outstanding immediately prior to such event bears to the total number of shares
of Common Stock to be outstanding immediately after such event.

               SECTION 10.   Registration Under The Securities Act of 1933.

               The Company agrees to register for resale the shares of Common
Stock issued or issuable upon exercise of Warrants under the Securities Act of
1933, as amended (the "Act") as more fully set forth in Section IV of the
Subscription Agreement between the Company and each of the investors in the
Private Placement.

               SECTION 11.   Fractional Warrants and Fractional Shares.

               (a) If the number of shares of Common Stock purchasable upon the
exercise of each Warrant is adjusted pursuant to Section 8 hereof, the Company
shall nevertheless not be required to issue fractions of shares of Common Stock,
upon exercise of the Warrants or otherwise, or to distribute certificates that
evidence fractional shares. With respect to any fraction of a share of Common
Stock called for upon any exercise of a Warrant, the Company shall pay to the
Registered Holder an amount in cash equal to such fraction multiplied by the
current market value of such fractional share, determined as follows:

                      (1) If the Common Stock is listed on a national securities
               exchange or admitted to unlisted trading privileges on such
               exchange or listed for trading on the Nasdaq National Market
               System or Nasdaq SmallCap Market, the current market value shall
               be the last reported sale price of the Common Stock on such
               exchange on the last trading day prior to the date of exercise of
               the applicable Warrant or if no such sale is made on such day or
               no last reported sale price is quoted, the average of the closing
               bid and asked prices for such day on such exchange or system; or

                      (2) If the Common Stock is listed in the over-the-counter
               market (other than on Nasdaq) or admitted to unlisted trading
               privileges, the current market value shall be the mean of the
               last reported bid and asked prices reported by the National
               Quotation Bureau, Inc. on the last business day prior to the date
               of the exercise of this Warrant; or

                      (3) If the Common Stock is not so listed or admitted to
               unlisted trading privileges and bid and asked prices are not so
               reported, the current market value shall be an amount determined
               in such reasonable manner as may be prescribed by the Board of
               Directors of the Company.

               SECTION 12. Warrant Holders Not Deemed Stockholders. No Holder of
Warrants shall, as such, be entitled to vote or to receive dividends or be
deemed the Holder of 



                                      -14-

<PAGE>   15

Common Stock that may at any time be issuable upon exercise of such Warrants for
any purpose whatsoever, nor shall anything contained herein be construed to
confer upon the holder of Warrants, as such, any of the rights of a stockholder
of the Company or any right to vote for the election of directors or upon any
matter submitted to stockholders at any meeting thereof, or to give or withhold
consent to any corporate action (whether upon any recapitalization, issue or
reclassification of stock, change of par value or change of stock to no par
value, consolidation, merger or conveyance or otherwise), or to receive notice
of meetings, or to receive dividends or subscription rights, until such Holder
shall have exercised an applicable Warrant and been issued shares of Common
Stock with respect thereto in accordance with the provisions hereof.

               SECTION 13. Rights of Action. All rights of action with respect
to this Agreement are vested in the respective Registered Holders of the
Warrants, and any Registered Holder of a Warrant, without consent of the Company
or of the holder of any other Warrant, may, on its own behalf and for its own
benefit, enforce against the Company his right to exercise its Warrant for the
purchase of shares of Common Stock in the manner provided in the Warrant
Certificate and this Agreement.

               SECTION 14. Agreement of Warrant Holders. Every holder of a
Warrant, by his acceptance thereof, consents and agrees with the Company, and
every other holder of a Warrant that:

               (a) The Warrants are transferable only on the registry books of
the Company by the Registered Holder thereof in person or by his attorney duly
authorized in writing and only if the Warrant Certificates representing such
Warrants are surrendered at the Corporate Office of the Company, duly endorsed
or accompanied by a proper instrument of transfer satisfactory to the Company in
their sole discretion, together with payment of any applicable transfer taxes;
and

               (b) The Company may deem and treat the person in whose name the
Warrant Certificate is registered as the holder and as the absolute, true and
lawful owner of the Warrants represented thereby for all purposes, and the
Company shall not be affected by any notice or knowledge to the contrary, except
as otherwise expressly provided in Section 7 hereof.

               SECTION 15. Cancellation of Warrant Certificates. If the Company
shall purchase or acquire any Warrant or Warrants, the Warrant Certificate or
Warrant Certificates evidencing the same shall thereupon be cancelled by the
Company and retired; the Company shall also cancel Common Stock following
exercise of any or all of the Warrants represented thereby or delivered to it
for transfer, splitup, combination or exchange.

               SECTION 16. Modification of Agreement. Subject to the provisions
of Section 4(b), the parties hereto may by supplemental agreement make any
changes or 



                                      -15-

<PAGE>   16

corrections in this Agreement (i) that it shall deem appropriate to
cure any ambiguity or to correct any defective or inconsistent provision or
manifest mistake or error herein contained; (ii) to reflect an increase in the
number of Warrants which are to be governed by this Agreement pursuant to the
adjustment provisions of Section 8 hereof or resulting from an increase in the
size of the Private Placement; or (iii) that it may deem necessary or desirable
and which shall not adversely affect the interests of the holders of Warrant
Certificates; provided, however, that this Agreement shall not otherwise be
modified, supplemented or altered in any respect except with the consent in
writing of the Registered Holders of Warrant Certificates representing not less
than 50% of the Warrants then outstanding; and provided, further, that no change
in the number or nature of the securities purchasable upon the exercise of any
Warrant, or the Purchase Price therefor, or the acceleration of the Warrant
Expiration Date, shall be made without the consent in writing of the Registered
Holder of the Warrant Certificate representing such Warrant, other than as
otherwise provided herein.

               SECTION 17. Notices. All notices, requests, consents and other
communications hereunder shall be in writing and shall be deemed to have been
made when delivered or mailed first class registered or certified mail, postage
prepaid as follows: if to the Registered Holder of a Warrant Certificate, at the
address of such holder as shown on the registry books maintained by the Warrant
Agent; if to the Company, at 900 North Franklin Street, Suite 401, Chicago, IL
60610, Attention: Paul F. Lavallee, Chairman and Chief Executive Officer; and if
to Commonwealth at Commonwealth Associates, 830 Third Avenue, New York, New York
10022, Attention: Keith Rosenbloom.

               SECTION 18. Governing Law. This Agreement shall be governed by
and construed in accordance with the laws of the State of New York, without
reference to principles of conflict of laws.

               SECTION 19. Binding Effect. This Agreement shall be binding upon
and inure to the benefit of the Company (and their respective successors and
assigns) and the Registered Holders from time to time of Warrant Certificates.
Nothing in this Agreement is intended or shall be construed to confer upon any
other person any right, remedy or claim, in equity or at law, or to impose upon
any other person any duty, liability or obligation.

               SECTION 20. Termination. This Agreement shall terminate on the
earlier to occur of (i) the close of business on the Expiration Date of all the
Warrants; or (ii) the date upon which all Warrants have been exercised.

               SECTION 21. Counterparts. This Agreement may be executed in two
or more counterparts, each of which shall constitute an original and all of
which together shall constitute a single document.

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



                                      -16-


<PAGE>   17

                                       ACCUMED INTERNATIONAL, INC.



                                       By:    /s/ PAUL F. LAVALLEE, Chairman and
                                                      Chief Executive Officer


                                       COMMONWEALTH ASSOCIATES


                                       By:    /s/ JOSEPH P. WYNNE



                                      -17-

<PAGE>   18



THIS WARRANT AND ANY SHARES OF COMMON STOCK ISSUABLE UPON ITS EXERCISE HAVE NOT
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES
ACT") AND MAY NOT BE TRANSFERRED UNTIL (1) A REGISTRATION STATEMENT UNDER THE
SECURITIES ACT SHALL HAVE BECOME EFFECTIVE WITH RESPECT THERETO, OR (2) RECEIPT
BY THE ISSUER OF AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE ISSUER TO
THE EFFECT THAT REGISTRATION UNDER THE SECURITIES ACT IS NOT REQUIRED IN
CONNECTION WITH SUCH PROPOSED TRANSFER NOR IS SUCH TRANSFER IN VIOLATION OF ANY
APPLICABLE STATE SECURITIES LAWS.

No.                                                                     Warrants


                          VOID AFTER ____________, 2005

                        WARRANT CERTIFICATE FOR PURCHASE
                                 OF COMMON STOCK

                           ACCUMED INTERNATIONAL, INC.


               This certifies that FOR VALUE RECEIVED ________________________
or registered assigns (the "Registered Holder") is the owner of the number of
Warrants ("Warrants") specified above. Each Warrant initially entitles the
Registered Holder to purchase, subject to the terms and conditions set forth in
this Certificate and the Warrant Agreement (as hereinafter defined), one fully
paid and nonassessable share of Common Stock, $0.01 par value per share ("Common
Stock") of AccuMed International, Inc., a Delaware corporation (the "Company"),
at any time commencing on , 1998, with respect to Warrants to purchase up to
________ shares ( %) of Common Stock represented hereby, and (ii) the date in
which the Company has a sufficient number of authorized shares of Common Stock
reserved for issuance (after taking into account all shares reserved for
issuance on the conversion of convertible securities and the exercise of
outstanding options and warrants) to permit the issuance of the shares of Common
Stock to be issued pursuant to the exercise of the Warrants ("Authorized Share
Date") with respect to Warrants to purchase up to _______ shares ( %) of Common
Stock represented hereby, and in both cases,and prior to the Expiration Date (as
hereinafter defined), upon the presentation and surrender of this Warrant
Certificate with the Exercise Form on the reverse hereof properly completed and
duly executed, at the corporate office of the Company, accompanied by payment of
an amount equal to $_______ for each Warrant (the "Purchase Price") in lawful
money of the United States of America in cash or by official bank or certified
check made payable to AccuMed International, Inc. The Company may, at its
election, reduce the Purchase Price.

               This Warrant Certificate and each Warrant represented hereby are
issued 



                                      A-1

<PAGE>   19

pursuant to and are subject in all respects to the terms and conditions set
forth in the Warrant Agreement (the "Warrant Agreement"), dated March __, 1998
between the Company and Commonwealth Associates in connection with a private
placement (the "Private Placement") of Units of the Company.

               In the event of certain contingencies provided for in the Warrant
Agreement, the Purchase Price or the number of shares of Common Stock subject to
purchase upon the exercise of each Warrant represented hereby are subject to
modification or adjustment.

               Each Warrant represented hereby is exercisable at the option of
the Registered Holder, but no fractional shares of Common Stock will be issued
in respect thereto. In the case of the exercise of less than all the Warrants
represented hereby, the Company shall cancel this Warrant Certificate upon the
surrender hereof and shall execute and deliver to the Registered Holder a new
Warrant Certificate or Warrant Certificates of like tenor, which the Company
shall countersign, for the balance of such Warrants.

               The term "Expiration Date" shall mean 5:00 P.M. (New York time)
on March __, 2005, or such earlier date as the Warrants shall be redeemed,
provided that if such date shall in the State of New York be a holiday or a day
on which the banks are authorized to close, then the Expiration Date shall mean
5:00 P.M. (New York time) the next following day which in the State of New York
is not a holiday or a day on which banks are authorized to close. The Company
may, at its sole election, extend the Expiration Date.

               This Warrant Certificate is exchangeable, upon the surrender
hereof by the Registered Holder at the corporate office of the Company, for a
new Warrant Certificate or Warrant Certificates of like tenor representing an
equal aggregate number of Warrants, each of such new Warrant Certificates to
represent such number of Warrants as shall be designated by such Registered
Holder at the time of such surrender. Upon due presentment with any tax or other
governmental charge imposed in connection therewith, for registration of
transfer of this Warrant Certificate at such office, a new Warrant Certificate
or Warrant Certificates representing an equal aggregate number of Warrants will
be issued to the transferee in exchange therefor, subject to the limitations
provided in the Warrant Agreement.

               Prior to the exercise of any Warrant represented hereby, the
Registered Holder shall not be entitled to any of the rights of a stockholder of
the Company, including, without limitation, the right to vote or to receive
dividends or other distributions, and shall not be entitled to receive any
notice of any proceedings of the Company, except as provided in the Warrant
Agreement.

               The Warrants represented hereby may be redeemed at the option of
the Company, at a redemption price of $.25 per Warrant at any time after the
date hereof, provided (i) the Market Price (as defined in the Warrant Agreement)
for the Common Stock shall equal or exceed $4.50 per share and (ii) there is an
effective registration statement 



                                      A-2

<PAGE>   20

covering the shares of Common Stock issuable upon exercise of the Warrants.
Notice of redemption shall be given not later than the thirtieth day before the
date fixed for redemption, all as provided in the Warrant Agreement. On and
after the date fixed for redemption, the Registered Holder shall have no rights
with respect to the Warrants represented hereby except to receive the $.25 in
cash per Warrant upon surrender of this Warrant Certificate.

               Prior to due presentment for registration of transfer hereof, the
Company may deem and treat the Registered Holder as the absolute owner hereof
and of each Warrant represented hereby (notwithstanding any notations of
ownership or writing hereon made by anyone other than a duly authorized officer
of the Company) for all purposes and shall not be affected by any notice to the
contrary.

               This Warrant Certificate shall be governed by and construed in
accordance with the laws of the State of New York without regard to the conflict
of law provisions thereof.

               IN WITNESS WHEREOF, the Company has caused this Warrant
Certificate to be duly executed, manually or in facsimile by two of its officers
thereunto duly authorized and a facsimile of its corporate seal to be imprinted
hereon.

                                            ACCUMED INTERNATIONAL, INC.


Dated:  _____________, 1998

                                            By:_____________________________


                                            By:______________________________
[seal]


Attest:



_____________________________
Joyce Wallach
Secretary and General Counsel



                                       A-3

<PAGE>   21



                               NOTICE OF EXERCISE

                     To Be Executed by the Registered Holder
                          in Order to Exercise Warrants

               The undersigned Registered Holder hereby irrevocably elects to
exercise ______________________ Warrants represented by this Warrant
Certificate, and to purchase the securities issuable upon the exercise of such
Warrants, and requests that certificates for such securities shall be issued in
the name of

            PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER

                     _______________________________________
                     _______________________________________
                     _______________________________________
                     _______________________________________
                     [please print or type name and address]

and be delivered to

                     _______________________________________
                     _______________________________________
                     _______________________________________
                     _______________________________________
                     [please print or type name and address]

and if such number of Warrants shall not be all the Warrants evidenced by this
Warrant Certificate, that a new Warrant Certificate for the balance of such
Warrants be registered in the name of, and delivered to, the Registered Holder
at the address stated below.

               The undersigned represents that the exercise of the within
Warrant was solicited by a member of the National Association of Securities
Dealers, Inc. If not solicited by an NASD member, please write "unsolicited" in
the space below.

                                            ____________________________________
                                            (Name of NASD Member)
Dated:  ______________________
X______________________
        _________________
        __________________
                                     Address

                                            ______________________
Taxpayer Identification Number

__________________________
Signature Guaranteed

____________________



                                       A-4

<PAGE>   22



                                   ASSIGNMENT


                     To Be Executed by the Registered Holder
                           in Order to Assign Warrants


FOR VALUE RECEIVED, ___________________ hereby sells, assigns and transfers unto


                   PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER




                     _______________________________________
                     _______________________________________
                     _______________________________________
                     _______________________________________
                     [please print or type name and address]


                                                            
_________________________ of the Warrants represented by this Warrant
Certificate, and hereby irrevocably constitutes and appoints
___________________________________________________________________ Attorney to
transfer this Warrant Certificate on the books of the Company, with full power
of substitution in the premises.


Dated:  ____________________
X________________________

Signature Guaranteed


_________________________


THE SIGNATURE TO THE ASSIGNMENT OR THE SUBSCRIPTION FORM MUST CORRESPOND TO THE
NAME AS WRITTEN UPON THE FACE OF THIS WARRANT CERTIFICATE IN EVERY PARTICULAR,
WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATSOEVER, AND MUST BE
GUARANTEED BY A COMMERCIAL BANK OR TRUST COMPANY OR A MEMBER FIRM OF THE
AMERICAN STOCK EXCHANGE, NEW YORK STOCK EXCHANGE, PACIFIC STOCK EXCHANGE OR
MIDWEST STOCK EXCHANGE.



                                       A-5

<PAGE>   23


                                    AMENDMENT
                                     TO THE
                                WARRANT AGREEMENT



        Amendment No. 1 to the Warrant Agreement (the "Warrant Agreement") dated
March 19, 1998 between AccuMed International, Inc., a Delaware corporation (the
"Company"), and Commonwealth Associates (the "Placement Agent"). Capitalized
terms not otherwise defined herein shall have the respective meanings set forth
in the Warrant Agreement.

        The parties hereto agree to the following amendments to the terms of the
Warrant Agreement:

        1. The number "8,000,000" in the first "WHEREAS" clause is hereby
deleted and the number "8,686,667" is inserted in lieu thereof.

        2. Section 1(d) of the Warrant Agreement is hereby deleted, and the
following is inserted in lieu thereof:

               "(d) "Initial Warrant Exercise Date" shall mean (i) March 19,
        1998 with respect to Warrants to purchase up to 3,456,424 shares
        (39.79%) of Common Stock issuable pursuant to this Warrant Agreement and
        (ii) the date in which the Company has a sufficient number of authorized
        shares of Common Stock reserved for issuance (after taking into account
        all shares reserved for issuance on the conversion of convertible
        securities and the exercise of outstanding options and warrants) to
        permit the issuance of the shares of Common Stock to be issued pursuant
        to the exercise of the Warrants ("Authorized Share Date") with respect
        to Warrants to purchase up to 5,230,243 shares (60.21%) of Common Stock
        issuable pursuant to this Warrant Agreement.

        3. The date "March 19, 2005" in Section 1(i) is hereby deleted and the
date "March 23, 2005" is inserted in lieu thereof.

        4. The number "8,000,000" in Section 2(b) is hereby deleted and the
number "8,686,667" is inserted in lieu thereof.



<PAGE>   24


        Except as expressly provided herein, the terms of the Warrant Agreement
shall remain in full force and effect without modification or amendment.

        IN WITNESS WHEREOF, the parties have caused this Amendment No. 1 to be
executed as of March 23, 1998.

                                   ACCUMED INTERNATIONAL, INC.



                                   By: /s/ PAUL F. LAVALLEE
                                      ---------------------
                                      Name:  Paul F. Lavallee
                                      Title: Chairman, Chief Executive Officer
                                                       and President


                                   COMMONWEALTH ASSOCIATES,
                                   a New York limited partnership

                                   By:  COMMONWEALTH MANAGEMENT CO., INC.,
                                   a New York corporation, its general partner



                                   By: \s\ JOSEPH D. WYNNE
                                      ---------------------
                                      Name: Joseph D. Wynne
                                      Title: Chief Financial Officer



                                       -7-