Document:

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                                   Exhibit 4.7

         Senior Subordinated Debenture to Shoreline Micro-Cap Fund, L.P.

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE UNITED
STATES SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"). THE HOLDER
HEREOF, BY PURCHASING SUCH SECURITIES AGREES FOR THE BENEFIT OF THE COMPANY THAT
SUCH SECURITIES MAY BE OFFERED, SOLD OR OTHERWISE TRANSFERRED ONLY (A) TO THE
COMPANY, (B) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES
ACT, OR (C) IF REGISTERED UNDER THE SECURITIES ACT AND ANY APPLICABLE STATE
SECURITIES LAWS. IN ADDITION, A SECURITIES PURCHASE AGREEMENT, DATED AS OF THE
DATE HEREOF, A COPY OF WHICH MAY BE OBTAINED FROM THE COMPANY AT ITS PRINCIPAL
EXECUTIVE OFFICE, CONTAINS CERTAIN ADDITIONAL AGREEMENTS AMONG THE PARTIES,
INCLUDING, WITHOUT LIMITATION, PROVISIONS WHICH (A) LIMIT THE CONVERSION RIGHTS
OF THE HOLDER, (B) SPECIFY VOLUNTARY AND MANDATORY REPAYMENT, PREPAYMENT AND
REDEMPTION RIGHTS AND OBLIGATIONS AND (C) SPECIFY EVENTS OF DEFAULT FOLLOWING
WHICH THE REMAINING BALANCE DUE AND OWING HEREUNDER MAY BE ACCELERATED.

No.  3                                                               $220,000.00

                  3% SENIOR SUBORDINATED CONVERTIBLE DEBENTURE
                                       of

         Boston Biomedica, Inc., a Massachusetts corporation (together with its
successors, the "Company"), for value received hereby promises to pay to:

                         SHORELINE MICRO-CAP FUND, L.P.

(The "Holder") and registered assigns, the principal sum of $220,000.00 or, if
less, the principal amount of this Senior Subordinated Convertible Debenture
(this "Convertible Debenture") then outstanding, on the Maturity Date by wire
transfer of immediately available funds to the Holder in such coin or currency
of the United States of America as at the time of payment shall be legal tender
for the payment of public and private debts, and to pay interest which shall
accrue beginning the date hereof, quarterly in arrears, on (i) the last day of
March, June, September and December of each year until the Maturity Date,
commencing September 30, 2000 (unless such day is not a Business Day, in which
event on the next succeeding Business Day) (each an "Interest Payment Date"),
(ii) the Maturity Date, (iii) each Conversion Date, as hereafter defined, and
(iv) the date the principal amount of the Convertible Debentures shall be
declared to be or shall automatically become due and

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payable, on the principal sum hereof outstanding in like coin or currency, at
the rates per annum set forth below, from the most recent Interest Payment Date
to which interest has been paid on this Convertible Debenture, or if no interest
has been paid on this Convertible Debenture, from the date of this Convertible
Debenture until payment in full of the principal sum hereof has been made. The
Maturity Date is August 25, 2003.

         The interest rate shall be three percent (3%) per annum (the "Interest
Rate") or, if less, the maximum rate permitted by applicable law. Past due
amounts (including interest, to the extent permitted by law) will also accrue
interest at the Interest Rate plus 2% per annum or, if less, the maximum rate
permitted by applicable law, and will be payable on demand ("Default Interest").
Interest on this Convertible Debenture will be calculated on the basis of a
360-day year of twelve 30 day months. All payments of principal and interest
hereunder shall be made for the benefit of the Holder pursuant to the terms of
the Agreement (hereafter defined). At the option of the Company, interest may be
paid in cash or in shares of Common Stock. If the Company determines to pay
interest in shares of Common Stock, it shall be required to notify the Holder of
such election on the Closing Date. On each Conversion Date, interest shall be
paid in shares of Common Stock on the portion of the principal balance of the
Convertible Debenture then being converted. The number of shares of Common Stock
issued as interest shall be determined by dividing the dollar amount of interest
due on the applicable Interest Payment Date by the Conversion Price then in
effect.

         This Convertible Debenture is a duly authorized issuance of Convertible
Debentures of the Company referred to in that certain Securities Purchase
Agreement dated as of the date hereof between the Company and the Purchaser
named therein (the "Agreement"). The Agreement contains certain additional
agreements among the parties with respect to the terms of this Convertible
Debenture, including, without limitation, provisions which (A) limit the
conversion rights of the Holder, (B) specify voluntary and mandatory repayment,
prepayment and redemption rights and obligations and (C) specify Events of
Default following which the remaining balance due and owing hereunder may be
accelerated. All such provisions are an integral part of this Convertible
Debenture and are incorporated herein by reference. This Convertible Debenture
is transferable and assignable to one or more Persons, in accordance with the
limitations set forth in the Agreement.

         This Convertible Debenture shall rank senior to any indebtedness of the
Company except (a) the Company's outstanding credit facility with Fleet Bank and
any successor thereof, including increases to such credit facility; (b) the
Company's mortgage loan with Commerce Bank; and (c) any future sale and lease
back transaction in connection with the Company's headquarters building in West
Bridgewater, MA, to which it shall be junior in ranking. This Convertible
Debenture shall rank on a pari passu basis with the Company's outstanding 3%
convertible debentures.

         The Company shall keep a register (the "Register") in which shall be
entered the names and addresses of the registered holder of this Convertible
Debenture and particulars of this Convertible Debenture held by such holder and
of all transfers of this Convertible Debenture. References to the Holder or
"Holders" shall mean the Person listed in the Register as registered holder of
such

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Convertible Debentures. The ownership of this Convertible Debenture shall be
proven by the Register.

         1.       CERTAIN TERMS DEFINED. All terms defined in the Agreement and
not otherwise defined herein shall have for purposes hereof the meanings
provided for in the Agreement.

         2.       COMPANY COVENANTS. The Company covenants and agrees to observe
and perform each of its covenants, obligations and undertakings contained in the
Agreement, which obligations and undertakings are expressly assumed herein by
the Company and made for the benefit of the holder hereof.

         3.       PAYMENT OF PRINCIPAL. The Company shall repay the remaining
unpaid balance of this Convertible Debenture on the Maturity Date. The Company
may, and shall be obligated to, prepay all or a portion of this Convertible
Debenture on the terms specified in the Agreement.

         4.       CONVERSION.

         4.1      CONVERSION OF CONVERTIBLE DEBENTURE. Subject to Section 5
         hereof, the Holder shall have the right, at its option, at any time
         from and after the 90th day following the date of issuance of this
         Convertible Debenture, to convert the principal amount of this
         Convertible Debenture, or any portion of such principal amount, into
         that number of fully paid and nonassessable shares of Common Stock (as
         such shares shall then be constituted) determined pursuant to this
         Section 4.1. The number of shares of Common Stock to be issued upon
         each conversion of this Convertible Debenture shall be determined by
         dividing the Conversion Amount (as defined below) by the Conversion
         Price in effect on the date (the "Conversion Date") a Notice of
         Conversion is delivered to the Company, as applicable, by the Holder by
         facsimile dispatched prior to 5:00 p.m., E.S.T. Prior to sending the
         facsimile Notice of Conversion to the Company, the Holder shall notify
         the Company of such conversion by telephone to one of the following
         individuals on the following order of priority: (1) Richard T.
         Schumacher, (2) Kevin Quinlan and (3) Kathi Benjamin (or to each of the
         individual's voicemail if none of the individuals is available) as set
         forth in Section 4.4 hereto. The Company may change the individuals to
         whom such telephone notice shall be directed by notifying the Holder of
         any such change. The term "Conversion Amount" means, with respect to
         any conversion of this Convertible Debenture, the sum of (1) the
         principal amount of this Convertible Debenture to be converted in such
         conversion plus (2) accrued and unpaid interest, if any, on such
         principal amount at the interest rates provided in this Convertible
         Debenture to the Conversion Date plus (3) Default Interest, if any, on
         the interest referred to in the immediately preceding clause (2) plus
         (4) at the Holder's option, any amounts owed to the Holder pursuant to
         Section 4.3 hereof, Section 10.1 of the Agreement or Section 10.4 of
         the Agreement.

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         4.2      CONVERSION PRICE. At the option of the Holder, any portion or
         all of the outstanding principal amount of this Convertible Debenture
         shall be converted into a number of shares of Common Stock at the
         conversion price (the "Conversion Price") equal to the lesser of (i)
         110% of the volume weighted average sales price of the Common Stock, as
         reported by Bloomberg L.P. on the day immediately preceding the Closing
         Date (the "Fixed Conversion Price") and (ii) 90% of the average of the
         five (5) lowest volume weighted average sales prices of the Common
         Stock as reported by Bloomberg L.P. during the 25 Trading Days
         immediately preceding but not including the date of the related Notice
         of Conversion (the "Formula Conversion Price").

         4.3      AUTHORIZED SHARES.

                  (1) Consistent with Section 7.11 of the Agreement, the Company
         (i) shall promptly irrevocably instruct the Company's transfer agent to
         issue certificates for the Common Stock issuable upon conversion of
         this Convertible Debenture and (ii) agrees that its issuance of this
         Convertible Debenture shall constitute full authority to its officers
         and agents who are charged with the duty of executing stock
         certificates to execute and issue the necessary certificates for shares
         of Common Stock in accordance with the terms and conditions of this
         Convertible Debenture.

                  (2) If at any time a Holder of this Convertible Debenture
         submits a Notice of Conversion (x) the Company does not have sufficient
         authorized but unissued shares of Common Stock available to effect such
         conversion in full in accordance with the provisions of this Article 4
         or (y) the Company is prohibited by the applicable rules of the OTC
         Bulletin Board or the National Market on which the shares of Common
         Stock are listed and traded at that time to effect such conversion in
         full as provided in subsection (3) below, without stockholder approval
         (each, a "Conversion Default"), the Company shall issue to the Holder
         all of the shares of Common Stock which are then available to effect
         such conversion. The portion of this Convertible Debenture which the
         Holder included in its Conversion Notice and which exceeds the amount
         which is then convertible into available shares of Common Stock (the
         "Excess Amount") shall, notwithstanding anything to the contrary
         contained herein, not be convertible into Common Stock in accordance
         with the terms hereof until (and at the Holder's option at any time
         after) the date additional shares of Common Stock are authorized by the
         Company, or its stockholders, as applicable, at which time the
         Conversion Price in respect thereof shall be the lower of (i) the
         Conversion Price on the Conversion Default Date (as defined below) and
         (ii) the Conversion Price on the Conversion Date thereafter elected by
         the Holder in respect thereof. The Company shall pay to the Holder
         payments ("Conversion Default Payments") for a Conversion Default in
         the amount of (N/365) x .24 x the Excess Amount on the Conversion Date
         in respect of the Conversion Default (the "Conversion Default Date"),
         where N = the number of days from the Conversion Default Date to the
         date (the "Authorization Date") that the Company, or its stockholders,
         as applicable, authorizes a sufficient number of shares of Common Stock
         to effect conversion

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         of the full outstanding principal balance of this Convertible Debenture
         or until the Company redeems the Excess Amount in accordance with the
         terms of this Convertible Debenture. The Company shall use its best
         efforts to authorize, or cause its stockholders to authorize within 40
         days of the occurrence of a Conversion Default, as applicable, a
         sufficient number of shares of Common Stock as soon as practicable
         following the earlier of (i) such time that the Holder notifies the
         Company or that the Company otherwise becomes aware that there are or
         likely will be insufficient shares to allow full conversion thereof and
         (ii) a Conversion Default. The Company shall send notice to the Holder
         of the authorization of additional shares of Common Stock, the
         Authorization Date and the amount of Holder's accrued Conversion
         Default Payments. The accrued Conversion Default Payments for each
         calendar month shall be paid in cash or shares of Common Stock (at such
         time as there are sufficient authorized shares of Common Stock) at the
         Holder's option, as follows:

                           (a) In the event the Holder elects to take such
                  payment in cash, cash payment shall be made to Holder by the
                  fifth Business Day of the month following the month in which
                  it has accrued; and

                           (b) In the event the Holder elects to take such
                  payment in Common Stock, the Holder may convert such payment
                  amount into Common Stock at the Conversion Price (as in effect
                  at the time of payment) at any time after the fifth Business
                  Day of the month following the month in which it has accrued
                  (at such time as there are sufficient authorized shares of
                  Common Stock) in accordance with the terms of this Article 4.

                  (3) The Holder's election pursuant to this Section 4.3 shall
         be made in writing to the Company at any time prior to 5:00 p.m.,
         E.S.T., on the third Business Day of the month following the month in
         which Conversion Default payments have accrued. If no election is made,
         the Holder shall be deemed to have elected to receive cash. Nothing
         herein shall limit the Holders right to pursue actual damages (to the
         extent in excess of the Conversion Default Payments) due to the
         Company's failure to maintain a sufficient number of authorized shares
         of Common Stock.

                  (4) In no event shall the Company issue more than the Maximum
         Number of Shares upon conversion of this Convertible Debenture, unless
         the Company shall have obtained approval by the stockholders of the
         Company ("Stockholder Approval") or a waiver of such requirement by the
         OTC Bulletin Board or the National Market on which the shares of Common
         Stock are listed and traded at that time. Once the Maximum Number of
         Shares has been issued (the date of which is hereinafter referred to as
         the "Maximum Conversion Date"), unless the Company shall have obtained
         Stockholder Approval or a waiver of such requirement by the OTC
         Bulletin Board or the National Market on which the shares of Common
         Stock are listed and traded at that time within 40 days of the Maximum
         Conversion Date, the Company shall pay to the Holder within five (5)
         Business Days of the Maximum

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         Conversion Date (or, if the Company is, in good faith, using its best
         efforts to obtain Stockholder Approval, then the earlier of (x) 40 days
         following the Maximum Conversion Date, and (y) such date that it
         becomes reasonably apparent that Stockholder Approval will not be
         obtained within such 40 days period), the Redemption Price for the
         Excess Amount plus accrued and unpaid Default Interest, if any.

                  (5) The Maximum Number of Shares shall be subject to
         adjustment from time to time for stock splits, stock dividends,
         combinations, capital reorganizations and similar events relating to
         the Common Stock occurring after the date hereof as contemplated by
         Article 11 of the Agreement. With respect to each Holder of Convertible
         Debentures, the Maximum Number of Shares shall refer to such Holder's
         pro rata share thereof based upon the aggregate principal balance of
         the Convertible Debentures then outstanding. In the event that the
         Company obtains Stockholder Approval, approval of the OTC Bulletin
         Board or the National Market on which the shares of Common Stock are
         listed and traded at that time, or otherwise is able to increase the
         number of shares to be issued above the Maximum Number of Shares (such
         increased number being the "New Maximum Number of Shares"), the
         references to Maximum Number of Shares above shall be deemed to be,
         instead, references to the New Maximum Number of Shares.

         4.4      METHOD OF CONVERSION.

                  (1) Prior to sending the Notice of Conversion via facsimile as
         set forth in Section 4.1 hereof, the Holder shall give notice to
         Richard T. Schumacher by telephone (and if Mr. Schumacher is not
         available to be reached by telephone, either Kevin Quinlan or Kathi
         Benjamin by telephone, or such other person designated by the Company
         after the Closing Date) that the Holder intends to submit a Notice of
         Conversion on such date. Notwithstanding anything to the contrary set
         forth herein, upon conversion of this Convertible Debenture in
         accordance with the terms hereof, the Holder shall not be required to
         physically surrender this Convertible Debenture to the Company unless
         the entire unpaid principal amount of this Convertible Debenture is so
         converted. Rather, the Holder shall send to the Company, and the
         Company shall send to the Holder, via overnight delivery service (a)
         the originally signed and executed Notice of Conversion and (b) an
         originally signed and executed ANNEX A to this Convertible Debenture
         indicating the amounts to be converted and the new principal balance of
         this Convertible Debenture taking into account the Notice of
         Conversion. The Company shall keep as part of its records the
         originally executed ledger and the Holder shall maintain a copy
         thereof. Upon execution of the conversion contemplated by the Notice of
         Conversion, the Company and the Holder shall deliver to one another an
         executed copy of ANNEX A. It is specifically contemplated that the
         Company shall act as the calculation agent for conversions and
         repayments. In the event there is a dispute as to the number of shares
         of Common Stock the Holder is entitled to receive upon a conversion of
         this Convertible Debenture (or the amount of cash to be received upon
         repayment or redemption of this Convertible Debenture), the amount of
         any

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         payments due upon an Event of Default under this Convertible Debenture
         or the calculation of any of the foregoing, the Holder and the Company
         agree that (i) the Company shall issue to the Holder the undisputed
         number of shares of Common Stock (or pay any undisputed cash amounts
         with respect to a redemption or default payments) and (ii) each party
         will use its best efforts to resolve such dispute within one business
         day following the receipt of a Notice of Conversion (or Notice of
         Redemption, as applicable). If such dispute cannot be resolved within
         the one-day period, the Company and the Holder shall submit the dispute
         to an independent accountant mutually agreed upon by the Company and
         the Holder to make a determination as to the amounts due to the Holder.
         Any such determination shall be final and binding on the Company and
         the Holder. The Company shall issue shares of Common Stock or pay any
         cash amounts owed to the Holder as a result of the resolution of the
         dispute within two business days following the receipt of the
         independent accountant's determination. The Holder and any assignee, by
         acceptance of this Convertible Debenture, acknowledge and agree that,
         by reason of the provisions of this paragraph, following a conversion
         of a portion of this Convertible Debenture, the principal amount
         represented by this Convertible Debenture will be the amount indicated
         on the ledger evidenced by ANNEX A attached hereto (which may be less
         than the amount stated on the face hereof).

                  (2) The Company shall not be required to pay any tax which may
         be payable in respect of any transfer involved in the issuance and
         delivery of shares of Common Stock or other securities or property on
         conversion of this Convertible Debenture in a name other than that of
         the Holder (or in street name), and the Company shall not be required
         to issue or deliver any such shares or other securities or property
         unless and until the person or persons (other than the Holder or the
         custodian in whose street name such shares are to be held for the
         Holder's account) requesting the issuance thereof shall have paid to
         the Company the amount of any such tax or shall have established to the
         satisfaction of the Company that such tax has been paid.

                  (3) Subject to Section 5 hereof, upon receipt by the Company
         of a Notice of Conversion, the Holder shall be deemed to be the holder
         of record of the Common Stock issuable upon such conversion, the
         outstanding principal amount and the amount of accrued and unpaid
         interest on this Convertible Debenture shall be deemed reduced to
         reflect such conversion, and, unless the Company defaults on its
         obligations under this Article 4, all rights with respect to the
         portion of this Convertible Debenture being so converted shall
         forthwith terminate except the right to receive the Common Stock or
         other securities, cash or other assets, as herein provided, on such
         conversion. Subject to Section 5 hereof, if the Holder shall have given
         a Notice of Conversion as provided herein, the Company's obligation to
         issue and deliver the certificates for shares of Common Stock shall be
         absolute and unconditional, irrespective of the absence of any action
         by the Holder to enforce the same, any waiver or consent with respect
         to any provisions thereof, the recovery of any judgment against any
         person or any action by the Holder to enforce the same, any failure or
         delay in the enforcement of any other obligation of the Company to the
         Holder of record, or

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         any setoff, counterclaim, recoupment, limitation or termination, other
         than a breach by the Holder of any obligation to the Company, and
         subject to Section 4.4(1) irrespective of any other circumstance which
         might otherwise limit such obligation of the Company to the Holder in
         connection with such conversion. The date of receipt (including receipt
         via telecopy) of such Notice of Conversion shall be the Conversion Date
         so long as it is received and the telephone notice thereof in
         accordance with Section 4.4(1) is made before 5:00 p.m., E.S.T., on
         such date.

                  (4) Notwithstanding the foregoing, if a Holder has not
         received certificates for all shares of Common Stock prior to the
         expiration of the Deadline with respect to a conversion of any portion
         of this Convertible Debenture for any reason, then (unless the Holder
         otherwise elects to retain its status as a holder of Common Stock by so
         notifying the Company), the Holder shall regain the rights of a Holder
         of this Convertible Debenture with respect to such unconverted portions
         of this Convertible Debenture and the Company shall, as soon as
         practicable, return such unconverted Convertible Debenture to the
         holder or, if the Convertible Debenture has not been surrendered,
         adjust its records to reflect that such portion of this Convertible
         Debenture not been converted. In all cases, the Holder shall retain all
         of its rights and remedies (including, without limitation, (i) the
         right to receive Conversion Default Payments to the extent required
         thereby for such Conversion Default and any subsequent Conversion
         Default and (ii) the right to have the Conversion Price with respect to
         subsequent conversions determined in accordance with Section 4.3 for
         the Company's failure to convert this Convertible Debenture.)

                  (5) In lieu of delivering physical certificates representing
         the Common Stock issuable upon conversion, provided the Company's
         transfer agent is participating in the Depository Trust Company ("DTC")
         Fast Automated Securities Transfer program, upon request of the Holder
         and its compliance with the provisions contained in Section 4.1 and in
         this Section 4.4, the Company shall use its best efforts to cause its
         transfer agent to electronically transmit the Common Stock issuable
         upon conversion to the Holder by crediting the account of Holder's
         prime broker (as designated by Holder from time to time) with DTC
         through its Deposit Withdrawal Agent Commission System.

         5.       REDEMPTION BY COMPANY.

         5.1      COMPANY'S RIGHT TO REDEEM UPON RECEIPT OF NOTICE OF
         CONVERSION. In addition to the redemption rights set forth in the
         Agreement, upon delivery of a Notice of Conversion by the Holder (the
         "Initial Notice of Conversion"), if the Closing Bid Price of the
         Company's Common Stock on the date of the Notice of Conversion is less
         than 65% of the Closing Bid Price of the Common Stock on the Closing
         Date, the Company may elect to redeem in whole or in part, the
         remaining unpaid principal amount of this Convertible Debenture, for
         cash at a redemption price (the "Redemption Price") equal to (x) the
         number of shares of Common Stock into which this Convertible Debenture
         is then convertible, times (y) the average

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         Closing Bid Price of Common Stock for the five (5) Trading Days as
         reported by Bloomberg L.P. immediately prior to the date that this
         Convertible Debenture is called for redemption, plus accrued and unpaid
         interest. The election by the Company to redeem any amount of this
         Convertible Debenture shall be applicable to any subsequent amount to
         be converted as set forth in any Notice of Conversion received by the
         Company in the twenty (20) calendar day period following the date of
         the Initial Notice of Conversion, subject to the provisions of Section
         5.2 below.

         5.2      MECHANICS OF REDEMPTION. The Company shall provide written
         notice of its election to redeem rather than convert the amounts set
         forth in the Notice of Conversion ("Redemption Notice") via facsimile
         to the Holder within one Business Day of the Confirmed Delivery of the
         Notice of Conversion to the Company, if such Confirmed Delivery is on a
         Business Day or by 5:00 E.S.T. of the next Business Day if such Notice
         of Conversion is not delivered on a Business Day, with a copy by either
         overnight or 2-day courier to the Holder of this Convertible Debenture
         to be redeemed at the address and facsimile number of such Holder
         appearing in the Company's register for the Convertible Debentures. The
         Company shall effect each such redemption within three (3) Business
         Days of giving the Redemption Notice. Such Redemption Notice shall
         indicate whether the Company will redeem all or part of such portion of
         the Convertible Debenture to be redeemed and the applicable Redemption
         Price. The Company shall not be entitled to send any notice of
         redemption and begin the redemption procedure unless it has (i) the
         full amount of the Redemption Price, in cash, available in a demand or
         other immediately available account in a bank or similar financial
         institution or (ii) immediately available credit facilities, in the
         full amount of the Redemption Price, with a bank or similar financial
         institution on the date the Redemption Notice is sent to the Holders of
         this Convertible Debenture. Provided, however, the Company will process
         any Notice of Conversion received prior to the issuance of a Redemption
         Notice; and further provided that, after a Redemption Notice has been
         issued, the Holder may issue a Notice of Conversion which will not be
         honored unless the Company fails to make the redemption payment when
         due. In the event of such failure, the Notice of Conversion will be
         honored as of the date of the Notice of Conversion. Additionally, if
         the Company fails to make full payments of the Redemption Price of this
         Convertible Debenture being redeemed by the third Business Day
         following the Notice of Redemption, then the Company waives its right
         to redeem any of the remaining then outstanding Convertible Debentures
         pursuant to Section 5.1, unless approved in writing by the Holder.

         5.3      PAYMENT OF REDEMPTION PRICE. The Redemption Price shall be
         paid to the Holder of this Convertible Debenture within three (3)
         Business Days of the delivery of the Redemption Notice.

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         6.       HOLDER'S RIGHT TO ADVANCE NOTICE OF ELECTION TO REDEEM.

         6.1      HOLDER'S RIGHT TO ELECT TO RECEIVE NOTICE OF CASH REDEMPTION
         BY COMPANY. The Holder of this Convertible Debenture shall have the
         right to require the Company to provide advance notice stating whether
         the Company will elect to redeem all or part of the redeemable portion
         in cash, pursuant to the Company's redemption rights discussed in
         Section 5.1 above.

         6.2      MECHANICS OF HOLDER'S ELECTION NOTICE. Holder shall give
         notice to the Company by facsimile (the "Election Notice"), requiring
         that the Company disclose whether the Company would elect to redeem the
         redeemable portion of this Convertible Debenture (in whole or in part)
         if the Holder were to provide a Notice of Conversion within the next
         four (4) Business Days and sought to convert the Convertible Debenture
         in such principal amount as is specified in the Election Notice.

         6.3      COMPANY'S RESPONSE. Company must respond, disclosing its
         election, within two (2) Business Days of receipt of Holder's Election
         Notice via facsimile. If Company does not respond to Holder within two
         (2) Business Days (by 12:00 noon, if required above) via facsimile,
         Company shall be deemed to have forfeited its right to exercise
         redemption pursuant to Section 5.1 upon its receipt of (but only with
         respect to) that Notice of Conversion.

         7.       HOLDER'S COVENANTS. The Holder of this Convertible Debenture,
by its acceptance thereof, covenants and agrees that the Convertible Debenture
is being acquired as an investment and not with a view to the distribution
thereof in violation of the Securities Act, and that the Convertible Debenture
may not be transferred, sold, assigned, hypothecated or otherwise disposed of,
in whole, or in part, except as provided on the first page hereof and provided
that the Holder shall have furnished to the Company an opinion of counsel, in
form and substance reasonably satisfactory to the Company, to the effect that
such transfer is exempt from the registration requirements of the Securities Act
and any applicable state securities laws.

         8.       MISCELLANEOUS. This Convertible Debenture shall be deemed to
be a contract made under the laws of the State of Massachusetts, and for all
purposes shall be governed by and construed in accordance with the laws of said
State. The parties hereto, including all guarantors or endorsers, hereby waive
presentment, demand, notice, protest and all other demands and notices in
connection with the delivery, acceptance, performance and enforcement of this
Convertible Debenture, except as specifically provided herein, and assent to
extensions of the time of payment, or forbearance or other indulgence without
notice. The Company hereby submits to the exclusive jurisdiction of the United
States District Court for Boston, Massachusetts and of any Massachusetts state
court sitting in Boston, Massachusetts for purposes of all legal proceedings
arising out of or relating to this Convertible Debenture. The Company
irrevocably waives, to the fullest extent permitted by law, any objection which
it may now or hereafter have to the laying of the venue of any such proceeding

                                       10

<PAGE>

brought in such a court and any claim that any such proceeding brought in such a
court has been brought in an inconvenient forum. The Company hereby irrevocably
waives any and all right to trial by jury in any legal proceeding arising out of
or relating to this Convertible Debenture.

         The Holder of this Convertible Debenture by acceptance of this
Convertible Debenture agrees to be bound by the provisions of this Convertible
Debenture which are expressly binding on such Holder.

                            [Signature page follows]

                                       11

<PAGE>

                      SIGNATURE PAGE TO SHORELINE DEBENTURE

         IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed.

         Dated as of August 25, 2000

                                         BOSTON BIOMEDICA, INC.

                                         By: /s/ Kevin W. Quinlan

                                         Name: Kevin W. Quinlan
                                         Title: President

<PAGE>

                                     ANNEX A

                         CONVERSION AND REPAYMENT LEDGER

<TABLE>
<CAPTION>

----------- ------------------ ------------------------ -------------------- --------------------- ---------------- ----------------
                                  INTEREST CONVERTED    PRINCIPAL CONVERTED
  DATE      PRINCIPAL BALANCE          OR PAID                 OR PAID       NEW PRINCIPAL BALANCE  ISSUER INITIALS  HOLDER INITIALS
----------- ------------------ ------------------------ -------------------- --------------------- ---------------- ----------------
<S>         <C>                <C>                      <C>                  <C>                   <C>              <C>

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

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

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

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

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

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

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

</TABLE>

BOSTON BIOMEDICA, INC.                       HOLDER:

By: ________________________                   By:____________________________

Name:_______________________                   Name:__________________________

Title: _____________________                   Title:_________________________

<PAGE>

FULL NAME AND ADDRESS OF SUBSCRIBER FOR REGISTRATION PURPOSES:

NAME:

ADDRESS:

TEL NO:

FAX NO:

CONTACT
NAME:

DELIVERY INSTRUCTIONS (IF DIFFERENT FROM REGISTRATION NAME):

NAME:

ADDRESS:

TEL NO:

FAX NO:

CONTACT
NAME:

SPECIAL INSTRUCTIONS:
                     -----------------------------------------------------------

<PAGE>

                              NOTICE OF CONVERSION

                    (To be Executed by the Registered Holder

                 in order to Convert the Convertible Debenture)

                  The undersigned hereby irrevocably elects to convert $________
of the principal balance of the Convertible Debenture into shares of Common
Stock, $.01 par value per share (the "Common Stock"), of Boston Biomedica, Inc.
(the "Company") according to the conditions hereof, as of the date written
below. No fee will be charged to the Holder for any conversion, except for
transfer taxes, if any. The undersigned, as contemplated by Section 5.1 of the
Securities Purchase Agreement pursuant to which the Convertible Debenture was
issued, hereby states that the representations and warranties of the undersigned
set forth therein are true and correct in all material respects as of the date
hereof.

Conversion calculations:

                                            ------------------------------------
                                            Date of Conversion

                                            ------------------------------------
                                            Applicable Conversion Price

                                            ------------------------------------
                                            Number of Shares

                                            ------------------------------------
                                            Name/Signature

                                            Address:

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

                                            ------------------------------------<PAGE>

                                   Exhibit 4.8

                          Warrant to Richard P. Kiphart

THIS COMMON STOCK PURCHASE WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"). THE HOLDER HEREOF, BY PURCHASING
THIS COMMON STOCK PURCHASE WARRANT, AGREES FOR THE BENEFIT OF THE COMPANY THAT
SUCH SECURITIES MAY BE OFFERED, SOLD OR OTHERWISE TRANSFERRED ONLY (A) TO THE
COMPANY, (B) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES
ACT, OR (C) IF REGISTERED UNDER THE SECURITIES ACT AND ANY APPLICABLE STATE
SECURITIES LAWS.

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

                             BOSTON BIOMEDICA, INC.

                          COMMON STOCK PURCHASE WARRANT

--------------------------------------------------------------------------------
                                         No. 4
Number of shares:   27,734               Holder: Richard P. Kiphart
Expiration Date:    August 25, 2005      c/o William Blair & Company
                                         222 West Adams Street
                                         Chicago, IL 60606
Purchase Price Per Share:  $3.60

For identification only.The governing terms of this Warrant are set forth below.
--------------------------------------------------------------------------------

     Boston Biomedica, Inc., a Massachusetts corporation (the "COMPANY"), hereby
certifies that, for value received, Richard P. Kiphart, or his assigns (the
"HOLDER"), is entitled, subject to the terms set forth below, to purchase from
the Company at any time or from time to time after the date hereof and prior to
the fifth anniversary hereof (the "EXERCISE PERIOD"), at the Purchase Price
hereinafter set forth, twenty-seven thousand seven hundred thirty-four (27,734)
shares of the fully paid and nonassessable shares of common stock of the
Company, $0.01 par value per share (the "Common Stock"). The number and
character of such shares of Common Stock and the Purchase Price are subject to
adjustment as provided herein.

     The purchase price per share of Common Stock issuable upon exercise of this
Warrant (the "PURCHASE PRICE") shall initially be equal to 120% of the average
Closing Bid Price as published by Bloomberg, L.P. of the Common Stock on the day
immediately preceding the date hereof; PROVIDED, HOWEVER, that the Purchase
Price shall be adjusted from time to time as provided herein.

     Capitalized terms used herein not otherwise defined shall have the meanings
ascribed thereto in that certain Securities Purchase Agreement of even date
herewith between the Company, the Holder and Shoreline Micro-Cap Fund, L.P. (the
"Purchase Agreement"). By execution of this Warrant, the Holder hereof agrees to
be bound by and to benefit from the provisions of the Purchase

                                       1
<PAGE>

Agreement set forth herein. As used herein the following terms, unless the
context otherwise requires, have the following respective meanings:

          (a) The term "COMPANY" shall include Boston Biomedica, Inc. and any
     corporation that shall succeed or assume the obligations of such
     corporation hereunder.

          (b) The term "COMMON STOCK" includes (a) the Company's common stock,
     par value $0.01 per share, (b) any other capital stock of any class or
     classes (however designated) of the Company, authorized on or after the
     date hereof, the Holders of which shall have the right, without limitation
     as to amount, either to all or to a share of the balance of current
     dividends and liquidating dividends after the payment of dividends and
     distributions on any shares entitled to preference, and the Holders of
     which shall ordinarily, in the absence of contingencies, be entitled to
     vote for the election of a majority of directors of the Company (even
     though the right so to vote has been suspended by the happening of such a
     contingency) and (c) any other securities into which or for which any of
     the securities described in (a) or (b) may be converted or exchanged
     pursuant to a plan of recapitalization, reorganization, merger, sale of
     assets or otherwise.

          (c) The term "OTHER SECURITIES" refers to any stock (other than Common
     Stock) and other securities of the Company or any other person (corporate
     or otherwise) that the Holder of this Warrant at any time shall be entitled
     to receive, or shall have received, on the exercise of this Warrant, in
     lieu of or in addition to Common Stock, or that at any time shall be
     issuable or shall have been issued in exchange for or in replacement of
     Common Stock or Other Securities pursuant to Section 4 or otherwise.

     1.   EXERCISE OF WARRANT.

          1.1  METHOD OF EXERCISE.

          (a)  This Warrant may be exercised in whole or in part (but not as to
     a fractional share of Common Stock), at any time and from time to time
     during the Exercise Period by the Holder hereof by delivery of a notice of
     exercise (a "NOTICE OF EXERCISE") substantially in the form attached hereto
     as EXHIBIT A via facsimile to the Company. Prior to sending the Notice of
     Exercise via facsimile, the Holder shall give Richard Schumacher notice of
     its intent to submit a Notice of Exercise by telephone (and if Mr.
     Schumacher is not available to be reached by telephone, either Kevin
     Quinlan or Kathi Benjamin by telephone, or such other person designated by
     the Company after the Closing Date). Promptly thereafter the Holder shall
     surrender this Warrant (if the entire amount of the Warrant is subject to
     the Notice of Exercise) to the Company at its principal office via
     overnight delivery service, accompanied by payment of the Purchase Price
     multiplied by the number of shares of Common Stock for which this Warrant
     is being exercised (the "EXERCISE PRICE"). Payment of the Exercise Price
     shall be made, at the option of the Holder, (i) by check or bank draft
     payable to the order of the Company, or (ii) by wire transfer to the
     account of the Company. Upon exercise, the Holder shall be entitled to
     receive within three Trading Days of the Exercise Date (as defined herein),
     one or more certificates, issued in the Holder's name or

                                       2
<PAGE>

     in such name or names as the Holder may direct, subject to the limitations
     on transfer contained herein, for the number of shares of Common Stock so
     purchased. The shares of Common Stock so purchased shall be deemed to be
     issued as of the close of business on the date on which the Company shall
     have received from the Holder payment in full of the Exercise Price (the
     "EXERCISE DATE").

          (b)  Upon exercise of a portion of this Warrant in accordance with the
     terms hereof, records showing the amount so exercised and the date of
     exercise shall be maintained on a ledger substantially in the form of ANNEX
     B attached hereto (an originally signed and executed copy of which shall be
     delivered to the Company with each Notice of Exercise). The Company shall
     maintain the originally signed and executed ledger and the Holder shall
     maintain a copy thereof. Upon execution of the exercise of the Warrants
     contemplated by the Notice of Exercise, the Company shall deliver to the
     Holder a copy of ANNEX B signed and executed by the Company, and the Holder
     shall deliver to the Company a copy of Annex B signed by the Holder. It is
     specifically contemplated that the Company shall act as the calculation
     agent for all exercises of this Warrant. The Holder and any assignee, by
     acceptance of this Warrant, acknowledges and agrees that, by reason of the
     provisions of this paragraph, following an exercise of a portion of this
     Warrant, the number of shares of Common Stock represented by this Warrant
     will be the amount indicated on ANNEX B attached hereto (which may be less
     than the amount stated on the face hereof).

          (c)  In the event there is a dispute as to the number of shares of
     Common Stock the Holder is entitled to receive upon exercise of this
     Warrant, the Company shall issue to the Holder the number of shares not in
     dispute and the Company and the Holder will use their best efforts to
     resolve such dispute within one Business Day following the receipt of a
     Notice of Exercise. If such dispute cannot be resolved within such one-day
     period, the Company and the Holder shall submit the dispute to an
     independent accountant mutually agreed upon by the Company and the Holder
     to make a final and binding determination of the number of shares owed to
     the Holder. The Company shall issue shares of Common Stock owed to Holder
     as a result of the resolution of the dispute within two Business Days
     following the receipt of the accountant's independent determination.

          1.2  REGULATION D RESTRICTIONS. The Holder hereof represents and
warrants to the Company that it has acquired this Warrant and anticipates
acquiring the shares of Common Stock issuable upon exercise of the Warrant
solely for its own account for investment purposes and not with a view to or for
resale of such securities unless such resale has been registered with the
Commission or an applicable exemption is available therefor and provided that
the Holder shall have furnished to the Company an opinion of counsel in form and
substance reasonably satisfactory to the Company, to the effect that such
transfer is exempt from the registration requirements of the Securities Act and
any applicable state securities laws.

          1.3  COMPANY ACKNOWLEDGMENT. The Company will, at the time of the
exercise of this Warrant, upon request of the Holder hereof, acknowledge in
writing its continuing obligation to afford to such Holder the registration
rights to which such Holder shall continue to be entitled

                                       3
<PAGE>

after such exercise in accordance with the provisions of a Registration Rights
Agreement dated the date hereof (the "Registration Rights Agreement").

          1.4  LIMITATION ON EXERCISE. Notwithstanding the rights of the Holder
to exercise all or a portion of this Warrant as described herein, such exercise
rights shall be limited, solely to the extent set forth in the Purchase
Agreement as if such provisions were specifically set forth herein. In addition,
the number of shares of Common Stock issuable upon exercise of this Warrant is
subject to reduction as specified in Section 10.3 of the Purchase Agreement.

     2.   DELIVERY OF STOCK CERTIFICATES, ETC., ON EXERCISE. As soon as
practicable after the exercise of this Warrant, and in any event within three
(3) Business Days thereafter, the Company at its expense (including the payment
by it of any applicable issue, stamp or transfer taxes) will cause to be issued
in the name of and delivered to the Holder thereof, or, to the extent
permissible hereunder, to such other person as such Holder may direct, a
certificate or certificates for the number of fully paid and nonassessable
shares of Common Stock (or Other Securities) to which such Holder shall be
entitled on such exercise, plus, in lieu of any fractional share to which such
Holder would otherwise be entitled, cash equal to such fraction multiplied by
the then applicable Purchase Price, together with any other stock or other
securities and property (including cash, where applicable) to which such Holder
is entitled upon such exercise pursuant to Section 1 or otherwise.

     3.   ADJUSTMENT FOR EXTRAORDINARY EVENTS. The Purchase Price to be paid by
the Holder upon exercise of this Warrant, and the consideration to be received
upon exercise of this Warrant, shall be adjusted in case at any time or from
time to time pursuant to Article 11 of the Purchase Agreement as if such
provisions were specifically set forth herein.

     4.   NO IMPAIRMENT. The Company will not, by amendment of its Certificate
of Incorporation or through any reorganization, transfer of assets,
consolidation, merger, dissolution, issue or sale of securities or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the terms of this Warrant, but will at all times in good faith assist in the
carrying out of all such terms and in the taking of all such action as may be
necessary or appropriate in order to protect the rights of the Holder of this
Warrant against impairment. Without limiting the generality of the foregoing,
the Company (a) will not increase the par value of any shares of stock
receivable on the exercise of this Warrant above the amount payable therefor on
such exercise, (b) will take all such action as may be necessary or appropriate
in order that the Company may validly and legally issue fully paid and
unassessable shares of stock on the exercise of this Warrant, and (c) will not
transfer all or substantially all of its properties and assets to any other
person (corporate or otherwise), or consolidate with or merge into any other
person or permit any such person to consolidate with or merge into the Company
(if the Company is not the surviving person), unless such other person shall
expressly assume in writing and will be bound by all the terms of this Warrant.

     5.   CERTIFICATE AS TO ADJUSTMENTS. In each case of any adjustment or
readjustment in the shares of Common Stock (or Other Securities) issuable on the
exercise of this Warrant, the Company will promptly cause its principal
financial officer to compute such adjustment or

                                       4
<PAGE>

readjustment in accordance with the terms of this Warrant and prepare a
certificate setting forth such adjustment or readjustment and showing in detail
the facts upon which such adjustment or readjustment is based, including a
statement of (a) the consideration received or receivable by the Company for any
additional shares of Common Stock (or Other Securities) issued or sold or deemed
to have been issued or sold, (b) the number of shares of Common Stock (or Other
Securities) outstanding or deemed to be outstanding, and (c) the Purchase Price
and the number of shares of Common Stock to be received upon exercise of this
Warrant, in effect immediately prior to such issue or sale and as adjusted and
readjusted as provided in this Warrant. The Company will forthwith mail a copy
of each such certificate to the Holder of this Warrant, and will, on the written
request at any time of the Holder of this Warrant, furnish to such Holder a like
certificate setting forth the Purchase Price at the time in effect and showing
how it was calculated.

     6.   NOTICES OF RECORD DATE, ETC.

          In the event of

               (a)  any taking by the Company of a record of the Holders of any
     class of securities for the purpose of determining the Holders thereof who
     are entitled to receive any dividend or other distribution, or any right to
     subscribe for, purchase or otherwise acquire any shares of stock of any
     class or any other securities or property, or to receive any other right,
     or

               (b)  any capital reorganization of the Company, any
     reclassification or recapitalization of the capital stock of the Company or
     any transfer of all or substantially all the assets of the Company to or
     consolidation or merger of the Company with or into any other Person, or

               (c)  any voluntary or involuntary dissolution, liquidation or
     winding-up of the Company,

then and in each such event the Company will mail or cause to be mailed to the
Holder of this Warrant a notice specifying (i) the date on which any such record
is to be taken for the purpose of such dividend, distribution or right, and
stating the amount and character of such dividend, distribution or right, and
(ii) the date on which any such reorganization, reclassification,
recapitalization, transfer, consolidation, merger, dissolution, liquidation or
winding-up is to take place, and the time, if any, as of which the Holders of
record of Common Stock (or Other Securities) shall be entitled to exchange their
shares of Common Stock (or Other Securities) for securities or other property
deliverable on such reorganization, reclassification, recapitalization,
transfer, consolidation, merger, dissolution, liquidation or winding-up. Such
notice shall be mailed at least 20 days prior to the date specified in such
notice on which any action is to be taken.

     7.   RESERVATION OF STOCK, ETC. ISSUABLE ON EXERCISE OF WARRANT. The
Company will at all times reserve and keep available, solely for issuance and
delivery on the exercise of this Warrant, all shares of Common Stock (or Other
Securities) from time to time issuable on the exercise of this Warrant.

                                       5
<PAGE>

     8.   EXCHANGE OF WARRANT. On surrender for exchange of this Warrant,
properly endorsed and in compliance with the restrictions on transfer set forth
in the legend on the face of this Warrant, to the Company, the Company at its
expense will issue and deliver to or on the order of the Holder thereof a new
Warrant of like tenor, in the name of such Holder or as such Holder (on payment
by such Holder of any applicable transfer taxes) may direct, calling in the
aggregate on the face or faces thereof for the number of shares of Common Stock
called for on the face of the Warrant so surrendered or for such lesser number
of shares of Common Stock as may be reflected on the Warrant Exercise Ledger
attached as Annex B.

     9.   REPLACEMENT OF WARRANT. On receipt of evidence reasonably satisfactory
to the Company of the loss, theft, destruction or mutilation of this Warrant
and, in the case of any such loss, theft or destruction of this Warrant, on
delivery of an indemnity agreement or security reasonably satisfactory in form
and amount to the Company or, in the case of any such mutilation, on surrender
and cancellation of this Warrant, the Company at its expense will execute and
deliver, in lieu thereof, a new Warrant of like tenor.

     10.  REMEDIES. The Company stipulates that the remedies at law of the
Holder of this Warrant in the event of any default or threatened default by the
Company in the performance of or compliance with any of the terms of this
Warrant are not and will not be adequate, and that such terms may be
specifically enforced by a decree for the specific performance of any agreement
contained herein or by an injunction against a violation of any of the terms
hereof or otherwise.

     11.  NEGOTIABILITY, ETC.. This Warrant is issued upon the following terms,
to all of which each Holder or owner hereof by the taking hereof consents and
agrees:

          (a)  until this Warrant is transferred on the books of the Company,
the Company may treat the registered Holder hereof as the absolute owner hereof
for all purposes, notwithstanding any notice to the contrary; and

          (b)  this Warrant may not be sold, transferred or assigned except
pursuant to an effective registration statement under the Securities Act or
pursuant to an applicable exemption therefrom.

     12.  REGISTRATION RIGHTS. The Company is obligated to register the shares
of Common Stock issuable upon exercise of this Warrant in accordance with the
terms of the Registration Rights Agreement.

     13.  WARRANT REDEMPTION. Upon occurrence of the events described in
Sections 3.4 and 10.4(c) of the Purchase Agreement, the Company, at the request
of Holder, shall redeem all outstanding Warrants that remain unexercised at a
redemption price equal to the greater of (x) an appraised value of the Warrants,
as determined by Black Sholes, on the date they are called for redemption and
(y) the number of Warrants being redeemed multiplied by the excess of (A) the
average Closing Bid Price of the Common Stock for the five trading days
immediately prior to the date that the Warrants are called for redemption over
(B) the exercise price of the Warrants.

                                       6
<PAGE>

     14.  NOTICES, ETC. All notices and other communications from the Company to
the Holder of this Warrant shall be mailed by first class registered or
certified mail, postage prepaid, at such address as may have been furnished to
the Company in writing by such Holder or, until any such Holder furnishes to the
Company any address, then to, and at the address of, the last Holder of this
Warrant who has so furnished an address to the Company.

     15.  MISCELLANEOUS. This Warrant and any term hereof may be changed,
waived, discharged or terminated only by an instrument in writing signed by the
party against which enforcement of such change, waiver, discharge or termination
is sought. This Warrant shall be construed and enforced in accordance with and
governed by the internal laws of the State of Massachusetts. The headings in
this Warrant are for the purposes of reference only, and shall not limit or
otherwise affect any of the terms hereof. The invalidity or unenforceability of
any provision hereof shall in no way affect the validity or enforceability of
any other provision.

                                       7
<PAGE>

                        SIGNATURE PAGE TO KIPHART WARRANT

     DATED as of August 25, 2000.

                                            BOSTON BIOMEDICA, INC.

                                            By: /s/ Kevin W. Quinlan
                                                --------------------
                                            Name: Kevin W. Quinlan
                                            Title: President

                                       8
<PAGE>

                                    EXHIBIT A
                        FORM OF NOTICE EXERCISE - WARRANT
                       (To be executed only upon exercise
                       of the Warrant in whole or in part)

To ____________________________________________

     The undersigned registered Holder of the accompanying Warrant, hereby
exercises such Warrant or portion thereof for, and purchases thereunder,
__________(1) shares of Common Stock (as defined in such Warrant) and herewith
makes payment therefor in the amount and manner set forth below, as of the date
written below. The undersigned requests that the certificates for such shares of
Common Stock be issued in the name of, and delivered to,________________________
whose address is__________________________ .

     The Exercise Price is paid as follows:

     |_| Certified Bank draft payable to the Company in the amount of
     $_____________.

     |_| Wire transfer to the account of the Company in the amount of
     $___________.

     Upon exercise pursuant to this Notice of Exercise, the Holder will be in
compliance with the Limitation on Exercise (as defined in the Securities
Purchase Agreement pursuant to which this Warrant was issued).

     The Holder of the shares of Common Stock received upon exercise of the
Warrant (the "Common Shares"), covenants and agrees that the Common Shares are
being acquired as an investment and not with a view to the distribution thereof
in violation of the Securities Act and that the Common Shares may not be
transferred, sold, assigned, hypothecated or otherwise disposed of, in whole or
in part except as provided in the legend on the first page of this Warrant and
provided that the Holder shall have furnished the Company an opinion of counsel
in form and substance reasonably acceptable to the Company to the effect that
such transfer is exempt from the registration requirements of the Securities Act
and any applicable state securities laws.*

Date:______________________________    _________________________________________
                                       (Name must conform to name of Holder as
                                       specified on the face of the Warrant)
                                       By:______________________________________
                                          Name:_________________________________
                                          Title:________________________________
                                       Address of Holder:_______________________
                                                      __________________________
                                                      __________________________

Date of exercise:__________________

*    If shares of common Stock are to be issued to anyone other than the Holder,
     this covenant and representation must be made by such other Person.

___________________________________
     1. Insert the number of shares of Common Stock as to which the accompanying
Warrant is being exercised. In the case of partial exercise, a new Warrant or
Warrant will be issued and delivered, representing the unexercised portion of
the accompanying Warrant, to the Holder surrendering the same.

<PAGE>

                                     ANNEX B

                             WARRANT EXERCISE LEDGER

<TABLE>

<CAPTION>

----------- --------------------- ------------- ------------------ --------------------- ---------------------- -------------------
              ORIGINAL NUMBER OF     WARRANTS     EXERCISE PRICE      NEW BALANCE              ISSUER                 HOLDER
    DATE         WARRANTS           EXERCISED         PAID           OF WARRANTS             INITIALS               INITIALS
----------- --------------------- ------------- ------------------ --------------------- ---------------------- -------------------
<S>         <C>                   <C>           <C>                <C>                   <C>                    <C>

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

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

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

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

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

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

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

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

</TABLE>

BOSTON BIOMEDICA, INC.                       HOLDER:

By:      _______________________             By: _____________________
Name:     ______________________             Name:____________________
Title:   _______________________             Title:___________________

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