NEITHER THIS WARRANT NOR THE SHARES OF STOCK ISSUABLE UPON EXERCISE  HEREOF HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.  NO SALE, TRANSFER
OR OTHER  DISPOSITION OF THIS WARRANT OR SAID SHARES MAY BE EFFECTED WITHOUT (i)
AN  EFFECTIVE  REGISTRATION  STATEMENT  RELATED  THERETO,  OR (ii) AN OPINION OF
COUNSEL,  REASONABLY  SATISFACTORY TO COUNSEL TO THE COMPANY,  THAT AN EXEMPTION
FROM REGISTRATION UNDER SAID ACT IS AVAILABLE.


Warrant                                                                   No. of
No. P-1                      STOCK PURCHASE WARRANT               Shares 400,000
                                                                         -------

                  To Subscribe for and Purchase Common Stock of


                             BOSTON BIOMEDICA, INC.

         THIS CERTIFIES that, for value received,  Paradigm Group,  L.L.C.  (the
"Holder"), is entitled, upon the terms and subject to the conditions hereinafter
set forth,  to  subscribe  for and  purchase  from  Boston  Biomedica,  Inc.,  a
Massachusetts  corporation  (hereinafter  called  the  "Company"),  at the price
hereinafter  set forth in Section 2 up to 400,000 fully paid and  non-assessable
shares of the Company's  common stock,  $.01 par value per share (the "Shares").
This  stock  purchase  warrant  (the  "Warrant")  is  issued  to the  Holder  in
connection  with,  and subject to the terms of, that  certain  Warrant  Purchase
Agreement dated August 18, 1999, by and between the Company and the Holder.

         1.  Definitions.  As used  herein  the  following  term  shall have the
             -----------
following meaning:

         "Act" means the Securities Act of 1933 as amended, or a similar Federal
          ---
statute and the rules and  regulations of the Commission  issued under that Act,
as they each may, from time to time, be in effect.

         2. Purchase Rights. The purchase rights represented by this Warrant are
            ---------------
exercisable by the Holder in whole or in part, at any time and from time to time
commencing on the date hereof and ending at 5:00 p.m. on February 17, 2000. This
Warrant may be  exercised  for Shares at a price of $4.25 per share,  subject to
adjustment as provided in Section 6 (the "Warrant Purchase Price").

         3. Exercise of Warrant. Subject to Section 2 above, the purchase rights
            -------------------
represented by this Warrant may be exercised,  in whole or in part and from time
to time,  by the  surrender  of this  Warrant  and the duly  executed  Notice of
Exercise (the form of which is attached as Exhibit A) at the principal office of
the Company and by the payment to the Company,  by wire transfer of  immediately
available  funds,  of an amount equal to the then  applicable  Warrant  Purchase
Price per share  multiplied by the number of Shares then being  purchased.  Upon
exercise,  the Holder shall be entitled to receive,  within a reasonable time, a
certificate  or  certificates,  issued in the  Holder's  name or in such name or
names as the  Holder may  direct,  for the  number of Shares so  purchased.  The
Shares so purchased  shall be deemed to be issued as of the close of business on
the date on which this Warrant shall have been exercised.


<PAGE>

         4. Shares to be Issued;  Reservation of Shares.  The Company  covenants
            -------------------------------------------
that the Shares that may be issued  upon the  exercise  of the  purchase  rights
represented   by  this  Warrant  will,   upon   issuance,   be  fully  paid  and
non-assessable,  and free from all liens and charges  with  respect to the issue
thereof.  During the period within which the purchase rights  represented by the
Warrant may be  exercised,  the Company  will at all times have  authorized  and
reserved,  for the purpose of issuance  upon  exercise  of the  purchase  rights
represented by this Warrant,  a sufficient  number of shares of its Common Stock
to provide for the exercise of the right represented by this Warrant.

         5. No Fractional  Shares. No fractional shares shall be issued upon the
            ---------------------
exercise of this Warrant. In lieu thereof, a cash payment shall be made equal to
such  fraction  multiplied  by the fair  market  value of such  shares of Common
Stock, as determined in good faith by the Company's Board of Directors.

         6. Adjustments of Warrant Purchase Price and Number of Shares. If there
            ----------------------------------------------------------
shall  be any  change  in  the  Common  Stock  of the  Company  through  merger,
consolidation, reorganization,  recapitalization, stock dividend, stock split or
other change in the corporate structure of the Company,  appropriate adjustments
shall be made by the Board of Directors of the Company (or if the Company is not
the surviving corporation in any such transaction, the Board of Directors of the
surviving  corporation)  in the aggregate  number and kind of shares  subject to
this  Warrant,  and the  number  and kind of shares and the price per share then
applicable to shares covered by the unexercised portion of this Warrant.

         7. No Rights as Shareholders.  This Warrant does not entitle the Holder
            -------------------------
to any voting  rights or other rights as a  shareholder  of the Company prior to
exercise  of  this  Warrant  and  the  payment  for  the  Shares  so  purchased.
Notwithstanding the foregoing, the Company agrees to transmit to the Holder such
information,  documents and reports as are generally  distributed  to holders of
the capital stock of the Company  concurrently with the distribution  thereof to
the shareholders. Upon valid exercise of this Warrant and payment for the Shares
so purchased  in  accordance  with the terms of the  Warrant,  the Holder or the
Holder's  designee,  as the case may be,  shall be deemed a  shareholder  of the
Company.

         8. Sale or Transfer of the Warrant;  Legend.  The Warrant  shall not be
            ----------------------------------------
sold or transferred.  The Shares shall not be sold or transferred  unless either
(i) they first  shall have been  registered  under the Act,  or (ii) the Company
first shall have been furnished with an opinion of legal counsel satisfactory to
the  Company  to the  effect  that such  sale or  transfer  is  exempt  from the
registration  requirements of the Act. Each certificate representing any Warrant
shall  bear the legend  set out on page 1 hereof.  Unless  the Shares  have been
registered under the Act, each certificate  representing any Shares shall bear a
legend substantially in the following form, as appropriate:

         THE SHARES  REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED
         FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN CONNECTION  WITH,
         THE SALE OR DISTRIBUTION  THEREOF. NO SUCH SALE OR DISPOSITION
         MAY BE EFFECTED  WITHOUT AN EFFECTIVE  REGISTRATION  STATEMENT
         RELATED  THERETO OR AN OPINION OF COUNSEL  SATISFACTORY TO THE
         COMPANY  THAT  SUCH  REGISTRATION  IS NOT  REQUIRED  UNDER THE
         SECURITIES ACT OF 1933, AS AMENDED.

                                      -2-

<PAGE>

Such Warrant and Shares may be subject to  additional  restrictions  on transfer
imposed under applicable state and federal securities law.

         9. Modifications and Waivers. This Warrant may not be changed,  waived,
            -------------------------
discharged or terminated  except by an instrument in writing signed by the party
against which enforcement of the same is sought.

         10.  Notices.  Any  notice,  request  or  other  document  required  or
              -------
permitted  to be  given or  delivered  to the  Holder  or the  Company  shall be
delivered, or shall be sent by certified or registered mail, postage prepaid, to
the Holder at its address shown on the books of the Company or to the Company at
the address  indicated  therefor on the signature  page of this Warrant,  or, if
different, at the principal office of the Company.

         11. Loss,  Theft,  Destruction  or Mutilation  of Warrant.  The Company
             -----------------------------------------------------
covenants  with  the  Holder  that  upon  its  receipt  of  evidence  reasonably
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant or any stock  certificate  and, in the case of any such loss, theft
or destruction,  of an indemnity or security reasonably  satisfactory to it, and
upon reimbursement to the Company of all reasonable expenses incidental thereto,
and upon surrender and  cancellation  of this Warrant or stock  certificate,  if
mutilated, the Company will make and deliver a new Warrant or stock certificate,
of like tenor, in lieu of the lost,  stolen,  destroyed or mutilated  Warrant or
stock certificate.

         12.  Representations  and  Warranties  of  Holder.  By  accepting  this
              --------------------------------------------
Warrant, the Holder represents and warrants that he, she or it is acquiring this
Warrant and the Shares for his, her or its own account,  for  investment and not
with a view to, or for sale in connection with, any distribution  thereof or any
part  thereof.  Holder  represents  and  warrants  that  he,  she  or it is  (a)
experienced in the evaluation of businesses similar to the Company,  (b) is able
to fend for himself, herself or itself in the transactions  contemplated by this
Warrant, (c) has such knowledge and experience in financial and business matters
as to be capable of  evaluating  the  merits and risks of an  investment  in the
Company,  (d) has the ability to bear the economic risks of an investment in the
Company, (e) has been furnished with or has had access to such information as is
specified in subparagraph  (b)(2) of Rule 502 promulgated  under the Act and (f)
has been afforded the  opportunity  to ask  questions of and to receive  answers
from the Company and to obtain any additional  information  necessary to make an
informed investment decision with respect to an investment in the Company.

         13. Binding  Effect on  Successors.  This Warrant shall be binding upon
             ------------------------------
any corporation  succeeding the Company by merger,  consolidation or acquisition
of all or substantially all of the Company's assets,  and all of the obligations
of the Company  relating to the Shares  issuable  upon  exercise of this Warrant
shall  survive  the  exercise  and  termination  of this  Warrant and all of the
covenants  and  agreements  of the  Company  shall  inure to the  benefit of the
successors and assigns of the Holder.

         14.  Governing Law.  This Warrant  shall be  construed  and enforced in
              -------------
accordance with, and the rights of the parties shall be governed by, the laws of
the Commonwealth of Massachusetts.

                                      -3-

<PAGE>


         IN WITNESS WHEREOF,  BOSTON BIOMEDICA,  INC. has caused this Warrant to
be executed under seal by its officer thereunto duly authorized.

Dated: August 18, 1999

                                               BOSTON BIOMEDICA, INC.
CORPORATE
  SEAL

                                               By: /S/ Richard T. Schumacher
                                                   -----------------------------
                                                   Richard T. Schumacher,
                                                   Its President

                                                   Address:  375 West Street

                                                   West Bridgewater, MA 02379






#838389 v\3 - fitzgemr - hywl01!.doc_ - 11563/1


                                      -4-



<PAGE>


                                    EXHIBIT A


                               NOTICE OF EXERCISE
                               ------------------


         To: BOSTON BIOMEDICA, INC.

         1. The undersigned  hereby elects to purchase  _______ shares of Common
Stock of BOSTON  BIOMEDICA,  INC. (the  "Company")  pursuant to the terms of the
attached  Warrant,  and tenders  herewith  payment of the purchase price of such
shares in full.

         2. Please issue a certificate or certificates  representing said shares
in the name of the  undersigned  or in such other name or names as are specified
below.

         3. The  undersigned  represents  and warrants as follows (the following
applies  only in the  event  said  shares  have not been  registered  under  the
Securities Act of 1933, as amended):

         The  undersigned  is  purchasing  or acquiring  the  aforesaid
         shares of Common Stock for its own account for  investment and
         not with a present  view to, or for sale in  connection  with,
         any  distribution   thereof  in  violation  of  the  Act.  The
         undersigned represents and warrants that the undersigned:  (a)
         is experienced in the evaluation of businesses  similar to the
         Company,  (b) has such  knowledge and  experience in financial
         and business matters as to be capable of evaluating the merits
         and risks of an investment in the Company, (c) has the ability
         to bear the economic  risks of an  investment  in the Company,
         (d)  has  been  furnished  with  or has  had  access  to  such
         information as is specified in subparagraph (b)(2) of Rule 502
         promulgated  under  the  Act and has  carefully  reviewed  and
         understood  such  information,   (e)  has  been  afforded  the
         opportunity  to ask  questions of and to receive  answers from
         the Company and to obtain any additional information necessary
         to make an informed  investment  decision  with  respect to an
         investment in the Company, and (f) is an "Accredited Investor"
         as such  term  is  defined  in  subparagraph  (a) of Rule  501
         promulgated under the Act.

         4. In the event of partial  exercise,  please  re-issue an  appropriate
Warrant exercisable into the remaining shares.

                                                 -------------------------------
                                                 (Name)

                                                 -------------------------------
                                                 (Address)

                                                 -------------------------------
                                                 (Signature)

                                                  ------------------------------
                                                  (Date)



#838389 v\2 - fitzgemr - hywl02!.doc_ - 11563/1

                                      -5-

<PAGE>
NEITHER THIS WARRANT NOR THE SHARES OF STOCK ISSUABLE UPON EXERCISE  HEREOF HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.  NO SALE, TRANSFER
OR OTHER  DISPOSITION OF THIS WARRANT OR SAID SHARES MAY BE EFFECTED WITHOUT (i)
AN  EFFECTIVE  REGISTRATION  STATEMENT  RELATED  THERETO,  OR (ii) AN OPINION OF
COUNSEL,  REASONABLY  SATISFACTORY TO COUNSEL TO THE COMPANY,  THAT AN EXEMPTION
FROM REGISTRATION UNDER SAID ACT IS AVAILABLE.


Warrant                                                                   No. of
No. P-2                      STOCK PURCHASE WARRANT               Shares 100,000
                                                                         -------

                  To Subscribe for and Purchase Common Stock of


                             BOSTON BIOMEDICA, INC.

         THIS CERTIFIES that, for value received,  Paradigm Group,  L.L.C.  (the
"Holder"), is entitled, upon the terms and subject to the conditions hereinafter
set forth,  to  subscribe  for and  purchase  from  Boston  Biomedica,  Inc.,  a
Massachusetts  corporation  (hereinafter  called  the  "Company"),  at the price
hereinafter  set forth in Section 2 up to 100,000 fully paid and  non-assessable
shares of the Company's  common stock,  $.01 par value per share (the "Shares").
This  stock  purchase  warrant  (the  "Warrant")  is  issued  to the  Holder  in
connection  with,  and subject to the terms of, that  certain  Warrant  Purchase
Agreement dated August 18, 1999, by and between the Company and the Holder.

         1.  Definitions.  As used  herein  the  following  term  shall have the
             -----------
following meaning:

         "Act" means the Securities Act of 1933 as amended, or a similar Federal
          ---
statute and the rules and  regulations of the Commission  issued under that Act,
as they each may, from time to time, be in effect.

         2. Purchase Rights. The purchase rights represented by this Warrant are
            ---------------
exercisable by the Holder in whole or in part, at any time and from time to time
commencing on the date hereof and ending at 5:00 p.m. on February 17, 2000. This
Warrant may be  exercised  for Shares at a price of $5.25 per share,  subject to
adjustment as provided in Section 6 (the "Warrant Purchase Price").

         3. Exercise of Warrant. Subject to Section 2 above, the purchase rights
            -------------------
represented by this Warrant may be exercised,  in whole or in part and from time
to time,  by the  surrender  of this  Warrant  and the duly  executed  Notice of
Exercise (the form of which is attached as Exhibit A) at the principal office of
the Company and by the payment to the Company,  by wire transfer of  immediately
available  funds,  of an amount equal to the then  applicable  Warrant  Purchase
Price per share  multiplied by the number of Shares then being  purchased.  Upon
exercise,  the Holder shall be entitled to receive,  within a reasonable time, a
certificate  or  certificates,  issued in the  Holder's  name or in such name or
names as the  Holder may  direct,  for the  number of Shares so  purchased.  The
Shares so purchased  shall be deemed to be issued as of the close of business on
the date on which this Warrant shall have been exercised.

<PAGE>

         4. Shares to be Issued;  Reservation of Shares.  The Company  covenants
            -------------------------------------------
that the Shares that may be issued  upon the  exercise  of the  purchase  rights
represented   by  this  Warrant  will,   upon   issuance,   be  fully  paid  and
non-assessable,  and free from all liens and charges  with  respect to the issue
thereof.  During the period within which the purchase rights  represented by the
Warrant may be  exercised,  the Company  will at all times have  authorized  and
reserved,  for the purpose of issuance  upon  exercise  of the  purchase  rights
represented by this Warrant,  a sufficient  number of shares of its Common Stock
to provide for the exercise of the right represented by this Warrant.

         5. No Fractional  Shares. No fractional shares shall be issued upon the
            ---------------------
exercise of this Warrant. In lieu thereof, a cash payment shall be made equal to
such  fraction  multiplied  by the fair  market  value of such  shares of Common
Stock, as determined in good faith by the Company's Board of Directors.

         6. Adjustments of Warrant Purchase Price and Number of Shares. If there
            ----------------------------------------------------------
shall  be any  change  in  the  Common  Stock  of the  Company  through  merger,
consolidation, reorganization,  recapitalization, stock dividend, stock split or
other change in the corporate structure of the Company,  appropriate adjustments
shall be made by the Board of Directors of the Company (or if the Company is not
the surviving corporation in any such transaction, the Board of Directors of the
surviving  corporation)  in the aggregate  number and kind of shares  subject to
this  Warrant,  and the  number  and kind of shares and the price per share then
applicable to shares covered by the unexercised portion of this Warrant.

         7. No Rights as Shareholders.  This Warrant does not entitle the Holder
            -------------------------
to any voting  rights or other rights as a  shareholder  of the Company prior to
exercise  of  this  Warrant  and  the  payment  for  the  Shares  so  purchased.
Notwithstanding the foregoing, the Company agrees to transmit to the Holder such
information,  documents and reports as are generally  distributed  to holders of
the capital stock of the Company  concurrently with the distribution  thereof to
the shareholders. Upon valid exercise of this Warrant and payment for the Shares
so purchased  in  accordance  with the terms of the  Warrant,  the Holder or the
Holder's  designee,  as the case may be,  shall be deemed a  shareholder  of the
Company.

         8. Sale or Transfer of the Warrant;  Legend.  The Warrant  shall not be
            ----------------------------------------
sold or transferred.  The Shares shall not be sold or transferred  unless either
(i) they first  shall have been  registered  under the Act,  or (ii) the Company
first shall have been furnished with an opinion of legal counsel satisfactory to
the  Company  to the  effect  that such  sale or  transfer  is  exempt  from the
registration  requirements of the Act. Each certificate representing any Warrant
shall  bear the legend  set out on page 1 hereof.  Unless  the Shares  have been
registered under the Act, each certificate  representing any Shares shall bear a
legend substantially in the following form, as appropriate:

         THE SHARES  REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED
         FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN CONNECTION  WITH,
         THE SALE OR DISTRIBUTION  THEREOF. NO SUCH SALE OR DISPOSITION
         MAY BE EFFECTED  WITHOUT AN EFFECTIVE  REGISTRATION  STATEMENT
         RELATED  THERETO OR AN OPINION OF COUNSEL  SATISFACTORY TO THE
         COMPANY  THAT  SUCH  REGISTRATION  IS NOT  REQUIRED  UNDER THE
         SECURITIES ACT OF 1933, AS AMENDED.


                                  -2-

<PAGE>

Such Warrant and Shares may be subject to  additional  restrictions  on transfer
imposed under applicable state and federal securities law.

         9. Modifications and Waivers. This Warrant may not be changed,  waived,
            -------------------------
discharged or terminated  except by an instrument in writing signed by the party
against which enforcement of the same is sought.

         10.  Notices.  Any  notice,  request  or  other  document  required  or
              -------
permitted  to be  given or  delivered  to the  Holder  or the  Company  shall be
delivered, or shall be sent by certified or registered mail, postage prepaid, to
the Holder at its address shown on the books of the Company or to the Company at
the address  indicated  therefor on the signature  page of this Warrant,  or, if
different, at the principal office of the Company.

         11. Loss,  Theft,  Destruction  or Mutilation  of Warrant.  The Company
             -----------------------------------------------------
covenants  with  the  Holder  that  upon  its  receipt  of  evidence  reasonably
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant or any stock  certificate  and, in the case of any such loss, theft
or destruction,  of an indemnity or security reasonably  satisfactory to it, and
upon reimbursement to the Company of all reasonable expenses incidental thereto,
and upon surrender and  cancellation  of this Warrant or stock  certificate,  if
mutilated, the Company will make and deliver a new Warrant or stock certificate,
of like tenor, in lieu of the lost,  stolen,  destroyed or mutilated  Warrant or
stock certificate.

         12.  Representations  and  Warranties  of  Holder.  By  accepting  this
              --------------------------------------------
Warrant, the Holder represents and warrants that he, she or it is acquiring this
Warrant and the Shares for his, her or its own account,  for  investment and not
with a view to, or for sale in connection with, any distribution  thereof or any
part  thereof.  Holder  represents  and  warrants  that  he,  she  or it is  (a)
experienced in the evaluation of businesses similar to the Company,  (b) is able
to fend for himself, herself or itself in the transactions  contemplated by this
Warrant, (c) has such knowledge and experience in financial and business matters
as to be capable of  evaluating  the  merits and risks of an  investment  in the
Company,  (d) has the ability to bear the economic risks of an investment in the
Company, (e) has been furnished with or has had access to such information as is
specified in subparagraph  (b)(2) of Rule 502 promulgated  under the Act and (f)
has been afforded the  opportunity  to ask  questions of and to receive  answers
from the Company and to obtain any additional  information  necessary to make an
informed investment decision with respect to an investment in the Company.

         13. Binding  Effect on  Successors.  This Warrant shall be binding upon
             ------------------------------
any corporation  succeeding the Company by merger,  consolidation or acquisition
of all or substantially all of the Company's assets,  and all of the obligations
of the Company  relating to the Shares  issuable  upon  exercise of this Warrant
shall  survive  the  exercise  and  termination  of this  Warrant and all of the
covenants  and  agreements  of the  Company  shall  inure to the  benefit of the
successors and assigns of the Holder.

         14.  Governing Law.  This Warrant  shall be  construed  and enforced in
              -------------
accordance with, and the rights of the parties shall be governed by, the laws of
the Commonwealth of Massachusetts.

                                      -3-

<PAGE>


         IN WITNESS WHEREOF,  BOSTON BIOMEDICA,  INC. has caused this Warrant to
be executed under seal by its officer thereunto duly authorized.

Dated: August 18, 1999

                                               BOSTON BIOMEDICA, INC.
CORPORATE
  SEAL

                                               By: /S/ Richard T. Schumacher
                                                   -----------------------------
                                                   Richard T. Schumacher,
                                                   Its President

                                                   Address:  375 West Street

                                                   West Bridgewater, MA 02379






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                                      -4-

<PAGE>


                                    EXHIBIT A


                               NOTICE OF EXERCISE
                               ------------------


         To: BOSTON BIOMEDICA, INC.

         1. The undersigned  hereby elects to purchase  _______ shares of Common
Stock of BOSTON  BIOMEDICA,  INC. (the  "Company")  pursuant to the terms of the
attached  Warrant,  and tenders  herewith  payment of the purchase price of such
shares in full.

         2. Please issue a certificate or certificates  representing said shares
in the name of the  undersigned  or in such other name or names as are specified
below.

         3. The  undersigned  represents  and warrants as follows (the following
applies  only in the  event  said  shares  have not been  registered  under  the
Securities Act of 1933, as amended):

         The  undersigned  is  purchasing  or acquiring  the  aforesaid
         shares of Common Stock for its own account for  investment and
         not with a present  view to, or for sale in  connection  with,
         any  distribution   thereof  in  violation  of  the  Act.  The
         undersigned represents and warrants that the undersigned:  (a)
         is experienced in the evaluation of businesses  similar to the
         Company,  (b) has such  knowledge and  experience in financial
         and business matters as to be capable of evaluating the merits
         and risks of an investment in the Company, (c) has the ability
         to bear the economic  risks of an  investment  in the Company,
         (d)  has  been  furnished  with  or has  had  access  to  such
         information as is specified in subparagraph (b)(2) of Rule 502
         promulgated  under  the  Act and has  carefully  reviewed  and
         understood  such  information,   (e)  has  been  afforded  the
         opportunity  to ask  questions of and to receive  answers from
         the Company and to obtain any additional information necessary
         to make an informed  investment  decision  with  respect to an
         investment in the Company, and (f) is an "Accredited Investor"
         as such  term  is  defined  in  subparagraph  (a) of Rule  501
         promulgated under the Act.

         4. In the event of partial  exercise,  please  re-issue an  appropriate
Warrant exercisable into the remaining shares.

                                                 -------------------------------
                                                 (Name)

                                                 -------------------------------
                                                 (Address)

                                                 -------------------------------
                                                 (Signature)

                                                  ------------------------------
                                                  (Date)


#838491 v\3 - fitzgemr - hyzf03!.doc_ - 11563/1

                                      -5-

<PAGE>

NEITHER THIS WARRANT NOR THE SHARES OF STOCK ISSUABLE UPON EXERCISE  HEREOF HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.  NO SALE, TRANSFER
OR OTHER  DISPOSITION OF THIS WARRANT OR SAID SHARES MAY BE EFFECTED WITHOUT (i)
AN  EFFECTIVE  REGISTRATION  STATEMENT  RELATED  THERETO,  OR (ii) AN OPINION OF
COUNSEL,  REASONABLY  SATISFACTORY TO COUNSEL TO THE COMPANY,  THAT AN EXEMPTION
FROM REGISTRATION UNDER SAID ACT IS AVAILABLE.


Warrant                                                                   No. of
No. N-2__                    STOCK PURCHASE WARRANT                Shares 40,000
                                                                          ------

                  To Subscribe for and Purchase Common Stock of


                             BOSTON BIOMEDICA, INC.

         THIS  CERTIFIES  that, for value  received,  National  Securities  (the
"Holder"), is entitled, upon the terms and subject to the conditions hereinafter
set forth,  to  subscribe  for and  purchase  from  Boston  Biomedica,  Inc.,  a
Massachusetts  corporation  (hereinafter  called  the  "Company"),  at the price
hereinafter  set forth in Section 2 up to 40,000  fully paid and  non-assessable
shares of the Company's common stock, $.01 par value per share (the "Shares"),

         1.  Definitions.  As used  herein  the  following  term  shall have the
             -----------
following meaning:

         "Act" means the Securities Act of 1933 as amended, or a similar Federal
          ---
statute and the rules and  regulations of the Commission  issued under that Act,
as they each may, from time to time, be in effect.

         2. Purchase Rights.  Reference is made to that certain Warrant Purchase
            ---------------
Agreement  dated August 18, 1999 by and between the Company and  Paradigm  Group
L.L.C.  (the  "Investor") and the related warrant to purchase  400,000 shares of
the  Company's  Common Stock (the "$4.25  Warrant")  and the related  warrant to
purchase  100,000 shares of the Company's Common Stock (the "$5.25 Warrant) (the
$4.25  Warrant  and  the  $5.25  Warrant  are  collectively  referred  to as the
"Warrants"). The purchase rights represented by this Warrant may be exercised by
the Holder in whole or in part only at such time as the $4.25  Warrant  has been
exercised by the Investor  and then from time to time  thereafter  and ending at
5:00 p.m. on August 15, 2001, but this Warrant may be exercised during such time
only for that  percentage of the 40,000  Shares equal to the same  percentage of
the 400,000  shares for which the Investor has exercised its $4.25  Warrant.  If
and whenever the $4.25 Warrant has been  exercised by the Investor,  the Company
will provide  notice of such exercise to the Holder within ten (10) days of such
exercise.  This  Warrant  may be  exercised  for  Shares at a price of $4.25 per
share,  subject to the foregoing and to adjustment as provided in Section 6 (the
"Warrant Purchase Price").

         3. Exercise of Warrant. Subject to Section 2 above, the purchase rights
            -------------------
represented by this Warrant may be exercised,  in whole or in part and from time
to time,  by the  surrender  of this  Warrant  and the duly  executed  Notice of
Exercise (the form of which is attached as Exhibit


<PAGE>

A) at the principal office of the Company and by the payment to the Company,  by
wire transfer of  immediately  available  funds,  of an amount equal to the then
applicable  Warrant  Purchase Price per share multiplied by the number of Shares
then being  purchased.  Upon exercise,  the Holder shall be entitled to receive,
within a reasonable  time, a certificate or certificates  issued in the Holder's
name for the number of Shares so  purchased.  The Shares so  purchased  shall be
deemed  to be  issued  as of the  close of  business  on the date on which  this
Warrant shall have been exercised.

         4. Shares to be Issued;  Reservation of Shares.  The Company  covenants
            -------------------------------------------
that the Shares that may be issued  upon the  exercise  of the  purchase  rights
represented   by  this  Warrant  will,   upon   issuance,   be  fully  paid  and
non-assessable,  and free from all liens and charges  with  respect to the issue
thereof.  During the period within which the purchase rights  represented by the
Warrant may be  exercised,  the Company  will at all times have  authorized  and
reserved,  for the purpose of issuance  upon  exercise  of the  purchase  rights
represented by this Warrant,  a sufficient  number of shares of its Common Stock
to provide for the exercise of the right represented by this Warrant.

         5. No Fractional  Shares. No fractional shares shall be issued upon the
            ---------------------
exercise of this Warrant. In lieu thereof, a cash payment shall be made equal to
such  fraction  multiplied  by the fair  market  value of such  shares of Common
Stock, as determined in good faith by the Company's Board of Directors.

         6. Adjustments of Warrant Purchase Price and Number of Shares. If there
            ----------------------------------------------------------
shall  be any  change  in  the  Common  Stock  of the  Company  through  merger,
consolidation, reorganization,  recapitalization, stock dividend, stock split or
other change in the corporate structure of the Company,  appropriate adjustments
shall be made by the Board of Directors of the Company (or if the Company is not
the surviving corporation in any such transaction, the Board of Directors of the
surviving  corporation)  in the aggregate  number and kind of shares  subject to
this  Warrant,  and the  number  and kind of shares and the price per share then
applicable to shares covered by the unexercised portion of this Warrant.

         7. No Rights as Shareholders.  This Warrant does not entitle the Holder
            -------------------------
to any voting  rights or other rights as a  shareholder  of the Company prior to
exercise  of  this  Warrant  and  the  payment  for  the  Shares  so  purchased.
Notwithstanding the foregoing, the Company agrees to transmit to the Holder such
information,  documents and reports as are generally  distributed  to holders of
the capital stock of the Company  concurrently with the distribution  thereof to
the shareholders. Upon valid exercise of this Warrant and payment for the Shares
so purchased  in  accordance  with the terms of the  Warrant,  the Holder or the
Holder's  designee,  as the case may be,  shall be deemed a  shareholder  of the
Company.

         8. Sale or Transfer of the Warrant;  Legend. The Warrant and the Shares
            ----------------------------------------
shall not be sold or  transferred  unless  either (i) they first shall have been
registered  under the Act, or (ii) the Company  first shall have been  furnished
with an opinion of legal counsel  satisfactory to the Company to the effect that
such sale or transfer is exempt from the  registration  requirements of the Act.
Each certificate  representing any Warrant shall bear the legend set out on page
1  hereof.  Each  certificate  representing  any  Shares  shall  bear  a  legend
substantially in the following form, as appropriate:

         THE SHARES  REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED
         FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN

                                  -2-
<PAGE>

         CONNECTION  WITH, THE SALE OR  DISTRIBUTION  THEREOF.  NO SUCH
         SALE OR  DISPOSITION  MAY BE  EFFECTED  WITHOUT  AN  EFFECTIVE
         REGISTRATION  STATEMENT  RELATED  THERETO  OR  AN  OPINION  OF
         COUNSEL  SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS
         NOT REQUIRED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.

Such Warrant and Shares may be subject to  additional  restrictions  on transfer
imposed under applicable state and federal securities law.


9. REGISTRATION RIGHTS
   -------------------

         9.1 Piggyback Registrations.

         (a) If at any time or times within two (2) years after the date hereof,
the Company shall determine to register any of its securities  under the Act and
in connection therewith the Company may lawfully register any of the Shares, the
Company  will  promptly  give  written  notice  thereof to the Holder.  Upon the
written  request of the Holder within thirty (30) days after receipt of any such
notice from the Company, the Company will, except as herein provided,  cause all
Shares which the Holder has  requested to be  registered  to be included in such
Registration Statement,  all to the extent requisite to permit the sale or other
disposition of the Shares. However nothing herein shall prevent the Company from
at any time abandoning or delaying any registration.

         (b) If the Company  determines not to proceed with a registration after
the Registration  Statement has been filed with the Commission and the Company's
decision not to proceed is primarily based upon the anticipated  public offering
price of the  securities  to be sold by the Company,  upon request of the Holder
who has requested  registration  hereunder,  the Company shall promptly complete
the  registration for the benefit of those selling security holders who indicate
a desire  to  complete  the  registration  and who  agree  to bear all  expenses
incurred by the Company as the result of such registration after the Company has
decided not to proceed.

         (c)  If  any  registration  pursuant  to  this  Section  9.1  shall  be
underwritten  in whole or in part,  the  Company  may  require  that the  Shares
requested  for  inclusion  pursuant  to  this  Section  9.1 be  included  in the
underwriting on the same terms and conditions as the securities  otherwise being
sold  through  the  underwriters.  In the event  that the Shares  requested  for
inclusion  pursuant to this  Section 9.1 would  constitute  more than 25% of the
total  number  of  shares  to be  included  in a  proposed  underwritten  public
offering,  and if in the good faith judgment of the managing underwriter of such
public  offering  the  inclusion  of all of the Shares  originally  covered by a
request for registration  would reduce the number of shares to be offered by the
Company  or  interfere  with the  successful  marketing  of the  shares of stock
offered by the  Company,  then the number of Shares  otherwise to be included in
the underwritten public offering may be reduced.

                                      -3-
<PAGE>


         9.2 Registration Procedures. If and whenever the Company is required by
the  provisions of Sections 9.1 to effect the  registration  of Shares under the
Act, the Company will:

         (a) prepare and file with the Commission a Registration  Statement with
respect to such securities,  and use its best efforts to cause such Registration
Statement to become and remain  effective  for such period as may be  reasonably
necessary to effect the sale of such securities, not to exceed nine (9) months;

         (b)  prepare  and file  with the  Commission  such  amendments  to such
Registration  Statement and supplements to the prospectus  contained  therein as
may be necessary to keep such Registration  Statement  effective for such period
as may be reasonably  necessary to effect the sale of such Shares, not to exceed
nine (9) months;

         (c) furnish to the Holder participating in such registration and to the
underwriters of the securities being registered such reasonable number of copies
of the Registration Statement, preliminary prospectus, final prospectus and such
other  documents  as such  underwriters  may  reasonably  request  in  order  to
facilitate the public offering of such securities;

         (d) use its best efforts to register or qualify the securities  covered
by such  Registration  Statement under the state  securities or blue sky laws of
such  jurisdictions as such  participating  Holder may reasonably request within
twenty (20) days following the original filing of such  Registration  Statement,
except  that the  Company  shall not for any  purpose be  required  to execute a
general  consent to service of process or to qualify to do business as a foreign
corporation in any jurisdiction wherein it is not so qualified;

         (e) notify  the Holder  participating  in such  registration,  promptly
after it shall  receive  notice  thereof,  of the time  when  such  Registration
Statement has become effective or a supplement to any prospectus  forming a part
of such registration statement has been filed;

         (f) notify the Holder promptly of any request by the Commission for the
amending or  supplementing of such  Registration  Statement or prospectus or for
additional information;

         (g) prepare and file with the Commission,  promptly upon the request of
the Holder,  any  amendments or supplements  to such  Registration  Statement or
prospectus which, in the opinion of counsel for such Holder (and concurred in by
counsel for the Company), is required under the Act or the rules and regulations
thereunder in connection with the distribution of the Shares by such Holder;

         (h) prepare and promptly file with the Commission  and promptly  notify
such Holder of the filing of such  amendment or supplement to such  Registration
Statement

                                      -4-
<PAGE>

or prospectus as may be necessary to correct any  statements or omissions if, at
the time  when a  prospectus  relating  to such  securities  is  required  to be
delivered  under the Act,  any event shall have  occurred as the result of which
any such  prospectus or any other  prospectus as then in effect would include an
untrue statement of a material fact or omit to state any material fact necessary
to make the statements  therein, in the light of the circumstances in which they
were made, not misleading; and

         (i) advise  such  Holder,  promptly  after it shall  receive  notice or
obtain  knowledge  thereof,  of the issuance of any stop order by the Commission
suspending the effectiveness of such Registration Statement or the initiation or
threatening of any proceeding for that purpose and promptly use its best efforts
to prevent the  issuance of any stop order or to obtain its  withdrawal  if such
stop order should be issued.

         9.3  Expenses.   With  respect  to  each   inclusion  of  Shares  in  a
Registration  Statement  pursuant  to Section 9.1  hereof,  all fees,  costs and
expenses of and incidental to such  registration,  inclusion and public offering
(as specified in paragraph (b) below) in connection  therewith shall be borne by
the Company,  other than the fees and costs of counsel to the Holder, which fees
and costs shall be borne by the Holder; and provided, however, that any security
holders  participating in such  registration  shall bear their pro rata share of
(i) the  underwriting  discount and commissions and transfer taxes, and (ii) the
expense of any special audit of the Company's financial statements if the notice
requesting  registration does not permit use of existing or contemplated audited
statements.

         9.4 Indemnification.

         (a) The Company  will  indemnify  and hold  harmless  each Holder whose
Shares are included in a  Registration  Statement  pursuant to the provisions of
this Section 9 and any  underwriter  (as defined in the Act) for such Holder and
each person,  if any, who controls such Investor or such underwriter  within the
meaning of the Act, from and against,  and will reimburse such Investor and each
such  underwriter  and  controlling  person  with  respect to, any and all loss,
damage,  liability,  cost  and  expense  to  which  such  Investor  or any  such
underwriter or controlling person may become subject under the Act or otherwise,
insofar as such losses,  damages,  liabilities,  costs or expenses are caused by
any untrue  statement or alleged untrue statement of any material fact contained
in  such  Registration  Statement,  any  prospectus  contained  therein  or  any
amendment or supplement  thereto, or arise out of or are based upon the omission
or alleged  omission  to state  therein a material  fact  required  to be stated
therein  or  necessary  to  make  the  statements   therein,  in  light  of  the
circumstances in which they were made, not misleading;  provided,  however, that
the  Company  will not be liable in any such  case to the  extent  that any such
loss,  damage,  liability,  cost or  expense  arises  out of or is based upon an
untrue  statement or alleged untrue statement or omission or alleged omission so
made in conformity with information  furnished by such Holder,  such underwriter
or such  controlling  person in writing  specifically for use in the preparation
thereof.

                                      -5-
<PAGE>

         (b) The Holder whose Shares are  included in a  Registration  Statement
pursuant to the  provisions of this Article will indemnify and hold harmless the
Company,  any  underwriter  and any  controlling  person of the  Company or such
underwriter  from and against,  and will  reimburse the Company,  underwriter or
controlling person with respect to, any and all loss, damage, liability, cost or
expense to which the Company,  any underwriter or any controlling person thereof
may become subject under the Act or otherwise,  insofar as such losses, damages,
liabilities,  costs or  expenses  are  caused by any  untrue or  alleged  untrue
statement of any material fact  contained in such  Registration  Statement,  any
prospectus  contained therein or any amendment or supplement  thereto,  or arise
out of or are based upon the omission or the alleged omission to state therein a
material fact required to be stated  therein or necessary to make the statements
therein,  in light of the circumstances in which they were made, not misleading,
in each case to the extent,  but only to the extent,  that such untrue statement
or alleged  untrue  statement  or  omission or alleged  omission  was so made in
reliance upon and in strict  conformity  with written  information  furnished by
such Investor specifically for use in the preparation thereof.

         (c) Promptly  after  receipt by an  indemnified  party  pursuant to the
provisions  of  paragraph  (a) or (b)  of  this  Section  9.4 of  notice  of the
commencement  of any  action  involving  the  subject  matter  of the  foregoing
indemnity  provisions,  such indemnified party will, if a claim thereof is to be
made against the indemnifying  party pursuant to the provisions of paragraph (a)
or (b), promptly notify the indemnifying party of the commencement  thereof; but
the  omission to so notify the  indemnifying  party will not relieve it from any
liability which it may have to any  indemnified  party otherwise than hereunder.
In case such action is brought against any indemnified party and it notifies the
indemnifying  party of the commencement  thereof,  the indemnifying  party shall
have the right to participate  in, and, to the extent that it may wish,  jointly
with any other  indemnifying  party  similarly  notified,  to assume the defense
thereof, with counsel satisfactory to such indemnified party; provided, however,
that if the defendants in any action include both the indemnified  party and the
indemnifying  party and the indemnified  party shall have  reasonably  concluded
that  there  may be legal  defenses  available  to it and/or  other  indemnified
parties  which  are  different  from or  additional  to those  available  to the
indemnifying  party,  or if there is a conflict of interest  which would prevent
counsel for the indemnifying party from also representing the indemnified party,
the indemnified party or parties shall have the right to select separate counsel
to participate in the defense of such action on behalf of such indemnified party
or parties. After notice from the indemnifying party to the indemnified party of
its election so to assume the defense of any action, the indemnifying party will
not be liable to such indemnified party pursuant to the provisions of paragraphs
(a) or (b) hereof for any legal or other expense  subsequently  incurred by such
indemnified  party in connection  with the defense thereof other than reasonable
costs of  investigation,  unless (i) the  indemnified  party shall have employed
counsel in accordance  with the provision of the  preceding  sentence,  (ii) the
indemnifying  party  shall  not  have  employed  counsel   satisfactory  to  the
indemnified  party to represent the  indemnified  party within a reasonable time
after the notice of the  commencement of the action,  or (iii) the  indemnifying
party has authorized the employment of counsel for the indemnified  party at the
expense of the indemnifying party.

                                      -6-

<PAGE>

         9.5  Exclusive  Obligation  to  Register.  Except as  provided  in this
Section 9, the Company will have no obligation  to the Holder to register  under
the Act any Shares received by such Holder pursuant to this Agreement.

         10. Modifications and Waivers. This Warrant may not be changed, waived,
             -------------------------
discharged or terminated  except by an instrument in writing signed by the party
against which enforcement of the same is sought.

         11.  Notices.  Any  notice,  request  or  other  document  required  or
              -------
permitted  to be  given or  delivered  to the  Holder  or the  Company  shall be
delivered, or shall be sent by certified or registered mail, postage prepaid, to
the Holder at its address shown on the books of the Company or to the Company at
the address  indicated  therefor on the signature  page of this Warrant,  or, if
different, at the principal office of the Company.

         12. Loss,  Theft,  Destruction  or Mutilation  of Warrant.  The Company
             -----------------------------------------------------
covenants  with  the  Holder  that  upon  its  receipt  of  evidence  reasonably
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant or any stock  certificate  and, in the case of any such loss, theft
or destruction,  of an indemnity or security reasonably  satisfactory to it, and
upon reimbursement to the Company of all reasonable expenses incidental thereto,
and upon surrender and  cancellation  of this Warrant or stock  certificate,  if
mutilated, the Company will make and deliver a new Warrant or stock certificate,
of like tenor, in lieu of the lost,  stolen,  destroyed or mutilated  Warrant or
stock certificate.

         13.  Representations  and  Warranties  of  Holder.  By  accepting  this
              --------------------------------------------
Warrant, the Holder represents and warrants that he, she or it is acquiring this
Warrant and the Shares for his, her or its own account,  for  investment and not
with a view to, or for sale in connection with, any distribution  thereof or any
part  thereof.  Holder  represents  and  warrants  that  he,  she  or it is  (a)
experienced in the evaluation of businesses similar to the Company,  (b) is able
to fend for himself, herself or itself in the transactions  contemplated by this
Warrant, (c) has such knowledge and experience in financial and business matters
as to be capable of  evaluating  the  merits and risks of an  investment  in the
Company,  (d) has the ability to bear the economic risks of an investment in the
Company, (e) has been furnished with or has had access to such information as is
specified in subparagraph  (b)(2) of Rule 502 promulgated  under the Act and (f)
has been afforded the  opportunity  to ask  questions of and to receive  answers
from the Company and to obtain any additional  information  necessary to make an
informed investment decision with respect to an investment in the Company.

         14. Binding  Effect on  Successors.  This Warrant shall be binding upon
             ------------------------------
any corporation  succeeding the Company by merger,  consolidation or acquisition
of all or substantially all of the Company's assets,  and all of the obligations
of the Company  relating to the Shares  issuable  upon  exercise of this Warrant
shall  survive  the  exercise  and  termination  of this  Warrant and all of the
covenants  and  agreements  of the  Company  shall  inure to the  benefit of the
successors and assigns of the Holder.

         15.  Governing Law.  This Warrant  shall be  construed  and enforced in
              -------------
accordance with, and the rights of the parties shall be governed by, the laws of
the Commonwealth of Massachusetts.

                                      -7-

<PAGE>


         IN WITNESS WHEREOF,  BOSTON BIOMEDICA,  INC. has caused this Warrant to
be executed under seal by its officer thereunto duly authorized.

Dated: August 18, 1999

                                               BOSTON BIOMEDICA, INC.
CORPORATE
  SEAL

                                               By: /S/ Richard T. Schumacher
                                                   -----------------------------
                                                   Richard T. Schumacher,
                                                   Its President

                                                   Address:  375 West Street

                                                   West Bridgewater, MA 02379



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                                      -8-


<PAGE>


                                    EXHIBIT A


                               NOTICE OF EXERCISE
                               ------------------

         To: BOSTON BIOMEDICA, INC.

         1. The undersigned  hereby elects to purchase  _______ shares of Common
Stock of BOSTON  BIOMEDICA,  INC. (the  "Company")  pursuant to the terms of the
attached  Warrant,  and tenders  herewith  payment of the purchase price of such
shares in full.

         2. Please issue a certificate or certificates  representing said shares
in the name of the  undersigned  or in such other name or names as are specified
below.

         3. The  undersigned  represents  and warrants as follows (the following
applies  only in the  event  said  shares  have not been  registered  under  the
Securities Act of 1933, as amended):

         The  undersigned  is  purchasing  or acquiring  the  aforesaid
         shares of Common Stock for its own account for  investment and
         not with a present  view to, or for sale in  connection  with,
         any  distribution   thereof  in  violation  of  the  Act.  The
         undersigned represents and warrants that the undersigned:  (a)
         is experienced in the evaluation of businesses  similar to the
         Company,  (b) has such  knowledge and  experience in financial
         and business matters as to be capable of evaluating the merits
         and risks of an investment in the Company, (c) has the ability
         to bear the economic  risks of an  investment  in the Company,
         (d)  has  been  furnished  with  or has  had  access  to  such
         information as is specified in subparagraph (b)(2) of Rule 502
         promulgated  under  the  Act and has  carefully  reviewed  and
         understood  such  information,   (e)  has  been  afforded  the
         opportunity  to ask  questions of and to receive  answers from
         the Company and to obtain any additional information necessary
         to make an informed  investment  decision  with  respect to an
         investment in the Company, and (f) is an "Accredited Investor"
         as such  term  is  defined  in  subparagraph  (a) of Rule  501
         promulgated under the Act.

         4. In the event of partial  exercise,  please  re-issue an  appropriate
Warrant exercisable into the remaining shares.

                                                 -------------------------------
                                                 (Name)

                                                 -------------------------------
                                                 (Address)

                                                 -------------------------------
                                                 (Signature)

                                                  ------------------------------
                                                  (Date)


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                                      -9-

<PAGE>

NEITHER THIS WARRANT NOR THE SHARES OF STOCK ISSUABLE UPON EXERCISE  HEREOF HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.  NO SALE, TRANSFER
OR OTHER  DISPOSITION OF THIS WARRANT OR SAID SHARES MAY BE EFFECTED WITHOUT (i)
AN  EFFECTIVE  REGISTRATION  STATEMENT  RELATED  THERETO,  OR (ii) AN OPINION OF
COUNSEL,  REASONABLY  SATISFACTORY TO COUNSEL TO THE COMPANY,  THAT AN EXEMPTION
FROM REGISTRATION UNDER SAID ACT IS AVAILABLE.


Warrant                                                                   No. of
No. N-1                     STOCK PURCHASE WARRANT                 Shares 10,000
                                                                          ------

                  To Subscribe for and Purchase Common Stock of


                             BOSTON BIOMEDICA, INC.

         THIS  CERTIFIES  that, for value  received,  National  Securities  (the
"Holder"), is entitled, upon the terms and subject to the conditions hereinafter
set forth,  to  subscribe  for and  purchase  from  Boston  Biomedica,  Inc.,  a
Massachusetts  corporation  (hereinafter  called  the  "Company"),  at the price
hereinafter  set forth in Section 2 up to 10,000  fully paid and  non-assessable
shares of the Company's common stock, $.01 par value per share (the "Shares"),

         1.  Definitions.  As used  herein  the  following  term  shall have the
             -----------
following meaning:

         "Act" means the Securities Act of 1933 as amended, or a similar Federal
          ---
statute and the rules and  regulations of the Commission  issued under that Act,
as they each may, from time to time, be in effect.

         2. Purchase Rights. The purchase rights represented by this Warrant are
            ---------------
exercisable by the Holder in whole or in part, at any time and from time to time
commencing  on the date hereof and ending at 5:00 p.m. on August 15, 2001.  This
Warrant may be  exercised  for Shares at a price of $5.25 per share,  subject to
adjustment as provided in Section 6 (the "Warrant Purchase Price").

         3. Exercise of Warrant. Subject to Section 2 above, the purchase rights
            -------------------
represented by this Warrant may be exercised,  in whole or in part and from time
to time,  by the  surrender  of this  Warrant  and the duly  executed  Notice of
Exercise (the form of which is attached as Exhibit A) at the principal office of
the Company and by the payment to the Company,  by wire transfer of  immediately
available  funds,  of an amount equal to the then  applicable  Warrant  Purchase
Price per share  multiplied by the number of Shares then being  purchased.  Upon
exercise,  the Holder shall be entitled to receive,  within a reasonable time, a
certificate or certificates issued in the Holder's name for the number of Shares
so  purchased.  The Shares so  purchased  shall be deemed to be issued as of the
close of business on the date on which this Warrant shall have been exercised.

         4. Shares to be Issued;  Reservation of Shares.  The Company  covenants
            -------------------------------------------
that the Shares that may be issued  upon the  exercise  of the  purchase  rights
represented by this Warrant

<PAGE>

will, upon issuance,  be fully paid and non-assessable,  and free from all liens
and charges with respect to the issue  thereof.  During the period  within which
the purchase  rights  represented  by the Warrant may be exercised,  the Company
will at all times have authorized and reserved, for the purpose of issuance upon
exercise of the purchase rights represented by this Warrant, a sufficient number
of  shares  of its  Common  Stock  to  provide  for the  exercise  of the  right
represented by this Warrant.

         5. No Fractional  Shares. No fractional shares shall be issued upon the
            ---------------------
exercise of this Warrant. In lieu thereof, a cash payment shall be made equal to
such  fraction  multiplied  by the fair  market  value of such  shares of Common
Stock, as determined in good faith by the Company's Board of Directors.

         6. Adjustments of Warrant Purchase Price and Number of Shares. If there
            ----------------------------------------------------------
shall  be any  change  in  the  Common  Stock  of the  Company  through  merger,
consolidation, reorganization,  recapitalization, stock dividend, stock split or
other change in the corporate structure of the Company,  appropriate adjustments
shall be made by the Board of Directors of the Company (or if the Company is not
the surviving corporation in any such transaction, the Board of Directors of the
surviving  corporation)  in the aggregate  number and kind of shares  subject to
this  Warrant,  and the  number  and kind of shares and the price per share then
applicable to shares covered by the unexercised portion of this Warrant.

         7. No Rights as Shareholders.  This Warrant does not entitle the Holder
            -------------------------
to any voting  rights or other rights as a  shareholder  of the Company prior to
exercise  of  this  Warrant  and  the  payment  for  the  Shares  so  purchased.
Notwithstanding the foregoing, the Company agrees to transmit to the Holder such
information,  documents and reports as are generally  distributed  to holders of
the capital stock of the Company  concurrently with the distribution  thereof to
the shareholders. Upon valid exercise of this Warrant and payment for the Shares
so purchased  in  accordance  with the terms of the  Warrant,  the Holder or the
Holder's  designee,  as the case may be,  shall be deemed a  shareholder  of the
Company.

         8. Sale or Transfer of the Warrant;  Legend. The Warrant and the Shares
            ----------------------------------------
shall not be sold or  transferred  unless  either (i) they first shall have been
registered  under the Act, or (ii) the Company  first shall have been  furnished
with an opinion of legal counsel  satisfactory to the Company to the effect that
such sale or transfer is exempt from the  registration  requirements of the Act.
Each certificate  representing any Warrant shall bear the legend set out on page
1  hereof.  Each  certificate  representing  any  Shares  shall  bear  a  legend
substantially in the following form, as appropriate:

         THE SHARES  REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED
         FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN CONNECTION  WITH,
         THE SALE OR DISTRIBUTION  THEREOF. NO SUCH SALE OR DISPOSITION
         MAY BE EFFECTED  WITHOUT AN EFFECTIVE  REGISTRATION  STATEMENT
         RELATED  THERETO OR AN OPINION OF COUNSEL  SATISFACTORY TO THE
         COMPANY  THAT  SUCH  REGISTRATION  IS NOT  REQUIRED  UNDER THE
         SECURITIES ACT OF 1933, AS AMENDED.

Such Warrant and Shares may be subject to  additional  restrictions  on transfer
imposed under applicable state and federal securities law.

<PAGE>

9. REGISTRATION RIGHTS
   -------------------

         9.1 Piggyback Registrations.

         (a) If at any time or times within two (2) years after the date hereof,
the Company shall determine to register any of its securities  under the Act and
in connection therewith the Company may lawfully register any of the Shares, the
Company  will  promptly  give  written  notice  thereof to the Holder.  Upon the
written  request of the Holder within thirty (30) days after receipt of any such
notice from the Company, the Company will, except as herein provided,  cause all
Shares which the Holder has  requested to be  registered  to be included in such
Registration Statement,  all to the extent requisite to permit the sale or other
disposition of the Shares. However nothing herein shall prevent the Company from
at any time abandoning or delaying any registration.

         (b) If the Company  determines not to proceed with a registration after
the Registration  Statement has been filed with the Commission and the Company's
decision not to proceed is primarily based upon the anticipated  public offering
price of the  securities  to be sold by the Company,  upon request of the Holder
who has requested  registration  hereunder,  the Company shall promptly complete
the  registration for the benefit of those selling security holders who indicate
a desire  to  complete  the  registration  and who  agree  to bear all  expenses
incurred by the Company as the result of such registration after the Company has
decided not to proceed.

         (c)  If  any  registration  pursuant  to  this  Section  9.1  shall  be
underwritten  in whole or in part,  the  Company  may  require  that the  Shares
requested  for  inclusion  pursuant  to  this  Section  9.1 be  included  in the
underwriting on the same terms and conditions as the securities  otherwise being
sold  through  the  underwriters.  In the event  that the Shares  requested  for
inclusion  pursuant to this  Section 9.1 would  constitute  more than 25% of the
total  number  of  shares  to be  included  in a  proposed  underwritten  public
offering,  and if in the good faith judgment of the managing underwriter of such
public  offering  the  inclusion  of all of the Shares  originally  covered by a
request for registration  would reduce the number of shares to be offered by the
Company  or  interfere  with the  successful  marketing  of the  shares of stock
offered by the  Company,  then the number of Shares  otherwise to be included in
the underwritten public offering may be reduced.

         9.2 Registration Procedures. If and whenever the Company is required by
the  provisions of Sections 9.1 to effect the  registration  of Shares under the
Act, the Company will:

         (a) prepare and file with the Commission a Registration  Statement with
respect to such securities,  and use its best efforts to cause such Registration
Statement to become and remain  effective  for such period as may be  reasonably
necessary to effect the sale of such securities, not to exceed nine (9) months;
<PAGE>

         (b)  prepare  and file  with the  Commission  such  amendments  to such
Registration  Statement and supplements to the prospectus  contained  therein as
may be necessary to keep such Registration  Statement  effective for such period
as may be reasonably  necessary to effect the sale of such Shares, not to exceed
nine (9) months;

         (c) furnish to the Holder participating in such registration and to the
underwriters of the securities being registered such reasonable number of copies
of the Registration Statement, preliminary prospectus, final prospectus and such
other  documents  as such  underwriters  may  reasonably  request  in  order  to
facilitate the public offering of such securities;

         (d) use its best efforts to register or qualify the securities  covered
by such  Registration  Statement under the state  securities or blue sky laws of
such  jurisdictions as such  participating  Holder may reasonably request within
twenty (20) days following the original filing of such  Registration  Statement,
except  that the  Company  shall not for any  purpose be  required  to execute a
general  consent to service of process or to qualify to do business as a foreign
corporation in any jurisdiction wherein it is not so qualified;

         (e) notify  the Holder  participating  in such  registration,  promptly
after it shall  receive  notice  thereof,  of the time  when  such  Registration
Statement has become effective or a supplement to any prospectus  forming a part
of such registration statement has been filed;

         (f) notify the Holder promptly of any request by the Commission for the
amending or  supplementing of such  Registration  Statement or prospectus or for
additional information;

         (g) prepare and file with the Commission,  promptly upon the request of
the Holder,  any  amendments or supplements  to such  Registration  Statement or
prospectus which, in the opinion of counsel for such Holder (and concurred in by
counsel for the Company), is required under the Act or the rules and regulations
thereunder in connection with the distribution of the Shares by such Holder;

         (h) prepare and promptly file with the Commission  and promptly  notify
such Holder of the filing of such  amendment or supplement to such  Registration
Statement  or  prospectus  as may be  necessary  to correct  any  statements  or
omissions  if, at the time when a  prospectus  relating  to such  securities  is
required to be  delivered  under the Act,  any event shall have  occurred as the
result of which any such  prospectus  or any other  prospectus as then in effect
would  include  an  untrue  statement  of a  material  fact or omit to state any
material  fact  necessary to make the  statements  therein,  in the light of the
circumstances in which they were made, not misleading; and

         (i) advise  such  Holder,  promptly  after it shall  receive  notice or
obtain  knowledge  thereof,  of the issuance of any stop order by the Commission
suspending the

<PAGE>

effectiveness of such Registration Statement or the initiation or threatening of
any proceeding for that purpose and promptly use its best efforts to prevent the
issuance of any stop order or to obtain its withdrawal if such stop order should
be issued.

         9.3  Expenses.   With  respect  to  each   inclusion  of  Shares  in  a
Registration  Statement  pursuant  to Section 9.1  hereof,  all fees,  costs and
expenses of and incidental to such  registration,  inclusion and public offering
(as specified in paragraph (b) below) in connection  therewith shall be borne by
the Company,  other than the fees and costs of counsel to the Holder, which fees
and costs shall be borne by the Holder; and provided, however, that any security
holders  participating in such  registration  shall bear their pro rata share of
(i) the  underwriting  discount and commissions and transfer taxes, and (ii) the
expense of any special audit of the Company's financial statements if the notice
requesting  registration does not permit use of existing or contemplated audited
statements.

         9.4 Indemnification.

         (a) The Company  will  indemnify  and hold  harmless  each Holder whose
Shares are included in a  Registration  Statement  pursuant to the provisions of
this Section 9 and any  underwriter  (as defined in the Act) for such Holder and
each person,  if any, who controls such Investor or such underwriter  within the
meaning of the Act, from and against,  and will reimburse such Investor and each
such  underwriter  and  controlling  person  with  respect to, any and all loss,
damage,  liability,  cost  and  expense  to  which  such  Investor  or any  such
underwriter or controlling person may become subject under the Act or otherwise,
insofar as such losses,  damages,  liabilities,  costs or expenses are caused by
any untrue  statement or alleged untrue statement of any material fact contained
in  such  Registration  Statement,  any  prospectus  contained  therein  or  any
amendment or supplement  thereto, or arise out of or are based upon the omission
or alleged  omission  to state  therein a material  fact  required  to be stated
therein  or  necessary  to  make  the  statements   therein,  in  light  of  the
circumstances in which they were made, not misleading;  provided,  however, that
the  Company  will not be liable in any such  case to the  extent  that any such
loss,  damage,  liability,  cost or  expense  arises  out of or is based upon an
untrue  statement or alleged untrue statement or omission or alleged omission so
made in conformity with information  furnished by such Holder,  such underwriter
or such  controlling  person in writing  specifically for use in the preparation
thereof.

         (b) The Holder whose Shares are  included in a  Registration  Statement
pursuant to the  provisions of this Article will indemnify and hold harmless the
Company,  any  underwriter  and any  controlling  person of the  Company or such
underwriter  from and against,  and will  reimburse the Company,  underwriter or
controlling person with respect to, any and all loss, damage, liability, cost or
expense to which the Company,  any underwriter or any controlling person thereof
may become subject under the Act or otherwise,  insofar as such losses, damages,
liabilities,  costs or  expenses  are  caused by any  untrue or  alleged  untrue
statement of any material fact  contained in such  Registration  Statement,  any
prospectus  contained therein or any amendment or supplement  thereto,  or arise
out of or are based upon the omission or the

<PAGE>

alleged  omission to state therein a material fact required to be stated therein
or necessary to make the statements  therein,  in light of the  circumstances in
which they were made, not  misleading,  in each case to the extent,  but only to
the extent,  that such untrue  statement or alleged untrue statement or omission
or alleged  omission was so made in reliance upon and in strict  conformity with
written  information  furnished  by such  Investor  specifically  for use in the
preparation thereof.

         (c) Promptly  after  receipt by an  indemnified  party  pursuant to the
provisions  of  paragraph  (a) or (b)  of  this  Section  9.4 of  notice  of the
commencement  of any  action  involving  the  subject  matter  of the  foregoing
indemnity  provisions,  such indemnified party will, if a claim thereof is to be
made against the indemnifying  party pursuant to the provisions of paragraph (a)
or (b), promptly notify the indemnifying party of the commencement  thereof; but
the  omission to so notify the  indemnifying  party will not relieve it from any
liability which it may have to any  indemnified  party otherwise than hereunder.
In case such action is brought against any indemnified party and it notifies the
indemnifying  party of the commencement  thereof,  the indemnifying  party shall
have the right to participate  in, and, to the extent that it may wish,  jointly
with any other  indemnifying  party  similarly  notified,  to assume the defense
thereof, with counsel satisfactory to such indemnified party; provided, however,
that if the defendants in any action include both the indemnified  party and the
indemnifying  party and the indemnified  party shall have  reasonably  concluded
that  there  may be legal  defenses  available  to it and/or  other  indemnified
parties  which  are  different  from or  additional  to those  available  to the
indemnifying  party,  or if there is a conflict of interest  which would prevent
counsel for the indemnifying party from also representing the indemnified party,
the indemnified party or parties shall have the right to select separate counsel
to participate in the defense of such action on behalf of such indemnified party
or parties. After notice from the indemnifying party to the indemnified party of
its election so to assume the defense of any action, the indemnifying party will
not be liable to such indemnified party pursuant to the provisions of paragraphs
(a) or (b) hereof for any legal or other expense  subsequently  incurred by such
indemnified  party in connection  with the defense thereof other than reasonable
costs of  investigation,  unless (i) the  indemnified  party shall have employed
counsel in accordance  with the provision of the  preceding  sentence,  (ii) the
indemnifying  party  shall  not  have  employed  counsel   satisfactory  to  the
indemnified  party to represent the  indemnified  party within a reasonable time
after the notice of the  commencement of the action,  or (iii) the  indemnifying
party has authorized the employment of counsel for the indemnified  party at the
expense of the indemnifying party.

         9.5  Exclusive  Obligation  to  Register.  Except as  provided  in this
Section 9, the Company will have no obligation  to the Holder to register  under
the Act any Shares received by such Holder pursuant to this Agreement.

         10. Modifications and Waivers. This Warrant may not be changed, waived,
             -------------------------
discharged or terminated  except by an instrument in writing signed by the party
against which enforcement of the same is sought.

<PAGE>

         11.  Notices.  Any  notice,  request  or  other  document  required  or
              -------
permitted  to be  given or  delivered  to the  Holder  or the  Company  shall be
delivered, or shall be sent by certified or registered mail, postage prepaid, to
the Holder at its address shown on the books of the Company or to the Company at
the address  indicated  therefor on the signature  page of this Warrant,  or, if
different, at the principal office of the Company.

         12. Loss,  Theft,  Destruction  or Mutilation  of Warrant.  The Company
             -----------------------------------------------------
covenants  with  the  Holder  that  upon  its  receipt  of  evidence  reasonably
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant or any stock  certificate  and, in the case of any such loss, theft
or destruction,  of an indemnity or security reasonably  satisfactory to it, and
upon reimbursement to the Company of all reasonable expenses incidental thereto,
and upon surrender and  cancellation  of this Warrant or stock  certificate,  if
mutilated, the Company will make and deliver a new Warrant or stock certificate,
of like tenor, in lieu of the lost,  stolen,  destroyed or mutilated  Warrant or
stock certificate.

         13.  Representations  and  Warranties  of  Holder.  By  accepting  this
              --------------------------------------------
Warrant, the Holder represents and warrants that he, she or it is acquiring this
Warrant and the Shares for his, her or its own account,  for  investment and not
with a view to, or for sale in connection with, any distribution  thereof or any
part  thereof.  Holder  represents  and  warrants  that  he,  she  or it is  (a)
experienced in the evaluation of businesses similar to the Company,  (b) is able
to fend for himself, herself or itself in the transactions  contemplated by this
Warrant, (c) has such knowledge and experience in financial and business matters
as to be capable of  evaluating  the  merits and risks of an  investment  in the
Company,  (d) has the ability to bear the economic risks of an investment in the
Company, (e) has been furnished with or has had access to such information as is
specified in subparagraph  (b)(2) of Rule 502 promulgated  under the Act and (f)
has been afforded the  opportunity  to ask  questions of and to receive  answers
from the Company and to obtain any additional  information  necessary to make an
informed investment decision with respect to an investment in the Company.

         14. Binding  Effect on  Successors.  This Warrant shall be binding upon
             ------------------------------
any corporation  succeeding the Company by merger,  consolidation or acquisition
of all or substantially all of the Company's assets,  and all of the obligations
of the Company  relating to the Shares  issuable  upon  exercise of this Warrant
shall  survive  the  exercise  and  termination  of this  Warrant and all of the
covenants  and  agreements  of the  Company  shall  inure to the  benefit of the
successors and assigns of the Holder.

         15.  Governing Law.  This Warrant  shall be  construed  and enforced in
              -------------
accordance with, and the rights of the parties shall be governed by, the laws of
the Commonwealth of Massachusetts.



<PAGE>


         IN WITNESS WHEREOF,  BOSTON BIOMEDICA,  INC. has caused this Warrant to
be executed under seal by its officer thereunto duly authorized.

Dated: August 18, 1999

                                               BOSTON BIOMEDICA, INC.
CORPORATE
  SEAL

                                               By: /S/ Richard T. Schumacher
                                                   -----------------------------
                                                   Richard T. Schumacher,
                                                   Its President

                                                   Address:  375 West Street

                                                   West Bridgewater, MA 02379



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<PAGE>


                                    EXHIBIT A


                               NOTICE OF EXERCISE
                               ------------------


         To: BOSTON BIOMEDICA, INC.

         1. The undersigned  hereby elects to purchase  _______ shares of Common
Stock of BOSTON  BIOMEDICA,  INC. (the  "Company")  pursuant to the terms of the
attached  Warrant,  and tenders  herewith  payment of the purchase price of such
shares in full.

         2. Please issue a certificate or certificates  representing said shares
in the name of the  undersigned  or in such other name or names as are specified
below.

         3. The  undersigned  represents  and warrants as follows (the following
applies  only in the  event  said  shares  have not been  registered  under  the
Securities Act of 1933, as amended):

         The  undersigned  is  purchasing  or acquiring  the  aforesaid
         shares of Common Stock for its own account for  investment and
         not with a present  view to, or for sale in  connection  with,
         any  distribution   thereof  in  violation  of  the  Act.  The
         undersigned represents and warrants that the undersigned:  (a)
         is experienced in the evaluation of businesses  similar to the
         Company,  (b) has such  knowledge and  experience in financial
         and business matters as to be capable of evaluating the merits
         and risks of an investment in the Company, (c) has the ability
         to bear the economic  risks of an  investment  in the Company,
         (d)  has  been  furnished  with  or has  had  access  to  such
         information as is specified in subparagraph (b)(2) of Rule 502
         promulgated  under  the  Act and has  carefully  reviewed  and
         understood  such  information,   (e)  has  been  afforded  the
         opportunity  to ask  questions of and to receive  answers from
         the Company and to obtain any additional information necessary
         to make an informed  investment  decision  with  respect to an
         investment in the Company, and (f) is an "Accredited Investor"
         as such  term  is  defined  in  subparagraph  (a) of Rule  501
         promulgated under the Act.

         4. In the event of partial  exercise,  please  re-issue an  appropriate
Warrant exercisable into the remaining shares.

                                                 -------------------------------
                                                 (Name)

                                                 -------------------------------
                                                 (Address)

                                                 -------------------------------
                                                 (Signature)

                                                  ------------------------------
                                                  (Date)



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<PAGE>
NEITHER THIS WARRANT NOR THE SHARES OF STOCK ISSUABLE UPON EXERCISE  HEREOF HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.  NO SALE, TRANSFER
OR OTHER  DISPOSITION OF THIS WARRANT OR SAID SHARES MAY BE EFFECTED WITHOUT (i)
AN  EFFECTIVE  REGISTRATION  STATEMENT  RELATED  THERETO,  OR (ii) AN OPINION OF
COUNSEL,  REASONABLY  SATISFACTORY TO COUNSEL TO THE COMPANY,  THAT AN EXEMPTION
FROM REGISTRATION UNDER SAID ACT IS AVAILABLE.


Warrant                                                                   No. of
No. N-3                      STOCK PURCHASE WARRANT                Shares 25,000
                                                                          ------

                  To Subscribe for and Purchase Common Stock of


                             BOSTON BIOMEDICA, INC.

         THIS  CERTIFIES  that, for value  received,  National  Securities  (the
"Holder"), is entitled, upon the terms and subject to the conditions hereinafter
set forth,  to  subscribe  for and  purchase  from  Boston  Biomedica,  Inc.,  a
Massachusetts  corporation  (hereinafter  called  the  "Company"),  at the price
hereinafter  set forth in Section 2 up to 25,000  fully paid and  non-assessable
shares of the Company's common stock, $.01 par value per share (the "Shares"),

         1.  Definitions.  As used  herein  the  following  term  shall have the
             -----------
following meaning:

         "Act" means the Securities Act of 1933 as amended, or a similar Federal
          ---
statute and the rules and  regulations of the Commission  issued under that Act,
as they each may, from time to time, be in effect.

         2. Purchase Rights.  Reference is made to that certain Warrant Purchase
            ---------------
Agreement  dated August 18, 1999 by and between the Company and  Paradigm  Group
L.L.C.  (the  "Investor") and the related warrant to purchase  400,000 shares of
the  Company's  Common Stock (the "$4.25  Warrant")  and the related  warrant to
purchase  100,000 shares of the Company's Common Stock (the "$5.25 Warrant) (the
$4.25  Warrant  and  the  $5.25  Warrant  are  collectively  referred  to as the
"Warrants"). The purchase rights represented by this Warrant may be exercised by
the Holder in whole or in part only at such time as the Investor  has  exercised
its Warrants in full, and then from time to time thereafter  ending at 5:00 p.m.
on August 15, 2001.  If and whenever  the  Warrants  have been  exercised by the
Investor,  the Company will provide notice of such exercise to the Holder within
ten (10) days of such  exercise.  This Warrant may be exercised  for Shares at a
price of $8.00 per share, subject to the foregoing and to adjustment as provided
in Section 6 (the "Warrant Purchase Price").

         3. Exercise of Warrant. Subject to Section 2 above, the purchase rights
            -------------------
represented by this Warrant may be exercised,  in whole or in part and from time
to time,  by the  surrender  of this  Warrant  and the duly  executed  Notice of
Exercise (the form of which is attached as Exhibit A) at the principal office of
the Company and by the payment to the Company,  by wire transfer of  immediately
available  funds,  of an amount equal to the then  applicable  Warrant  Purchase
Price per share  multiplied by the number of Shares then being  purchased.  Upon
exercise, the

<PAGE>

Holder shall be entitled to receive,  within a reasonable time, a certificate or
certificates  issued in the Holder's name for the number of Shares so purchased.
The Shares so purchased shall be deemed to be issued as of the close of business
on the date on which this Warrant shall have been exercised.

         4. Shares to be Issued;  Reservation of Shares.  The Company  covenants
            -------------------------------------------
that the Shares that may be issued  upon the  exercise  of the  purchase  rights
represented   by  this  Warrant  will,   upon   issuance,   be  fully  paid  and
non-assessable,  and free from all liens and charges  with  respect to the issue
thereof.  During the period within which the purchase rights  represented by the
Warrant may be  exercised,  the Company  will at all times have  authorized  and
reserved,  for the purpose of issuance  upon  exercise  of the  purchase  rights
represented by this Warrant,  a sufficient  number of shares of its Common Stock
to provide for the exercise of the right represented by this Warrant.

         5. No Fractional  Shares. No fractional shares shall be issued upon the
            ---------------------
exercise of this Warrant. In lieu thereof, a cash payment shall be made equal to
such  fraction  multiplied  by the fair  market  value of such  shares of Common
Stock, as determined in good faith by the Company's Board of Directors.

         6. Adjustments of Warrant Purchase Price and Number of Shares. If there
            ----------------------------------------------------------
shall  be any  change  in  the  Common  Stock  of the  Company  through  merger,
consolidation, reorganization,  recapitalization, stock dividend, stock split or
other change in the corporate structure of the Company,  appropriate adjustments
shall be made by the Board of Directors of the Company (or if the Company is not
the surviving corporation in any such transaction, the Board of Directors of the
surviving  corporation)  in the aggregate  number and kind of shares  subject to
this  Warrant,  and the  number  and kind of shares and the price per share then
applicable to shares covered by the unexercised portion of this Warrant.

         7. No Rights as Shareholders.  This Warrant does not entitle the Holder
            -------------------------
to any voting  rights or other rights as a  shareholder  of the Company prior to
exercise  of  this  Warrant  and  the  payment  for  the  Shares  so  purchased.
Notwithstanding the foregoing, the Company agrees to transmit to the Holder such
information,  documents and reports as are generally  distributed  to holders of
the capital stock of the Company  concurrently with the distribution  thereof to
the shareholders. Upon valid exercise of this Warrant and payment for the Shares
so purchased  in  accordance  with the terms of the  Warrant,  the Holder or the
Holder's  designee,  as the case may be,  shall be deemed a  shareholder  of the
Company.

         8. Sale or Transfer of the Warrant;  Legend. The Warrant and the Shares
            ----------------------------------------
shall not be sold or  transferred  unless  either (i) they first shall have been
registered  under the Act, or (ii) the Company  first shall have been  furnished
with an opinion of legal counsel  satisfactory to the Company to the effect that
such sale or transfer is exempt from the  registration  requirements of the Act.
Each certificate  representing any Warrant shall bear the legend set out on page
1  hereof.  Each  certificate  representing  any  Shares  shall  bear  a  legend
substantially in the following form, as appropriate:

         THE SHARES  REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED
         FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN CONNECTION  WITH,
         THE SALE OR DISTRIBUTION  THEREOF. NO SUCH SALE OR DISPOSITION
         MAY BE EFFECTED  WITHOUT AN EFFECTIVE  REGISTRATION  STATEMENT
         RELATED  THERETO OR AN OPINION OF

                                  -2-

<PAGE>

         COUNSEL  SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS
         NOT REQUIRED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.

Such Warrant and Shares may be subject to  additional  restrictions  on transfer
imposed under applicable state and federal securities law.


9. REGISTRATION RIGHTS
   -------------------

         9.1 Piggyback Registrations.

         (a) If at any time or times within two (2) years after the date hereof,
the Company shall determine to register any of its securities  under the Act and
in connection therewith the Company may lawfully register any of the Shares, the
Company  will  promptly  give  written  notice  thereof to the Holder.  Upon the
written  request of the Holder within thirty (30) days after receipt of any such
notice from the Company, the Company will, except as herein provided,  cause all
Shares which the Holder has  requested to be  registered  to be included in such
Registration Statement,  all to the extent requisite to permit the sale or other
disposition of the Shares. However nothing herein shall prevent the Company from
at any time abandoning or delaying any registration.

         (b) If the Company  determines not to proceed with a registration after
the Registration  Statement has been filed with the Commission and the Company's
decision not to proceed is primarily based upon the anticipated  public offering
price of the  securities  to be sold by the Company,  upon request of the Holder
who has requested  registration  hereunder,  the Company shall promptly complete
the  registration for the benefit of those selling security holders who indicate
a desire  to  complete  the  registration  and who  agree  to bear all  expenses
incurred by the Company as the result of such registration after the Company has
decided not to proceed.

         (c)  If  any  registration  pursuant  to  this  Section  9.1  shall  be
underwritten  in whole or in part,  the  Company  may  require  that the  Shares
requested  for  inclusion  pursuant  to  this  Section  9.1 be  included  in the
underwriting on the same terms and conditions as the securities  otherwise being
sold  through  the  underwriters.  In the event  that the Shares  requested  for
inclusion  pursuant to this  Section 9.1 would  constitute  more than 25% of the
total  number  of  shares  to be  included  in a  proposed  underwritten  public
offering,  and if in the good faith judgment of the managing underwriter of such
public  offering  the  inclusion  of all of the Shares  originally  covered by a
request for registration  would reduce the number of shares to be offered by the
Company  or  interfere  with the  successful  marketing  of the  shares of stock
offered by the  Company,  then the number of Shares  otherwise to be included in
the underwritten public offering may be reduced.

         9.2 Registration Procedures. If and whenever the Company is required by
the  provisions of Sections 9.1 to effect the  registration  of Shares under the
Act, the Company will:

                                      -3-

<PAGE>

         (a) prepare and file with the Commission a Registration  Statement with
respect to such securities,  and use its best efforts to cause such Registration
Statement to become and remain  effective  for such period as may be  reasonably
necessary to effect the sale of such securities, not to exceed nine (9) months;

         (b)  prepare  and file  with the  Commission  such  amendments  to such
Registration  Statement and supplements to the prospectus  contained  therein as
may be necessary to keep such Registration  Statement  effective for such period
as may be reasonably  necessary to effect the sale of such Shares, not to exceed
nine (9) months;

         (c) furnish to the Holder participating in such registration and to the
underwriters of the securities being registered such reasonable number of copies
of the Registration Statement, preliminary prospectus, final prospectus and such
other  documents  as such  underwriters  may  reasonably  request  in  order  to
facilitate the public offering of such securities;

         (d) use its best efforts to register or qualify the securities  covered
by such  Registration  Statement under the state  securities or blue sky laws of
such  jurisdictions as such  participating  Holder may reasonably request within
twenty (20) days following the original filing of such  Registration  Statement,
except  that the  Company  shall not for any  purpose be  required  to execute a
general  consent to service of process or to qualify to do business as a foreign
corporation in any jurisdiction wherein it is not so qualified;

         (e) notify  the Holder  participating  in such  registration,  promptly
after it shall  receive  notice  thereof,  of the time  when  such  Registration
Statement has become effective or a supplement to any prospectus  forming a part
of such registration statement has been filed;

         (f) notify the Holder promptly of any request by the Commission for the
amending or  supplementing of such  Registration  Statement or prospectus or for
additional information;

         (g) prepare and file with the Commission,  promptly upon the request of
the Holder,  any  amendments or supplements  to such  Registration  Statement or
prospectus which, in the opinion of counsel for such Holder (and concurred in by
counsel for the Company), is required under the Act or the rules and regulations
thereunder in connection with the distribution of the Shares by such Holder;

         (h) prepare and promptly file with the Commission  and promptly  notify
such Holder of the filing of such  amendment or supplement to such  Registration
Statement  or  prospectus  as may be  necessary  to correct  any  statements  or
omissions  if, at the time when a  prospectus  relating  to such  securities  is
required to be  delivered  under the Act,  any event shall have  occurred as the
result of which any such  prospectus  or any other  prospectus as then in effect

                                      -4-

<PAGE>

would  include  an  untrue  statement  of a  material  fact or omit to state any
material  fact  necessary to make the  statements  therein,  in the light of the
circumstances in which they were made, not misleading; and

         (i) advise  such  Holder,  promptly  after it shall  receive  notice or
obtain  knowledge  thereof,  of the issuance of any stop order by the Commission
suspending the effectiveness of such Registration Statement or the initiation or
threatening of any proceeding for that purpose and promptly use its best efforts
to prevent the  issuance of any stop order or to obtain its  withdrawal  if such
stop order should be issued.

         9.3  Expenses.   With  respect  to  each   inclusion  of  Shares  in  a
Registration  Statement  pursuant  to Section 9.1  hereof,  all fees,  costs and
expenses of and incidental to such  registration,  inclusion and public offering
(as specified in paragraph (b) below) in connection  therewith shall be borne by
the Company,  other than the fees and costs of counsel to the Holder, which fees
and costs shall be borne by the Holder; and provided, however, that any security
holders  participating in such  registration  shall bear their pro rata share of
(i) the  underwriting  discount and commissions and transfer taxes, and (ii) the
expense of any special audit of the Company's financial statements if the notice
requesting  registration does not permit use of existing or contemplated audited
statements.

         9.4 Indemnification.

         (a) The Company  will  indemnify  and hold  harmless  each Holder whose
Shares are included in a  Registration  Statement  pursuant to the provisions of
this Section 9 and any  underwriter  (as defined in the Act) for such Holder and
each person,  if any, who controls such Investor or such underwriter  within the
meaning of the Act, from and against,  and will reimburse such Investor and each
such  underwriter  and  controlling  person  with  respect to, any and all loss,
damage,  liability,  cost  and  expense  to  which  such  Investor  or any  such
underwriter or controlling person may become subject under the Act or otherwise,
insofar as such losses,  damages,  liabilities,  costs or expenses are caused by
any untrue  statement or alleged untrue statement of any material fact contained
in  such  Registration  Statement,  any  prospectus  contained  therein  or  any
amendment or supplement  thereto, or arise out of or are based upon the omission
or alleged  omission  to state  therein a material  fact  required  to be stated
therein  or  necessary  to  make  the  statements   therein,  in  light  of  the
circumstances in which they were made, not misleading;  provided,  however, that
the  Company  will not be liable in any such  case to the  extent  that any such
loss,  damage,  liability,  cost or  expense  arises  out of or is based upon an
untrue  statement or alleged untrue statement or omission or alleged omission so
made in conformity with information  furnished by such Holder,  such underwriter
or such  controlling  person in writing  specifically for use in the preparation
thereof.

         (b) The Holder whose Shares are  included in a  Registration  Statement
pursuant to the  provisions of this Article will indemnify and hold harmless the
Company,  any  underwriter  and any  controlling  person of the  Company or such
underwriter from and against,

                                      -5-

<PAGE>

and will reimburse the Company,  underwriter or controlling  person with respect
to, any and all loss, damage,  liability,  cost or expense to which the Company,
any underwriter or any  controlling  person thereof may become subject under the
Act or  otherwise,  insofar  as such  losses,  damages,  liabilities,  costs  or
expenses  are caused by any untrue or alleged  untrue  statement of any material
fact contained in such Registration Statement,  any prospectus contained therein
or any  amendment or supplement  thereto,  or arise out of or are based upon the
omission or the alleged omission to state therein a material fact required to be
stated  therein or necessary  to make the  statements  therein,  in light of the
circumstances  in which  they were  made,  not  misleading,  in each case to the
extent,  but only to the extent,  that such untrue  statement or alleged  untrue
statement or omission or alleged  omission  was so made in reliance  upon and in
strict   conformity  with  written   information   furnished  by  such  Investor
specifically for use in the preparation thereof.

         (c) Promptly  after  receipt by an  indemnified  party  pursuant to the
provisions  of  paragraph  (a) or (b)  of  this  Section  9.4 of  notice  of the
commencement  of any  action  involving  the  subject  matter  of the  foregoing
indemnity  provisions,  such indemnified party will, if a claim thereof is to be
made against the indemnifying  party pursuant to the provisions of paragraph (a)
or (b), promptly notify the indemnifying party of the commencement  thereof; but
the  omission to so notify the  indemnifying  party will not relieve it from any
liability which it may have to any  indemnified  party otherwise than hereunder.
In case such action is brought against any indemnified party and it notifies the
indemnifying  party of the commencement  thereof,  the indemnifying  party shall
have the right to participate  in, and, to the extent that it may wish,  jointly
with any other  indemnifying  party  similarly  notified,  to assume the defense
thereof, with counsel satisfactory to such indemnified party; provided, however,
that if the defendants in any action include both the indemnified  party and the
indemnifying  party and the indemnified  party shall have  reasonably  concluded
that  there  may be legal  defenses  available  to it and/or  other  indemnified
parties  which  are  different  from or  additional  to those  available  to the
indemnifying  party,  or if there is a conflict of interest  which would prevent
counsel for the indemnifying party from also representing the indemnified party,
the indemnified party or parties shall have the right to select separate counsel
to participate in the defense of such action on behalf of such indemnified party
or parties. After notice from the indemnifying party to the indemnified party of
its election so to assume the defense of any action, the indemnifying party will
not be liable to such indemnified party pursuant to the provisions of paragraphs
(a) or (b) hereof for any legal or other expense  subsequently  incurred by such
indemnified  party in connection  with the defense thereof other than reasonable
costs of  investigation,  unless (i) the  indemnified  party shall have employed
counsel in accordance  with the provision of the  preceding  sentence,  (ii) the
indemnifying  party  shall  not  have  employed  counsel   satisfactory  to  the
indemnified  party to represent the  indemnified  party within a reasonable time
after the notice of the  commencement of the action,  or (iii) the  indemnifying
party has authorized the employment of counsel for the indemnified  party at the
expense of the indemnifying party.

                                      -6-
<PAGE>

         9.5  Exclusive  Obligation  to  Register.  Except as  provided  in this
Section 9, the Company will have no obligation  to the Holder to register  under
the Act any Shares received by such Holder pursuant to this Agreement.

         10. Modifications and Waivers. This Warrant may not be changed, waived,
             -------------------------
discharged or terminated  except by an instrument in writing signed by the party
against which enforcement of the same is sought.

         11.  Notices.  Any  notice,  request  or  other  document  required  or
              -------
permitted  to be  given or  delivered  to the  Holder  or the  Company  shall be
delivered, or shall be sent by certified or registered mail, postage prepaid, to
the Holder at its address shown on the books of the Company or to the Company at
the address  indicated  therefor on the signature  page of this Warrant,  or, if
different, at the principal office of the Company.

         12. Loss,  Theft,  Destruction  or Mutilation  of Warrant.  The Company
             -----------------------------------------------------
covenants  with  the  Holder  that  upon  its  receipt  of  evidence  reasonably
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant or any stock  certificate  and, in the case of any such loss, theft
or destruction,  of an indemnity or security reasonably  satisfactory to it, and
upon reimbursement to the Company of all reasonable expenses incidental thereto,
and upon surrender and  cancellation  of this Warrant or stock  certificate,  if
mutilated, the Company will make and deliver a new Warrant or stock certificate,
of like tenor, in lieu of the lost,  stolen,  destroyed or mutilated  Warrant or
stock certificate.

         13.  Representations  and  Warranties  of  Holder.  By  accepting  this
              --------------------------------------------
Warrant, the Holder represents and warrants that he, she or it is acquiring this
Warrant and the Shares for his, her or its own account,  for  investment and not
with a view to, or for sale in connection with, any distribution  thereof or any
part  thereof.  Holder  represents  and  warrants  that  he,  she  or it is  (a)
experienced in the evaluation of businesses similar to the Company,  (b) is able
to fend for himself, herself or itself in the transactions  contemplated by this
Warrant, (c) has such knowledge and experience in financial and business matters
as to be capable of  evaluating  the  merits and risks of an  investment  in the
Company,  (d) has the ability to bear the economic risks of an investment in the
Company, (e) has been furnished with or has had access to such information as is
specified in subparagraph  (b)(2) of Rule 502 promulgated  under the Act and (f)
has been afforded the  opportunity  to ask  questions of and to receive  answers
from the Company and to obtain any additional  information  necessary to make an
informed investment decision with respect to an investment in the Company.

         14. Binding  Effect on  Successors.  This Warrant shall be binding upon
             ------------------------------
any corporation  succeeding the Company by merger,  consolidation or acquisition
of all or substantially all of the Company's assets,  and all of the obligations
of the Company  relating to the Shares  issuable  upon  exercise of this Warrant
shall  survive  the  exercise  and  termination  of this  Warrant and all of the
covenants  and  agreements  of the  Company  shall  inure to the  benefit of the
successors and assigns of the Holder.

         15.  Governing Law.  This Warrant  shall be  construed  and enforced in
              -------------
accordance with, and the rights of the parties shall be governed by, the laws of
the Commonwealth of Massachusetts.

                                      -7-

<PAGE>

         IN WITNESS WHEREOF,  BOSTON BIOMEDICA,  INC. has caused this Warrant to
be executed under seal by its officer thereunto duly authorized.

Dated: August 18, 1999

                                               BOSTON BIOMEDICA, INC.
CORPORATE
  SEAL

                                               By: /S/ Richard T. Schumacher
                                                   -----------------------------
                                                   Richard T. Schumacher,
                                                   Its President

                                                   Address:  375 West Street

                                                   West Bridgewater, MA 02379



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                                      -8-

<PAGE>


                                    EXHIBIT A


                               NOTICE OF EXERCISE
                               ------------------


         To: BOSTON BIOMEDICA, INC.

         1. The undersigned  hereby elects to purchase  _______ shares of Common
Stock of BOSTON  BIOMEDICA,  INC. (the  "Company")  pursuant to the terms of the
attached  Warrant,  and tenders  herewith  payment of the purchase price of such
shares in full.

         2. Please issue a certificate or certificates  representing said shares
in the name of the  undersigned  or in such other name or names as are specified
below.

         3. The  undersigned  represents  and warrants as follows (the following
applies  only in the  event  said  shares  have not been  registered  under  the
Securities Act of 1933, as amended):

         The  undersigned  is  purchasing  or acquiring  the  aforesaid
         shares of Common Stock for its own account for  investment and
         not with a present  view to, or for sale in  connection  with,
         any  distribution   thereof  in  violation  of  the  Act.  The
         undersigned represents and warrants that the undersigned:  (a)
         is experienced in the evaluation of businesses  similar to the
         Company,  (b) has such  knowledge and  experience in financial
         and business matters as to be capable of evaluating the merits
         and risks of an investment in the Company, (c) has the ability
         to bear the economic  risks of an  investment  in the Company,
         (d)  has  been  furnished  with  or has  had  access  to  such
         information as is specified in subparagraph (b)(2) of Rule 502
         promulgated  under  the  Act and has  carefully  reviewed  and
         understood  such  information,   (e)  has  been  afforded  the
         opportunity  to ask  questions of and to receive  answers from
         the Company and to obtain any additional information necessary
         to make an informed  investment  decision  with  respect to an
         investment in the Company, and (f) is an "Accredited Investor"
         as such  term  is  defined  in  subparagraph  (a) of Rule  501
         promulgated under the Act.

         4. In the event of partial  exercise,  please  re-issue an  appropriate
Warrant exercisable into the remaining shares.

                                                 -------------------------------
                                                 (Name)

                                                 -------------------------------
                                                 (Address)

                                                 -------------------------------
                                                 (Signature)

                                                  ------------------------------
                                                  (Date)



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                                      -9-