As amended through 9/3/96

                                     BY-LAWS

                                       of

                             SAGE LABORATORIES, INC.

                                    ARTICLE I

                              Seal and Fiscal Year

      The seal shall be circular in form with the name of the corporation around
the periphery and words and figures  "Incorporated 1955  Massachusetts"  within.
The fiscal year shall commence on July 1 of each year.

                                   ARTICLE II

                            Meetings of Stockholders

      Section  1.  Place.  Meetings  of the  stockholders  shall  be held at the
principal  office of the corporation in  Massachusetts or at such other place as
may be named in the call.

      Section 2. Annual Meetings.  The annual meeting of the stockholders  shall
be held on the second  Tuesday of November  in each year,  or on such other date
within six months  after the end of the fiscal  year of the  corporation  as the
directors  shall  determine,  at such  hour  and  place as the  directors  shall
determine.  In the event  that the annual  meeting  is not held on such date,  a
special  meeting in lieu of the annual meeting may be held with all of the force
and effect of an annual meeting.

      Section 3. Special  Meetings.  Special meetings of the stockholders may be
called by the president or by the directors,





and shall be called by the clerk or, in case of the death,  absence,  incapacity
or refusal of the clerk, by any other officer,  upon written  application of one
or more stockholders who hold at least one-tenth part in interest of the capital
stock entitled to vote thereat.

      Section 4.  Notice.  A written  notice of the date,  place and hour of all
meetings of  stockholders  stating the purposes of the meeting shall be given by
the clerk or an assistant clerk (or by any other officer who is entitled to call
such a meeting) at least  seven (7) days before the meeting to each  stockholder
entitled to vote thereat and to each stockholder who is entitled to such notice,
by leaving such notice with him or at his  residence or usual place of business,
or by mailing it,  postage  prepaid,  and addressed to such  stockholder  at his
address as it appears in the records of the  corporation.  Whenever  notice of a
meeting is required to be given a stockholder under applicable law, the articles
of organization or these by-laws,  a written waiver thereof,  executed before or
after the meeting by such stockholder or his attorney  thereunto  authorized and
filed  with the  records  of the  meeting,  shall be deemed  equivalent  to such
notice.

      Section 5. Quorum. A majority in interest of all stock issued, outstanding
and  entitled  to vote at a meeting  shall  constitute  a quorum,  but a smaller
number may adjourn  from time to time without  further  notice until a quorum is
secured.

      Section 6. Voting.  Stockholders  entitled to vote shall have one vote for
each share of stock owned by them and a





proportionate  vote for each  fractional  share;  provided that the  corporation
shall not directly or indirectly  vote any share of its own stock,  and provided
further  that stock shall not be voted if any  installment  of the  subscription
therefor has been duly demanded and is overdue and unpaid. Stockholders may vote
in person or by proxy.

      Section 7. Action by Consent. Any action required or permitted to be taken
at any  meeting  of the  stockholders  may be taken  without  a  meeting  if all
stockholders entitled to vote on the matter consent to the action in writing and
the written consents are filed with the records of the meetings of stockholders.
Such consents shall be treated for all purposes as a vote at a meeting.

                                   ARTICLE III

                             Officers and Directors

      Section 1.  Enumeration.  The  corporation  shall have a board of not less
than three  directors,  except  that  whenever  there  shall be fewer than three
stockholders,  the  number of  directors  may be less than three but in no event
less than the number of stockholders.  The number of directors shall be fixed at
the annual meeting,  and may be changed at any special  meeting,  by vote of the
stockholders  having the right to vote in the  election of  directors;  provided
that the board of directors may be enlarged at any time by vote of a majority of
the  directors  then in  office.  The  officers  of the  corporation  shall be a
president,  a treasurer,  a clerk and such other  officers as the  directors may
from time to time appoint.





      Section  2.   Qualifications.   Directors   and   officers   need  not  be
stockholders.  No officer need be a director. Two or more offices may be held by
the same  person.  The  clerk  shall be a  resident  of  Massachusetts  unless a
resident agent shall have been appointed pursuant to the Massachusetts  Business
Corporation Law.

      Section 3. Election.  The directors shall be elected at the annual meeting
of the stockholders by such stockholders as have the right to vote thereon.  The
directors  at their  annual  meeting in each year shall  elect a chairman of the
board,  a  president,  a treasurer  and a clerk,  and may at any time elect such
other  officers as they shall  determine.  Except as hereinafter  provided,  the
directors, the chairman of the board, the president, the treasurer and the clerk
shall hold office until the next annual meeting of stockholders  and until their
respective  successors are elected and qualified.  Other officers shall serve at
the pleasure of the directors.

      Section 4.  Removal.  Directors may be removed from office at any time for
cause by vote of a majority of the directors then in office, and with or without
cause by vote of the holders of a majority of the shares entitled to vote in the
election of  directors.  Officers  elected or appointed by the  directors may be
removed  from  their  respective  offices  with or  without  cause  by vote of a
majority of the directors  then in office.  A director or officer may be removed
for cause only after a reasonable  notice and opportunity to be heard before the
body proposing to remove him.





      Section 5.  Resignation.  Resignations  by officers or directors  shall be
given in writing to the chairman of the board, treasurer, clerk or directors.

      Section 6.  Vacancies.  Continuing  directors may act despite a vacancy or
vacancies  in the board and shall for this purpose be deemed to  constitute  the
full board. Any vacancy in the board of directors, however occurring,  including
a vacancy  resulting  from the  enlargement  of the board,  may be filled by the
directors,  unless previously filled by the stockholders entitled to vote in the
election  of  directors.  Vacancies  in any  other  office  may be filled by the
directors.

                                   ARTICLE IV

                   Powers and Duties of Directors and Officers

      Section 1. Directors.  The business of the corporation shall be managed by
the directors, who may exercise all such powers of the corporation as are not by
law, by the articles of organization or by the by-laws  required to be otherwise
exercised.  The directors  may from time to time to the extent  permitted by law
delegate any of their powers to committees, officers, attorneys or agents of the
corporation, subject to such limitations as the directors may impose.

      Section 2.  Chairman of the Board.  The chairman of the board shall be the
chief executive  officer of the corporation and, subject to the direction of the
directors,  have  general  supervision  and  control  of  the  business  of  the
corporation.  The  chairman  shall,  when  present,  preside at all  meetings of
stockholders and the directors. The chairman of the board and





chief  executive  officer  shall  perform  such other duties and shall have such
other powers as the directors may designate from time to time.

      Section 3. President.  The president shall be the chief operating  officer
of the  corporation  and shall have such powers and duties as may be  designated
from time to time by the directors or by the chairman.

      Section 4. Vice Presidents.  The vice presidents,  if any, shall have such
powers and duties as may be designated  from time to time by the directors or by
the president.

      Section 5. Treasurer.  Except as the directors shall otherwise  determine,
the  treasurer  shall be the  chief  financial  and  accounting  officer  of the
corporation and shall have such other powers and duties as customarily belong to
the  office  of  treasurer  or as may be  designated  from  time  to time by the
directors or by the chairman of the board.

      Section  6.  Clerk.   The  clerk  shall  record  all  proceedings  of  the
stockholders and directors in a book or books to be kept therefor and shall have
custody of the seal of the corporation.

      Section 7. Other Officers. Other officers shall have such powers as may be
designated from time to time by the directors.

                                    ARTICLE V

                            Meeting of the Directors

      Section 1. Regular  Meetings.  Regular  meetings may be held at such times
and places within or without the  Commonwealth of Massachusetts as the directors
may fix. An annual meeting shall





be held in each year immediately  after and at the place of the meeting at which
the board is elected.

      Section 2. Special  Meetings.  Special  meetings may be held at such times
and  places  within or  without  the  Commonwealth  of  Massachusetts  as may be
determined by the directors or by the president.

      Section  3.  Notice.  No  notice  need be given  for a  regular  or annual
meeting.  Forty-eight  hours'  notice by mail,  telegraph,  telephone or word of
mouth shall be given for a special  meeting  unless  shorter  notice is adequate
under the  circumstances.  A notice or waiver  of notice  need not  specify  the
purpose of any  special  meeting.  Notice of a meeting  need not be given to any
director  if a written  waiver of  notice,  executed  by him before or after the
meeting,  is filed  with the  records of the  meeting,  or to any  director  who
attends the meeting without  protesting prior thereto or at its commencement the
lack of notice to him.

      Section  4.  Quorum.  A majority  of the  directors  then in office  shall
constitute a quorum,  but a smaller  number may adjourn  finally or from time to
time without further notice until a quorum is secured. If a quorum is present, a
majority  of the  directors  present  may take any action on behalf of the board
except to the extent that a larger  number is required by law or the articles or
organization or the by-laws.

      Section 5. Action by Consent. Any action required or permitted to be taken
at any  meeting  of the  directors  may be taken  without a  meeting  if all the
directors  consent to the action in writing and the written  consents  are filed
with the





records of the meetings of  directors.  Such  consents  shall be treated for all
purposes as a vote at a meeting.

                                   ARTICLE VI

                            Stock and Transfer Books

      The corporation  shall keep in the  Commonwealth of  Massachusetts  at its
principal  office (or at an office of its  transfer  agent or of its clerk or of
its resident agent) stock and transfer records, which shall contain the names of
all  stockholders  and the record  address and the amount of stock held by each.
The  corporation for all purposes may  conclusively  presume that the registered
holder of a stock be absolute owner of the shares  represented  thereby and that
his record  address is his proper  address.  The  directors may fix in advance a
time,  which shall not be more than sixty days before the date of any meeting of
stockholders  or the date for the  payment of any  dividend or the making of any
distribution  to stockholders or the last day on which the consent or dissent of
stockholders  may be effectively  expressed for any purpose,  as the record date
for  determining the  stockholders  having the right to notice of and to vote at
such meeting and any  adjournment  thereof or the right to receive such dividend
or distribution  or the right to give such consent or dissent,  and in such case
only  stockholders  of  record  on such  record  date  shall  have  such  right,
notwithstanding  any transfer of stock on the books of the corporation after the
record date;  or without  fixing such record date the  directors  may for any of
such purposes close the transfer books for all or any part of such period.





If no record date is fixed and the transfer books are not closed:

      (1) The  record  date for  determining  stockholders  having  the right to
notice  of or to vote at a  meeting  of  stockholders  shall be at the  close of
business on the day next preceding the day on which notice is given.

      (2) The record date for  determining  stockholders  for any other  purpose
shall be at the  close of  business  on the day on which  the  board  acts  with
respect thereto.






                                   ARTICLE VII

                               Signature of Checks

      All checks drawn on bank accounts of the  corporation may be signed on its
behalf as authorized from time to time by the directors.

                                  ARTICLE VIII

                              Amendment of By-Laws

      These by-laws may be amended, altered or repealed in whole or in part, and
new by-laws  may be adopted,  by vote of the holders of a majority of the shares
of common stock  outstanding and entitled to vote. The directors may also amend,
alter or repeal these by-laws in whole or in part, or adopt new by-laws,  except
with respect to any provision thereof which by law, the articles of organization
or these by-laws requires action by the stockholders. Not later than the time of
giving  notice of the  meeting of  stockholders  next  following  the  amending,
altering,  repealing or adopting by the directors of any by-law,  notice thereof
stating the substance of such change shall be given to all stockholders entitled
to vote on amending  the by-laws.  Any by-law  adopted by the  directors  may be
amended or repealed by the stockholders.

                                   ARTICLE IX

                              Employment Contracts

      The  corporation  may enter into  employment  contracts  authorized by the
directors and the provisions of such contracts shall be valid in accordance with
their terms despite any





inconsistent  provision  of these  by-laws  relating  to terms of  officers  and
removal of officers with or without cause.

                                    ARTICLE X

                    Indemnification of Directors and Officers

      The corporation shall, to the extent legally  permissible,  indemnify each
person who may serve or who has  served at any time as a director  or officer of
the  corporation  or of any of its  subsidiaries,  or who at the  request of the
corporation  may  serve or at any time has  served  as a  director,  officer  or
trustee of, or in a similar capacity with,  another  organization or an employee
benefit  plan,  against all expenses and  liabilities  (including  counsel fees,
judgments,  fines,  excise taxes,  penalties and amounts payable in settlements)
reasonably  incurred  by or  imposed  upon such  person in  connection  with any
threatened,  pending or  completed  action,  suit or other  proceeding,  whether
civil,  criminal,  administrative  or  investigative,  in  which  he may  become
involved by reason of his serving or having served in such capacity  (other than
a proceeding voluntarily initiated by such person unless he is successful on the
merits, the proceeding was authorized by the corporation or the proceeding seeks
a  declaratory   judgment   regarding   his  own  conduct);   provided  that  no
indemnification shall be provided for any such person with respect to any matter
as to which he shall have been finally adjudicated in any proceeding not to have
acted in good  faith in the  reasonable  belief  that his action was in the best
interests of the  corporation  or, to the extent such matter  relates to service
with respect to any employee benefit plan, in the best





interests of the  participants or  beneficiaries  of such employee benefit plan;
and provided, further, that as to any matter disposed of by a compromise payment
by such  person,  pursuant  to a consent  decree or  otherwise,  the payment and
indemnification  thereof have been approved by the  corporation,  which approval
shall not be  unreasonably  withheld,  or by a court of competent  jurisdiction.
Such  indemnification  shall  include  payment  by the  corporation  of  expense
incurred in defending a criminal or action or proceeding in advance of the final
disposition of such action or proceeding,  upon receipt of an undertaking by the
person  indemnified  to repay such payment if he shall be  adjudicated to be not
entitled  to  indemnification  under  this  article,  which  undertaking  may be
accepted  without  regard  to the  financial  ability  of  such  person  to make
repayment.

      A person  entitled  to  indemnification  hereunder  whose  duties  include
service or responsibilities as a fiduciary with respect to a subsidiary or other
organization  shall be  deemed  to have  acted in good  faith in the  reasonable
belief that his action was in the best interests of the  corporation if he acted
in good faith in the reasonable belief that his action was in the best interests
of such subsidiary or organization or of the participants or  beneficiaries  of,
or other persons with interests in, such  subsidiary or  organization to whom he
had a fiduciary duty.

      Where indemnification  hereunder requires authorization or approval by the
corporation, such authorization or approval shall be conclusively deemed to have
been obtained, and in any case





where a director of the  corporation  approves  the payment of  indemnification,
such director shall be wholly protected, if:

            (i) the payment has been approved or ratified (1) by a majority vote
      of a quorum of the  directors  consisting  of persons  who are not at that
      time parties to the  proceeding,  (2) by a majority vote of a committee of
      two or more  directors who are not at that time parties to the  proceeding
      and are selected  for this  purpose by the full board (in which  selection
      directors who are parties may participate), or (3) by a majority vote of a
      quorum of the outstanding  shares of stock of all classes entitled to vote
      for  directors,  voting as a  single-class,  which quorum shall consist of
      stockholders who are not at that time parties to the proceeding; or

            (ii) the action is taken in reliance upon the opinion of independent
      legal  counsel (who may be counsel to the  corporation)  appointed for the
      purpose by vote of the  directors  or in the manner  specified  in clauses
      (1), (2) or (3) of subparagraph (i); or

            (iii) the payment is approved by a court of competent  jurisdiction;
      or

            (iv) the  directors  have  otherwise  acted in  accordance  with the
      standard of conduct set forth in the  Massachusetts  Business  Corporation
      Law. 

      Any  indemnification  or advance of expenses  under this article  shall be
paid  promptly,  and in any event  within  30 days,  after  the  receipt  by the
corporation of a written request





therefor from the person to be  indemnified,  unless with respect to a claim for
indemnification  the  corporation  shall have  determined that the person is not
entitled to indemnification. If the corporation denies the request or if payment
is not made within such 30 day period,  the person seeking to be indemnified may
at any time  thereafter  seek to  enforce  his  rights  hereunder  in a court of
competent  jurisdiction  and,  if  successful  in whole or in part,  he shall be
entitled also to  indemnification  for the expenses of prosecuting  such action.
Unless  otherwise  provided by law, the burden of proving that the person is not
entitled to indemnification shall be on the corporation.

      The right of indemnification  under this article shall be a contract right
inuring to the benefit of the directors,  officers and other persons entitled to
be  indemnified  hereunder  and no  amendment  or repeal of this  article  shall
adversely affect any right of such director, officer or other person existing at
the time of such amendment or repeal.

      The  indemnification  provided hereunder shall inure to the benefit of the
heirs,  executors  and  administrators  of a director,  officer or other  person
entitled to indemnification  hereunder.  The indemnification  provided hereunder
may,  to the  extent  authorized  by the  corporation,  apply to the  directors,
officers and other persons  associated with constituent  corporations  that have
been  merged  into or  consolidated  with the  corporation  who would  have been
entitled to  indemnification  hereunder had they served in such capacity with or
at the request of the corporation.





      The right of  indemnification  under this article  shall be in addition to
and not exclusive of all other rights to which such director or officer or other
persons may be entitled.  Nothing  contained  in this  article  shall affect any
rights to  indemnification  to which corporation  employees or agents other than
directors and officers and other persons entitled to  indemnification  hereunder
may be entitled by contract or otherwise under law.

                                   ARTICLE XI

                            Issue of Authorized Stock

      Any unissued capital stock from time to time authorized under the articles
of organization may be issued by vote of the directors.