ARTICLES OF INCORPORATION

                                       OF

                                  CLS/SG, INC.

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

          The undersigned, being a natural person and acting as the
incorporator, does hereby adopt the following Articles of Incorporation for the
purpose of forming a corporation pursuant to the provisions of Chapter 1701 of
the Revised Code of Ohio, as amended and implemented, and as hereinafter
sometimes referred to as the "General Corporation Law".

          FIRST: The name of the corporation (hereinafter called the
"Corporation") is CLS/SG, INC.

          SECOND: The place in the State of Ohio where the principal office of
the Corporation is to be located is City of Maple Heights, County of Cuyahoga
(44137-3054).

          THIRD: The purposes for which the Corporation is formed, which shall
be in addition to the authority to engage in any lawful act or activity for
which corporations may be formed under Chapter 1701 of the Revised Code of Ohio,
are as follows:

          (i)   to own and operate medical, clinical, industrial and research
                laboratories;

          (ii)  to research, manufacture, design, construct, use, buy, sell,
                lease, hire and deal in and with articles and property of all
                kinds; and

          (iii) to render services of all kinds.

          FOURTH: The authorized number of shares of the Corporation is 1,000,
all of which are without par value and are of the same class and are to be
common shares, each with a right to one vote.

          All or any part of said common shares without par value may be issued
by the Corporation from time to time and for such consideration as may be
determined upon and fixed by the Board of Directors, as provided by law. Any and
all such shares issued, for which the full consideration has been paid and
delivered, shall be deemed fully paid shares and the holder of such shares shall
not be liable for any further call or assessment or any other payment thereon.

          FIFTH: The period of existence of the Corporation is perpetual.



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      SIXTH: The Corporation may indemnify, to the full extent permitted by
Section 1701.13 of the General  Corporation  Law, as the same may be amended and
supplemented,  any person who was or is a party,  or is  threatened to be made a
party, to any threatened or pending action,  suit or proceeding,  whether civil,
criminal, administrative, or investigative, by reason of the fact that he or she
is or was a director or officer of the Corporation,  or was or is serving at the
request of the  Corporation,  as a director  or officer of another  corporation,
partnership,  joint  venture,  trust or other  enterprise.  Any  indemnification
pursuant to the foregoing shall be made by the Corporation only as authorized in
the specific case upon a determination  that  indemnification of the director or
officer is proper under the circumstances  because he or she has met any legally
applicable standard of conduct. Such determination may be made (i) by resolution
of the Board of Directors  adopted in the manner  provided in the Regulations of
the corporation, or (ii) if a quorum consisting of directors who are not parties
to such action, suit or proceeding, is not obtainable, or, even if obtainable, a
quorum of disinterested  directors so directs, by independent legal counsel in a
written opinion, or (iii) by the shareholders.

      SEVENTH: Notwithstanding any provision of the General Corporation Law
now or hereafter in force requiring, for any purpose, the vote, consent, waiver,
or release of the holders of a designated  proportion (but less than all) of the
shares of any particular  class or of each class,  of the shares are classified,
the vote,  consent,  waiver, or release if the holders of at least a majority of
the voting  power or of at least a majority of the shares  entitled to vote,  as
the case may be,  of such  particular  class or of each  class,  if  shares  are
classified,  shall be required in lieu of any such designated greater proportion
otherwise required by any provision of said General Corporation Law.

      EIGHTH: From time to time any of the provisions of these Articles of
Incorporation  may be  amended,  altered,  or  repealed,  and  other  provisions
authorized by the General  Corporation  Law and the laws of the State of Ohio at
the  time in  force  may be  added or  inserted  in the  manner  and at the time
prescribed  by  said  laws,  and all  rights  at any  time  conferred  upon  the
shareholders of the corporation by these Articles of  Incorporation  are granted
subject to the provisions of this Article EIGHTH.

Signed on September 4, 1992.


                                                     /s/ Peter J. Sheptak
                                                     --------------------
                                                     Peter J. Sheptak
                                                     Sole Incorporator


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                        SOUTHGATE MEDICAL SERVICES, INC.

                             CERTIFICATE OF ADOPTION
                             OF AGREEMENT OF MERGER


          The undersigned, Edward E. Siegler, President, and Charles J.
Silverman, Secretary, respectively, of Southgate Medical Services, Inc., an Ohio
corporation, do hereby certify that:

         1.       The  Agreement  of Merger,  dated as of  September  14,  1992,
                  between  Southgate Medical  Services,  Inc.  ("Southgate") and
                  CLS/SG, Inc., to which this Certificate is attached,  was duly
                  approved by the Board of  Directors  of Southgate in an action
                  without  a  meeting  dated  September  14,  1992  and was duly
                  executed by the President and the Secretary of Southgate; and

         2.       Pursuant to the  provisions of Section  1701.78(D) of the Ohio
                  Revised  Code,  such  Agreement of Merger was submitted to and
                  adopted by the  shareholders of Southgate in an action without
                  a meeting,  dated  September  14, 1992,  signed by each of the
                  shareholders of Southgate.

         IN WITNESS WHEREOF, the undersigned have duly executed this Certificate
this 14th day of September, 1992.



                                                /s/ Edward E. Siegler
                                                -------------------------------
                                                Edward E. Siegler, President


                                                /s/ Charles J. Silverman
                                                -------------------------------
                                                Charles J. Silverman, Secretary


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                                  CLS/SG, INC.

                             CERTIFICATE OF ADOPTION
                             OF AGREEMENT OF MERGER


         The undersigned,  Thomas D. Moses, President,  and Anthony J. Geramita,
Assistant  Secretary,   respectively,  of  CLS/SG,  Inc.,  an  Ohio  corporation
("Newco"), do hereby certify that:

1.       The  Agreement  of Merger,  dated as of  September  14,  1992,  between
         Southgate  Medical Services,  Inc., an Ohio corporation,  and Newco, to
         which this  Certificate is attached,  was duly approved by the Board of
         Directors of Newco in an action  without a meeting dated  September 11,
         1992, and was duly executed by the President and Assistant Secretary of
         Newco; and

2.       Pursuant to the  provisions  of Section  1701.78(D) of the Ohio Revised
         Code,  such Agreement of Merger was approved by the consent in writing,
         dated September 11, 1992,  signed by the sole shareholder of Newco, the
         only shareholder  entitled to notice of and to vote at a meeting of the
         shareholders held for the purpose of approving an agreement of merger.

         IN WITNESS WHEREOF, the undersigned have duly executed this Certificate
this 11th day of September, 1992.

                                   /s/ Thomas D. Moses
                                   ----------------------------------------
                                   Thomas D. Moses, President


                                   /s/ Anthony J. Geramita
                                   ----------------------------------------
                                   Anthony J. Geramita, Assistant Secretary


                                        4





                               AGREEMENT OF MERGER

THIS AGREEMENT OF MERGER ("Agreement") is made as of this 14th day of September,
1992, by and among Charles J. Silverman,  JoAnn Silverman, Frank J. Ilkanich and
Edward E.  Siegler,  M.D.,  as Trustee  (collectively,  the  "Shareholders"  and
individually,  a  "Shareholder");  Southgate  Medical  Services,  Inc.,  an Ohio
corporation ("Southgate"); CLS/SG, Inc., an Ohio corporation ("Newco"), a wholly
owned  subsidiary  of  Corning  Incorporated,  a New York  business  corporation
("Corning").

                                    RECITALS:

WHEREAS,  the Shareholders  own all of the issued and outstanding  shares of the
capital stock of Southgate,  as well as all outstanding rights to acquire shares
of such capital stock (the  "Shares");  and 

WHEREAS,  Corning desires to acquire all of the Shares in exchange for shares of
common stock of Corning,  par value $.50 per share (the "Corning Common Stock"),
pursuant  to a plan of  merger  upon the terms and  conditions  hereinafter  set
forth;  and  WHEREAS,  Corning has  organized  Newco in the State of Ohio as its
wholly-owned subsidiary corporation for the purpose of merging with Southgate as
provided herein. NOW, THEREFORE,  in consideration of the foregoing premises and
of the mutual and independent  promises hereinafter set forth, the parties agree
as follows:

                   ARTICLE I. The Merger



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                  Pursuant to the merger (the  "Merger")  to be  consummated  as
provided in this Agreement, Newco shall be merged with and into Southgate on the
Closing Date (as defined in Article III hereof),  and Newco's separate corporate
existence shall thereupon cease. The Articles of Incorporation of Newco shall be
amended  and  restated  to reflect  the change in  corporate  name,  in the form
attached   hereto  as  Exhibit  A,  which  Amended  and  Restated   Articles  of
Incorporation  shall be the  Articles  of  Incorporation  of  Southgate,  as the
surviving  corporation.  The Code of  Regulations  of Newco shall be the Code of
Regulations  of  Southgate,  as the  surviving  corporation.  The  directors and
officers of Newco at the Closing  Date shall be the  directors  and  officers of
Southgate, as the surviving corporation,  and shall hold office from the Closing
Date  until  their  respective  successors  are duly  elected or  appointed  and
qualified in the manner provided in the Code of Regulations of Southgate, as the
surviving corporation, or as otherwise provided by law.

                  ARTICLE II.  Exchange and Conversion of Shares

                   (a) On the Closing Date, each outstanding share of Southgate
common stock shall by virtue of the Merger and without any action on the part of
the holder thereof by exchanged for 1,594.5073 shares of Corning Common Stock.
No certificates representing fractional shares will be issued by Corning on
account of the Merger. The number of shares that each Shareholder is entitled to
receive shall be rounded up to the nearest whole share. 

                   (b) Each share of common stock, no par value, of Newco issued
and outstanding immediately prior to the Closing Date shall, by virtue of the
Merger and without any


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action on the part of the holder thereof,  be converted into one share of common
stock of Southgate.

                   ARTICLE III. Closing Date

                   The closing of the transactions contemplated by this
Agreement will take place on such date and at such time and place as may be
mutually agreed upon by the Shareholders and Corning ("Closing Date"). The
Merger shall become effective as of the filing of this Agreement in the office
of the Secretary of State of the State of Ohio on the Closing Date.

                   ARTICLE IV. Counterparts

                   This Agreement may be executed in one or more counterparts,
all of which shall be considered one and the same agreement and shall become
effective when one or more counterparts have been signed by each of the parties
hereto and delivered to each of the other parties hereto.

                   IN WITNESS WHEREOF, each of the parties hereto have caused
this Agreement to be executed on its behalf by this officers thereunto duly
authorized, all as of the day and year first above written.

                                                     SHAREHOLDERS


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                                              /s/ Charles J. Silverman
                                              -------------------------------
                                              Charles J. Silverman


                                              /s/ JoAnn Silverman
                                              -------------------------------
                                              JoAnn Silverman


                                              /s/ Frank J. Ilkanich
                                              -------------------------------
                                              Frank J. Ilkanich



                                              SOUTHGATE MEDICAL SERVICES, INC.


                                                by:  /s/ Edward E. Siegler
                                                     ------------------------
                                                title:  President


                                                by:  /s/ Charles J. Silverman
                                                     ------------------------
                                                title:  Secretary


                                              CLS/SG, INC.


                                                by:  /s/ Thomas D. Moses
                                                     ------------------------
                                                title:  President


                                                by:  /s/ Anthony J. Geramita
                                                     ------------------------
                                                title:  Assistant Secretary


                                        8





                                    EXHIBIT A

                              AMENDED AND RESTATED
                            ARTICLES OF INCORPORATION

                                       OF

                        SOUTHGATE MEDICAL SERVICES, INC.

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

                   FIRST: The name of the corporation (hereinafter called the
"Corporation") is SOUTHGATE MEDICAL SERVICES, INC.

                   SECOND: The place in the State of Ohio where the principal
office of the Corporation is to be located is City of Maple Heights, County of
Cuyahoga (44137-3054).

                   THIRD: The purposes for which the Corporation is formed,
which shall be in addition to the authority to engage in any lawful act or
activity for which corporations may be formed under Chapter 1701 of the Revised
Code of Ohio, are as follows:

                  (i)   to own and operate medical, clinical, industrial and
                        research laboratories;

                  (ii)  to research, manufacture, design, construct, use, buy,
                        sell, lease, hire and deal in and with articles and
                        property of all kinds; and

                  (iii) to render services of all kinds.

                   FOURTH: The authorized number of shares of the Corporation is
1,000, all of which are without par value and are of the same class and are to
be common shares, each with a right to one vote.

                   All or any part of said common shares without par value may
be issued by the Corporation from time to time and for such consideration as may
be determined upon and fixed by the Board of Directors, as provided by law. Any
and all such shares issued, for which the full consideration has been paid and
delivered, shall be deemed fully paid shares and the holder of such shares shall
not be liable for any further call or assessment or any other payment thereon.

                   FIFTH: The period of existence of the Corporation is
perpetual.

                   SIXTH: The Corporation shall indemnify, to the full extent
permitted by Section 1701.13 of the General Corporation Law, as the same may be
amended and supplemented, any person who was or is a party, or is threatened to
be made a party, to any


                                        9




threatened or pending  action,  suit or  proceeding,  whether  civil,  criminal,
administrative, or investigative, by reason of the fact that he or she is or was
a director or officer of the Corporation, or was or is serving at the request of
the Corporation,  as a director or officer of another corporation,  partnership,
joint venture,  trust or other enterprise.  Any indemnification  pursuant to the
foregoing  shall be made by the  Corporation  only as authorized in the specific
case upon a  determination  that  indemnification  of the director or officer is
proper under the circumstances  because he or she has met any legally applicable
standard of conduct.  Such  determination  may be made (i) by  resolution of the
Board of  Directors  adopted in the manner  provided in the  Regulations  of the
corporation,  or (ii) if a quorum consisting of directors who are not parties to
such action, suit or proceeding,  is not obtainable,  or, even if obtainable,  a
quorum of disinterested  directors so directs, by independent legal counsel in a
written opinion, or (iii) by the shareholders.

                   SEVENTH: Notwithstanding any provision of the General
Corporation Law now or hereafter in force requiring, for any purpose, the vote,
consent, waiver, or release of the holders of a designated proportion (but less
than all) of the shares of any particular class or of each class, of the shares
are classified, the vote, consent, waiver, or release if the holders of at least
a majority of the voting power or of at least a majority of the shares entitled
to vote, as the case may be, of such particular class or of each class, if
shares are classified, shall be required in lieu of any such designated greater
proportion otherwise required by any provision of said General Corporation Law.

                   EIGHTH: From time to time any of the provisions of these
Articles of Incorporation may be amended, altered, or repealed, and other
provisions authorized by the General Corporation Law and the laws of the State
of Ohio at the time in force may be added or inserted in the manner and at the
time prescribed by said laws, and all rights at any time conferred upon the
shareholders of the corporation by these Articles of Incorporation are granted
subject to the provisions of this Article EIGHTH.

                   NINTH: These Amended and Restated Articles of Incorporation
of the Corporation supersede and replace in their entirety the existing Articles
of Incorporation of the Corporation.



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