<PAGE>

      As filed with the Securities and Exchange Commission on June 26, 1997
                                                    Registration No. 333-


                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                   ----------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           THE SECURITIES ACT OF 1933

                                   ----------

                                TSENG LABS, INC.
             (Exact name of registrant as specified in its charter)

                 Utah                                         87-0391229
    (State or other jurisdiction of                        (I.R.S. Employer 
     incorporation or organization)                       Identification No.)

             6 Terry Drive
         Newtown, Pennsylvania                                  18940
 (Address of principal executive offices)                    (Zip Code)


                                TSENG LABS, INC.
                             1995 STOCK OPTION PLAN
                            (Full title of the plan)

                                 MARK H. KARSCH
                                Tseng Labs, Inc.
                     (Name and address of agent for service)
                                 (215) 968-0502
          (Telephone number, including area code, of agent for service)

                                   ----------

                         Copy of all communications to:
                            STEPHEN M. GOODMAN, ESQ.
                           Morgan, Lewis & Bockius LLP
                              2000 One Logan Square
                             Philadelphia, PA 19103
                                 (215) 963-5000

                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>

====================================================================================================================================
                                                              Proposed maximum            Proposed maximum
    Title of securities             Amount to be               offering price                aggregate               Amount of
     to be registered                registered                per share (1)             offering price (1)       registration fee
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                  <C>                           <C>                      <C>                      <C>      
Common Stock, par                    3,000,000                     $3.47                    $10,406,250              $3,153.41
value $.005
====================================================================================================================================
</TABLE>

(1)  Estimated pursuant to paragraphs (c) and (h) of Rule 457 solely for the
     purpose of calculating the registration fee, based upon the average of the
     high and low sales prices of shares of Common Stock on June 19, 1997, as
     reported on the Nasdaq National Market.
<PAGE>

                  This Registration Statement on Form S-8 (the "Registration
Statement") filed by Tseng Labs, Inc. (the "Registrant") relates to 3,000,000
shares (the "Shares") of the Company's Common Stock, par value $.005 (the
"Common Stock"), issuable pursuant to the Tseng Labs, Inc. 1995 Stock Option
Plan (the "Plan").

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

                      The following documents, as filed by the Registrant with
the Securities and Exchange Commission (the "Commission"), are incorporated by
reference in this Registration Statement:

                              (a) Annual Report on Form 10-K, filed with the
             Commission on March 31, 1997 for the fiscal year ended December 31,
             1996;

                              (b) Quarterly Report on Form 10-Q filed with the
             Commission on May 15, 1997 for the Quarter ended March 31, 1997;

                              (c) The descriptions of the Common Stock of the
             Registrant set forth in the Registrant's Registration Statements
             pursuant to Section 12 of the Exchange Act, and any amendment or
             report filed for the purpose of updating such description.

                      All reports and other documents filed by the Registrant
and the Plan pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities
Exchange Act of 1934, after the date of this registration statement and prior to
the filing of a post-effective amendment that indicates that all securities
offered hereby have been sold or that deregisters all securities then remaining
unsold, shall be deemed to be incorporated by reference herein and to be part
hereof from the date of filing of such documents.

                      Any statement contained in a document incorporated by
reference herein shall be deemed to be modified or superseded for purposes
hereof to the extent that a statement contained herein (or in any other
subsequently filed document that is also incorporated by reference herein)
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part hereof.

Item 4.  Description of Securities.

                      Not applicable.

Item 5.  Interests of Named Experts and Counsel.

                      The consolidated financial statements of the Registrant
for the year ended December 31, 1996, included in the Registrant's Annual Report
on Form 10-K for the fiscal year ended December 31, 1996, have been incorporated
by reference in this registration statement in reliance upon the report of
Arthur Andersen LLP, independent public accountants, and upon the authority of
such firm as experts in accounting and auditing in giving said report. Future
consolidated financial statements of the Registrant and the reports thereon of
Arthur Andersen LLP also will be incorporated by reference in this registration
statement in reliance upon the authority of such firm as experts in giving those
reports to the extent such firm has audited those consolidated financial
statements and consented to the use of their reports thereon.


                      
<PAGE>

Item 6.  Indemnification of Directors and Officers.

                      Article XII of the Registrant's Bylaws provides that each
officer, director, employee or agent of the Registrant who was or is a party to,
or is threatened to be made a party to, any threatened, pending, or completed
action, suit or proceeding, by reason of the fact that he or she is or was a
director, officer or employee or agent of the Registrant (or was serving at the
request of or for the benefit of the Registrant in any other capacity, including
as a director, officer, employee, agent, partner or fiduciary of another entity)
while serving in such capacity may be indemnified by the Registrant against
expenses, including attorney's fees, judgments, fines and amounts paid in
settlement actually and reasonably incurred by such person in connection
therewith if he or she acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the best interests of the Registrant and,
with respect to any criminal action or proceeding, had no reasonable cause to
believe his or her conduct was unlawful. The foregoing rights to indemnity
include actions by or in the right of the Registrant (i.e., shareholder
derivative actions), provided that such a person acted in good faith and in a
manner he or she reasonably believed to be in or not opposed to the best
interests of the Registrant, and except that no indemnification shall be made in
respect of any claim, issue or matter as to which the person shall have been
adjudged to be liable to the Registrant (unless the court in which such action
or suit was brought shall determine otherwise). Indemnification will be made by
the Registrant only upon a determination by a majority of a quorum of the Board
of Directors or the shareholders that the director, officer, employee or agent
has met the applicable standard of conduct.

                      To the extent that a director, officer, employee or agent
of the Registrant has been successful on the merits or otherwise in defense of
any action, suit or proceeding referred to above, he will be indemnified against
expenses, including reasonable attorney's fees, incurred in connection
therewith. The Registrant may advance to officers and directors expenses
incurred in defending the proceedings specified above in advance of their final
disposition, provided that such payment will only be made upon delivery to the
Registrant by the indemnified party of an undertaking to repay all amounts so
advanced if it will ultimately be determined that the person receiving such
payments is not entitled to be indemnified.

                      Any indemnification or advancement of expenses will
continue, unless otherwise provided when the indemnification or advancement of
expenses is authorized or ratified, as to a person who has ceased to be a
director, officer, employee or agent and shall inure to the benefit of his or
her heirs, executors, and administrators.

                      The Registrant may maintain insurance, at its expense, to
protect itself and any person against any expense, liability or loss, whether or
not the Registrant would have the power to indemnify him or her against the
liability under applicable law. The Registrant currently maintains such
insurance.

                      Insofar as indemnification for liabilities arising under
the Securities Act may be permitted to directors, officers or persons
controlling the Registrant pursuant to the foregoing provisions, the Registrant
has been informed that in the opinion of the Commission such indemnification is
against public policy as expressed in the Securities Act and is therefore
unenforceable.



                                        2

<PAGE>



Item 7.  Exemption from Registration Claimed.

                      Not applicable.


Item 8.  Exhibits.

                      The exhibits filed as part of this Registration Statement
are as follows:

Exhibit
Number                                    Exhibit
------                                    -------

 5              Opinion of Morgan, Lewis & Bockius LLP re legality.

10              Tseng Labs, Inc. 1995 Stock Option Plan, as amended.

23.1            Consent of Arthur Andersen LLP.

23.2            Consent of Morgan, Lewis & Bockius LLP (included in Exhibit 5).


Item 9.  Undertakings.

                      The undersigned Registrant hereby undertakes:

                              (1) To file, during any period in which offers or
sales are being made, a post-effective amendment to this registration statement
to include any prospectus required by Section 10(a)(3) of the Securities Act of
1933;

                                       (i) To include any prospectus required by
                       Section 10(a)(3) of the Securities Act of 1933;

                                       (ii) To reflect in the prospectus any
                       facts or events arising after the effective date of the
                       registration statement (or the most recent post-effective
                       amendment thereof) which, individually or in the
                       aggregate, represent a fundamental change in the
                       information set forth in the registration statement; and

                                       (iii) To include any material information
                      with respect to the plan of distribution not previously
                      disclosed in the registration statement or any material
                      change to such information in the registration statement;

                              Provided, however, that subparagraphs (a)(1)(i)
and (a)(1)(ii) of this section do not apply if the information required to be
included in a post-effective amendment by those subparagraphs is contained in
periodic reports filed by the Registrant pursuant to Section 13 or Section 15(d)
of the Securities Exchange Act of 1934 that are incorporated by reference in the
registration statement.

                              (2) That, for the purpose of determining any
liability under the Securities Act of 1933, each such post-effective amendment
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

                              (3) To remove from registration by means of a
post-effective amendment any of the

                                        3

<PAGE>



securities being registered that remain unsold at the termination of the
offering.

                      The undersigned Registrant hereby undertakes that, for the
purpose of determining any liability under the Securities Act of 1933, each
filing of the Registrant's annual report pursuant to Section 13(a) or Section
15(d) of the Securities Exchange Act of 1934 (and each filing of an employee
benefit plan's annual report pursuant to Section 15(d) of the Securities
Exchange Act of 1934) that is incorporated by reference in this registration
statement shall be deemed to be a new registration statement relating to the
securities offered herein and the offering of such securities at that time shall
be deemed to be the initial bona fide offering thereof.

                      Insofar as indemnification for liabilities arising under
the Securities Act of 1933 may be permitted to directors, officers and
controlling persons of the Registrant pursuant to the foregoing provisions, or
otherwise, the Registrant has been advised that in the opinion of the Securities
and Exchange Commission such indemnification is against public policy as
expressed in the Act and is, therefore, unenforceable. In the event that a claim
for indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.

                                        4

<PAGE>



                                   SIGNATURES

                      The Registrant. Pursuant to the requirements of the
Securities Act of 1933, the Registrant certifies that it has reasonable grounds
to believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in Newtown, Pennsylvania, on the 13th
day of June, 1997.

                                    TSENG LABS, INC.


                                    By: /s/ Jack Tseng
                                        ---------------------------------------
                                        Jack Tseng
                                        Chairman and President



                      Pursuant to the requirements of the Securities Act 1933,
this Registration Statement has been signed below by the following persons in
the capacities and on the date indicated.

<TABLE>
<CAPTION>

        Signature                                   Capacity                               Date
        ---------                                   --------                               ----
<S>                                          <C>                                     <C>
                                                                                   
/s/ Jack Tseng                               Chairman and President                 June 13, 1997        
-----------------------------                Director                           
Jack Tseng                                   (Principal Executive Officer)          
                                             
                      
/s/ John J. Gibbons                          Executive Vice President               June 13, 1997             
------------------------------               Chief Operating Officer
John J. Gibbons                              Director                                

                                             
/s/ David Kwok Ping Hui                      Executive Vice President               June 13, 1997           
------------------------------               Director                               
David Kwok Ping Hui     
                                             
                      
/s/ Mark H. Karsch                           Senior Vice President                  June 13, 1997              
-----------------------------                Chief Financial Officer
Mark H. Karsch                               Director                                
                                             (Principal Accounting Officer)
                                            
/s/ Mark Dorfman                             Director                               June 13, 1997 
-----------------------------
Mark Dorfman
                                             
/s/ Christopher F. Sutphin                   Director                               June 13, 1997
-----------------------------
Christopher F. Sutphin
</TABLE>





                                        5

<PAGE>



                                INDEX TO EXHIBITS


Exhibit
Number          Description
------          -----------

  5             Opinion of Morgan, Lewis & Bockius LLP re legality.

 10             Tseng Labs, Inc. 1995 Stock Option Plan, as amended.

 23.1           Consent of Arthur Andersen LLP.

 23.2           Consent of Morgan, Lewis & Bockius LLP (included in Exhibit 5).
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 18582}]
{"company-data": {"conformed-name": "TSENG LABS INC", "cik": "0000741742", "assigned-sic": "3577", "irs-number": "232277100", "state-of-incorporation": "UT", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-30105", "film-number": "97630678"}, "business-address": {"street1": "6 TERRY DR", "street2": "NEWTOWN COMMONS", "city": "NEWTOWN", "state": "PA", "zip": "18940", "phone": "2159680502"}, "mail-address": {"street1": "6 TERRY DRIVE", "city": "NEWTOWN", "state": "PA", "zip": "18940"}}
As filed with the Securities and Exchange Commission on June 26, 1997
                                                    Registration No. 333-

                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                   ----------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           THE SECURITIES ACT OF 1933

                                   ----------

                                TSENG LABS, INC.
             (Exact name of registrant as specified in its charter)

                 Utah                                         87-0391229
    (State or other jurisdiction of                        (I.R.S. Employer 
     incorporation or organization)                       Identification No.)

             6 Terry Drive
         Newtown, Pennsylvania                                  18940
 (Address of principal executive offices)                    (Zip Code)

                                TSENG LABS, INC.
                             1995 STOCK OPTION PLAN
                            (Full title of the plan)

                                 MARK H. KARSCH
                                Tseng Labs, Inc.
                     (Name and address of agent for service)
                                 (215) 968-0502
          (Telephone number, including area code, of agent for service)

                                   ----------

                         Copy of all communications to:
                            STEPHEN M. GOODMAN, ESQ.
                           Morgan, Lewis & Bockius LLP
                              2000 One Logan Square
                             Philadelphia, PA 19103
                                 (215) 963-5000

                         CALCULATION OF REGISTRATION FEE
====================================================================================================================================
                                                              Proposed maximum            Proposed maximum
    Title of securities             Amount to be               offering price                aggregate               Amount of
     to be registered                registered                per share (1)             offering price (1)       registration fee
-----------------------------------------------------------------------------------------------------------------------------------
Common Stock, par                    3,000,000                     $3.47                    $10,406,250              $3,153.41
value $.005
====================================================================================================================================
(1)  Estimated pursuant to paragraphs (c) and (h) of Rule 457 solely for the
     purpose of calculating the registration fee, based upon the average of the
     high and low sales prices of shares of Common Stock on June 19, 1997, as
     reported on the Nasdaq National Market.
This Registration Statement on Form S-8 (the "Registration
Statement") filed by Tseng Labs, Inc. (the "Registrant") relates to 3,000,000
shares (the "Shares") of the Company's Common Stock, par value $.005 (the
"Common Stock"), issuable pursuant to the Tseng Labs, Inc. 1995 Stock Option
Plan (the "Plan").

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

                      The following documents, as filed by the Registrant with
the Securities and Exchange Commission (the "Commission"), are incorporated by
reference in this Registration Statement:

                              (a) Annual Report on Form 10-K, filed with the
             Commission on March 31, 1997 for the fiscal year ended December 31,
             1996;

                              (b) Quarterly Report on Form 10-Q filed with the
             Commission on May 15, 1997 for the Quarter ended March 31, 1997;

                              (c) The descriptions of the Common Stock of the
             Registrant set forth in the Registrant's Registration Statements
             pursuant to Section 12 of the Exchange Act, and any amendment or
             report filed for the purpose of updating such description.

                      All reports and other documents filed by the Registrant
and the Plan pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities
Exchange Act of 1934, after the date of this registration statement and prior to
the filing of a post-effective amendment that indicates that all securities
offered hereby have been sold or that deregisters all securities then remaining
unsold, shall be deemed to be incorporated by reference herein and to be part
hereof from the date of filing of such documents.

                      Any statement contained in a document incorporated by
reference herein shall be deemed to be modified or superseded for purposes
hereof to the extent that a statement contained herein (or in any other
subsequently filed document that is also incorporated by reference herein)
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part hereof.

Item 4.  Description of Securities.

                      Not applicable.

Item 5.  Interests of Named Experts and Counsel.

                      The consolidated financial statements of the Registrant
for the year ended December 31, 1996, included in the Registrant's Annual Report
on Form 10-K for the fiscal year ended December 31, 1996, have been incorporated
by reference in this registration statement in reliance upon the report of
Arthur Andersen LLP, independent public accountants, and upon the authority of
such firm as experts in accounting and auditing in giving said report. Future
consolidated financial statements of the Registrant and the reports thereon of
Arthur Andersen LLP also will be incorporated by reference in this registration
statement in reliance upon the authority of such firm as experts in giving those
reports to the extent such firm has audited those consolidated financial
statements and consented to the use of their reports thereon.
Item 6.  Indemnification of Directors and Officers.

                      Article XII of the Registrant's Bylaws provides that each
officer, director, employee or agent of the Registrant who was or is a party to,
or is threatened to be made a party to, any threatened, pending, or completed
action, suit or proceeding, by reason of the fact that he or she is or was a
director, officer or employee or agent of the Registrant (or was serving at the
request of or for the benefit of the Registrant in any other capacity, including
as a director, officer, employee, agent, partner or fiduciary of another entity)
while serving in such capacity may be indemnified by the Registrant against
expenses, including attorney's fees, judgments, fines and amounts paid in
settlement actually and reasonably incurred by such person in connection
therewith if he or she acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the best interests of the Registrant and,
with respect to any criminal action or proceeding, had no reasonable cause to
believe his or her conduct was unlawful. The foregoing rights to indemnity
include actions by or in the right of the Registrant (i.e., shareholder
derivative actions), provided that such a person acted in good faith and in a
manner he or she reasonably believed to be in or not opposed to the best
interests of the Registrant, and except that no indemnification shall be made in
respect of any claim, issue or matter as to which the person shall have been
adjudged to be liable to the Registrant (unless the court in which such action
or suit was brought shall determine otherwise). Indemnification will be made by
the Registrant only upon a determination by a majority of a quorum of the Board
of Directors or the shareholders that the director, officer, employee or agent
has met the applicable standard of conduct.

                      To the extent that a director, officer, employee or agent
of the Registrant has been successful on the merits or otherwise in defense of
any action, suit or proceeding referred to above, he will be indemnified against
expenses, including reasonable attorney's fees, incurred in connection
therewith. The Registrant may advance to officers and directors expenses
incurred in defending the proceedings specified above in advance of their final
disposition, provided that such payment will only be made upon delivery to the
Registrant by the indemnified party of an undertaking to repay all amounts so
advanced if it will ultimately be determined that the person receiving such
payments is not entitled to be indemnified.

                      Any indemnification or advancement of expenses will
continue, unless otherwise provided when the indemnification or advancement of
expenses is authorized or ratified, as to a person who has ceased to be a
director, officer, employee or agent and shall inure to the benefit of his or
her heirs, executors, and administrators.

                      The Registrant may maintain insurance, at its expense, to
protect itself and any person against any expense, liability or loss, whether or
not the Registrant would have the power to indemnify him or her against the
liability under applicable law. The Registrant currently maintains such
insurance.

                      Insofar as indemnification for liabilities arising under
the Securities Act may be permitted to directors, officers or persons
controlling the Registrant pursuant to the foregoing provisions, the Registrant
has been informed that in the opinion of the Commission such indemnification is
against public policy as expressed in the Securities Act and is therefore
unenforceable.

                                        2
Item 7.  Exemption from Registration Claimed.

                      Not applicable.

Item 8.  Exhibits.

                      The exhibits filed as part of this Registration Statement
are as follows:

Exhibit
Number                                    Exhibit
------                                    -------

 5              Opinion of Morgan, Lewis & Bockius LLP re legality.

10              Tseng Labs, Inc. 1995 Stock Option Plan, as amended.

23.1            Consent of Arthur Andersen LLP.

23.2            Consent of Morgan, Lewis & Bockius LLP (included in Exhibit 5).

Item 9.  Undertakings.

                      The undersigned Registrant hereby undertakes:

                              (1) To file, during any period in which offers or
sales are being made, a post-effective amendment to this registration statement
to include any prospectus required by Section 10(a)(3) of the Securities Act of
1933;

                                       (i) To include any prospectus required by
                       Section 10(a)(3) of the Securities Act of 1933;

                                       (ii) To reflect in the prospectus any
                       facts or events arising after the effective date of the
                       registration statement (or the most recent post-effective
                       amendment thereof) which, individually or in the
                       aggregate, represent a fundamental change in the
                       information set forth in the registration statement; and

                                       (iii) To include any material information
                      with respect to the plan of distribution not previously
                      disclosed in the registration statement or any material
                      change to such information in the registration statement;

                              Provided, however, that subparagraphs (a)(1)(i)
and (a)(1)(ii) of this section do not apply if the information required to be
included in a post-effective amendment by those subparagraphs is contained in
periodic reports filed by the Registrant pursuant to Section 13 or Section 15(d)
of the Securities Exchange Act of 1934 that are incorporated by reference in the
registration statement.

                              (2) That, for the purpose of determining any
liability under the Securities Act of 1933, each such post-effective amendment
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

                              (3) To remove from registration by means of a
post-effective amendment any of the

                                        3
securities being registered that remain unsold at the termination of the
offering.

                      The undersigned Registrant hereby undertakes that, for the
purpose of determining any liability under the Securities Act of 1933, each
filing of the Registrant's annual report pursuant to Section 13(a) or Section
15(d) of the Securities Exchange Act of 1934 (and each filing of an employee
benefit plan's annual report pursuant to Section 15(d) of the Securities
Exchange Act of 1934) that is incorporated by reference in this registration
statement shall be deemed to be a new registration statement relating to the
securities offered herein and the offering of such securities at that time shall
be deemed to be the initial bona fide offering thereof.

                      Insofar as indemnification for liabilities arising under
the Securities Act of 1933 may be permitted to directors, officers and
controlling persons of the Registrant pursuant to the foregoing provisions, or
otherwise, the Registrant has been advised that in the opinion of the Securities
and Exchange Commission such indemnification is against public policy as
expressed in the Act and is, therefore, unenforceable. In the event that a claim
for indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.

                                        4
SIGNATURES

                      The Registrant. Pursuant to the requirements of the
Securities Act of 1933, the Registrant certifies that it has reasonable grounds
to believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in Newtown, Pennsylvania, on the 13th
day of June, 1997.

                                    TSENG LABS, INC.

                                    By: /s/ Jack Tseng
                                        ---------------------------------------
                                        Jack Tseng
                                        Chairman and President

                      Pursuant to the requirements of the Securities Act 1933,
this Registration Statement has been signed below by the following persons in
the capacities and on the date indicated.
Signature                                   Capacity                               Date
        ---------                                   --------                               ----
/s/ Jack Tseng                               Chairman and President                 June 13, 1997        
-----------------------------                Director                           
Jack Tseng                                   (Principal Executive Officer)          
                                             
                      
/s/ John J. Gibbons                          Executive Vice President               June 13, 1997             
------------------------------               Chief Operating Officer
John J. Gibbons                              Director                                

                                             
/s/ David Kwok Ping Hui                      Executive Vice President               June 13, 1997           
------------------------------               Director                               
David Kwok Ping Hui     
                                             
                      
/s/ Mark H. Karsch                           Senior Vice President                  June 13, 1997              
-----------------------------                Chief Financial Officer
Mark H. Karsch                               Director                                
                                             (Principal Accounting Officer)
                                            
/s/ Mark Dorfman                             Director                               June 13, 1997 
-----------------------------
Mark Dorfman
                                             
/s/ Christopher F. Sutphin                   Director                               June 13, 1997
-----------------------------
Christopher F. Sutphin
5
INDEX TO EXHIBITS

Exhibit
Number          Description
------          -----------

  5             Opinion of Morgan, Lewis & Bockius LLP re legality.

 10             Tseng Labs, Inc. 1995 Stock Option Plan, as amended.

 23.1           Consent of Arthur Andersen LLP.

 23.2           Consent of Morgan, Lewis & Bockius LLP (included in Exhibit 5).