Exhibit 3.1


                            CERTIFICATE OF AMENDMENT
                                       OF
                          CERTIFICATE OF INCORPORATION
                                       OF
                                    PDT, INC.


     PDT, INC., a corporation  organized and existing under and by virtue of the
General Corporation Law of the State of Delaware, DOES HEREBY CERTIFY:

     FIRST: That the Board of Directors of said  corporation,  at a meeting duly
convened and held, adopted the following resolution:

               RESOLVED:   That  the  Board  of  Directors  hereby  declares  it
advisable  and in the best  interest of the Company  that  Article  FIRST of the
Certificate of Incorporation be amended to read as follows:

                    FIRST:  The  name  of this  corporation  shall  be  MIRAVANT
               MEDICAL TECHNOLOGIES.

     SECOND: That the said amendment has been consented to and authorized by the
holders of a majority of the issued and  outstanding  stock  entitled to vote by
written  consent given in accordance  with the  provisions of Section 228 of the
General Corporation Law of the State of Delaware.

     THIRD: That the aforesaid amendment was duly adopted in accordance with the
applicable  provisions of Sections 242 and 228 of the General Corporation Law of
the State of Delaware.

     IN WITNESS  WHEREOF,  said  corporation  has caused this  Certificate to be
signed by GARY S. KLEDZIK,  its Chairman and Chief Executive Officer, and JOSEPH
E. NIDA, its Secretary, this 12th day of September, 1997.

                                            /S/ GARY S. KLEDZIK
                                            -------------------
                                            Gary S. Kledzik
                                            Chairman and Chief Executive Officer

ATTEST:

/S/ JOSEPH E. NIDA
- ------------------
Joseph E. Nida
Secretary