Exhibit 23.1

                   CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS

     As independent public accountants, we hereby consent to the incorporation
by reference in this registration statement of our report dated May 14, 1999
included in Repligen Corporation's form 10-K for the year ended March 31, 1999
and to all references to our Firm included in this registration statement.

                                      ARTHUR ANDERSEN LLP

Boston, Massachusetts
March 10, 2000