Completion of Purchase

Proteome Sciences PLC
4 July 2002





                                 PRESS RELEASE


                                                        4th July, 2002




                   Completion of Purchase From Aventis R & T




The Board of Proteome Sciences plc is pleased to announce that it has now
completed the acquisition of Xzillion Proteomics GmbH & Co. KG (Xzillion) the
proteomics division of Aventis Research and Technologies GmbH & Co KG (Aventis R
& T). The consideration, which valued Xzillion at £12.6m, was satisfied by the
issue to Aventis R & T of 18 million new ordinary shares of 1p each in the
Company, based on a price of 70p per share. Aventis R & T now owns 15.8% of the
enlarged share capital of Proteome Sciences plc.




                                    - Ends -






For further information please contact:

Proteome Sciences plc

Christopher Pearce, Chief Executive          Tel: [phone]

                                  E-mail : [e-mail]




Public Relations

Ikon Associates

Adrian Shaw                Tel: [phone]   Mobile: [phone]
                              
E-mail:[e-mail]








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