TERMINATION OF TMT 1 OPPOSITION PROCEEDINGS IN EUROPEAN PATENT 1,275,004

29th OCTOBER 2009

Proteome Sciences plc (“Proteome Sciences”) is pleased to announce that it has received formal notification from the European Patent Office that Applera Corporation has withdrawn its opposition to Proteome Sciences’ European Patent No. 1,275,004 relating to isobaric mass tags (the TMT 1 patent). In its notification the EPO confirms that it will not pursue the opposition. This will result in the TMT 1 patent being maintained in the form in which it was issued.

The TMT 1 patent provides broad coverage over the field of isobaric mass tagging and has been issued in the USA, Canada, Australia, New Zealand and Israel as well as in Europe. Corresponding cases are pending in Japan, China and Norway.

In April 2008 Proteome Sciences granted exclusive worldwide rights to sell its Tandem Mass Tags® (TMT®) reagents to Pierce Biotechnology Inc., a division of ThermoFisher Scientific. In September 2009 Pierce Biotechnology entered into an agreement with Life Technologies allowing Life to sell its iTRAQ® isobaric mass tags under license to the TMT 1 patent. Proteome Sciences retains the right to use TMT® in its own research and to support its PS Biomarker Services™ in both discovery and rapid assay development using TMTcalibrator™ and TMT-SRM™. One of the first clients for the enhanced PS Biomarker Services™ offering is Japan’s Takeda Pharmaceuticals through the contract announced on 28th October, 2009.

Commenting on the collaboration Dr. Ian Pike, Chief Business Officer of Proteome Sciences said:

"'We are delighted that the opposition against the TMT 1 patent in Europe has sensibly been withdrawn following the unequivocal preliminary opinion of the EPO that it lacked any merit. Proteome Sciences has established a field dominating patent portfolio in isobaric mass tagging and we now look forward to working with our partner Pierce Biotechnology to maximise the commercial potential for isobaric mass tags across life sciences".