ISSUANCE OF US PATENT FOR ISOBARIC TANDEM MASS TAGS^® (TMT^®)

13th November 2007

Proteome Sciences plc ("Proteome Sciences") announces the issuance of US Patent Number 7,294,456 entitled Mass Labels relating to isobaric tandem mass tags (TMT^®). Patents covering the TMT technologies are now issued in Australia, New Zealand, Canada, Europe and the USA. The US Patent contains broad claims to sets of isobaric mass tags.

Commenting on the Issuance of US Patent Number 7,254,456 Christopher Pearce, CEO of Proteome Sciences said:

"Following the issuance of the TMT1 patent in Europe, we are delighted today to have obtained the issuance of the TMT1 patent in the US. The issued TMT patents provide Proteome Sciences broad claims across the field of isobaric tandem mass tagging, with the ability to now exploit TMT^® in these substantial markets both as a product in its own right, and for third party licences for the manufacture or use of any type of isobaric tandem mass tags.

The patent issuance should allow us to complete commercialisation and outlicensing of TMT^® and to generate strong revenue through licence income, product sales and royalties in the rapidly growing market and applications for isobaric tandem mass tagging in biomarker discovery, validation and assay development across a broad range of applications including clinical research and in vitro diagnostics."