TMT Patent Update

PROTEOME SCIENCES plc                             

                                 PRESS RELEASE                                 

                              TMT® Patent Update                               

20th March, 2008. The Board of Proteome Sciences is pleased to confirm to
shareholders that it holds issued, granted and enforceable patents for its TMT®
technology in the major global jurisdictions, including the US and Europe.

Before grant in Europe, the European TMT® patent went through an extensive
examination process and was exposed to anonymous `third party observations' at
that time. These were dismissed and the patent went through to full grant and
issued on 13th June 2007 (EP 1275004).

The Board has noted that an opposition has been lodged at the European Patent
Office based largely on the same grounds that were made prior to grant through
`third party observations'. We will be submitting a full, robust and thorough,
response to the opposition in the same way as during the `third party
observations'.

Proteome Sciences plc and its patent counsel are in the process of reviewing
the opposition. Their initial view is that the opposition does not raise any
grounds of objection that prejudice the validity of the patent. These actions
confirm the importance and value of the TMT® isobaric tandem mass tags.

This does not in any way affect the existing status of the TMT® patent in
Europe which is issued and enforceable and the Board believes that any
manufacture or use of products using isobaric tandem mass tags that come under
the broad scope of the TMT® patent may need licences from Proteome Sciences.

It is not expected that this process will have any impact on the rapid growth
and demand for isobaric mass tags technology nor should it have any effect on
Proteome Sciences' ability to successfully conclude the outlicencing of TMT®
reagents in the early part of 2008.

                                     Ends                                      

Contact Proteome Sciences plc at www.proteomics.com

Christopher Pearce, Chief Executive Officer

James Malthouse, Finance Director, Proteome Sciences plc

Dr. Ian Pike, Chief Business Officer, Proteome Sciences plc

Tel: [phone]

Adrian Shaw, IKON Associates

Tel: [phone]

Matt Baldwin, COAST Communications

Tel: [phone]

Shaun Dobson, Landsbanki Securities (UK) Ltd

Tel: [phone]

Gareth Price, Landsbanki Securities (UK) Ltd

Tel: [phone]