Proteome Sciences plc

PROTEOME SCIENCES plc

                                             PRESS RELEASE

For immediate release                                                    3rd July 2008

                                         Proteome Sciences plc

Cobham, (July 3, 2008) - The Board of Proteome Sciences plc is aware of no reason that would account
for the recent share price fall following the publication of the Preliminary Statement and the Annual
Report and Accounts for 2007.

As noted in the 2007 Report and Accounts, the company recently concluded an outstanding license deal
with Thermo-Fisher Scientific for its TMT® isobaric mass tags in April.  This agreement provides
strong cash flow, which transforms the prospects for the company with sustainable, rising revenue from
all areas of our activities and the broad TMT® workflows will in addition accelerate the utility and
application of biomarkers in drug development and diagnostics.

The Board strongly endorses its comments from last week that this will provide the pharmaceutical and
life sciences industry with a much needed solution to the challenges in biomarker validation and
against this background the prospects for the business look most encouraging.

In order to allay any shareholder concern over the potential dilution that might theoretically arise
from the conversion of the loan from C.D.J. Pearce, the company's Chief Executive, it has today been
agreed that, were such conversion to take place, the company would use its best endeavours to enable
other shareholders to participate by way of equity subscription on similar terms.

                                                 Ends

Contact Proteome Sciences plc at www.proteomics.com

Christopher Pearce, Chief Executive Officer
James Malthouse, Finance Director
Tel: [phone]

Adrian Shaw, IKON Associates
Tel: [phone]

Matt Baldwin, COAST Communications
Tel: [phone]

Landsbanki Securities (UK) Limited
Shaun Dobson
Claes Spång
Tel: [phone]

Proteome Sciences