Press Release

Osmetech plc ('Osmetech' or the 'Company')

Disclosure of Significant Shareholdings

22 May 2009

Osmetech PLC ('Osmetech' or 'the Company') (AIM:OMH) announces that it was notified on 21 May 2009 that Jeffrey Taylor on 18 May 2009 purchased 8,125,000 ordinary 0.1p shares in the Company through Bankers Union Trust.
Jeffrey Taylor's total beneficial interest in Osmetech shares of is now 76,451,936 shares representing 8.57% or the current issued share capital. Jeffrey Taylor's beneficial interest is held in the following way:

Registered Owner	Number of ordinary shares	% if issued share capital
Crown Taylor Money Purchase Pension Plan	64,951,936	7.28%
Bankers Union Trust	11,500,000	1.29%
Total	76,451,936	8.57%

The total number of issued ordinary 0.1p shares is 891,607,157. Osmetech does not hold any ordinary shares in Treasury. Therefore, the total number of voting rights in Osmetech is 891,607,157.

For further information:

Osmetech plc:	+44 (0) 20 7849 6027
James White, Chief Executive
David Sandilands, Finance Director

Madano Partnership:	+44 (0) 207 593 4000
Mark Way

Canaccord Adams Limited:	+44 (0) 20 7050 6500
Robert Finlay
Henry Fitzgerald-O'Connor