Rule 2.10 Announcement

Microgen plc

16 August 2004

Rule 2.10 announcement

In accordance with Rule 2.10 of the City Code on Takeovers and Mergers,
Microgen plc announces that, as at close of business on 13 August 2004, it has
in issue 86,935,040 ordinary shares of 5p each ('Microgen Shares').

The International Securities Identification Number for the Microgen Shares is
GB0005869531.

                                     ENDS