Holding(s) in Company

22nd October 2007

Microgen plc (the "Company")

Notifiable Interests

The Company received notice from Blackrock, Inc on 19th October 2007 in
compliance with the Disclosure and Transparency Rules that Merrill Lynch
International Investment Funds is interested in 3,920,133 Ordinary Shares
representing 3.81% of the issued share capital of the Company, which is
currently 102,779,776 Ordinary Shares.

If you require further information please contact:

G.E. Liddle, Company Secretary

Tel: [phone]

www.microgen.com