Offer Update

Microgen plc

10th September 2004

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART IN OR INTO THE
UNITED STATES, CANADA, AUSTRALIA OR JAPAN.

                             Recommended Offer by                              

                              UBS Investment Bank                              

                                 on behalf of                                  

                                 Microgen plc                                  

                                      for                                      

                                AFA Systems plc                                

Result of Mix and Match Facility

The board of Microgen plc ('Microgen') announces that as at 3.00 p.m. (London
time) on 9 September 2004 it has received a number of valid elections under the
Mix and Match Facility both from AFA Shareholders wishing to receive additional
cash in respect of 20,462,416 AFA Shares and from those wishing to receive
additional New Microgen Shares in respect of some 14,324,549 AFA Shares.

Under the basic terms of the Offer for each AFA share an AFA Shareholder would
receive 4.51 pence in cash and 0.18168 in New Microgen Shares. As the Mix and
Match Facility is now closed, elections under the Mix and Match Facility will
be satisfied as follows:

  * for each AFA Share for which a valid election for additional cash was made
    7.67 pence in cash and 0.12862 in New Microgen Shares
   
  * for each AFA Share for which a valid election for additional New Microgen
    Shares was made 0.25748 New Microgen Shares
   
The Offer still remains open for acceptance until further notice.

Microgen                                                                       
Mike Phillips, Group Finance Director                                          
                                                                               
Phone: [phone]                                                            
                                                                               
UBS Investment Bank                                                            
Nick Adams                                                                     
                                                                               
Phone: [phone]                                                           
                                                                               
Financial Dynamics                                                             
Giles Sanderson                                                                
                                                                               
Phone: [phone]