Bacterial survival in water - Membrane diffusion chambers

[Chris Thomas]

Hi,

Does anybody know of a manufacturer of membrane diffusion chambers?  I am 
about to conduct experiments analysing the survival of bacteria in 
aqueous environments in which this piece of apparatus would be most 
useful, in allowing the bugs to interact to some extent with the 
environments components.

I have tried the usual suppliers such as Whatman and Sartorius with 
little success, so if anybody could shed some light on my problem I would 
gratefully appreciate it.

Yours faithfully

Chris Thomas