Protein cocentrators / centrifugal filter tubes - (Dec/11/2007 )

Hi, do you know any good protein concentrators (centrifugal filter tubes), that work with small volumes (eg. 0,5 - 1 ml)? Thanks.

I've been using ones from Pall/Gelman, they have a range of sizes and filters, including 0.5-3ml.
Hope that helps!
Rosie

centricon (millipore)

amicon ultra centrifugal filter devices, mwco 5k-100k