Filter size for polypeptides,amino acids,proteins - Filtration as described US Patent 4,455,302 (Apr/18/2007 )

US Patent 4,455,302 decribes filtering with diatomaceous earth. I need an equivalent fitration system to filter one litre of liquid or less at a time. The resulting protein material will be reduced to a gel and applied to skin. I need to ensure that I get the required protein at the receiver. It has been suggested I use 0.2 micron or 0.45 micron. Am looking for a replaceable cartridge filter system. It is not too important if I get larger material as well. Just as long as I don't use a filtration system that is too small in pore size.

well take me a littel to found back that post, but here it is.

Sum up :
we bough a reusable fiter unit (in which the filter is changed every time) from nalgene coming with 100 0.22µm filters. 205€.

filter units
membrane filters

THANKS