Noun
English Wikipedia has an article on:ultrafiltrationWikipedia
ultrafiltration (countable and uncountable, plural ultrafiltrations)
Filtration through a semipermeable membrane that only allows small molecules through.
Because of the size exclusion, the colloidal particles are unable to pass through the pores of an ultrafiltration membrane with a size smaller than their own dimension. Source: Internet
Recombinant proteins need many operations involving ultrafiltration and column chromatography. Source: Internet