Ultrafiltration of mixed protein solutions of lysozyme and lactoferrin: role of modified inorganic membranes and ionic strength on the selectivity

Abstract
Ultrafiltration of either single protein solutions (lysozyme 14,300 g mol−1, pI=11; lactoferrin 80,000 g mol−1, pI=8–9) or mixed protein solution was performed with inorganic membranes (MMCO 300,000 g mol−1, pore radius 14 nm) chemically modified in order to bear either pyrophosphate (PP, anionic) or ethylenediamine (EDA, cationic) groups.