Phase behavior and protein partitioning in aqueous two-phase systems formed by mixtures of polymer and cationic-anionic surfactants

A novel aqueous two-phase system can be formed by the mixtures of a polymer and cationic-anionic surfactants. Such a system can be used as a partition ing system of proteins. In this work, we investigated the formation, phase behavior and protein partitioning in aqueous two-phase systems formed by do decyltriethylammonium bromide/sodium dodecylsulfate/PEG and dodecyltriethyl ammonium bromide/sodium dodecylsulfate/dextran. The ligands with affinity w ere attached to the polymers and the affinity partitioning of proteins was investigated. It was shown that the surfactants and polymers are enriched i n different phases of aqueous two-phase systems. Phase separation are promo ted by increasing temperature and adding inorganic salts. Different protein s are partitioned in different phases. The selectivity of protein partition ing is increased by adding ligands with affinity.