Partitioning in aqueous two-phase systems: recent results

From analytical to commercial scale, aqueous two-phase systems have a niche in the purification, characterization, and study of biomaterials. Initially described by Beijerinck toward the end of last century, such phase systems were rediscovered and first employed in the 1950s by Albertsson for partitioning biomaterials. Aqueous two-phase systems are generally composed of a water solution of two structurally distinct hydrophilic polymers or of one polymer and certain salts (e.g., alkali phosphates).