Separation of proteins and viruses using two-phase aqueous micellar systems.

We discuss the utilization of a novel two-phase aqueous nonionic micellar system for the purification and concentration of biomolecules, such as proteins and viruses, by liquid-liquid extraction. The nonionic surfactant n-decyl tetra(ethylene oxide), C10E4, phase separates in water into two coexisting aqueous micellar phases by increasing temperature. The mild interactions of the C10E4 nonionic surfactant with biomolecules, combined with the high water content of the two coexisting micellar phases, suggest the potential utility of two-phase aqueous C10E4 micellar systems for the purification and concentration of biomolecules. In this paper, we review our recent experimental and theoretical studies involving the partitioning of several water-soluble proteins, including cytochrome c. soybean trypsin inhibitor, ovalbumin, bovine serum albumin, and catalase, in the two-phase aqueous C10E4 micellar system. In addition, we present results of our preliminary experimental investigation on the partitioning of bacteriophages, including phiX174, P22, and T4.