Electrophoretic transport of solutes in aqueous two-phase systems

Electrophoretic transport of proteins across the interface between the phases of an aqueous polymer two-phase system can be greatly impeded in comparison with transport within the individual phase. This effect can be controlled by modifying the affinity of the protein for a phase by suitable manipulations of such variables as pH. The effect is not caused by differences in the electrophoretic velocity between the two phases, nor by large changes in pH at the interface. An analogy exists between this phenomenon and the related subject of diffusion of electrolytes across the phase interface.