Polyethylene glycol/dextran solutions are used to induce formation of two aqueous phases in the presence of a protein mixture. Preferential partitioning between the phases results in separation of the protein components. An electrical field is applied to the solution to accelerate the separation of the two phases which form and to cause a further separation of proteins within the same phase. This project combines two of the most promising technologies for large-scale purification of biological compounds, a step critical to the commercialization of biotechnology. The combination seems to address a principle scale-up problem in electrophoresis, namely, the mixing which arises as thermal convection occurs; the interface between the phases is a barrier to convection, and the increased viscosity of the phases also dampens natural convection. The combination also addresses a limitation of aqueous two phase separations, the slow rate of separation of the phases, which has required the use of expensive centrifuges in the past.
