The purification or isolation of biological materials by two-water soluuuble but incompatible polymers, such as dextran and polyethylene glycol, are investigated experimentally by separating lipase and by computer calculation.
In two phase separation, the important factor in the separation processes is the selective distribution of proteins between phases, usually known in terms of partition coefficient K.
Experimentally the phase diagrams, i.e., the number of phases, and their compositions for many polymer polymer water systems have been investigated and for the thermodynamic description of the phase equuilibrium. The phase separations of an aqueous polymer solution containing dextran and polyethylene glycol were investigated by the blob model for phase diagrams and the tie-line or partitions.
In protein partitioning, a pseudophase separation, indicating the interfacial phase adsorbed on the protein surafce, were proposed by evaluating the surface concentrationog the phase forming forming component blobs and the model calculation provides the qualitative agreement with experiments.