Application of Pluronic F68 for Aqueous Two-Phase Extraction of Proteins

Studies were made of the application of a block copolymer of polyethylene oxide and polypropylene oxide, Pluronic F68, to aqueous two-phase extraction of proteins. For Pluronic F68/salt systems, the effects of temperature, salt concentration and pH on the binodials and protein partitioning were studied. Pluronic F68/ salt system had a region in which Pluronic F68 becomes solid in phase diagram at 25 °C. Partitioning of the proteins between the two phases could be controlled by varying salt composition. Further applicability of the Pluronic F68/ammonium sulfate system was examined for the purification of monoclonal antibodies from various hybridoma culture broths. Aqueous two-phase extraction provided a simple and rapid separation and concentration method with high recovery.