Efficiency of Polymer-Salt Aqueous Two-Phase Electrophoresis System on Partition of Bovine Serum Albumin

This study aims to investigate the polymer-salt aqueous two-phase electrophoresis system (ATPES) for protein partitioning. A model protein, bovine serum albumin (BSA) was adopted to evaluate the effects of polyethylene glycol (PEG) molecular weight, phase composition, position of electrode, voltage, electrophoresis operating time, and BSA load on the protein partitioning efficiency. Polyethylene glycol (PEG) and sodium citrate salt were selected as phase forming components due to their inexpensive cost and non-toxic characteristics. The highest partition coefficient, K (42.26 ± 1.95) and yield, Y (98.83% ± 0.05%) whereby BSA partitioned to the top phase was obtained in the polymer-salt ATPES which composed of 16% (w/w) PEG 1000, 15% (w/w) sodium citrate, 5% (w/w) BSA load, with anode in the top phase, cathode in the bottom phase, 3 V voltage, and 5-minute electrophoresis operating time. Therefore, polymer-salt ATPS integrated with electrophoresis is a promising method for the partitioning of proteins.