Bovine serum albumin partitioning in aqueous two-phase systems.

Bovine serum albumin (BSA) is an important protein, similar to human serum albumin, used as a basic component of several biological reagents for diagnostic use, mainly for immunohematological tests, such as the antisera used in reactions for in vitro detection of erythrocyte antigens or of specific antibodies. The extraction and purification of BSA, as most biomolecules, has a high cost and requires the use of more complicated techniques, in this context there is the aqueous two-phase systems (ATPS), which allow an extraction and purification of biomolecules with relatively lower costs, simpler techniques, besides allowing an expansion on a large scale. Partition of the BSA has been studied in aqueous two-phase systems prepared by mixing aqueous solutions of polymer or copolymer with aqueous salt solutions (sodium citrate and sodium tartarate). The BSA partition coefficient was investigated as a function of system pH, polymer molar mass, hydrophobicity, system tie-line length and nature of the electrolyte. The results showed a higher influence of hydrophobicity, nature of electrolyte and pH of the system on the partition coefficient of BSA. The partition coefficients related to the most influential factors exhibited values ranging from 0.125 to 0.440, indicating the potential of the two-phase extraction with ATPS in the purification of BSA. The BSA macromolecules were concentrated in the eletrolyte-rich phase. [ABSTRACT FROM AUTHOR]