Aqueous two-phase affinity partitioning systems: Current applications and trends

► A review that highlights the application and challenges of ATPAP is reported. ► The current trends for the purification of biological using ATPS are discussed. ► Chemical modification strategies for polymer activation are carefully analyzed. ► Natural polymers can be implemented as environmental alternatives in ATPAP systems. ► Liquid affinity systems allow integration and intensification of unit operations. Aqueous two-phase systems (ATPS) have been studied and used for product recovery and purification from diverse biological sources. ATPS are characterized by their versatility, easy scale up parameters, process integration capability and relative low cost. This technique is commonly regarded as a primary recovery stage mainly due to its low selectivity. However, the use of strategies involving the modification of ATPS with affinity ligands have resulted in significant increases in recovery yields and purification folds of biological products. The aim of this review is to highlight current applications, trends and challenges regarding affinity partitioning in aqueous two-phase systems for the fractionation, recovery and purification of biological products.