Optimization of Aqueous Two-phase System for Protease Extraction from Aspergillus oryzae by Response Surface Methodology Study on hydrolysis of baicalin into baicalein by immobilized β-glucosidase in a two-phase system Aqueous Two-phase System(ATPS) Extraction of Hyperin Advances in application of aqueous two-phase system in separation and purification of active constituents from Chinese materia medica