For extraction in aqueous two-phase system, defined amounts of solid PEG and(NH4)2SO4 were added to the latex preparation (30 g), and the total mixture was made up to 50 g with water. When studying the effect of pH on protease/papain
partitioning, the latex was adjusted to the desiredpHusing 6MHCl or 6MNaOH solutions prior to mixing with the phase components