Salting-out effects on the partition of proteins in aqueous two-phase systems

The partition of proteins in the salt-rich phase of polyethylene glycol (PEG)/salt aqueous two-phase systems is limited by the salting-out effects of salt. The logarithm of the concentration of proteins partitioned in the salt-rich phase decreases linearly with increases in the concentration of salt in the salt-rich phase (salting-out). Therefore, the partition of a given protein in the salt-rich phase of aqueous two-phase systems can be estimated from the salting-out constant. The slope of the solubility line (salting-out constant) for a given protein is determined by the type of salt in the two-phase systems.