Aqueous two-phase systems have found use in biochemical research lor the
separation and purification of macromolecules, cells and cell fragments. In order to
minimize the cost of two-phase systems based on purified polymers (such as
fractionated dextran and Reppal PES), new aqueous two-phase systems, formed by
crude polymers, haVe been introduced. In this work, partition properties of
macromolecules in poly(ethylene glycol) I locust bean gum; guar gum or derivatised
guar gum are reported. The effect of poly(ethlylene glycol) molecular weight, ionic
strength, affinity ligands, pH and temperature on partition behaviour and phase
diagram is identical in this systems and in traditional poly(ethylene glycol) I dextran
arid poly( ethylene glycol) I Reppal PES. Its application for enzyme affinity extraction is
investigated. Two-phase systems based on such crude polymers may have"the
drawback of their degree of purification, which may interfere with the separation
procedure. However, this should not prevent its successful use in aqueous two-phase
polymer extractions. Results clearly indicate that these systems are an interesting
alternative to conventional extraction systems
