TOROIDAL COIL COUNTERCURRENT CHROMATOGRAPHY SEPARATION AND ANALYSIS OF STAPHYLOCOCCAL ENTEROTOXIN A (SEA) IN MILK

Abstract

Countercurrent Chromatography (CCC) utilizes continuous partitioning of solute between two immiscible solvent phases without a solid support. The absence of solid support makes CCC a suitable method for food analysis because it permits analysis of crude and complex materials that are not amenable to conventional solid-supported chromatography. CCC was evaluated for its ability to separate Staphylococcal enterotoxin A (SEA), a common cause of food poisoning, from milk. Although many foods can be analyzed for SEA directly by Western blot analysis, milk samples generally require some purification because the high concentration of milk proteins distorts SDS-PAGE mobility. Milk samples containing SEA were separated by toroidal coil CCC and the fractions were analyzed by Western immunoblotting. Fractions containing SEA were pooled, concentrated by ultrafiltration, and rechecked by Western immunoblotting. Concentrating the fractions increased the sensitivity of Western immunoblotting by approximately an order of magnitude.