AbstractStaphylococcal enterotoxin E has been purified by a combination of Red‐A ligand chromatography and Mono‐S (cation – exchange) chromatography. Commencing with 30 litres of fermenter‐grown culture the method has been used to purify 17 mg of toxin, giving a purification yield of around 40%. The purity of the toxin was over 98% when analysed by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis, but demonstrated three isoelectric forms by isoelectric focusing, with pl values of 7.6, 7.4, and 7.0. This method adds to the versatility of the Red‐A matrix system which can also be used for the purification of staphylococcal enterotoxins A, B, and C2. © 1992 Wiley‐Liss, Inc.