Fractionation of a leucocidin from Staphylococcus aureus

Abstract

A medium suitable for large-scale production of leucocidin in high titer by Staphylococcus aureus was developed. An assay method for leucocidin suitable for routine use, based on the ability of leucocidin to prevent reduction of phenol-indophen6l-26-dichlorophenol by macrophages was developed. Crude leucocidin can be partially purified by fractionation with ammonium sulphate and on hydroxylapatite. On columns of cation-exchange resins leucocidin separates into 2 main fractions. There is loss of activity during the separation which is regained by mixing the fractions. The N contents, UV-absorption and amphoteric behavior of the fractions of leucocidin are characteristic of proteins.