Abstract
An antibody-combining-power method was developed for the determination of the concentration of the2 components of leucocidin. Both the F and the S fractions of the leucocidin preparation contain deoxyribonuclease. The F and the S components of leucocidin were purified with Dowex-2 (x8) and Amberlite CG-50. The F component of leucocidin crystallizes from 0.2 [image]-phosphate buffer, pH 6.7, in the form of needles or as hexagonal plates. The slow component of leucocidin was crystallized by salting out with ammonium sulphate from 0.05 [image]-phosphate buffer, pH 6.7, in the form of very fine needles. Both the F and S components of leucocidin behave immunologically as single substances and on electrophoresis or ultracentrifuging show a single boundary.