Quantitative method for determination of hemolytic activity of Clostridium septicum toxin

A quantitative method for titration of hemolytic activity of Clostridium septicum toxin was established. No linear dose-response line was obtained between the toxin dose and hemolysis ratio. Logit or Probit transformation of the hemolysis ratio changed this log-dose response curve into a linear line. We recommend a highly reproducible and accurate method based on parallel line assay using a well-standardized reference toxin for determination of hemolytic activity. The method consists of simultaneous titrations of the hemolysis ratios with each sample and a reference toxin, Logit or Probit transformation of the hemolysis ratio, and expression of the activity in the relative hemolytic value.