A Method for the Assay of ‘Slow Reacting Substance’.

Abstract

Abstract. A method is described for the biological assay of ‘slow reacting substance’ (‘SRS’) which appears in anaphylactic reaction. The log‐dose response of ‘SRS’ on the guinea pig ileum has a linear regression. Using a four‐point design of experiment, it is therefore possible to assay ‘SRS’ against a standard. It is shown by an analysis of variance that the method gives a reliable estimate of ‘SRS’ within relatively small limits of error.