OPTIMUM CONDITIONS FOR THE BIOLOGICAL ASSAY OF GONADOTROPHINS

Abstract

SUMMARY The assay of gonadotrophic preparations by means of the uterine weight of the immature mouse has been studied using a preparation of chorionic gonadotrophin. An optimum biological assay, with a linear segment of the log dose-log response line covering a twenty-fold dose range is obtained if the following conditions are fulfilled: (i) The total dose is administered 44 hr prior to killing. (ii) Mice of similar body weight and age are used immediately after weaning. (iii) Responses are corrected by covariance for variation in body weight. Significant secular variation in both position and slope of the dose-response line occurs. It is stressed that adoption of factorial methods of experimentation considerably facilitates the development of a biological assay technique.