COLLABORATIVE ASSAY OF TWO GONADOTROPHIN PREPARATIONS FROM HUMAN POSTMENOPAUSAL URINE

Abstract
SUMMARY: 1. The gonadotrophic activity of two preparations from human postmenopausal urine (HMG-20A and HMG-J) has been compared. Various bioassay methods were used and the experiments were conducted in six different laboratories. 2. The mean relative potency of HMG-J in terms of HMG-20A varied according to the assay method used. Possible reasons for the differing potency ratios are discussed. 3. It is concluded that for the assay of pituitary gonadotrophins in urine the method of preparation of extracts should be similar to that of the standard.