STUDIES ON THE BIOASSAY OF HORMONES—THE ASSAY OF ESTROGENS BY A CHICK OVIDUCT METHOD

Abstract

The material was injected subcut. once daily for 5 days and the determination of oviduct wt. and body wt. was done at autopsy 24 hrs. after the last injn. The total material per animal was dissolved in 0.5 ml. of corn oil and 0.1 ml. was injected daily. The estrogens studied were stilbesterol, estrone, estradiol benzoate, estradiol, and methoxy bisdehydro doisynolic acid (MDDA). Using the design of Bliss (1944) it was possible to ascertain the potency ratio, the error range, and the significance of the difference of the slopes. At concns. of 25 [gamma] and 50 [gamma] of stilbesterol, the potency ratio was detd. with standard errors of [image]10% and [image]7%, respectively, when totals of 20 and 40 chicks were used. Similar high accuracy was obtained for certain conens. of estrone and estradiol benzoate.