EVALUATION OF VARIOUS METHODS FOR THE ASSAY OF CYTOPLASMIC OESTROGEN RECEPTORS IN EXTRACTS OF CALF UTERI AND HUMAN BREAST CANCERS

Abstract

ABSTRACT A calf uterus extract and a human mammary cancer extract were assayed for cytoplasmic oestrogen receptors by six different methods. Highest and almost identical yields were obtained by agar gel electrophoresis and Sephadex chromatography, followed by the charcoal technique (62%, 49%), glass bead adsorption (17%, 41%), density gradient centrifugation (16%, 30%) and protamine precipitation (10%, 23%).