Evaluation of and Additional Data on an Improved Simple Charcoal Method to Determine Oestrogen Receptors

Abstract
Additional information and some modifications of an earlier published method for the assay of the estrogen receptor in human breast tumors are presented. The correlation between the results obtained with this method and the electrophoresis procedure of Wagner was good. The use of glycerol stabilized calf uterus extract for quality control is proposed. Various factors affecting the assay and discrimination between receptor positive and receptor negative are critically discussed.