Steroid receptors in human endometrium. comparison of data obtained by three different methods

1. 1. To find a method for steroid receptor measurement in small endometrial tissue samples (< 100 mg), an isoelectric focusing assay has been compared with a dcxtran-coated charcoal assay for oestradiol receptor. 2. 2. The results correlated well ( r = 0.85) and this indicates that isoelectric focusing is a good technique for oestradiol receptor determination. 3. 3. The isoelectric focusing of progesterone receptor has been compared with a dextran-coated charcoal assay and sucrose density gradient centrifugation. 4. 4. Isoelectric focusing gave recoveries of 0–26% compared to receptor values obtained with the two other methods, which correlated well ( r = 0.97). 5. 5. The low recovery implies that the isoelectric focusing assay is not suitable for progesterone receptor determination.