Estrogen receptor immunocytochemistry.

Estrogen receptor activity was preserved in fixed, paraffin-embedded tissue and demonstrated by binding of estrogen which, in turn, was detected immunocytochemically. Estrogen was added to rat endocervial epithelium to protect specifically receptors during fixation. The protective estrogen was apparently lost during embedding and had to be resupplied before staining. Estradiol-mediated immunocytochemical staining was inhibited by diethylstilbestrol and nafoxidine hydrochloride.