Characterization of guinea pig anti-progestin receptor antiserum

Antibody against the progestin receptor was raised in a guinea pig utilizing a partially purified receptor preparation from rabbit uterus. The antibody recognizes the cytosol and nuclear progestin receptor but not glucocorticoid, androgen, or estrogen receptors. In addition, the antibody recognizes the progestin receptor in normal human endometrium as well as that in human breast and endometrial tumor cytosols. Antigen: antibody complex formation between receptor and preimmune or immune serum was judged by shift in sedimentation coefficient on high-salt sucrose gradients, by exclusion from DEAE Affi-Gel Blue columns, and by adsorption with Protein A.