A three-step procedure to enrich estradiol receptor protein froin calf
uterus nearly 30,000-fold has been described. Over-all yield is 12%.
Control of the single steps has been performed by sodium dodecyl sulfa
te-electrophoresis, sucrose density gradient centrifugation, gel filtr
ation and determination of receptor quantity. Immunological properties
of the preparation obtained have not been controlled.