Gel centrifugation as a method of separation in radioimmunological determination of serum estrogens

A report of an experiment is presented which showed the use of Sephadex G-25 minicolumns in a gel centrifugation of serum estrogens. Tritiated estrogens (estrone estradiol 17beta and estriol) and radioactive serum albumin and globulin were used. 97% of the globulin but 1.0% of the free tritiated estrogens passed through the columns. The precision of this gel-centrifugation is high with a variation coefficient between 2.5-5.4%. The stripping effect exhibited by the columns was insignificant after a fixed incubation period of 5 minutes. The activity of the effluent after elution was low assuring the reliability of the minicolumns.