| abstract |
Radiolabeled steroid derivatives having the formula <IMAGE> wherein St is des-hydroxy steroid moiety of (i) a hydroxy steroid intended for radioimmunoassay or (ii) a hydroxy containing derivative of a steroid intended for radioimmunoassay, said derivative having a strong affinity for the antibodies of the steroid intended for radioimmunoassay; R is hydrogen or alkyl of 1 to 3 carbon atoms; n is 0, 1, 2, 3 or 4 and the asterisk (*) indicates tagging with a radioisotope, are useful as tracers in radioimmunoassays. |