Radioimmunoassay of free genistein in human serum.
Two radioimmunoassay (RIA) systems for genistein have been established, based on polyclonal antibodies against genistein-4'-O-(carboxymethyl)ether-bovine serum albumin and genistein-7-O-(carboxymethyl)ether-bovine serum albumin conjugates. The sensitivities of assays were 4.44 and 10.4 fmol (1.2 and 2.8 pg)/tube, respectively, the intraassay coefficients of variation ranged from 3.54 to 9.30%, the interassay C.V. varied from 6.72 to 19.7%, depending on the type of method and on genistein concentration. The cross-reactivities with other chemically related compounds (with exception of genistein derivatives at the position used for construction of the immunogen) were 5.5 and 6.1% for daidzein and 3.9 and 0.04% for formononetin in RIAs using reagents prepared through positions 4'- and 7- of genistein, respectively. The method was used for measurement of genistein levels in 26 omnivore subjects and in three volunteers after consumption of a meal prepared from 125 g of cooked whole soybeans. The values obtained in ether extracts from human sera were almost identical for both RIA systems, indicating that both RIAs measure the same entity.
Lapcík
O
O
Institute of Endocrinology, Prague 1, Czech Republic. olapcik@endo.lib.cas.cz
Hampl
R
R
Hill
M
M
Wähälä
K
K
Maharik
N A
NA
Adlercreutz
H
H
D003429:Cross Reactions; D019833:Genistein / Q000097:blood*; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism; D007529:Isoflavones / Q000097:blood; D011863:Radioimmunoassay / Q000379:methods*; D012680:Sensitivity and Specificity; D013025:Glycine max / Q000378:metabolism
D007457:Iodine Radioisotopes; D007529:Isoflavones; D019833:Genistein