title: Immunoassay for biochanin A.
abstract: Two variants of immunoassay for the determination of biochanin A (5,7-dihydroxy 4'-methoxy isoflavone), i.e., a radioimmunoassay (RIA) and an indirect ELISA, have been developed and evaluated. Both methods employ the same rabbit antiserum to a 7-O-carboxymethyl-5-hydroxy-4'-methoxyisoflavone-bovine serum albumin (BSA) conjugate. A 125I-labeled hapten-tyrosine methyl ester (TME) conjugate was used as a radioligand for the RIA. The indirect ELISA uses immunogen-coated microtitration plates and a peroxidase-labeled antirabbit Ig antibody. Both methods are specific for biochanin A with a comparable sensitivity (3.1 pg/tube for RIA; 5.3 pg/well for ELISA); however, their sensitivity to individual cross-reactants differs. The main cross-reactants are sissotrin (the cross-reactivity 15.7% for RIA; 120% for ELISA), 5-hydroxy, 4',7-dimethoxy isoflavone (51.5% for RIA; 46.5% for ELISA), prunetin (4.5% for RIA; 5.0% for ELISA), genistein (0.8% for RIA; 2.8% for ELISA) and formononetin (0.4% for RIA; 0.3% for ELISA). These methods were used for the analysis of biochanin A in alfalfa and in several nonleguminous plants.
authors.affiliation: Department of Chemistry of Natural Compounds, Institute of Chemical Technology, Technická 5, 166 28 Praha 6, Czech Republic. oldrich.lapcik@vscht.cz
authors.forename: Oldrich
authors.initials: O
authors.lastname: Lapcík
authors.forename: Michaela
authors.initials: M
authors.lastname: Vítková
authors.forename: Borivoj
authors.initials: B
authors.lastname: Klejdus
authors.forename: Nawaf
authors.initials: N
authors.lastname: Al-Maharik
authors.forename: Herman
authors.initials: H
authors.lastname: Adlercreutz
mesh_terms: D000818:Animals; D000918:Antibody Specificity / Q000276:immunology; D002417:Cattle; D003429:Cross Reactions / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D019833:Genistein / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D006241:Haptens / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D007106:Immune Sera / Q000737:chemistry* / Q000276:immunology; D007074:Immunoglobulin G / Q000737:chemistry / Q000276:immunology; D007529:Isoflavones / Q000032:analysis / Q000276:immunology; D000455:Medicago sativa / Q000737:chemistry*; D009195:Peroxidase / Q000737:chemistry; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods*; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000276:immunology
chemical_list: D006241:Haptens; D007106:Immune Sera; D007074:Immunoglobulin G; D007529:Isoflavones; D012710:Serum Albumin, Bovine; D019833:Genistein; D009195:Peroxidase; C004541:biochanin A