indirect competitive chemiluminescence immunoassay for glycosides daidzin and genistin in soy products

Daidzin (dz) and genistin (gen) are the main glucosidic components of soy isoflavone; the detection of dz and gen can provide insight for the appropriate ingestion of soy products. an indirect competitive chemiluminescence immunoassay (icclia) method based on n-(aminobutyl)-n-(ethylisoluminol) (abei) as chemiluminescent (cl) label was developed to assay dz in soy products. meanwhile, gen also could be determined due to the cross reaction with dz monoclonal antibody (mab). fluorescein isothiocyanate (fitc) was used to label the pure dz antigen to compete with dz in toy products. magnetic beads (mbs) capped with anti-fitc antibody were both the solid phase and separator. the chemiluminescence signal produced by the emission of photons from abei was inversely proportional to the amount of dz and gen in the sample solution. the method was linear to 6000 ng/ml dz with a detection limit of 1.34 ng/ml. the intra-assay imprecision results [mean (coefficient of variation, cv)] were less than 6%. the average recoveries ranged from 92 to 98%. the relationship between the proposed method and high-performance liquid chromatography (hplc) exhibited a correlation. the proposed method demonstrates acceptable performance for rapid quantification of dz and gen and can be used to rapidly detect these substances in soy products.