Development of Indirect Competitive Enzyme-Linked Immunosorbent Assay for the Detection of Estradiol

In order to establish a simple and fast assay for the detection of estradiol in foods,estradiol hapten was synthesized and identified by nuclear magnetic resonance(NMR) and infrared spectroscopy.The hapten was activated by DCC/NHS ester method and covalently coupled to carrier proteins(bovine serum albumin and ovalbumin).Polyclonal antibodies were obtained from immunized rabbits.The optimal reaction conditions of indirect competitive enzyme-linked immunosorbent assay(icELISA) were established.The IC50 and LOD of the developed method were 3.9 ng/mL and 0.3 ng/mL,respectively.The cross-reactivity with one of 8 structural analogues of estradiol was less than 1.21%.High sensitivity and specificity will contribute to the development of commercial ELISA kits for the detection of estradiol in foods.