Abstract:

Objective: To establish a sensitive, specific and rapid chemiluminescent immunoassay (CLIA) method for the detection of ochratoxin A (OA) in food. Methods: The optimal conditions of CLIA for OA detection including the concentration of OA-bovine serum albumin (BSA) conjugate, the volume of OA-BSA solution for immobilization, the working concentrations of both antibodies against OA and a horseradish peroxidase-labeled anti-antibody, were explored by chessboard titration experiments. The linear range and the limit of detection (LOD) were studied as well. Certified reference material (CRM) of corn samples containing OA obtained from Food Analysis Performance Assessment Scheme (FAPAS) were analyzed by the developed CLIA method. Results: The optimal CLIA conditions for OA detection were 0.06μg/mL coating concentration of OA-BSA, 100μL/well of coating volume and 1:400 of working titer of the antibody against OA. The linear range of the developed CLIA was 6－400 ng/mL. The half inhibitory concentration was 145 ng/mL and the LOD was 0.04μg/kg for OA in food samples. The recovery rate was in the range of 66%－124% with the spiked sample level of 0.1－2μg/kg. CRM corn samples were analyzed and the results were consistent with the real values. Conclusion: The developed CLIA method was simple, fast, sensitive and can be employed in the screening of OA in foods．

Key words: ochratoxin A(OA), chemiluminescent immunoassay (CLIA), detection