DEVELOPMENT OF A CHEMILUMINESCENT ELISA FOR DETERMINING OKADAIC ACID IN SHELLFISH

An indirect competitive enzyme-linked immunosorbent assay with chemiluminescent (CL-ELISA) detection for okadaic acid (OA) in mussel muscle was developed. A hybridoma cell line secreting monoclonal antibody against OA was established after immunization of BALB/c mice with artificially synthesized OA-bovine serum albumin as antigen. Luminol solution was used as the substrate for horseradish peroxidase. The detection limit was 0.175 ng/g. The range of average fortified recovery was 91.8-102.6% when OA was spiked in mussel muscle at levels of 50, 160 and 800 mu g/kg. The standard curve for OA showed good linearity over the concentration range of 0.08125-20 ng/mL. The cross-reactivity with dinophysistoxin1 and saxitoxin was 51.82 and 0%, respectively. In a residue study, the results obtained by CL-ELISA correlated well within those obtained using the commercial ABRAXIS kit (ABRAXIS, Warminster, PA). The developed method is therefore suitable for detecting the residues of OA in shellfish.