Rapid enzyme-linked immunosorbent assay and colloidal gold immunoassay for assessing okadaic acid and its derivatives in shellfish

Abstract

ABSTRACT Okadaic acid (OA) and the analogs of dinophysistoxin (DTX) are important members of diarrhetic shellfish poisoning (DSP) toxins. In this study, five OA-specific mAbs (monoclonal antibodies) were developed from five stable cells of hybridoma. The anti-OA mAb-2D7 showed high sensitivity to OA, the IC50 of the antibody was 0.24 ng/mL, and its cross-reactivity was 91.6% with DTX-1 and 110.5% with DTX-2., In dcELISA, the IC50 was set at 0.182 ng/mL, and the detection limit was set at 0.023 ng/mL by using the anti-OA mAb-2D7. The level of OA recovered from spiked mussel samples was 2–50 ng/g, ranging from 97.6 ± 7.2% to 106.4 ± 9.8%. In contrast, the immunostrip assay with a limit of 5 ng/mL, conducted for detecting OA, was completed in 10 min. The mAb-based dcELISA and immunostrip assay developed were precise and sensitive enough to quickly assess OA, DTX-1, and DTX-2 in shellfish specimens.