Development of a Monoclonal Antibody against Domoic Acid and Its Application in Enzyme-Linked Immunosorbent Assay and Colloidal Gold Immunostrip

Abstract

A monoclonal antibody (mAb) specific to domoic acid was produced from a stable hybridoma cell line, 9F1F11, generated by the fusion of P3/NS1/1-AG4-1 myeloma cells with spleen cells isolated from a Balb/c mouse immunized with domoic acid--keyhole limpet hemocyanin. The 9F1F11 mAb belongs to the immunoglobulin G1 (kappa-chain) isotype. A competitive direct enzyme-linked immunosorbent assay (cdELISA) and a competitive indirect ELISA were established for antibody characterization. In the cdELISA, the concentration causing 50% inhibition (IC50) of binding of domoic acid-horseradish peroxidase to the antibody by domoic acid was found to be 0.58 ng/mL. A sensitive and rapid mAb-based colloidal gold immunostrip was also developed. The immunostrip assay, which has a detection limit of 5 ng/mL for domoic acid, can be completed in 10 min. Analysis of domoic acid in blue mussel samples revealed that data obtained from immunostrip were in a good agreement with those obtained from cdELISA. The mAb-based cdELISA and immunostrip assay established in this study were sensitive and accurate for rapid screening of domoic acid in shellfish samples.