Development of a new monoclonal antibody based direct competitive enzyme-linked immunosorbent assay for detection of brevetoxins in food samples

Brevetoxin B (PbTx-2) was covalently linked to carrier protein bovine serum albumin and human gamma globulin. A monoclonal antibody against PbTx-2, which showed high cross-reactivity values with PbTx-1, PbTx-3 and PbTx-9 (more than 89%) was obtained from ascites and some characteristics of monoclonal antibody were studied. An direct competitive enzyme-linked immunosorbent assay (ELISA) for detection of PbTxs was developed, which showed an IC50 value of 5.3 ng mL⁻¹ with a detection limit of 0.6 ng well⁻¹. The recoveries of PbTxs from cockle (88.4%–102.3%) and oyster (89.4%–104.3%) demonstrated that the matrices of cockle and oyster where PbTxs are found do not interfere with the assay. The newly developed competitive ELISA appears to be a reliable and useful method for mass monitoring of PbTxs in mollusk.