Preparation of Monoclonal Antibody for Brevetoxin 1 and Development of Ic-ELISA and Colloidal Gold Strip to Detect Brevetoxin 1.

Brevetoxin-1 (BTX-1), a marine toxin mostly produced by the dinoflagellatae Karenia brevis , has caused the death of marine organisms and has had numerous toxicological effects on human health. Hence, it is very necessary to develop a rapid, economical, and reliable immunoassay method for BTX-1 detection. In this study, two kinds of complete antigen were synthesized using the succinic anhydride and isobutyl chloroformate two-step methods. Conjugate BTX-1-OVA was used as an antigen for mice immunization, and BTX-1-BSA for measuring the titer of the produced antibodies. A hybridoma cell line 6C6 stably secreting monoclonal antibody (mAb) against BTX-1 was obtained by fusing SP2/0 myeloma cells with the spleen cells from the immunized mouse. The hybridoma 6C6 was injected into the abdomen of BALB/c mice to obtain ascites, and the anti-BTX-1 mAb was harvested from ascites by precipitation with caprylic acid/ammonium sulfate (CA-AS). The anti-BTX-1 mAb was identified as an IgG1 subtype, and the cross-reactivity results showed that anti-BTX-1 mAb was highly specific to BTX-1 with the affinity of 1.06 × 10⁸ L/mol. The indirect competitive ELISA results indicated that the linear range for BTX-1 detection was 14-263 ng/mL with IC50 of 60 ng/mL, and a detection limit of 14 ng/mL. The average recovery rate from the spiked samples was 88 ± 2% in intra-assay and 89 ± 2% in inter-assay. The limit of detection (LOD) using the colloidal gold strip was 200 ng/mL with high specificity. Therefore, the anti-BTX-1 mAb can be used to detect BTX-1 in shellfish and other related samples.