Production and characterization of monoclonal antibody and its recombinant single chain variable fragment specific for a food-born mycotoxin, fumonisin B1

Fumonisin B1 (FMB1) is a food-born mycotoxin produced by Fusarium moniliforme. Monoclonal antibody against FMB1 (anti-FMB1 mAb) was produced in the hybridoma DV9, which was established from a BALB/c mouse immunized with bovine serum albumin conjugated FMB1 (FMB1-BSA). A competitive direct enzyme-linked immunosorbent assay (ELISA) showed that anti-FMB1 mAb has about 10 ppb of minimum FMB1 detection concentration and 220 ppb of 50% inhibition concentration (IC50). Much lower cross-reactivity of anti-FMB1 mAb on ochratoxin A, aflatoxin B1 and deoxynivalenol provided that anti-FMB1 mAb was specific for FMB1. The gene coding single chain variable fragment against FMB1 (anti-FMB1 scFv) was cloned from the hybridoma DV9 and was expressed in recombinant Escherichia coli. Insoluble anti-FMB1 scFv required optimization of its refolding condition, and hence functional scFv was obtained. By using indirect ELISA, about 12-fold lower binding activity of anti-FMB1 scFv on FMB1-BSA was obtained in comparison with that of the parental mAb.