Characterisation of monoclonal antibody against aflatoxin B1 produced in hybridoma 2C12 and its single-chain variable fragment expressed in recombinant Escherichia coli

An anti-aflatoxin B1 monoclonal antibody (anti-AFB1 mAb) from the hybridoma 2C12 was established and its inhibition concentration fifty (IC50) for AFB1 and relative cross-reactivities (CRs) to other mycotoxins were estimated to be 8 ng/mL and less than 4% compared with AFB1 by a competitive direct enzyme-linked immunosorbent assay. For production of anti-AFB1 single-chain variable fragment (anti-AFB1 scFv) in recombinant Escherichia coli, its scFv-coding genes were cloned from the hybridoma 2C12. The anti-AFB1 scFv formed inclusion bodies in the cytoplasm of E. coli required in vitro refolding process and hence recovered to retain binding activity successfully. Surface plasmon resonance analysis resulted that anti-AFB1 scFv possessed 1.16 × 10−7 M of equilibrium dissociation constant (KD), which was about 17 times higher than the parental anti-AFB1 mAb of 6.95 × 10−9 M.