Properties of Polyclonal, Monoclonal, and Recombinant Antibodies Recognizing the Organophosphorus Pesticide Chlorpyrifos-ethyl

A rabbit polyclonal antiserum and two murine monoclonal antibodies recognizing the organophosphorus pesticide chlorpyrifos-ethyl were produced. The two hybridoma cell lines were then used as sources of immunoglobulin genes for the generation of recombinant scFv antibodies in Escherichia coli. The two scFvs showed either similar or improved limits of detection in an ELISA when compared with the monoclonal antibodies. Cross-reactivity studies showed that all of the antibodies were specific toward the chlorinated aromatic ring. Furthermore, scFv gene sequences were linked directly to sequences coding for either a c-Myc tag, a His-tag, or alkaline phosphatase. The fusion products generated were functional, and their properties were determined. The problems associated with producing scFvs and scFv derivatives for detection of pesticide residues from hybridoma are addressed and discussed. Keywords: Variable region; antibody engineering; immunoassay; recombinant antibody; pesticide analysis