Monoclonal antibodies for dioxin: antibody characterization and assay development

A set of 5 anti-dioxin monoclonal antibodies (mAbs), named DD-1, DD-3, DD-4, DD-5 and DD-6, have been isolated. In order to evaluate the ability of these mAbs to recognize various kinds of polychlorinated dibenzodioxins and dibenzofurans, a competition enzyme-linked immunosorbtion assay (ELISA) was developed. All 5 antibodies recognize tetrachloro- and pentachloro-dibenzodioxins and -dibenzofurans. They fail to bind either non-chlorinated, mono-, hexa-, or octa-chlorinated dibenzodioxins, nor do they recognize non-chlorinated, octachloro- or 1,2,3,4,8,9-hexachloro-dibenzofurans. Chlorine substitution on both rings appears necessary for antibody recognition. In the course of our experiments, 3 of the mAbs did not recognize any of the polychlorinated biphenyls (PCBs) tested, while 2 mAbs (DD-1 and DD-6) weakly recognized the 3,3',4,4'-tetrachloro congener. DD-4 and DD-5 are the most specific of the antibodies for the dibenzodioxin and dibenzofuran structure. They do not recognize any of a panel of chlorinated phenols, benzenes, or pesticides. Significantly, these antibodies do not react with PCBs, pentachlorophenol, 2,4-dichlorophenoxyacetic acid, trichlorophenol, or 2,4,5-trichlorophenoxyacetic acid (the latter is weakly recognized by DD-6), any or all of which might be present in large quantities in some dioxin-contaminated samples. Finally, the competition ELISA is able to easily detect 0.5 ng of the most toxic dioxin congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin. It should thus prove useful as an environmental screen for contamination.