Hapten synthesis and antibody development for polychlorinated dibenzo-p-dioxin immunoassays

摘要

This paper reports the synthesis of haptens and the generation and preliminary evaluation of polyclonal antibodies for the detection of dioxins such as TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) by ELISA (enzyme-linked immunosorbent assay). These novel haptens contain unsaturation between the halogenated dibenzo-p-dioxin ring system and the protein to which it is conjugated, presenting a rigid handle structure. The substitution pattern is identical with or similar to that of TCDD (i.e., 2,3,7,8- or 1,2,3,7,8-). Finally, the haptens lack polar groups for hydrogen bonding. In direct binding assays using the new polyclonal antibodies there was excellent recognition of hapten-protein conjugates, including recognition of those hapten conjugates that were not used as immunogens (i.e., assay systems heterologous in hapten structure). These haptens do elicit selective immune responses in rabbits. Their evaluation in an ELISA format demonstrated the usefulness of these haptens for the detection of dioxins. An IC50 of 0.8 ng/well (16 ng/mL) was observed for an unoptimized system that used 2,3,7-trichloro-8-methyldibenzo-p-dioxin as an analytical surrogate standard. [References: 56]