Hapten synthesis for the development of a competitive inhibition enzyme-immunoassay for thiram

An enzyme-linked immunosorbent assay (ELISA) was developed for the fungicid e thiram. Two types of haptens were synthesized. The first type exhibits th e two symmetrical N-alkyl dithiocarbamate patterns of thiram with a spacer arm linked to one of the N-methyl terminal group. The second type exhibits one of the two symmetrical N-alkyl dithiocarbamate patterns of thiram with a variable-length spacer arm linked to one sulfur atom. Polyclonal antibodi es suitable for thiram detection were obtained from immunization with an ha pten of the first type, while haptens of the second type were used as coati ng antigens to develop a competitive ELISA against thiram. The IC50 value f or thiram was estimated to be 0.24 mug/mL, with a detection limit of 0.03 m ug/mL. The assay seems to be thiram-specific since no or little cross-react ion with other dithiocarbamates were observed.