Production of monoclonal antibodies to the N-methylcarbamate pesticide propoxur

Monoclonal antibodies (MAbs) to the pesticide propoxur were produced from h aptens with carboxylic spacer arms of different lengths introduced at the c arbamate group of the analyte structure. MAbs were subsequently characteriz ed in the conjugate-coated format using these immunizing haptens and newly synthesized compounds as homologous and heterologous assay conjugates, resp ectively. Appropriate combinations of immunoreagents resulted in competitiv e enzyme immunoassays (ELISA) with I-50 values in the low nanomolar range ( 6.5-17.9 nM). A modification of the conjugate-coated format consisting of t he simultaneous incubation of the MAb and the peroxidase-labeled secondary antibody in the presence of the analyte resulted in an assay with an I-50 v alue of 4.4 nM. This one-step conjugate-coated ELISA format is as simple an d fast as the antibody-coated format but without the need of synthesizing e nzyme-hapten conjugates. Major N-methylcarbamate pesticides were not recogn ized by the MAb. This immunoassay should reasonably allow the rapid, low-co st, and sensitive determination of propoxur in food, soils, and the environ ment at levels of regulatory and practical importance.