MONOCLONAL-ANTIBODIES FOR IMMUNOASSAY OF AVERMECTINS

We have developed a panel of mouse monoclonal antibodies (MAbs) that recognize ivermectin and abamectin, the major avermectins used in veterinary and agricultural formulations. Conjugates of ivermectin 4′-hemisuccinate on three different proteins were used to raise the antibodies and develop a quantitative competition enzyme immunoassay (EIA) for avermectins. The five MAbs that gave the lowest detection limits for ivermectin and abamectin were used to optimize the EIA. Several types of EIA plates, plate coating conditions, blocking agents, incubation times and temperatures, and enzyme-conjugated detecting antibodies were compared to determine acceptable assay conditions. One of the MAbs, C4D6, bound ivermectin in buffers containing up to 30% (v/v) of organic solvent. The lower limit of detection for standards in this EIA was approximately 0.5 ppb for ivermectin and 1 ppb for abamectin, with half-maximal inhibition (I50) around 3 ppb for ivermectin and 7 ppb for abamectin. The MAbs and EIA appear to be usable for quantifying avermectin residues in agricultural and environmental matrices. © 1990, American Chemical Society. All rights reserved.