Production and characterisation of polyclonal antibodies to a range of nitroimidazoles Original Research Article

The nitroimidazoles dimetridazole and ronidazole are metabolised to hydroxydimetridazole, while metronidazole is metabolised to hydroxymetronidazole. To screen for a large number of samples by immunoassay for the presence of this family of drugs and metabolites, it was necessary to produce an antibody with broad-spectrum recognition. Metronidazole and hydroxydimetridazole were selected as antigens as they could be coupled to large (immunogenic) carrier proteins at two different positions of the general nitroimidazole structure. The resulting conjugates were used to immunise rabbits, sheep and goats. Seventeen out of thirty-nine animals immunised produced a detectable antibody titre and these antibodies were consequently characterised as regards sensitivity and cross-reactivity. The panel of antisera produced exhibited IC50 ranging from 1.26 to 73.76 ng ml−1 using a competitive ELISA assay. Cross-reactivity studies showed that sera from several animals were capable of significant binding of six of the seven nitroimidazole compounds tested.