Development of a high affinity monoclonal antibody against imazapyr and its configuration in a sensitive ELISA suitable for field use

Although polyclonal antibodies specific for the herbicide imazapyr have been described and have formed the basis of an immunoassay (at one time commercially available but since withdrawn), it is clear that this molecule has limited immunogenicity. We evaluated various hapten–protein conjugates for their capacity to elicit antibody binding to imazapyr from multiply immunized murine hosts, as assessed by hapten‐competed inhibition of reactivity with hapten conjugated to a heterologous carrier. From one highly reactive individual, we subsequently developed a monoclonal antibody exhibiting a high reactivity to this agrochemical. With this antibody we have been able to configure immunoassays in formats suitable for either laboratory or field use that exhibit both high performance and convenience, such that sensitivities for imazapyr in the range of 1 ng/ml can be achieved. While further testing of this anti‐imazapyr antibody in field conditions is required, the availability of a constant source of immunoreactive immunoglobulin may be important in the development of useful immunoanalytical approaches for the assessment of imazapyr at the point‐of‐need. © 2002 Wiley Periodicals, Inc. Field Analyt Chem Technol 5: 281–287, 2001; DOI 10.1002/fact.10012