TABLE 1

The relative binding affinities of monoclonal antibodies 2E2 and h2E2 for cocaine and its metabolites

The relative binding affinities (RBAs) were measured using a competition enzyme-linked immunosorbent assay, as described in Materials and Methods. The measured IC₅₀ values for each metabolite were compared with that of cocaine, which was designated a RBA of 1. Values higher or lower than 1 indicate, respectively, a lower or higher affinity for h2E2 than that of cocaine.