Evaluation and Testing of Charm Test II Receptor Assays for the Detection of Antimicrobial Residues in Meat

Charm Test II receptor assays for β-lactams, sulfonamides, streptomycin and erythromycin were tested with standard solutions of targeted antimicrobials and with fortified kidney, liver and muscle samples. The degree of response obtained with the β-lactam assay varied among equimolar amounts of 8 β-lactams. The sulfa assay was positive, with varying response, to equimolar amounts of four different sulfonamides and negative for trimethoprim. The streptomycin assay also detected dihydrostreptomycin, but was negative for gentamicin and neomycin. The erythromycin assay was negative for oleandomycin but positive for tilmicosin and tylosin. No evidence of cross reactivity was detected among the compounds targeted by the four assays.