Biochemical

The method is based on a competitive colorimetric ELISA assay. The drug of interest (beta-lactam antibiotic) has been coated in the plate wells. The sample to be tested is mixed with a high-affinity beta-lactam capture protein and added to the well. If the beta-lactam target is present in the sample, it will compete for the capture protein, thereby preventing the capture protein from binding to the drug attached to the well. The secondary antibody, tagged with a peroxidase enzyme, targets the capture protein bound to the drug coated on the plate wells. The resulting color intensity, after addition of substrate, has an inverse relationship with the target concentration in the sample. The levels of beta-lactam antibiotic in the sample are determined by comparison of the color intensity of unknown samples with the standard curve, which is made using the beta-lactam standard provided in the kit.