No abstract

The carbodiimide active ester method was employed to synthesise the antigen of 1-cyclopropyl-7-(4-ethylpiperazin-1-yl)-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid [Enrofloxacin (ENFX)], and male Balb/c mice were used to produce anti-ENFX monoclonal antibody. Based on the checkerboard titration, an indirect competitive enzyme-linked immunosorbent assay standard curve was established. This assay was sensitive and highly specific to ENFX with the half maximal inhibitory concentration and limit of detection values of 0.15 ng mL −1 and 0.028ng mL −1 , respectively. Similarly, the antibody had a high affinity as seen in A max values. Spiked cow milk beef liver and fish samples analysed using this kit had recoveries in the range of 90.2-110.2%, 70.7-81.5% and 89.1-101%, respectively, showing satisfactory results. The results suggest that this ELISA kit could be applied as a screening method to detect and control the illegal content of ENFX in food products. ARTICLE HISTORY

A specific monoclonal antibody (MAb) against apramycin (AP) was produced and used to develop an indirect competitive enzymelinked immunosorbent assay (idcELISA) and a rapid testing strip for the detection of AP residues in foods. MAb exhibited negligible cross-reactivity with other aminoglycosides. Under optimized conditions in 0.01 M PBS, the half maximum inhibitory concentration (IC 50) of MAb was 0.41 ng/ml with a limit of detection (LOD) of 0.15 ng/ml. The ELISA results were obtained within 90 min. The mean recoveries from all the spiked food samples were within the range of 79.02-105.49%, with coefficients of variation in the range of 2.21-11.4%. The strip test results obtained within 5 min had visual LODs in the range 2.5-5 µg/kg (ng/ml) for all food samples tested. Therefore, the developed strip test represents a fast and convenient detection method of AP residues in foods.