Preparation of anti-danofloxacin antibody and development of an indirect competitive enzyme-linked immunosorbent assay for detection of danofloxacin residue in chicken liver

BACKGROUND: Danofloxacin is used widely as both a clinical medicine for humans and a veterinary drug in animal husbandry. In this study a polyclonal anti-danofloxacin antibody was prepared for the first time and a simple and rapid indirect competitive enzyme-linked immunosorbent assay (cELISA) method based on the antibody was developed to monitor danofloxacin residue in chicken liver. RESULTS: The prepared antibody showed high sensitivity, with an IC50 value of 2.0 ng mL(-1) towards danofloxacin, and good specificity, with significant cross-reactivity only towards pefloxacin (22%) and fleroxacin (21%) among commonly used (fluoro)quinolones evaluated in the study. The developed cELISA test kit had a detection limit of 0.8 ng mL(-1), and satisfactory results were obtained when it was applied to chicken liver spiked with various levels of danofloxacin. The cELISA test kit was also used to detect danofloxacin in chicken liver samples purchased from a local food market, and the results were confirmed by liquid chromatography/mass spectrometry. CONCLUSION: The anti-danofloxacin antibody prepared in this study exhibits excellent quality, with high sensitivity and good specificity. The cELISA test kit based on the antibody has a very low detection limit and is suitable for use as an efficient screening method to detect danofloxacin residue in foods and food products. (C) 2009 Society of Chemical Industry