Development of a Broad Specific Monoclonal Antibody for Fluoroquinolone Analysis

Fast and sensitive screening of antibiotics is a great need in food quality assurance. A monoclonal antibody specific to fluoroquinolones (FQ) was obtained using ciprofloxacin (CPF) derivant as hapten. The antibody was characterized with broad recognition to CPF (100 %), enrofloxacin (ENF, 73.89 %), norfloxacin (73.57 %), nadifloxacin (67.28 %), danofloxacin (53.09 %), pefloxacin (50.26 %), lomefloxacin (35.66 %), enoxacin (12.40 %), and sarafloxacin (3.23 %). Then, an enzyme linked immunosorbent assay (ELISA) was established. The optimized concentrations of coating antigen and antibody were 0.1 and 0.5 mu g/ml, respectively. Various parameters including pH values, ionic strength and the concentration of antibody and antigen were optimized for this assay. The ELISA was found to have the best sensitivity in assay buffer of pH 6 and sodium chloride content 1.6 % (m/v) using CPF as tested compound. Fortified milk samples with CPF and ENF (50 and 250 mu g/l) and fortified chicken samples (10 and 50 mu g/kg) were analyzed with the proposed measure. The ELISA was examined with recovery range of 94-104 % for milk detection and 93-108 % for chicken detection. The coefficient variation data for intra-assay and inter-assay ranged from 4.24 % to 12.16 %. All results indicate the potential extensive application prospects of this ELISA in FQ monitoring for food safety.