Abstract:

The ciprofloxacin-bovine serum albumin conjugate (CIP-BSA) was prepared by a modified carbodiimide method, and identified by ultraviolet spectrometry and polyacrylamide gel electrophoresis (SDS-PAGE). Then CIP-BSA was used as immunogen to immunize BALB/c mice, inducing the secretion of antibodies against hapten CIP. The monoclonal antibodies (Mabs) against CIP were obtained by hybridoma technology and their titer, affinity and specificity were identified. The results showed that CIP-BSA coupling ratio was 30:1, and two Mabs secreted by cell lines JY-1 or JY-2 belonging to IgG1a were screened by the indirect ELISA method. The titers of purified JY-1 and JY-2 Mabs were 5.12 × 106 and 2.56 × 106, respectively; both the Mabs showed high affinity to CIP with affinity coefficients of 2.88 × 109 and 2.46 × 109 L/mol respectively. A competitive inhibition curve of the JY-1 Mab was developed, and the IC50 was 9.83 ng/mL. The JY-1 Mab exhibited high cross-reactivity (95%) with enrofloxacin. These results suggested that the JY-1 Mab was useful for determination of CIP residues in aqua-products.

Key words: ciprofloxacin, hapten, antibody, immunity