Preparation of a Polyclonal Antibody Based Indirect Competitive ELISA for Enrofloxacin Residue

A rapid indirect competitive ELISA (icELISA) for the determination of enrofloxacin (ENR) residue has been developed. EDC method was employed to synthesize the artificial antigen of ENR-BSA, and anti-serum produced from rabbits was selected. Based on the square matrix titration, an icELISA method was developed with the polyclonal antibody. The Linear range was from 0.006 to 31.5 ng/mL, with LOD and IC50 values of 0.003 ng/mL and 0.45 ng/mL, respectively. Except for a high cross-reactivity (105.2%) to ciprofloxacin, negligible cross-reactivity to other compounds was observed. The recoveries of ENR were in the range of 98.3-127.5%, 85.7-112.5% and 97.4-103.8% for chicken muscle, liver and kidney, respectively. Therefore, this assay has the potential to be incorporated into a quantitative monitoring program for the rapid screening of ENR residue in food.