Abstract：A Competitive ELISA kit for detection of Difloxacin（DIF-Kit）was developed with generating hybridoma lines that secrete DIFmonoclonal antibodies（DIF mAb）and the method of ciELISA,its traits were identified. The DIF-Kit had 0.24% cross-reactivity towards Danofloxacin,and little or no cross-reactivity towards other FQNS and sulfamido.The detection limit for DIF was 0.1µg/L and IC50 was 2.2µg/L.The The precision and accuracy of the assay as determined by inter-assay and intra-assay coefficient variation were below 15% in range of 0.1～128.0µg/L. The recoveries from milk and chicken were 89.3% and 83.9%,respectively,when 0.4、2.0、10.0、50.0.0µg/L DIF were spiked. The validity of DIF-Kit in 4℃ was above six months.The DIF-Kit possesses high accuracy, good reproducibility,specificity.That is proved to be used for the rapid detection of DIF residues in animal food.
