Production and Characterization of Monoclonal Antibodies against Sarafloxacin and Cross-Reactivity Studies of Related Fluoroquinolones

Monoclonal antibodies were developed that bind sarafloxacin, a fluoroquinolone approved by the Food and Drug Administration for use against Escherichia coli in poultry. Splenocytes from mice immunized with a bovine serum albumin−sarafloxacin conjugate were fused with SP2/0 myeloma cells, and hybridomas secreting antibodies against sarafloxacin were selected and cloned. An enzyme-linked immunoassay was developed, and 50% inhibition of control values ranged from 7.3 to 48.3 ppb using sarafloxacin as the competitor. Tissue samples were spiked with sarafloxacin, and the average percent recoveries at 10, 50, and 100 ppb were 132, 78, and 81%, respectively. Monoclonal antibodies exhibiting high relative affinity for sarafloxacin were also characterized for their ability to detect five structurally related quinolones. The specificity and cross-reactivities of these antibodies are discussed in relation to three-dimensional, computer-generated molecular models of the fluoroquinolones.