Development of an Immunoenzyme Assay to Control the Total Content of Antibiotics of the Fluoroquinolone Group in Milk

A method for preparing antibodies that specifically recognize antibiotics of the fluoroquinolone group with the same radical in the first position of the quinolone nucleus is proposed. The specificity of rabbit antisera prepared at different cycles of immunization by changing the structure of the hapten in the composition of immunogens was characterized. The selected antibodies provided a group-specific analysis of 16 representatives of fluoroquinolones, including a combination of the following compounds that are controlled in animal products: ciprofloxacin, norfloxacin, pefloxacin, ofloxacin, and enrofloxacin. Using these antibodies, an indirect competitive enzyme-linked immunosorbent assay was developed that was characterized by a detection limit of ciprofloxacin of 0.2 ng/mL and a duration of 2 h. The assay was approbated for the detection of fluoroquinolones in milk.