Abstract:

A chemiluminescent enzyme-linked immumosorbent assay (CL-ELISA) based on polyclonal antibody for lomefloxacin was developed. Assay conditions, including the concentration of coating antigen, the dilution degree of the primary antibody and IgG-HRP, and the type of micro-titer plate. were studied. The optimized CL-ELISA presented high sensitivity with an IC₅₀ value of 0.22ng／mL and detection limit of 0.032ng／mL. Good specificity was acquired with only norfloxacin and fleroxacin showing a percentage of cross-reactivity higher than 1％ (6.88％ and 2.16％ respectively) among the ten detected representative quinolones. The method developed was applied in the detection of lomefloxacin recovery in spiked milk. The average recovery rates were in the ranges of 88.7％～103.4％ and 97.8％～107.2％ for intra- and inter-assay respectively while the corresponding coefficient of variation (CV％) were in the ranges of  6.3％～ 8.6％ and 2.4％～ 8.0％.

Key words: antibody; chemiluminesence; ELISA; drug residue; lomefloxacin