Magnetic nanoparticle based purification and enzyme-linked immunosorbent assay using monoclonal antibody against enrofloxacin

Kim, Nam-Gun; Kim, Myeong-Ae; Park, Young-Il; Jung, Tae-Sung; Son, Seong-Wan; So, ByungJae; Kang, Hwan-Goo

ENR conjugates were synthesized by linkage of the carboxylic acid group of ENR with the amino group of the carrier protein. This reaction resulted in an amide bond between the ENR and Fig. 1 shows the standard inhibition curve for ENR obtained using the developed ELISA system. The lowest detectable level of ENR in this ELISA was 0.7 ng/mL. To determine the specificity of the prepared antibody, cross-reactivity towards various FQs was carried out by direct competitive ELISA using ENR-BSA as the coating antigen. Cross-reactivity was measured by comparison of the IC50 to that of ENR. The IC50 values of the mAb for enrofloxacin, ciprofloxacin, difloxacin, sarafloxacin, pefloxacinand norfloxacinwere 5.0, 8.3, 9.7, 21.7, 36 .0, and 63.7 ng/mL, respectively. Cross-reactivity levels of the mAb to ciprofloxacin, difloxacin, sarafloxacin, pefloxacin and norfloxacin were 60, 52, 23, 14 and 8%, respectively ( Table 1) .