Abstract:In order to solve the problem of ciprofloxacin residue which was the major metabolite of enrofloxacin in milk，a colloidal gold test strip for rapid detection of ciprofloxacin residues in milk was established.In this paper，ciprofloxacin coated antigen was prepared and the ciprofloxacin antibody was characterized and the conditions of colloidal gold labeling were optimized. The optimal labeling pH and the optimal protein addition were selected.The nitrocellulose membrane was used as the solid phase carrier with coated antigen as test line and goat anti-rabbit as control line.According to the principle of immuno competition method，a method for rapid detection of ciprofloxacin in milk by colloidal gold immunochromatographic test strip was established.The detection limit of the method was 6.25 ng/mL，and the detection limit of milk samples was 12.50 ng/mL.The sample pretreatment method was simple and the result could be visually judged within 10 minutes.