The Study Of Detection Of Clenbuterol And Ractopamine In Residues Of Veterinary Drug By Immunoassay

Objectives:A multianalyte lateral-flow immunochromatographic technique using colloidal gold-labeled antibodies was developed for the rapid simultaneous detection of clenbuterol (CL) and ractopamine (RAC) in swine urine samples.To improve the detection sensitivity, A new fluorescence immunochromatographic assay for rapid detection of ractopamine (RAC) was primarily developed.Methods:The ascites of RAC were purified by ammonium sulfate precipitation, and determination with the BCA kit for antibody concentration. Colloidal gold was prepared by controlled reduction of gold chloride with sodium citrate. The proper concentration of CL, RAC antibody were conjugated to Au nanoparticles. CL-BSA and RAC-BSA were coated in NC membrane surface, as test line (T1 and T2 lines), goat anti-mouse IgG-coated nitrocellulose (NC) membrane surface, as a control line (C lines). During detection process, CL-BSA, RAC-BSA competed with the CL, RAC in the samples to combine the anti-CL, RAC mAb labeled with colloidal gold. The color visual display according to the semi-quantitative test results. The same way, the colloidal gold labeler replaced by the fluorescent latex particles, which emit fluorescence in the UV lamp. According to this feature to develop RAC latex fluorescence immunochromatographic rapid detection method.Results:The CL-BSA and RAC-BSA were synthesized successfully. Successfully prepared 30 nm size colloidal gold. A multianalyte lateral-flow immunochromatographic technique for the rapid simultaneous detection of clenbuterol (CL) and ractopamine (RAC) in swine urine samples was developed. It can be observed with the naked eye in 5 minutes; the sensitivity of CL and the RAC were 5ng/mL; also it had high specificity, CL, RAC, SAL and other analogues have no cross-reaction; stability, room temperature 7 weeks without fail. The antibody of RAC wsa successfully conjugated to fluorescent latex particles. The RAC latex fluorescence immunochromatographic rapid detection methods was primarily developde, and the sensitivity can reach 0.5 ng/mL in the UV lamp.Conclusions:A sensitive, specific, accurate, stable, convenient and cheap gold immunochromatographic assay for detection of clenbuterol (CL), ractopamine (RAC) in swine urine samples was developed. A more sensitive fluorescence immunochromatographic assay for rapid detection of ractopamine (RAC) was primarily developed.