ABSTRACT
A high affinity polyclonal antibody-based enzyme linked immunosorbent assay (ELISA) was developed for the quantification of zeranol in bovine urine. On the basis of urine matrix studies, the optimized dilution factors producing insignificant matrix interference were selected as 1:5 in pretreatment. In the improved ELISA, the linear response range was between 0.02 and 1 microg/ml, and the detection limit was 0.02 microg/ml for the assay. The overall recoveries and the coefficients of variation (CVs) were in the range of 82% to approximately 127% and 3.5% to approximately 8.8%, respectively. Thirty-six bovine urine samples spiked with zeranol (ranging from 0.2 to 10 microg/ml) were detected by the ELISA and liquid chromatography (LC) method, and good correlations were obtained between the two methods (R(2)=0.9643). We conclude that this improved ELISA is suitable tool for a mass zeranol screening and can be an alternative for the conventional LC method for zeranol in bovine urine.
Subject(s)
Animals , Cattle , Calibration , Chromatography, High Pressure Liquid , Enzyme-Linked Immunosorbent Assay , Methods , Indicator Dilution Techniques , Zeranol , Allergy and Immunology , UrineABSTRACT
<p><b>AIM</b>To synthesize and identify artificial antigen of podophyllotoxin for the production of podophyllotoxin polyclonal antibody.</p><p><b>METHODS</b>The hapten was synthesized by two different chemical approaches and characterized by TLC, IR, NMR, and MS. Mixed anhydride reaction (MAR) and active ester method (AEM) were used to couple the podophyllotoxin to carrier proteins (BSA and OVA). Characterization of artificial antigens was done by using spectroscopy and electrophoresis. The anti-podophyllotoxin polyclonal antibodies were obtained through immunizing rabbits.</p><p><b>RESULTS</b>The results from IR, NMR and MS showed that 4-O-succinoyl podophyllotoxin (hapten) was successfully synthesized. The coupling molar ratios of the hapten and carrier proteins were 88.6 for Hapten-BSA1, 40.3 for Hapten-BSA2, 17.8 for Hapten-OVA1, and 54.2 for Hapten-OVA2. Hapten conjugates coupled with BSA yielded two sets of the specific and affinitive polyclonal antibodies. One set of antibodies showed an IC50 value of 2.21 microg.mL(-1) with a detection limit of 0.12 microg.mL(-1).</p><p><b>CONCLUSION</b>Antigenic conjugates were artificially synthesized, and based on these artificial antigens, polyclonal antibodies against podophyllotoxin were raised from rabbits immunized with two different immunogens and characterized with an indirect ELISA format.</p>