RESUMO
A novel suspension array technology was established for the detection of three kinds of veterinary drug residues: chloramphenicol, clenbuterol and 17-β-estradiol. The three conjugates in which veterinary drugs coupled with BSA were immobilized on the solid carrier of the suspension microarray-polystyrene fluorescent microspheres/beads as detective probes. Indirect competitive technology was employed. Competitive reactions between the veterinary drugs in the aqueous phase and the veterinary drugs-BSA conjugates on the beads for coupling with their complimentary specific biotinylated monoclonal antibodies were carried out. And then, straptavidin-phycoerythrin was added for coupling and the fluorescent signals were captured. Afterwards the detective standard curves were plotted. The regular ELISA standard curves of the three veterinary drugs were also plotted. Comparison between suspension array and regular enzymE-linked immunosorbent assay(ELISA) was in the respects of the detective technology, the detection limits, the detective ranges, the samples detection and the multi-analysis. Suspension array technology is distinct advantageous except for specificity. There was well consistent performance between the two methods. The high-throughput suspension array provides a novel method for multi-analysis of veterinary drugs with simple operation, sensitive, rapid and low costing.
RESUMO
<p><b>OBJECTIVE</b>To establish a novel suspension microarray technology for the detection of three kinds of veterinary drug residues: chloramphenicol, clenbuterol and 17-beta-estradiol (CAP, CL and E2).</p><p><b>METHODS</b>The three conjugates that veterinary drug coupled with bovine serum albumin (BSA) were synthesized and identified by ultraviolet (UV) spectrophotometry and mass spectrum. The veterinary drug conjugates were immobilized on the polystyrene fluorescent microspheres/beads. There were competitive reactions between the veterinary drugs in the aqueous phase and that on the beads for combination with their specific biotinylated monoclonal antibodies. The optimum amount of the veterinary drug conjugates and the antibodies were optimized and selected. The detective standard curves were plotted. The specificity and the unknown samples were also determined by grouping according to different concentrations of the interferes and the samples. Meantime, the different microstructures of the surfaces of the beads were also observed by scanning electron microscope.</p><p><b>RESULTS</b>Couplings were completed between small molecular veterinary drugs and BSA. The amounts of the three conjugates and the antibodies were optimized. The detective standard curves of the suspension array and their corresponding coefficients of determination (R2) were good (R2 > 0.99). The detection ranges of the three veterinary drugs were (40.00 - 6.25) x 10(5) ng/L, (50.00-7.81) x 10(5) ng/L and 1.00 x 10(3) - 7.29 x 10(5) ng/L respectively. Simultaneously, the specific detection of the suspension microarray was excellent and did not indicate significant cross-reactions. Errors between the found and the real are in the range of 8.09% - 17.03%. It can be considered that the relative standard deviations were relatively small. Successful couplings were also directly confirmed by the observation for microstructures of the surfaces of the beads by scanning of electron microscope and laid good foundation for the following responses.</p><p><b>CONCLUSION</b>The high-throughput suspension microarray should provide a novel method for multi-analysis of the veterinary drugs and have a wide applicative prospects with simple operation, sensitive, rapid and low cost.</p>