犬血清弓形虫IgG抗体胶体金免疫层析检测试纸条的研制

Development of colloidal gold immunochromatography test strips for the detection of immunoglobulin G against Toxoplasma gondii infection in canine sera

采用柠檬酸还原法制备胶体金颗粒,将其标记葡萄球菌蛋白A（SPA）并喷于玻璃纤维上制备胶体金垫。将弓形虫重组抗原（SAG1）和山羊IgG分别包被至硝酸纤维素膜的检测线与质控线上。依次将样品垫、胶体金垫、硝酸纤维素膜和吸水纸组装成胶体金免疫层析快速检测试纸条。试验结果显示,该快速检测试纸条在阳性血清稀释至16倍时仍可见清晰条带,整个检测过程可在5~10 min内完成,肉眼即可判断,无须其他检测设备。与弓形虫ELISA试剂盒进行对照试验,检测结果符合率较高。结果表明,该试纸条适用于犬血清中弓形虫IgG抗体的现场快速检测和筛选工作。

Colloidal gold particles prepared by sodium citrate redution method were labeled with staphylococcal protein A,and sprayed onto the glass fiber.Toxoplasma gondii-specific recombinant antigens（SAG1）,and goat Ig G were sprayed onto a nitrocellulose membrane in strips at positions designated as T and C lines,respectively.Then,the sample pad,colloidal gold pad,nitrocellulose membrane and absorbent paper were assembled as test strips.The lowest detectable limit of the assay was determined as the highest dilution（1 ∶ 16） of positive serum.The test could be completed within 5 to 10 min and the results could be read by naked eyes. There was no need for expensive equipments. A high degree of consistency was observed between the ICT and the standard ELISA kit, supporting the reliability of the test strip. The results showed that the test strips met requirements for use in rapid testing and screeing of immunoglobulin G against T.gondii in canine sera