三聚氰胺胶体金免疫层析试纸条的研制

通过胶体金免疫层析技术建立一种特异、便捷、快速的三聚氰胺抗原检测方法,对奶制品及饲料中的三聚氰胺残留水平监测提供参考。用柠檬酸三钠还原法制备的胶体金,标记纯化的三聚氰胺单克隆抗体,喷于试纸的金标垫。将MEL-OVA(三聚氰胺和卵清白蛋白的偶练物)和纯化的羊抗鼠IgG分别喷于试纸的T(检测线)处和C(质控线)处,通过挑选试纸条材料和调试工艺参数,并最终组装成试纸条。结果显示,制备的试纸监测体系方法检出限为50 g/L。试纸条对牛奶、奶粉和饲料中的三聚氰胺残留的检出限分别为100 g/L、100 ng/g和200 ng/g。将该法与LC-MS/MS法对比检测牛奶、奶粉和饲料样品,在试纸条检测范围内,与LC-MS/MS法检测结果一致性好,从而验证了该方法的有效性。制备的三聚氰胺胶体金检测试纸在常温干燥环境下至少可保质6个月,能够检测出三聚氰胺含量大于50 g/L的样品,适用于现场实际样品三聚氰胺残留水平监测,具有良好的应用前景。

Colloidal gold immunochromatographic strip for rapid detection of melamine

To develop a specific, rapid, and convenient immunochromatography assay (ICA) to detect melamine residues in dairy products and feed sample. Colloidal gold particles labeled with purified monoclonal antibody against anti-melamine were used as the detector reagent. The MEL-OVA (the conjugate of melamine and ovalbumin) and goat anti-mouse melamine IgG were blotted on the test and control regions of nitrocellulose membrane. The strip was then assembled with sample pad, absorbing pad, and dorsal shield. The limit of detection (LOD) is 50 mg/L. The test trip was applied to detect melamine in milk, milk powder, and animal feeds, with detection limits of 100 mg/L for milk, 100 ng/g for milk powder, 200 ng/g for feeds. Compared to LC-MS/MS, the ICA could be used to screen a large number of dairy products and feed samples for melamine residue.