银加强技术在滴金免疫测定法中的应用

The application of silver enhancement to dot immunogold assay

为了提高斑点金免疫渗滤试验（滴金法）的敏感度，进行了银加强滴金法的研究。通过最适条件的选择，建立了如下的方法。银染液的组成为乙酸银，阿拉伯树胶，对苯二酚，溶于ｐＨ３．８柠檬酸盐缓冲液中。洗涤液为含Ｔｗｅｅｎ－２０的ｐＨ８．２Ｔｒｉｓ缓冲盐水。在滴金法试验完成后，在渗滤装置的小孔中按滴金法操作依次加入洗涤液、双蒸水、ｐＨ３．８柠檬酸缓冲液，最后加入银染液。７分钟后观察结果，膜上出现棕黑色斑点者为阳性。银染过程在室温中进行，无需避光。以测定肌红蛋白的滴金法为模式进行如上的银加强实验，敏感度提高８倍。本法试剂稳定，操作简便，适用于各种斑点金免疫结合试验。

To improve the sensitivity of dot immunogold filtration assay (DIGFA), we studied on silver enhanced DIGFA. Choosing the best conditions, following method was established. Dissolved in pH 3. 8 citrate buffer, silver acetate, gum arabic and hydroquinone make up the recipe of the silver enhancer. Washing solution is pH 8.2 Tris buffer saline (TBS) which contains Tween-20. After fulfilling DIGFA, Washing solution, double distilled water,pH 3.8 citrate buffer are added sequentially into the well of filtration device,just as the operation of DIGFA, and finally the silver enhancer is added. The result is observed seven minutes later and dark brown dot on the membrane shows the positive result. The process of silver enhancement is done in the room temperature and is light insensitive. Take the determination of myoglobin as a model,we applied silver enhancement to DIGFA, the sensitivity increases 8 times. Reagents being stable, operation being convenient, this assay can be used in various dot immunogold binding assays.