Colloidal gold technology is a new immunolabeling technology that uses colloidal gold as a tracer marker to apply to antigens and antibodies. The English abbreviation is gict. Colloidal gold is polymerized into gold particles of specific size by chloroauric acid (HAuCl4) under the action of reducing agents such as white phosphorus, ascorbic acid, sodium citrate and tannic acid. Due to static electricity, it is colloidal gold, The adsorption of colloidal gold to protein mainly depends on the pH value. Under alkaline conditions, they are likely to form a strong binding. Under acidic conditions, they will aggregate and lose their binding ability. In addition, the size of colloidal gold particles, ionic strength and molecular weight of protein will affect the binding of colloidal gold to protein.

2. Composition of colloidal gold test paper: the components of typical chromatographic detection reagents seen in the market can be divided into three parts. One is porous materials, including sample pad, absorption pad, binding pad and nitrocellulose membrane; The other is reagent, such as antibody, gold standard combination, etc; The third is laminated structure and card box, such as PVC board, double-sided tape box, etc.

3. Influence of each component of colloidal gold test strip: the components of chromatographic detection reagent are not simply superimposed on each other. Changing any component may cause changes in the overall performance of the product. The characteristics of nitric acid fiber membrane are mainly reflected in its flow rate. The size and concentration of colloidal gold particles, the performance of the separation pad, the amount of gold standard separation, the characteristics of the sample pad, the position and width of the detection line, the stacking strength of the nitric acid fiber membrane and the separation pad, the affinity of the captured antibody, the amount of the captured antibody in the detection line, and the characteristics of the isolated antibody.

4. Advantages of colloidal gold chromatography: in practice, the immunocolloidal gold detection reagent of chromatography is an application method composed of the separation of immune gold marker technology and antigen antibody response. Compared with ELISA reagent, in addition to different markers, it also obeys the characteristics of antigen antibody response. This detection method has obvious advantages.
1，Easy to use, manifested in simple operation, without special training.
2，The test results can be obtained in a short time, and the conclusion can be drawn in 10-15 minutes.
3，It has good stability in different environments and does not need refrigeration.
4，In contrast, its consumption cost and testing cost are low.
5，There are many kinds of test specimens: they can be used for blood and urine examination, so they are suitable for various examinations.