胶体金试纸条技术

Colloidal god
It is gold chloride acid (HAuCl4) hydrosol, gold chloride acid can aggregat into a certain size of gold particles under the action of reducing agent and become a stable colloidal state by electrostatic interactions.
Sample pad
Strip structure
Colloidal gold pad The line of control line (C) absorbent paper
Tomographic direction
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PVC baseplate
holding wire（T）
NC membrane
measure
The colloidal gold strip testing technology
胶体金试纸条检测技术
Introduction
The colloidal gold strip diagnosis is developed by colloidal gold immune chromatography technology. The technology was established on the basis of the immune infiltration technology in the early 90 s. It is a simple and rapid immunological detection technology. The first to use it to detect human chorionic gonadotropin (HCG)and hepatitis B virus surface antigen(HBsAg),and so on.
Immunogold labeling technique: it is a new type of immune markers technology. As a tracer marker, colloidal gold is applied to the antigen-antibody reaction
The principle of the colloidal gold strip diagnosis technology
Using the nitrocellulose membrane as the carrier and making use of the capillary effect of microporous membrane, we add liquid on one side of the membrane, then the liquid move to the other end slowly. After the combination of antigenantibody, we can take advantage of the colloidal gold color reaction to detect antigen or antibody. It is the most commonly method to detect antigen by using double clamp method
➢ When measuring, we make the bottom of test paper strip immerse in the liquid samples, then the bottom absorbs liquid and move towards the upper end. when the liquid flow through the C , the immune gold complex dissolve on the strip.
➢ If there are a test specific antigen in the specimen, it can be combined with immune antibodies in the gold complexes. when the antigen-antibody complex flows to the test area, it can be captured by solid phase antibody and show reaction red line on the membrane.
➢ When excess immune gold compounds flow to the reference area and combine with solidphase anti-mouse IgG(monoclonal antibodies in the immune gold compounds is mouse IgG), then it will show the red quality control line.
• Poor quality colloidal gold: the solution is purple, size is differ, a variety of shapes.
The principle of colloidal gold labeling: colloidal gold is negatively charged in alkaline conditions. Therefore, it can form a solid combination with protein molecules positively charged groups by electrostatic attraction.
➢ The quality of the colloidal gold standard:
• Good quality colloidal gold: the solution is red, colloidal gold particle is spherical, uniform size, no edges and corners.