Shanghai ELISA testing experiment

The principle of Shanghai ELISA testing

The basis of Shanghai ELISA detection experiment is the antigen or antibody solidification and enzyme label of antigen or antibody. An antigen or antibody binding to the surface of the solid-phase carrier remains its immunological activity, the enzyme-labeled antigen or antibody retains its immunological activity, and reserved the activity of the enzyme.

When the detection, the subject (antigen or antibody) in the sample is bonded to a fixed antibody or antigen. The non-combined antigen or antibody was removed by washing the plate, and then the enzyme amount capable of immobilization was associated with the amount of the sample in the sample. After the substrate is added to the substrate reaction, the content of the substance in the sample, qualitative or quantitative analysis can be determined according to the darkness of the color.

Due to the high catalytic efficiency of the enzyme, the results of the immune response are amplified indirectly, the measurement method achieves high sensitivity. The basic type of

ELISA can be used to determine an antigen or to determine antibodies. There are three reagents in this assay:

1. solid phase antigen or antibody;

2. u0026 Nbsp; Enzyme labeled antigen or antibody;
[123 ] 3. u0026 Nbsp; substrate for enzyme action.

Various different types of detection methods can be designed in accordance with the conditions of the origin of the reagent and the characteristics of the specimen.


1. Different antibody sandwich method antigen

For anti-organisms The monoclonal antibodies of two different antigenic determinants were respectively as a solid phase antibody and an enzyme antibody, respectively. Suitable for measuring two or more macromolecular antigens, not suitable for determining semi-antigen and small molecular monovalent antigen, because it cannot form two sites sandwich.

2. u0026 Nbsp; Competition method test antigen

First, the specific antibody package is The surface of the solid phase carrier is divided into two groups after washing: a set of enzyme-labeled antigen and mixed liquid of the antigen, another group of enzyme-labeled antigen, after washing, after washing, add substrate color, these two sets of substrates The difference in degradation is, that is, the amount of unknown antigen to be determined. The antigen measured by this method is often used for small molecular antigen such as hormone and drug classes. The advantage is fast, the disadvantage is to require more enzyme labeled antigen.

3. u0026 Nbsp; Immunusculation method of antigen

The quoted specimen on the degree of inhibition of the substrate is proportional to the amount of the antigen contained in the specimen, and the difference is a predictive antigen.quantity.

4. Indirect Method

is a method of detecting an antibody commonly used, which is a detected antibody that is labeled with an enzyme to detect an inspection antibody that has been combined with the solid phase.

As long as the different solid phase antigen can be used to detect various antibodies accordingly.Mainly used to diagnosis of infectious diseases for detection of pathogens.