Introduction

The first tissue or cells in some chemical substances extracted, as antigen or semi-antigen, by immunizing animals to obtain specific antibodies, and then the antibody to detect the same kind of antigen in the tissue or cells.? Because the complex of antigen and antibody is colorless, it is necessary to show the binding site of antigen and antibody by means of histochemistry, in order to achieve the qualitative, localization or quantitative study of unknown antigen in tissues or cells.

1 Immunohistochemical methods

1.1 Immunofluorescence cytochemistry

Known antibodies are labeled with fluorescein, which is used as a probe to examine corresponding antigens in cells or tissues and observed under a fluorescence microscope. When the fluorescein in the antigen antibody complex is irradiated by excited light, it will emit a certain wavelength of fluorescence, so as to determine the location or quantification of antigen in the tissue.

1.2 Immunoenzyme cytochemistry

It is the most commonly used technique in immunohistochemical studies. The basic principle is to first with enzyme labeled antibody and tissue or cells, and then add enzyme substrate, the generation of colored insoluble products or particles with a certain electron density, through light or electron microscopy, the corresponding antigen in cells or tissues for positioning or qualitative research.

1.3 Immunocolloidal gold technology

It is to use colloidal gold labeled primary antibody, secondary antibody or other specific immunoglobulin binding molecules (such as Staphylococcal A protein) as probes to conduct qualitative, locational or quantitative studies of antigens in tissues or cells. Due to its high electron density colloidal gold is often used in the localization of single or multiple markers in immunoelectron microscopy.

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