Immunofluorescence is one of many techniques in biomedical research and diagnosis. It uses the sensitivity and selectivity of fluorescence to analyze biological tissues. The basic reaction of immunology is antigen-antibody reaction. when antigen-antibody reaction occurs, as long as one factor is known, the other factor can be determined, due to the high specificity of the reaction. Immunofluorescence technology is to label the fluorescent pigment that does not affect the activity of antigen and antibody on the antibody (or antigen), combine it with its corresponding antigen (or antibody), and show a specific fluorescence reaction under the fluorescence microscope. Hence, immunofluorescence technique can be used to detect proteins and other biomolecules in cells and tissues.