Immunofluorescence is a technique for fluorescent labeling of specific biological targets in samples using antibodies. Antibody is a Y-type high molecular glycoprotein, also known as immunoglobulin, which can bind specifically to other molecules (often referred to as antigens or epitopes). Fluorescent antibody labeling technique is to combine fluorescein with specific antibody by chemical method to form fluorescein-protein conjugate (fluorescent labeled antibody), which still retains antibody activity and has the tracer effect of fluorescein. When it was specifically bound to the corresponding antigen, it showed bright specific fluorescence with the help of fluorescence microscope. labeling antibodies with fluorochromes https://bioconjugation.bocsci.com/services/fluorescence-labeling-of-antibody.html