Immunohistochemistry, using the basic principles of immunology - the antigen-antibody reaction, namely antigen and antibody specific binding principle, by chemical reaction of the labeled antibody reagent (luciferase, an enzyme, metal ions, isotopes) to confirm the antigens (peptides and proteins) in tissues, its location, qualitative and quantitative research, called immunohistochemistry (immunohistochemistry) or immunocytochemistry techniques (immunocytochemistry).It combined the specific of immune response with visibility of histochemistry by means of a microscope (including fluorescence microscopy, electron microscopy) imaging and amplification, detection of various antigens in a cell, subcellular level, such as proteins, polypeptides, enzymes, hormones, pathogens, and receptors. Immunohistochemical techniques have developed rapidly in recent years. It was limited to immunofluorescence techniques in 1950s, but gradually developed after the 1950s to establish a highly sensitive and more practical immunization enzyme technology.
Subcellular localization refers to the presence site of a protein in the cell, for example, in the nucleus, cytoplasm or cell membrane. If a protein locates in the cytoplasm, the cytoplasm will be stained, while other locations will not be stained. Immunohistochemistry is an efficient and accurate method of detecting subcellular localization of a protein.