Immunohistochemistry, involves the process of selectively imaging antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues.

This is especially useful for diagnosing abnormal cells in diseases such as cancer. In general, the information gained from IHC provides a valuable perspective that provide context for data obtained using other methods.

Immunohistochemical staining is accomplished with antibodies that recognize the target antigen. Since antibodies are highly specific, the antibody will bind only to the antigen of interest in the tissue section. The antibody-antigen interaction is then visualized using either chromogenic detection, in which an enzyme conjugated to the antibody catalyzes the conversion of a substrate to produce a colored precipitate at the location of the antigen.