Immunohistochemistry is a technique used in biomedical research to visualize the presence and distribution of specific proteins or antigens in tissues. This technique involves the use of antibodies that are specific to the target protein, which are then visualized using a detection system such as fluorescence or enzyme-based staining. Immunohistochemistry is commonly used in various fields of research, including cancer biology, neuroscience, and immunology, to study protein expression patterns, cellular localization, and cell signaling pathways. It is a valuable tool for understanding the molecular mechanisms underlying biological processes and disease states.