Immunohistochemistry is a type of laboratory test that uses antibodies to detect specific proteins or markers in tissue samples. It is a specialized skill that allows researchers and clinicians to analyze the distribution and localization of proteins within cells and tissues, providing valuable insights into disease pathology, diagnosis, and treatment. The technique involves a series of steps, including tissue preparation, antigen retrieval, blocking, primary antibody incubation, detection, and visualization. Skilled practitioners are essential for producing accurate, high-quality results.