How is immunohistochemistry performed?

Immunohistochemistry (IHC) is a micro-enzyme immunoassay technique commonly used to detect the expression of different proteins in cells. By combining immunological principles, antigen detection, and micro-enzyme histochemical techniques, it enables precise determination of the expression levels and subcellular localization of specific proteins within cells. The IHC procedure generally includes several steps: sample preparation, tissue processing, antigen retrieval, antibody staining, staining evaluation, and result analysis. Tissue processing involves preserving tissues from a water-soluble state into a fixed state, thereby maintaining the immunoreactivity of intracellular proteins. Antigen retrieval and antibody staining detect the presence of antigens through localized antigen-antibody reactions, binding of specific antibodies, and subsequent staining. During staining evaluation, samples are examined under conventional or fluorescence microscopy to allow detailed analysis of staining results, enabling better identification of changes in the expression patterns of specific proteins under normal or pathological conditions. Finally, through result analysis, researchers can investigate the simultaneous expression of multiple proteins within cells, determine protein localization, and explore potential interactions among proteins.