Immunohistochemistry-paraffin (IHC-P) of paraffin-embedded tissue sections is a technique for detecting the expression of specific proteins in tissues through antigen-antibody reactions. It is used to observe protein expression in preserved tissue sections. Paraffin sectioning is the most common and basic method for preparing tissue specimens. It preserves tissue morphology well, allows for serial sectioning, which is beneficial for various staining controls; it also allows for long-term archiving for retrospective studies. Although the paraffin sectioning process has some impact on antigen exposure within the tissue, antigen retrieval is possible, making it the preferred tissue specimen preparation method in immunohistochemistry.
Immunocytochemistry (ICC)
Immunocytochemistry (ICC), also known as Immunohistochemistry (IHC). is a method for detecting and localizing protein expression in tissue sections. Immune complexes are visualized by reacting tissue sections with specific antibodies. Target proteins can be visualized and localized under a microscope using stains or fluorescent labels. IHC is widely used in cancer diagnosis, pathology research, and biomedical research, providing key information for understanding the expression and localization of proteins in tissues.
Related Experimental Schemes
Immunohistochemistry-Frozen (IHC-F) of frozen samples is a widely used technique for detecting and locating specific antigens within preserved cellular structures. Unlike formalin-fixed paraffin-embedded samples, frozen tissues retain their natural antigenicity, making them particularly suitable for targets sensitive to chemical fixation, and the procedure is relatively simple and rapid.
Multiplex immunohistochemistry (mIHC), also known as tyramide dignal amplification (TSA), is an enzymatic detection method that uses horseradish peroxidase (HRP) to perform high-density in-situ labeling of target proteins or nucleic acids.
Multiplex immunofluorescence IHC detects multiple protein biomarkers in one tissue section by sequential antibody staining, HRP-mediated tyramide fluorophore deposition, heat-mediated antibody stripping, nuclear counterstaining, multispectral imaging, spectral unmixing, and digital cell phenotyping; TSA deposits fluorophore near the antigen so the fluorescence signal remains after primary and secondary antibodies are removed, enabling repeated staining cycles, including with antibodies from the same host species. Classic FFPE tumor immune-profiling applications use panels such as CD3, CD8, CD68/CD163, FOXP3, PD-1, PD-L1, pancytokeratin, Ki67, and DAPI to identify tumor cells, immune-cell subsets, checkpoint-marker expression, co-expression phenotypes, cell density, and spatial relationships in the tumor microenvironment.
