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.

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.