What is the Difference Between Immunohistochemistry and Immunocytochemistry

The main difference between immunohistochemistry and immunocytochemistry is that immunohistochemistry helps to detect proteins in fixed tissues, whereas immunocytochemistry helps to detect proteins in isolated cells.

Immunohistochemistry and immunocytochemistry are methods of detecting and visualizing proteins. Generally, both methods are important in analyzing protein localization.

Key Areas Covered

1. What is Immunohistochemistry
     – Definition, Features, Importance
2. What is Immunocytochemistry
     – Definition, Features, Importance
3. Similarities Between Immunohistochemistry and Immunocytochemistry
     – Outline of Common Features
4. Difference Between Immunohistochemistry and Immunocytochemistry
     – Comparison of Key Differences

Key Terms

Immunocytochemistry, ImmunohistochemistryImmunohistochemistry vs Immunocytochemistry - Comparison summary

What is Immunohistochemistry

Immunohistochemistry (IHC) is an important application of antibodies to determine the distribution of a particular antigen in health and disease. Therefore, it is important in the detection of specific tumor antigens and cancer. Most importantly, immunohistochemistry is important in the detection of benign and malignant tumors using specific tumor markers. Generally, the technique can identify the cell types and the origin of metastasis.

Compare Immunohistochemistry and Immunocytochemistry - What's the difference?

Figure 1: Immunohistochemistry

Furthermore, immunohistochemistry uses monoclonal or polyclonal antibodies to detect the specific antigens in the tissues. Primary and secondary antibodies are the two types of antibodies in immunohistochemistry assay. Generally, primary antibodies bind with the specific antigen in the tissue sample, while secondary antibodies bind to the primary antibodies. The linker molecules in the secondary antibodies, such as biotin, help in the detection of the binding of the secondary antibodies.

What is Immunocytochemistry

Immunocytochemistry (ICC) is a common technique of immunology important for the visualization and localization of specific proteins or antigens in cells. Therefore, it uses isolated cells in the detection of proteins. Here, the targeted protein or antigen specifically binds with the primary antibody, which allows the visualization of proteins. The primary antibody binds with a secondary antibody containing a conjugated fluorophore. This allows the detection of the primary antibody under the fluorescence microscope.

Immunohistochemistry vs Immunocytochemistry

Figure 2: Immunocytochemistry

Moreover, immunocytochemistry differs from immunohistochemistry, using intact cells for the detection of proteins. Only the extracellular matrix of the cells is removed. Therefore, it uses cells from isolated blocks of solid tissues, cells depositing from suspensions, cells grown within cultures, cells from smears, etc. However, immunohistochemistry uses biological tissues surrounded by tissue architecture with other components of the tissue apart from cells, normally the intact tissue.

Similarities Between Immunohistochemistry and Immunocytochemistry

  • Immunohistochemistry and immunocytochemistry are two methods to analyze protein localization.
  • Both use antibodies to detect proteins and chromogenic methods to visualize proteins.
  • They are important in the detection and visualization of proteins.

Difference Between Immunohistochemistry and Immunocytochemistry

Definition

Immunohistochemistry refers to a laboratory method that uses antibodies to check for certain antigens (markers) in a sample of tissue, while immunocytochemistry refers to the range of microscopical techniques used in the study of the immune system.

Significance

Immunohistochemistry is important to detect proteins in fixed tissues, while immunocytochemistry is important to detect proteins in isolated cells. 

Cell Fixation

In immunohistochemistry, tissues are formalin-fixed and embedded in paraffin; in immunocytochemistry, cells are prepared with methanol or other fixatives.

Conclusion

In brief, immunohistochemistry and immunocytochemistry are two methods that use antibodies to detect and visualization of proteins in samples. Immunohistochemistry uses fixed tissues to detect proteins. Therefore, these tissues are formalin-fixed and embedded in paraffin. In comparison, immunocytochemistry uses isolated cells to detect proteins. It uses cells prepared with methanol or other fixative. After that, both methods use chromogenic methods to detect proteins. Therefore, the main difference between immunohistochemistry and immunocytochemistry is the type of fixation of the material for the detection of proteins.

References:
  1. Duraiyan J, Govindarajan R, Kaliyappan K, Palanisamy M. Applications of immunohistochemistry. J Pharm Bioallied Sci. 2012 Aug;4(Suppl 2):S307-9. doi: 10.4103/0975-7406.100281. PMID: 23066277; PMCID: PMC3467869.
  2. Burry RW. Controls for immunocytochemistry: an update. J Histochem Cytochem. 2011 Jan;59(1):6-12. doi: 10.1369/jhc.2010.956920. PMID: 20852036; PMCID: PMC3201116.
Image Courtesy:
  1. Main staining patterns on immunohistochemistry.” By Mikael Häggström – Own work (CC0) via Commons Wikimedia
  2. 38F3-ChkNFH-DAPI-Shsy5y” By GerryShaw – Own Work (CC BY-SA 4.0) via Commons Wikimedia

About the Author: Lakna

Lakna, a graduate in Molecular Biology and Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things. She has a keen interest in writing articles regarding science.

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