Group 3 Project- Immunohistochemistry
- 1 What is Immunohistochemistry?
- 2 History
- 3 Methods
- 4 Comparison Between Methods
- 5 Current Research/Breakthroughs
- 6 Glossary
What is Immunohistochemistry?
Immunohistochemistry is a technique that is regularly used in cell biology, biological research and diagnostic pathology. It relies upon the interaction between antibodies and antigens, allowing for substances to be identified within tissue samples. An antigen is a substance that is recognised by the immune system as foreign, prompting the production of antibodies and causing an immune response within the body. Antigens are usually large, complex proteins or polysaccharide molecules (M. A. Hayat, 2002). An antibody is a glycoprotein that is produced by B lymphocytes in response to the presence of an antigen. Also called immunglobulins, antibodies neutralise or destroy antigens by binding to them in a specific interaction, made possible by a 'lock and key' mechanism, where specific antibodies are only able to bind with specific antigens.
Immunohistochemistry (IHC) is a technique used to locate antigens or proteins in tissue sections. It utilises this antigen-antibody interation by labelling antibodies which will react with specific antigens. This interation is visualised by a marker which may be a fluorescent dye, enzymes, radioactive elements or even colloidal gold.
1941 - Albert H. Coons first introduced immunofluorescence as initial attempts to label antibodies were unsuccessful as the labels were not visible enough under the microscope. Using specific antibodies, Coons labeled them with fluorescent dyes in order to localise substances in tissues. This allowed for the detection of antibodies, antigens and antigenic proteins in tissues. (Mao, Su-Yau, Javois, Lorette C., Kent, Ute M. "Overview of Antibody Use in Immunocytochemistry" From: Methods in Molecular Biology, Vol. 115: Immunocytochemical Methods and Protocols, Edited by L. C. Javois, Humana Press Inc, Totowa, New Jersey)
1942 - Albert H. Coons, Hugh Creech, Norman Jones and Ernst Berliner succeeded in tagging antibodies and using these antibodies to detect foreign antigens in tissues. This involved using a single antipneumococcal antibody to find pnuemococcal antigens in mice injected with large numbers of pneumococci. (http://www.nap.edu/readingroom.php?book=biomems&page=acoons.html)
The ABC method in immunohistochemistry is a type of indirect method and stands for Avidin-Biotin Complex method.
Comparison Between Methods
Fluorescent-PCR | RNA Interference | Immunohistochemistry | Cell Culture | Electron Microsopy | Confocal Microscopy | Monoclonal Antibodies | Microarray | Fluorescent Proteins | Somatic Cell Nuclear Transfer