Immunohistochemistry

Immunohistochemistry ( IHC) (also called immunohistochemistry or immune or antibody staining ) is a method used in biology and medicine, can be made visible with the proteins or other structures using labeled antibodies. Are the antibodies labeled with fluorescent dyes, one speaks of immunofluorescence.

The method can be determined for example, in which the fabric of the protein is present and in which compartment of the cell it is located. For example, transcription factors, which are localized in the nucleus, are dyed only in the nucleus, membrane-bound proteins used in parts of the cell membrane, etc. is used for antibody staining fixed tissue, either from whole animals ( embryos from zebrafish, Drosophila, etc.) or from tissue sections can be made (for example microtome organs of mouse or human ). Grown cells from body fluids or aspirates and the like. , Which were applied to a glass slide by centrifugation, or on a slide are ( cell culture technique ), can also be examined by immunohistochemistry.

In medical histology IHC is typically the identification and classification of tumor cells expressing specific antigen. Thus, morphologically similar appearing tumors that are observable in their growth or Absiedelungsverhalten ( aggressiveness, metastasis ) or differ in their response to therapy, be assigned. Recently, certain cell properties can be directly related to the effectiveness of therapeutic molecules ( targeted therapy, such as Herceptin at best. Breast cancer). Researchers are working intensively on such " tumor antibodies " that are directed against cancer cells.

Principle of Immunohistochemical Staining

The detection is based on the affinity of antibodies to a particular tissue characterization ( epitope) as the antigen -antibody reaction. Ideally, there is a specific and strong binding between antibody and epitope. The antibody is coupled to a detection system, which makes its presence in the product visible. Using various detection systems small amounts of epitope can already be represented reinforced. The goal is ( only), to recognize a signal of sufficient strength at the location of the epitope.