Immunohistochemistry or IHC refers to the process of localizing
proteins in cells of a tissue section exploiting the principle of
antibodies binding specifically to antigens in biological tissues.
Immunohistochemical staining is widely used in the diagnosis of abnormal
cells such as those found in cancerous tumors. Specific molecular
markers are characteristic of particular cellular events such as
proliferation or cell death (apoptosis). IHC breast cancer diagnosis is also widely used in
basic research to understand the distribution and localization of
biomarkers and differentially expressed proteins in different parts of a
biological tissue.
Typically, a tissue section is mounted on a slide and incubated with antibodies (polyclonal or monoclonal) specific to the antigen (primary reaction). The antigen-antibody signal is then amplified using a second antibody conjugated to a complex of peroxidase-antiperoxidase (PAP), avidin-biotin-peroxidase (ABC), or avidin-biotin alkaline phosphatase. In the presence of substrate and chromogen, the enzyme forms a colored deposit at the sites of antibody-antigen binding.
Typically, a tissue section is mounted on a slide and incubated with antibodies (polyclonal or monoclonal) specific to the antigen (primary reaction). The antigen-antibody signal is then amplified using a second antibody conjugated to a complex of peroxidase-antiperoxidase (PAP), avidin-biotin-peroxidase (ABC), or avidin-biotin alkaline phosphatase. In the presence of substrate and chromogen, the enzyme forms a colored deposit at the sites of antibody-antigen binding.
