Immunohistochemistry is a method for detecting specific antigens in tissues or cells based on an antigen-antibody reaction. The initial technique was developed in 1940s using immunofluorescence on frozen tissue. Enzyme-based IHC was introduced in 1970s. A series of advancements in the technology, particularly during late 1980s and 1990s, led to the development of antigen retrieval techniques to make IHC possible on nearly all archival tissue. This, coupled with sensitive detection systems, and better antibodies has made this technique routine in surgical pathology and research.
Our laboratory offers a variety of immunohistochemical services, including the development of assay with new antibodies. We have a stepwise approach to assay development. As a first step, we identify the best primary antibody using several web-based search engines. We utilize the new generation labeled streptavidin, tyramide, and polymer-based amplification systems.
The next important aspect of IHC is selection of the positive and negative controls. Once it is selected, the initial test focuses on identification of best antigen retrieval condition.
The next step is to adjust the sensitivity of the assay and this is typically established by altering the concentration of the primary antibody and sometimes by adjusting the detection system concentration. The ideal immunohistochemical assay is the one, which can detect a reasonably wide range of protein expression.