Immunochemistry is the identification of a certain antigen in a histological tissue section or cytological preparation by an antibody specific to that antigen. Immunohistochemistry refers specifically to histological tissue sections.
Immunohistochemistry Techniques uses antibodies, reagents and stains for the diagnosis and research of cancer. The common nuclear counterstains are: Hematoxylin, Light Green, Fast Red, Toliudine Blue and Methylene Blue. Also an Alum-Mordant base on Hematoxylin is used such as Harris's Hematoxylin (now is offered without mercury). Mayer's Hematoxylin is one of the most popular mordants used in immunohistochemistry as well as Gill's Hematoxylins that are classified as 1,2,3. Immunohistochemistry Techniques uses different methods and approaches. The specimen needs to be well fixed. One of the most popular fixatives is 10% Neutral Formalin and Zinc Formalin. A lso in immunohistochemistry, a transport solution is needed to transport the specimen. The most popular is Michel's Immunofluorescence Working. Immunohistochemical techniques detect antigens in tissue sections by means of immunological and chemical reactions. This technique is highly sensitive and specific and can detect a wide variety of antigens in multiple animal species. This chapter reviews common immunohistochemical methods used in the characterization of normal and pathologic tissue and the reagents used. Pretreatments such as blocking steps for endogenous activities and antigen retrieval are included. Standard procedures on formalin-fixed, paraffin-embedded tissues as well as method standardization for new antibodies and troubleshooting are emphasized.