Immunomicroscopy

Abstract

Immunomicroscopy is widely employed to localize in situ various components of cells and tissues in both normal and pathological situations (1-4). The method is based on the extremely sensitive interaction of a specific antibody (immunoglobulin) with its antigen. An antibody binds specifically only to a small site on the antigen, called an epitope. An epitope usually consists of one to six monosaccharides or five to eight amino acids. The epitope recognized by a specific antibody may consist of a linear primary sequence of a protein or it may be dependent on the three-dimensional conformation of the antigen. Although the antibodies most commonly used are against proteins, antibodies can be raised against any cellular component including nucleic acids, lipids, and carbohydrates. Today there is a wide variety of antibodies available commercially. The supplier of an antibody against a particular antigen can be located by searching the scientific literature, searching the world wide web either by using a search engine such as Google and Lycos or through a search engine linked to a commercial site such as Abcam's World's Antibody Gateway (www.abcam. com), by searching a site dedicated to immunohistochemisty such as ICH World (www.ichworld.com) or by searching Linscott's Directory of Immunological and Biological Reagents (www.linscottsdirectory.com). Alternatively, antibodies can be obtained from a friend or a colleague or produced in the laboratory. However, whatever the source, the antibodies used for immunocytochemistry should be of the highest purity available to avoid unwanted background and cross reactivity with other molecules. There is no universal protocol for immunostaining that will apply to all samples in every situation. The exact conditions of immunostaining will have to be empirically developed by the user. © 2008 Humana Press.