A histological technique in which labelled antibodies are used to ‘stain’ the antigen of interest. Generally a double-antibody method (indirect immunofluorescence) is used in which the antigen-specific antibody (e.g. a rabbit IgG) is unlabelled and a second labelled antibody (anti-rabbit IgG) is used to locate the first. The second antibody, which can be used with a range of specific antibodies and serves to amplify the response, can be conjugated with fluorochromes (e.g. rhodamine), enzymes (e.g. peroxidase) for colorimetric reactions, gold beads (for electron microscopy), or with the biotin–avidin system.
Subjects: Medicine and Health.