Herbert Fanger

The use of avidin-biotin interaction in immunoenzymatic techniques provides a simple and sensitive method to localize antigens in formalin-fixed tissues. Among the several staining procedures available, the ABC method, which involves an application of biotin-labeled secondary antibody followed by the addition of avidin-biotin-peroxidase complex, gives a superior result when compared to the unlabeled antibody method. The availability of biotin-binding sites in the complex is created by the incubation of a relative excess of avidin with biotin-labeled peroxidase. During formation of the complex, avidin acts as a bridge between biotin-labeled peroxidase molecules; and biotin-labeled peroxidase molecules, which contains several biotin moieties, serve as a link between the avidin molecules. Consequently, a "lattice" complex containing several peroxidase molecules is likely formed. Binding of this complex to the biotin moieties associated with secondary antibody results in a high staining intensity.

Journal Article A Comparative Study of the Peroxidase-antiperoxidase Method and an Avidin-Biotin Complex Method for Studying Polypeptide Hormones with Radioimmunoassay Antibodies Get access Su-ming Hsu, Su-ming Hsu Search for other works by this author on: Oxford Academic Google Scholar Laurence Raine, Laurence Raine Search for other works by this author on: Oxford Academic Google Scholar Herbert Fanger Herbert Fanger Search for other works by this author on: Oxford Academic Google Scholar American Journal of Clinical Pathology, Volume 75, Issue 5, 1 May 1981, Pages 734–738, https://doi.org/10.1093/ajcp/75.5.734 Published: 01 May 1981 Article history Received: 21 July 1980 Accepted: 24 November 1980 Published: 01 May 1981

Avidin has an extraordinary affinity for the small-molecule vitamin biotin. Covalently coupling biotin or avidin to peroxidase molecules does not interfere with their normal biochemical functions. The avidin or biotin molecules, either peroxidase conjugated or unconjugated, can be brought to the antigen sites by means of an antiavidin antibody. Several immunohistochemical staining technics based on this principal have been described. The method utilizing an avidin-biotin-peroxidase complex was found to be more sensitive than the unlabeled antibody (PAP) method. This method involved four sequential staining procedures: (1) primary antibody (goat anti-human antigen); (2) secondary antibody (rabbit antigoat IgG) added in relative excess; (3) goat antiavidin antibody; (4) avidin-biotin-peroxidase complex. The applications of this technic are discussed.

Russell bodies have been previously regarded as aggregates of immunoglobulin. Light and electron microscopic immunoperoxidase studies show no detectable immunoglobulin determinants in the Russell body cores. Denaturation of antigens during tissue preparation appears to be an unlikely explanation, since immunoglobulins in the cytoplasm of plasma cells are clearly demonstrated. The presence of immunoglobulins on the surface of small intracellular Russell bodies may represent the immunoglobulin determinants in the surrounding rough endoplasmic reticulum. It seems likely that Russell bodies contain non-immunoglobulin molecules, by-products of immunoglobulin synthesis, or some altered form of immunoglobulins that no longer can be recognized by the anti-immunoglobulin antibody. The non-uniform dye staining pattern of Russell bodies further suggests that Russell bodies may be heterogenous in nature.