title: Use of avidin-biotin-peroxidase complex (ABC) in immunoperoxidase techniques: a comparison between ABC and unlabeled antibody (PAP) procedures.
abstract: 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.
mesh_terms: D001360:Avidin; D001710:Biotin; D006801:Humans; D007124:Immunoenzyme Techniques; D010047:Ovalbumin / Q000031:analogs & derivatives; D010544:Peroxidases; D013194:Staining and Labeling
chemical_list: D001360:Avidin; D001710:Biotin; D010047:Ovalbumin; D010544:Peroxidases