The ABH crosslinker binds to the Fc portion of an antibody molecule, away from the antigen binding site, resulting in a
divalent immunologically active immunoglobulin derivative. Pierce - [Read ABH (p-Azidobenzoyl hydrazide) PDF]
Once tissues are fixed and permeabilized, the antibodies are added. These antibodies can be labeled directly or detected by a labeled secondary reagent. For indirect detection, any reagent that binds specifically to the primary antibody can be "tagged" and used to locate the antibody. The possible reagents include anti-immunoglobulin antibodies, protein A or G, or, if the first antibody is labeled with biotin, streptavidin. They can be labeled with enzymes or gold. - [Read Binding Antibodies to Tissue Sections Protocol]
The blot is blocked to prevent nonspecific adsorption of the immunological reagents. Antibodies are then bound to the proteins immobilized on the membrane, and the antigen is detected by labeling the antibodies with conveniently identified tags. Common labeling methods for chemiluminescent detection include anti-immunoglobulin antibody-coupled enzymes such as horseradish peroxidase, which catalyzes the oxidation of luminol and in turn releases light. - [Read Immunoblotting: Antigen Detection Using Chemiluminescence Protocol]
Provides a protocol for indirect immunofluorescence, which is a method that provides information about the locations of specific molecules and the structure of the cell. Antibody molecules for a specific target molecule are exposed to the cell or tissue being investigated. The binding of these molecules is detected by incubating the sample with a secondary antibody specific for immunoglobulin molecules and conjugated to fluorophore. - [Read Immunofluorescence Staining Protocol]