A key to successful identification of cytokines by immunohistochemical staining involves careful selection of a cytokine-specific antibody. Optimal staining can be achieved using antigen affinity-purified polyclonal antibodies. The benefits of antigen affinity-purified antibodies are increased staining intensity and minimal non-specific staining.
Increased staining intensity: the polyclonal antibody pool recognizes more than one antigenic epitope giving a stronger staining signal than monoclonal antibodies in immunohistochemical procedures.
Minimal non-specific staining: because they contain little or no non-specific immunoglobulin, background staining is less than with traditional polyclonal antibodies, making them ideal for cytokine-specific immunostaining.
Figure 1. | Figure 2. | Figure 3. |
Figure 1. Typical IL-1 beta staining using biotinylated antigen affinity-purified anti-IL-1 beta polyclonal antibody (Catalog # BAF201) in cultured human blood monouclear cells stimulated with LPS for 4 hours. A strong nuclear staining in monocytes is the most prominent feature. Magnification 400x.
Figure 2. Typical IL-2 staining using goat anti-human IL-2 (Catalog # AF-202-NA) and indirect immunohistochemistry technique in a tissue section from a human tonsil, surgically removed because of severe EBV-induced mononucleosis. Magnification 250x. Figure 3. IL-4 staining using biotinylated antigen affinity-purified anti-IL-4 polyclonal antibody (Catalog # BAF204) in cultured human MNC after 24 hours of stimulation with SPE-A. IL-4 is produced in a lymphocyte in close collaboration with a SPE-A presenting monocyte. The cytokine-producing lymphocyte directs its Golgi organelle towards the antigen presenting cell to deliver the signal in a focal, directed way. Magnification 400x. |