Immunohistochemistry techniques utilize an antibody to probe and visualize cellular antigens in situ, by chromogenic or fluorescent methods. The immunohistochemist has a number of standard tools to optimize the detection of a particulate analyte. The direct method uses a labeled reagent, such as a fluorescent tag or an enzyme labeled antibody, which can be visualized without further antibody interaction. Indirect methods increase the number of assay steps, but enable the user to amplify their assay for improved sensitivity. For greatest sensitivity, a biotin-streptavidin system should be used. Another related technique, the ELISpot (Enzyme Linked ImmunoSpot) assay also provides a means of detecting antigens or antibodies in single cells on a solid support.  All of the techniques mentioned above rely on a labeled antibody or conjugate as the signaling molecule to detect the protein initially bound to the solid phase. The enzyme labeled reagents are detected with the appropriate chromogenic or chemiluminescent substrate, which is converted into a colored or luminescent product, respectively. The intensity of signal produced is proportional to the amount of measured antigen bound to the surface. 

KPL offers a comprehensive line of kits and reagents for Immunohistochemistry (IHC) that includes:

• HistoMark Immunochemical Staining Systems
• Biotin-Streptavidin Kits
• Counterstains
• IHC support reagents, including serum block.

HistoMark kits and reagents provide rapid, precise localization of antigens in cells and tissues and are optimized for maximum sensitivity and convenience. A variety of colorimetric systems are available for horseradish peroxidase, alkaline phosphatase and beta-galactosidase enzymes that facilitate multiple staining applications.