Detection of proteins in tissue using immunological techniques (immunohistochemistry) is a well established laboratory technique. Frozen, paraffin embedded or plastic embedded tissues may be used, all of which are compatible with TSA. TSA has been successfully applied to a wide variety of IHC applications, including those using enzyme systems such as PAP (peroxidase anti-peroxidase), APAP (alkaline phosphatase anti-alkaline phosphatase), and ABC (avidin-biotinylated HRP-complex) as well as immunogold detection systems. For chromogenic detection, TSA can also be used with a variety of substrates, including DAB and BCIP/NBT. In all cases, the use of TSA results in a significant increase in sensitivity or an ability to utilize a reduced concentration of valuable antibodies.