What are the applications of 3,3'-Diaminobenzidine (DAB)?

In immunohistochemistry, DAB serves as a substrate for a peroxidase enzyme linked to either a primary or secondary antibody. Histochemical staining methods using DAB include staining for peroxisomes, utilizing the presence of catalase in these organelles, as well as staining for mitochondrial cytochrome c oxidase (COX) activity. Tissues stained with DAB are frequently utilized in subsequent molecular analyses like quantitative PCR (qPCR). DAB also has applications in in-situ hybridization (ISH). In ISH, DAB is used as a chromogen to detect the presence of specific nucleic acid sequences within tissues or cells. DAB offers a wide spectrum of color intensity, is very stable and is not soluble in water or alcohol. It is also the most frequently used chromogen for IHC.