As a naturally occurring compound, Haematoxylin is extracted from the heartwood of the logwood tree which is widely used as the basis of a dye in the laboratory all over the world. It was first discovered by Spanish explorers to the Yucatan in 1502 and the hematoxylin-based protocols can date back over one hundred years.
Haematoxylin is commonly used in the staining procedures of immunohistochemical (IHC), in which it serves as a counterstain to promote the visualisation and localization of the colored end product of the IHC procedure. It is also widely applied to stain nuclei in microscope slide preparations in histology together with eosin, forming the haematoxylin and eosin stain, which is a permanent stain instead of temporary stains. Besides, it can be applied in the manufacture of ink because of its property.
