A colorless crystalline compound extracted from logwood (Haematoxylon campechianum) and used in various histological stains. When oxidized, hematoxylin is converted to hematein, which imparts a blue color to certain parts of cells, especially cell nuclei. Heidenhain’s iron hematoxylin is used to stain sections that are to be photographed, since it gives great clarity’ at high magnification.
A dye widely used in histology, often in conjunction with eosin. It has an affinity for cell nuclei, which stain a deep blue.