Haematoxylin, hematoxylin, Natural Black 1, or C.I. 75290 is extracted from the wood of the logwood tree. When oxidised it forms haematein, a compound with rich blue-purple colour, and is used, together with a suitable mordant (most commonly Fe(III) or Al(III) salts), to stain cell nuclei prior to examination under a microscope. Structures that stain with haematoxylin are called basophilic.

Haematoxylin and eosin stain is one of the most commonly used stains in histology.

Other common stain is phosphotungstic acid haematoxylin, a mix of haematoxylin with phosphotungstic acid.

In 1970's, due to clear felling of forests in Brazil and Central America, there was a shortage of logwood and therefore of haematoxylin. Its price went to record heights, which affected the cost of diagnostic histopathology, and prompted a search for alternative nuclear stains. Before these became established as alternatives to hematoxylin, it returned to the market, albeit at a higher price and resumed its place in histopathology. There were several dyes recommended as replacements: Celestine blue B (CI 51050), Gallocyanin (CI 51030), Gallein (CI 45445) and Solochrome cyanin (CI 43820). All four used Fe(III) as the mordant.

See also

• staining (biology)
• Stainsfile
• Mayer's Hematoxylin Preparation

Hämatoxylin

Natural dyes | Staining dyes