Hematoxylin

Hematoxylin

Hematoxylin (CAS# 517-28-2) is a natural dye extracted from the heartwood of the logwood tree, Haematoxylum campechianum, native to Central America. Also known as Natural Black 1, Hydroxybrasilin, Haematoxylin, or C.I. 75290, it has a chemical formula of C₁₆H₁₄O₆ and a molecular weight of 302.28 g/mol (anhydrous basis). Hematoxylin itself is nearly colorless; the actual staining agent is hematein, formed by oxidation of hematoxylin. When complexed with a metallic mordant (typically aluminum or iron salts), hematein binds strongly to acidic cellular components such as DNA, RNA, and phosphate groups in the nucleus, producing the characteristic deep blue-violet nuclear stain seen in histology slides.

This makes hematoxylin one of the most important and widely used biological stains in the world. It is the "H" in the universal H&E (Hematoxylin & Eosin) stain, the gold standard for routine histopathology, and is also a core component of the Papanicolaou (PAP) stain used in cytology screening. Hematoxylin is supplied as a fine powder, white to yellowish or light tan in color, that gradually reddens on exposure to light. It is soluble in ethanol, hot water, and slightly soluble in cold water.

Product Specifications

Applications and Benefits:

• Routine H&E staining for paraffin and frozen tissue sections
• Papanicolaou (PAP) staining for cytology screening
• Nuclear counterstaining in immunohistochemistry (IHC)
• Preparation of Harris, Mayer's, Gill's, Weigert's, and Heidenhain's hematoxylin formulations
• Progressive and regressive staining protocols
• Research and educational histology applications
• Specialized staining for muscle, fibrin, and elastic fibers
• Excellent nuclear contrast with blue-violet staining intensity
• Strong affinity for DNA, RNA, and acidic cellular structures
• Historical use in inks, textile, and leather dyeing

Caution:

Hematoxylin may cause skin, eye, and respiratory irritation. The powder reddens and degrades on exposure to light. Always handle with appropriate PPE (gloves, safety glasses, lab coat) and work in a well-ventilated area or fume hood. Avoid contact with strong oxidizers. Store in tightly closed containers, protected from light, at room temperature. Consult the SDS before use.