World Library  
Flag as Inappropriate
Email this Article

Hematein

Article Id: WHEBN0003234711
Reproduction Date:

Title: Hematein  
Author: World Heritage Encyclopedia
Language: English
Subject: H&E stain, Staining dyes, Miřetice
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Hematein

Hematein
Names
IUPAC name
3,4,6a,10-Tetrahydroxy-6,7-dihydroindeno[2,1-c]chromen-9-one
Other names
Haematein; Haematein
Identifiers
 Y
ChEBI  Y
ChEMBL  N
ChemSpider  N
Jmol-3D images Image
MeSH
PubChem
UNII  Y
Properties
C16H12O6
Molar mass 300.27 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 N  (: Y/N?)

Hematein (US spelling) or haematein is an oxidized derivative of haematoxylin, used in staining. Haematein must not be confused with haematin, which is a brown to black iron-containing pigment formed by decomposition of haemoglobin. In the Colour Index (but nowhere else), haematein is called haematine, a confusing word that wrongly implies that the compound is an amine.

Hematein exhibits indicator-like properties, being blue and less soluble in aqueous alkaline conditions, and red and more soluble in alcoholic acidic conditions. Dissolved haematein slowly reacts with atmospheric oxygen, yielding products that are not useful.

In acidic solutions, complexes of hematein with metals (usually aluminium or iron, but also chromium, zirconium and several others) are used as biological stains. Aluminium-haematein (haemalum) is the "routine" stain for cell nuclei in sections of human and other animal tissues. Metal-haematein stains are available also for objects other than nuclei, including myelin sheaths of nerve fibres and various cytoplasmic organelles. The color of the stained objects depends on the salt used. Aluminium-haematein complexes are usually blue, whereas ferric complexes are very dark blue or black.

Aluminium-haematein complexes (haemalum) bind to the chromatin of the nuclei of cells. Although haemalum staining methods have been in use since the 1860s, the chemical identity of the substance or substances that bind the dye-metal complex is still not known with certainty. Some histochemical investigations clearly indicate that a cationic aluminium-haematein complex is attracted to the phosphate anions of DNA. Others implicate the arginine residues of nuclear histones as the substrate of nuclear staining by haemalum.[1]

Structures that stain with aluminium-hematein (haemalum) are often said to be basophilic, but the staining mechanism is not as simple as for basic (cationic) dyes with smaller molecules. Truly basophilic structures are ones containing nucleic acids or other polyanions such as glycosaminoglycans of extracellular matrix or acidic glycoproteins in many types of mucus. As usually used, aluminium-hematein stains only nuclear chromatin and a few other materials such as keratohyalin granules and calcified deposits. Very dilute solutions of aluminium-haematein, used at pH 3.2 (higher than is usual for staining), contain a cationic dye-metal complex and will slowly stain nucleic acids.[2] Haemalum solutions used for routine staining are more concentrated and more acidic (pH 2-2.5) and are able to stain nuclei after chemical or enzymatic extraction of DNA and RNA from the tissue.[3]

References

  1. ^ Puchtler, H., Meloan, S.N., Waldrop, F.S. (1986). "Application of current chemical concepts to metal-haematein and -brazilein stains". Histochemistry 85 (5): 353–364.  
  2. ^ Bettinger, C. & Zimmermann, H.W. (1991). "New investigations on hematoxylin, hematein, and hematein-aluminium complexes. 2. Hematein-aluminium complexes and hemalum staining". Histochemistry 96 (3): 215–228.  
  3. ^ Lillie, R.D., Donaldson, P.T. & Pizzolato, P. (1976). "The effect of graded 60C nitric acid extraction and of deoxyribonuclease digestion on nuclear staining by metachrome mordant dye metal salt mixtures". Histochemistry 46 (4): 297–306.  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.