Toluidine blue

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Structural formula
Structural formula of toluidine blue
General
Non-proprietary name Tolonium chloride
other names
  • 7-Amino- N , N , 8-trimethyl-3 H -phenothiazine-3-iminium chloride ( IUPAC )
  • 3-Amino-7- (dimethylamino) -2-methylphenothiazine-5-ium chloride
  • N ', N ', 2-trimethylphenothiazine-3,7-diamine chloride
  • CI Basic Blue 17
  • CI 52040
  • Toluidine blue O
Molecular formula C 15 H 16 ClN 3 S
Brief description

black solid with a faint odor

External identifiers / databases
CAS number 92-31-9
EC number 202-146-2
ECHA InfoCard 100,001,952
PubChem 7083
ChemSpider 6816
Wikidata Q80868
properties
Molar mass 305.83 g · mol -1
density

410 kg / m³ (bulk density)

solubility

soluble in water: 30 g · l −1 at 25 ° C

safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
Toxicological data

215 mg kg −1 ( LD 50 ,  rat ,  ip )

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Toluidine blue , also known as tolonium chloride , is a blue cationic dye that is used for histological and intravital staining. In addition, toluidine blue is an antidote for poisoning with methaemoglobin formers .

histology

Microscopic section of a snail's eye after toluidine blue staining. VK anterior chamber, L lens, R retina, SN optic nerve. Epoxy embedding

The staining with toluidine blue is also suitable for specimens that are embedded in epoxy resin . In contrast to many other dyes, toluidine blue is able to penetrate the dense epoxy resin and dye the enclosed tissue in different shades of blue. The different shades of blue correspond to the relative electron density of the examined material. The toluidine blue staining is therefore particularly used in toluidine blue staining and in the light microscopic preliminary examination of electron microscopic sections.

Intravital staining

The toluidine blue test is used to differentiate between benign and precancerous leukoplakia . The affected mucosal area is stained with toluidine blue. If the blue coloration persists even after cleaning with dilute acetic acid, this can be an indication of impaired keratinization of the mucous membrane. The disadvantage of this method is its low specificity .

Furthermore, the toluidine blue coloration is used in forensic medical examinations for the evaluation or detection of vaginal injuries after violent penetration ( rape ). It is part of the so-called "Sexual Assault Care Kit".

Use as an antidote

In methaemoglobinemia , toluidine blue can be administered as an antidote to accelerate the physiological reduction in methaemoglobin .

literature

  • Peter Fritsch: Dermatology. 3rd revised and corrected edition. Springer, Berlin a. a. 1990, ISBN 3-540-52686-2 , p. 465.
  • KJ Freund: Toxicology. In: C.-J. Estler: Pharmacology and Toxicology. Textbook for medical professionals, veterinarians, pharmacists and natural scientists. 4th completely revised edition. Schattauer, Stuttgart a. a. 1995, ISBN 3-7945-1645-1 , p. 666.
  • Alan Stevens, James Lowe: Human Histology. 2nd Edition. Chapman & Hall, London a. a. 1997, ISBN 3-8261-0113-8 , p. 7.

Individual evidence

  1. ↑ a b c d e data sheet toluidine blue (PDF) from Merck , accessed on December 18, 2011.
  2. ↑ Entry on toluidine blue in the ChemIDplus database of the United States National Library of Medicine (NLM) .
  3. ^ Hochmeister MN, Whelan M, Borer UV, et al. : Effects of toluidine blue and destaining reagents used in sexual assault examinations on the ability to obtain DNA profiles from postcoital vaginal swabs . In: Journal of Forensic Sciences . 42, No. 2, March 1997, pp. 316-319. PMID 9068192 .