Ethyl Green
- C. I. 42590
- Methyl green ( mistakenly )
- 4 - ( (4 - ( dimethylamino ) phenyl) (4 - ( dimethyliminio ) -cyclohexa -2 ,5- dien-1- ylidene ) methyl) - N-ethyl- N, N- dimethylanilinium bromide chloride ( zinc chloride)
Dark brown crystalline solid
Fixed
207 ° C
70 g · L- 1 in water (20 ° C ), 1 g · l -1 ethanol, not in xylene
Risk
Template: Infobox chemical / molecular formula search available
Ethylgrün is a green triphenylmethane. Ethylgrün is often also referred to as methyl green and sold.
Methyl green and terminology
Ethylgrün (CI 42590 ) is often used as methyl green (CI 42585, CAS no. 82-94-0 ) denotes, although the latter is probably no longer in production for years. At Merck Index, and Sigma-Aldrich the related methyl green is however listed as Ethylgrün.
Methyl Green is an ethyl group instead of a methyl group on the nitrogen atom; this methyl group can dissociate easily, so that it creates crystal violet. Physically, the two dyes hardly differ, so that the use of methyl green has no effect.
Synthesis
By ethylation of crystal violet with ethyl bromide and sodium chloride in the following salting Ethylgrün is made. Therefore Ethylgrün is mostly present as a mixed bromide - chloride. However, it is unlikely that the stoichiometry of Cl -to Br exactly 1:1. Ethylgrün normally sold as a zinc salt.
Properties
Ethylgrün forms a green, water-soluble powder. It closely resembles the dye crystal violet. Ethylgrün is slightly more stable than methyl green as its methyl group can dissociate easily.
In the pH range of 0.8 to 1.8, the transition point is Ethylgrüns of yellow to blue.
Use
Ethylgrün is frequently used as a dye. It is used, inter alia, in microscopy as a core and mitochondria dye. Thereby Ethylgrün is also used as counterstain for staining histology, immunostaining and in situ hybridization for its bluish- green color.
Ethylgrün is also used to color differentiation between diphtheria and other bacteria. In conjunction with pyronin G it is also in the differentiation between DNA and RNA using ( Unna- Pappenheim stain). For this purpose, the dye mixture may contain no crystal violet, which can be isolated but with a Chloroformausschüttelung the methyl green.
Chance Ethylgrün was also used for vital staining of ciliates. In addition, it is used in the confocal microscope is used to detect double-stranded DNA in skin cells.
Finally Ethylgrün has also been used in forensics.