Azure A

Azure A

Names
IUPAC name N',N'-dimethylphenothiazin-5-ium-3,7-diamine chloride
Other names asym-Dimethylthionine Chloride; Methylene Azure A
Identifiers
CAS Number	531-53-3  Y
3D model (JSmol)	Interactive image
Beilstein Reference	3922287
ChEBI	CHEBI:87637  N
ChemSpider	11218930  Y
ECHA InfoCard	100.007.738
PubChem CID	13735
UNII	M731V243EF  Y
CompTox Dashboard (EPA)	DTXSID2040157
InChI InChI=1S/C14H14N3S.ClH/c1-17(2)10-4-6-12-14(8-10)18-13-7-9(15)3-5-11(13)16-12;/h3-8H,15H2,1-2H3;1H/q+1;/p-1 Y Key: PGWTYMLATMNCCZ-UHFFFAOYSA-M Y
SMILES [Cl-].CN(C)c1cc2[s+]c3cc(N)ccc3nc2cc1
Properties
Chemical formula	C14H14ClN3S
Appearance	green to dark brown powder
Density	1.776
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

Azure A is an organic compound with the chemical formula C₁₄H₁₄ClN₃S. It is a light blue to dark blue dye. It is used as a screening test for mucopolysaccharides. It can also be used to stain lysosomes in blood smears, and is often used in Giemsa stain. It's formed via oxidation of Methylene blue. ^[1]

References

1. "Azure A - Dyes for Histology". StainsFile. Retrieved 2025-07-28.