Ruthenium red

The inorganic dye ammoniated ruthenium oxychloride, also known as ruthenium red, is used in histology to stain aldehyde fixed mucopolysaccharides.

Ammoniated ruthenium oxychloride

Identifiers
CAS Number	11103-72-3 N
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL2068405 N
ChemSpider	7827798 Y
ECHA InfoCard	100.228.922
PubChem CID	9548875
UNII	KU6M163B0R N
CompTox Dashboard (EPA)	DTXSID80108179
InChI InChI=1S/6ClH.14H3N.2H2O.3Ru/h6*1H;14*1H3;2*1H2;;;/q;;;;;;;;;;;;;;;;;;;;;;+4;2*+5/p-6 Y Key: CIBHIQPXTCXIRW-UHFFFAOYSA-H Y InChI=1/6ClH.14H3N.2H2O.3Ru/h6*1H;14*1H3;2*1H2;;;/q;;;;;;;;;;;;;;;;;;;;;;+4;2*+5/p-6 Key: CIBHIQPXTCXIRW-CYFPFDDLAK
SMILES [Ru+5].[Ru+5].[Ru+4].[Cl-].[Cl-].[Cl-].[Cl-].[Cl-].[Cl-].O.O.N.N.N.N.N.N.N.N.N.N.N.N.N.N
Properties
Chemical formula	Cl6H42N14O2Ru3
Molar mass	786.34 g·mol−1
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

Ruthenium red (RR) has also been used as a pharmacological tool to study specific cellular mechanisms. Selectivity is a significant issue in such studies as RR is known to interact with many proteins.^[1] These include mammalian ion channels (CatSper1, TASK, RyR1, RyR2, RyR3, TRPM6, TRPM8, TRPV1, TRPV2, TRPV3, TRPV4, TRPV5, TRPV6, TRPA1, mCa1, mCa2, CALHM1^[2][3]) TRPP3,^[4] a plant ion channel, Ca²⁺-ATPase, mitochondrial Ca²⁺ uniporter,^[5] tubulin, myosin light-chain phosphatase, and Ca²⁺ binding proteins such as calmodulin. Ruthenium red displays nanomolar potency against several of its binding partners (e.g. TRPV4, ryanodine receptors,...). For example, it is a potent inhibitor of intracellular calcium release by ryanodine receptors (Kd ~20 nM).^[6] As a TRPA1 blocker, it assists in reducing the airway inflammation caused by pepper spray.

RR has been used on plant material since 1890 for staining pectins, mucilages, and gums. RR is a stereoselective stain for pectic acid, insofar as the staining site occurs between each monomer unit and the next adjacent neighbor.^[7]