Evans blue

For the Canadian rock band, see Evans Blue.

Evans blue
IUPAC name tetrasodium (6E,6'E)-6,6-[(3,3'-dimethylbiphenyl-4,4'-diyl)di(1E)hydrazin-2-yl-1-ylidene]bis(4-amino-5-oxo-5,6-dihydronaphthalene-1,3-disulfonate)
Identifiers
CAS number	314-13-6 Y
PubChem	6321418
KEGG	C19422 N
MeSH	Evans+blue
ChEMBL	CHEMBL1200712 N
Jmol-3D images	Image 1
SMILES [Na+].[Na+].[Na+].[Na+].[O-]S(=O)(=O)c6cc(c(N)c5c6C=C/C(=N\Nc1ccc(cc1C)c4ccc(N\N=C3/C=Cc2c(cc(c(N)c2C3=O)S([O-])(=O)=O)S([O-])(=O)=O)c(C)c4)C5=O)S([O-])(=O)=O
Properties
Molecular formula	C34H24N6Na4O14S4
Molar mass	960.81 g mol−1
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

T-1824 or Evans Blue, often incorrectly rendered as Evan's Blue, is an azo dye which has a very high affinity for serum albumin. Because of this, it can be useful in physiology in estimating the proportion of body water contained in blood plasma.

Evans blue dye has been used as a viability assay on the basis of its penetration into non-viable cells, although the method is subject to error because damaged cells may be capable of repair

Evans blue is also used to assess the permeability of the blood-brain barrier to macromolecules. Because serum albumin cannot cross the barrier, and virtually all Evans Blue is bound to albumin, normally the neural tissue remains unstained. When the BBB has been compromised, albumin-bound Evans blue enters the CNS. It fluoresces with excitation peaks at 470 and 540 nm and an emission peak at 680 nm.

It was named after Herbert McLean Evans, an American chemist.

External links

• el-Sayed H, Goodall S, Hainsworth R (1995). "Re-evaluation of Evans blue dye dilution method of plasma volume measurement". Clin Lab Haematol 17 (2): 189–94. PMID 8536425.