Chemical Properties
Evans Blue is a blue crystal with a green metallic luster. It is very soluble in water, slightly soluble in ethanol, and almost insoluble in benzene, chloroform, and ether. It is soluble in acids and alkalis. It is hygroscopic, inducing moisture. It changes color when the pH is close to 10.
Uses
Evans Blue is used for estimation of blood volume and in double-labeling procedure for studying axonal branching. It acts as an inhibitor of L-glutamate and kainate receptor-mediated currents. It is also a P2X-selective purinoceptor antagonist. It is also useful in molecular biology.
Preparation
3,3′-Dimethylbenzidine double nitriding, in alkaline conditions and 4-Amino-5-hydroxynaphthalene-1,3-disulfonic acid (2 Moore) coupled.
Definition
ChEBI: Evans blue is an organic sodium salt that is the tetrasodium salt of 6,6'-{(3,3'-dimethyl[1,1'-biphenyl]-4,4'-diyl)bis[diazene-2,1-diyl]}bis(4-amino-5-hydroxynaphthalene-1,3-disulfonate). It is sometimes used as a counterstain, especially in fluorescent methods to suppress background autofluorescence. It has a role as a histological dye, a fluorochrome, a teratogenic agent and a sodium channel blocker. It contains an Evans blue(4-).
General Description
Blue crystals with a greenish-bronze luster or a black powder.
Air & Water Reactions
Azo dyes can be explosive when suspended in air at specific concentrations. Soluble in water.
Reactivity Profile
Direct Blue 53 is an azo compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides. Direct Blue 53 can react with strong reducing and oxidizing agents.
Fire Hazard
Flash point data for Direct Blue 53 are unavailable; however, Direct Blue 53 is probably combustible.
Biological Activity
Potent inhibitor of L-glutamate uptake into synaptic vesicles. Also inhibits AMPA and kainate receptor-mediated currents (IC 50 values are 220 and 150 nM respectively). P2X-selective purinoceptor antagonist.
Safety Profile
Poison by intraperitoneal route.Moderately toxic by intravenous route. An experimentalteratogen. Other experimental reproductive effects.Questionable carcinogen with experimental tumorigenicdata. Mutation data reported. When heated todecomposition it
in vitro
evans blue inhibits the kainate-mediated responses of the non-nmda receptor subunits (giurl, g1ur1,2, g1url,3, and g1ur2,3) expressed in xenopus oocytes without the response of glur3 and g1ur6 at low concentrations (ic50= 355 nm for the subunit combination glur1,2). this pocess was partially reversible without competing with kainate for the agonist binding site [1]. in whole-cell patch clamp recordings of transfected human embryonic kidney 293 cells, evans blue is a potent inhibitor of glutamate-evoked currents mediated by the kainate-type receptor giur6 as long as the ampa-type receptor glurl. interestingly, pretreating with the lectin concanavalin cells recorded relatively little eb inhibition of giur6 currents, eliminating kainate receptor desensitization. in addition to decreasing glur6-mediated peak current amplitude, eb significantly changed receptor desensitization by slowing the rate of onset by ~2-fold (1 m eb) and the rate of recovery by ~2-fold (0.1 p.m eb), and enhancing the steady state to peak current amplitude ratio by ~50-fold (1 m eb) [2].
IC 50
220 and 150 nm for glurl and giur6, respectively.
Staining Procedures
Evans Blue (3,7-Diamino-5-phenylphenazinium chloride) is used as a vital stain. It is used in a 0.05-0.25% aqueous solution for 5 minutes. Living cells remain unstained, while dead cells become blue.
Properties and Applications
dark green light blue. Soluble in water for bright blue. The strong sulfuric acid for blue-ray green, diluted for light yellow. The dye solution to join hydrochloric acid as bright blue; Add sodium hydroxide solution for the purple and red.
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Standard
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Acid Resistance
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Alkali Resistance
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Light Fastness
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Soaping
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Water
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Fading
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Stain
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Fading
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Stain
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ISO
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5
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4-5
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1-2
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2
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2
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References
[1] roseth s, fykse em, fonnum f. uptake of l-glutamate into rat brain synaptic vesicles: effect of inhibitors that bind specifically to the glutamate transporter. j neurochem. 1995 jul;65(1):96-103.
[2] price cj, raymond la. evans blue antagonizes both alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate and kainate receptors and modulates receptor desensitization. mol pharmacol. 1996 dec; 50 (6):1665-71.
