E8751

Ethidium bromide

~95% (HPLC)

• Synonym(s): 3,8-Diamino-5-ethyl-6-phenylphenanthridinium bromide, EtBr, Homidium bromide
• Empirical Formula (Hill Notation): C₂₁H₂₀BrN₃
• CAS Number: 1239-45-8
• Molecular Weight: 394.31
• Beilstein/REAXYS Number: 3642536
• EC Number: 214-984-6
• MDL number: MFCD00011724
• UNSPSC Code: 41105322
• PubChem Substance ID: 24894683
• NACRES: NB.22

Properties

• assay: ~95% (HPLC)
• Quality Level: 200
• mp: 260-262 °C (dec.) (lit.)
• SMILES string: [Br-].CC[n+]1c(-c2ccccc2)c3cc(N)ccc3c4ccc(N)cc14
• InChI: 1S/C21H19N3.BrH/c1-2-24-20-13-16(23)9-11-18(20)17-10-8-15(22)12-19(17)21(24)14-6-4-3-5-7-14;/h3-13,23H,2,22H2,1H3;1H
• InChI key: ZMMJGEGLRURXTF-UHFFFAOYSA-N

Description

Application

Ethidium bromide (EtBr) is the most commonly used nucleic acid stain for PAGE or agarose gel electrophoresis. The fluorescence of EtBr increases 21-fold upon binding to double-stranded RNA and 25-fold on binding double-stranded DNA so that destaining the background is not necessary with a low stain concentration (10 μg/ml). Ethidium bromide has been used in a number of fluorimetric assays for nucleic acids. It has been shown to bind to single-stranded DNA (although not as strongly) and triple-stranded DNA. Because of its ability to bind to DNA, EtBr is an inhibitor of DNA polymerase.

Frameshift mutagen which intercalates double-stranded DNA and RNA.

Biochem/physiol Actions

Ethidium bromide intercalates double-stranded DNA and RNA and acts as a frameshift mutagen. It can also be used in conjunction with acridine orange to differentiate between viable, apoptotic and necrotic cells.

Reconstitution

For staining a gel after electrophoresis, dilute a sample of the stock solution to 0.5 μg/ml with water and incubate the gel for 15-30 min. Destaining is usually not needed but can be carried out in water for 15 min if decreased background is necessary. The DNA bands can then be detected on a UV light box (254 nm wavelength). Ethidium bromide can also be incorporated into the gel and running buffer at 0.5 μg/ml and visualized immediately after electrophoresis.

Safety Information

• pictograms: GHS06,GHS08
• signalword: Danger
• hcodes: H302 - H330 - H341
• pcodes: P202 - P260 - P264 - P271 - P301 + P312 - P304 + P340 + P310
• Hazard Classifications: Acute Tox. 1 Inhalation - Acute Tox. 4 Oral - Muta. 2
• Storage Class: 6.1A - Combustible, acute toxic Cat. 1 and 2 / very toxic hazardous materials
• wgk_germany: WGK 1
• flash_point_f: Not applicable
• flash_point_c: Not applicable
• ppe: Eyeshields, Faceshields, Gloves, type P3 (EN 143) respirator cartridges