E1385

Ethidium bromide solution

BioReagent, 500 μg/mL in H₂O

• 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: 3642536
• MDL number: MFCD00011724
• UNSPSC Code: 41105322
• PubChem Substance ID: 24894408
• NACRES: NA.31

Properties

• grade: Molecular Biology
• Quality Level: 200
• product line: BioReagent
• concentration: 500 μg/mL in H₂O
• technique(s): electrophoresis: suitable
• suitability: suitable for gel electrophoresis
• 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.

Ethidium bromide solution has been used to deplete mtDNA to investigate mitochondrial damage signals in autophagy. It has also been used to detect DNA damage using comet assay.

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

• Storage Class Code: 12 - Non Combustible Liquids
• WGK: nwg
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable