CAS No. 1239-45-8

Batch: Purity:99.05
Ethidium bromide Chemical Structure
Chemical Structure
Check the Ethidium bromide product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Chemical Information

IUPAC Name 5-ethyl-6-phenylphenanthridin-5-ium-3,8-diamine bromide
CAS Number 1239-45-8
Molecular Formula

C21H20N3.Br

Molecular Weight (MW) 394.31
SMILES CC[N+]1=C2C=C(C=CC2=C3C=CC(=CC3=C1C4=CC=CC=C4)N)N.[Br-]
InChIKey ZMMJGEGLRURXTF-UHFFFAOYSA-N

Ordering Information

Biological Activity

Ethidium bromide is a classical nucleic acid intercalating agent and fluorescent stain. It non-covalently inserts between adjacent nitrogenous base pairs of double-stranded DNA and RNA, causing structural distortion of the double helix. This intercalation blocks nucleic acid synthesis and replication while dramatically enhancing the compound's fluorescence quantum yield upon binding, making it a widely utilized tool for nucleic acid detection and visualization.

How to Prepare Stock Solution?

Concentration Volume Mass
1 mg 5 mg 10 mg
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Solubility

Batch:
All in vitro solubility values are batch-tested experimental data (non-literature values).
Solvent Solubility & Note
DMSO 78 mg/mL (197.81 mM)
(Moisture-contaminated DMSO may reduce solubility. Use fresh, anhydrous DMSO. The recommended stock concentration is 10 mM in DMSO.)
Water 7 mg/mL
Ethanol 1 mg/mL
FAQ
Q: Why does a DMSO stock precipitate in media/saline?
A: It is caused by unheated aqueous media (supersaturation), local solvent shock, or incorrect mixing sequence.
How to fix it?
  • Preheat media/saline to 37°C.
  • Mix rapidly (pipette/vortex) upon addition.
  • For complex mixes, always add the aqueous phase last.
  • Re-dissolve minor precipitates with a 37°C water bath and sonication (≤30 min).
Note: Technical data last updated: Sep 1, 2026.