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Fluorescent dyes and stains

Ethidium

Also known as homidium, Ethidium cation, Babidium

CAS 3546-21-2Formula C21H20N3+Molar mass 314.41 g/mol
16 suppliers listed
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Ethidium chemical structure, C21H20N3+, CAS 3546-21-2
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
3546-21-2
Formula
C21H20N3+
Molar mass
314.41 g/mol
HS code
293399
Category
Fluorescent dyes and stains

What is Ethidium?

Plain description, key identifiers and synonyms

Ethidium is the fluorescent compound widely used in experimental cell biology and biochemistry to reveal double-stranded DNA and RNA. It has a role as an intercalator and a fluorochrome. It derives from a hydride of a phenanthridine.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
5-ethyl-6-phenylphenanthridin-5-ium-3,8-diamine
CAS number
3546-21-2 CAS number cross-checked
Molecular formula
C21H20N3+
UNII
EN464416SI
InChIKey
QTANTQQOYSUMLC-UHFFFAOYSA-O
InChI
InChI=1S/C21H19N3/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/p+1
SMILES (canonical and isomeric)
CC[N+]1=C2C=C(C=CC2=C3C=CC(=CC3=C1C4=CC=CC=C4)N)N

Synonyms

  • homidium
  • Ethidium cation
  • Babidium
  • Homidium cation
  • Homidium ion
  • 3,8-Diamino-5-ethyl-6-phenylphenanthridinium
  • Phenanthridinium, 3,8-diamino-5-ethyl-6-phenyl-
  • 2,7-diamino-9-phenyl-10-ethylphenanthridinium
  • 3,8-diamino-5-ethyl-6-phenylphenanthridin-5-ium
  • 2,7-Diamino-10-ethyl-9-phenylphenanthridinium
  • Novidium
  • 5-ethyl-6-phenylphenanthridin-5-ium-3,8-diamine
  • 5-ethyl-6-phenyl-phenanthridin-5-ium-3,8-diamine
  • Piperine & Ethidium bromide
  • Reserpine & Ethidium bromide
  • 5-22-11-00352 (Beilstein Handbook Reference)
  • DivK1c_000940

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

No measured properties are recorded for this substance yet. Ask suppliers for a technical data sheet.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
314.41 g/molcalc.
Exact mass
314.1652 Dacalc.
LogP (octanol/water)
4.13calc.
Topological polar surface area
55.92 Ųcalc.
Hydrogen bond donors
2calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
2calc.
Heavy atoms
24calc.
Rings
4calc.
Aromatic rings
4calc.
Fraction sp3 carbons
0.1calc.
Formal charge
1calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, c1ccc(-c2nc3ccccc3c3ccccc23)cc1

c1ccc(-c2nc3ccccc3c3ccccc23)cc1

4 rings, 20 atoms, the Phenanthridine, 6-phenyl- ring system.

122 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

No GHS hazard classification is recorded for this substance yet. That does not mean it is harmless.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Ethidium suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 16 suppliers
16 of 16 offers
  • AgroIntelBioScan.com
    Singapore, SingaporeUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • AHH Chemical co.,ltd
    China, ChangzhouUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • AiFChem
    United States, SomervilleUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • Alfa Chemistry
    United States, HolbrookUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • Alinda Chemical Trade Company Ltd
    Hong Kong, Hong KongUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • Ambinter
    France, OrleansUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • Biorbyt Ltd.
    United Kingdom, CambridgeUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • Biosynth
    United Kingdom, ComptonUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • BLD Pharm
    China, ShanghaiUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
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  • EvitaChem
    China, BeijingUnclaimed profile
    EthidiumGrade, purity and minimum order on request
    Price on request
    View

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

16 suppliers in 7 countries

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Ethidium price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

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Uses and applications

What the substance is used for, by industry and function

Pharmacological actions

  • Enzyme Inhibitors
  • Fluorescent Dyes
  • Indicators and Reagents
  • Nicotinic Antagonists
  • Trypanocidal Agents

Roles

  • aetiopathogenetic role
  • dye
  • fluorescent dye
  • fluorochrome
  • genotoxin
  • intercalator
  • mutagen

Regulatory status

Inventories, regulations and trade controls that list this substance

No regulatory list memberships are recorded for this substance yet. Always check the rules of the importing and exporting country before trade.

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Ethidium is traded under.

HS 2933.99Indicative HS code

Heterocyclic compounds with nitrogen hetero-atom(s) only, other

World exports in 2024
$12.1B
−31.0% vs 2023, imports $28.8B
2019 to 2024
Top exporters
  1. China30.5%
  2. India * partner reported16.3%
  3. Ireland9.0%
Top importers
  1. Slovenia31.7%
  2. Italy24.2%
  3. United States5.0%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Ethidium is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Ethidium, based on the data on this page

What is Ethidium?

Ethidium is the fluorescent compound widely used in experimental cell biology and biochemistry to reveal double-stranded DNA and RNA. It has a role as an intercalator and a fluorochrome. It derives from a hydride of a phenanthridine.

What is the CAS number of Ethidium?

The CAS registry number of Ethidium is 3546-21-2.

What is the molecular formula and weight of Ethidium?

The molecular formula of Ethidium is C21H20N3+ and its molar mass is 314.41 g/mol.

What is Ethidium used for?

Known uses and roles of Ethidium include fluorescent probes in research and laboratory, biochemical and pharmacological tools in research and laboratory, aetiopathogenetic role, dye, fluorescent dye and 9 more.

Is Ethidium hazardous?

No GHS hazard classification for Ethidium is recorded on CompoundList yet. That does not prove it is safe. Always read the supplier safety data sheet.

What is the HS code of Ethidium?

Ethidium is usually classified under HS code 293399 (Heterocyclic compounds with nitrogen hetero-atom(s) only, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Ethidium?

CompoundList lists 16 suppliers of Ethidium in China, United States, United Kingdom, France and 3 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

What is the price of Ethidium?

Suppliers quote Ethidium on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Ethidium

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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