19123 Sigma-Aldrich

Nile Red

BioReagent, suitable for fluorescence, ≥98.0% (HPLC)

Synonym: Nile Blue A Oxazone

  • CAS Number 7385-67-3

  • Empirical Formula (Hill Notation) C20H18N2O2

  • Molecular Weight 318.37

  •  Beilstein/REAXYS Number 279110

  •  EC Number 230-966-0

  •  MDL number MFCD00011639

  •  PubChem Substance ID 57647780



Related Categories Alphabetical, Biochemicals and Reagents, Fluorescent Indicators and Probes, Fluorescent Labels, Fluorescent Probes, Labels, Particles and Stains,
product line   BioReagent
assay   ≥98.0% (HPLC)
mp   203-205 °C (lit.)
  205-215 °C
absorption   λmax 553 nm
fluorescence   λex 530 nm; λem 635 nm in methanol
suitability   suitable for fluorescence


General description

Nile Red is an uncharged hydrophobic molecule and a benzophenoxazone dye. It functions as a fluorescent probe for intracellular lipids and hydrophobic domains of proteins. This dye is fluorescent in all organic solvents. Its fluorescence colors range from golden yellow to deep red.


Nile Red has been used for the staining of intracellular lipid droplets and neutral lipids.


Bottomless glass bottle. Contents are inside inserted fused cone.

Safety & Documentation

Safety Information

NONH for all modes of transport
WGK Germany 


Certificate of Analysis


Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.
How do I get lot-specific information or a Certificate of Analysis?
The lot specific COA document can be found by entering the lot number above under the "Documents" section.
What is Nile Red, Product 19123, soluble in?
Nile Red is soluble in methanol (1 mg/mL), ethanol (1mg/mL), water (0.2 mg/mL), and 2-methoxyethanol (1mg/mL).
How should Nile Red, Product 19123, be stored?
We recommend storing this product at 2-8 °C, which is in accordance with our MSDS.
How do I find price and availability?
There are several ways to find pricing and availability for our products.Once you log onto our website, you will find the price and availability displayed on the product detail page.You can contact any of our Customer Sales and Service offices to receive a quote. USA customers: 1-800-325-3010 orview local office numbers.
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.
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Ask a Scientist here.
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Protocols & Articles


Stimuli-Responsive Materials as Intelligent Drug Delivery Systems

Amit Singh and Mansoor M. Amiji* Department of Pharmaceutical Sciences, School of Pharmacy Northeastern University, Boston, MA 02115 USA *Email:; Tel: 617-373-3137
Keywords: Absorption, Aerobic, Angiogenesis, Apoptosis, Atomic absorption spectroscopy, Cancer, Chromatin immunoprecipitation, Clinical, Deprotonations, Diseases, Electron spin resonance, Enzyme activity, Gastrointestinal, Glycolysis, Growth factors, Infrared spectroscopy, Ligands, Magnetic resonance imaging, Materials Science, Nanomaterials, Nanotubes, Pharmaceutical, Polymerization reactions, Sol-gel, transformation

Peer-Reviewed Papers


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