84120

Safranin O

for microscopy (Bact., Bot., Hist.), indicator (pH 0.3-1.0)

• Synonym(s): Basic Red 2, Cotton Red, Gossypimine, Safranin T, Safranin Y or A
• Empirical Formula (Hill Notation): C₂₀H₁₉ClN₄
• CAS Number: 477-73-6
• Molecular Weight: 350.84
• Colour Index Number: 50240
• Beilstein: 3924099
• EC Number: 207-518-8
• MDL number: MFCD00011759
• UNSPSC Code: 12171500
• PubChem Substance ID: 329769290
• NACRES: NA.47

Properties

• grade: for microscopy (Bact., Bot., Hist.); indicator (pH 0.3-1.0)
• form: powder or crystals
• technique(s): titration: suitable
• pH: 10 (20 °C, 10 g/L)
• solubility: methanol: 0.01 g/10 mL, red
• εmax: ≥1000 at 525-535 nm in 50% ethanol
• application(s): diagnostic assay manufacturing; hematology; histology; microbiology
• storage temp.: room temp
• SMILES string: [Cl-].Cc1cc2nc3cc(C)c(N)cc3[n+](-c4ccccc4)c2cc1N
• InChI: 1S/C20H18N4.ClH/c1-12-8-17-19(10-15(12)21)24(14-6-4-3-5-7-14)20-11-16(22)13(2)9-18(20)23-17;/h3-11H,1-2H3,(H3,21,22);1H
• InChI key: OARRHUQTFTUEOS-UHFFFAOYSA-N

Description

General description

Safranin O, also known as Basic Red 2, is a basic, cationic, and metachromatic azine dye used as a biological stain. The characteristic azine chromophore contains the phenazine, a planar, tricyclic dibenzopyrazine, which consists of two non-planar benzene rings linked by two nitrogen atoms. A delocalized positive charge, an alternation of aromatic and quinonoid structures, and diazotizable amine groups constitute the chromophoric system. c-Methylation makes this dye of moderate overall size. The trimethyl cationic form of safranine is lipophilic, whereas the dimethyl forms are weakly hydrophilic. The dye is commercially available as a chloride.

Application

• Safranin O is widely employed as a microbiological stain, especially as a counterstain in Gram staining to distinguish Gram-positive from Gram-negative micro-organisms, and for staining bacterial spores.
• It is used to demonstrate glycosaminoglycans in human and animal histological specimens and nuclei.
• It is a component of Benda′s polychrome stain.
• It is a component of various polychromes and lignin stains for botanical staining applications.
• It has also been applied for the demonstration of mast cells in cytospin preparations and staining surgical frozen sections.

Safety Information

• Pictograms: GHS05
• Signal Word: Danger
• Hazard Statements: H318
• Precautionary Statements: P280 - P305 + P351 + P338
• Hazard Classifications: Eye Dam. 1
• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 3
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves