CTAB arrives on the chemical catalog like a slick-haired secret agent: cationic, powerful, and sometimes a little too good at dissolving cell membranes. Here are the key details you asked for.
Cetyl Trimethyl Ammonium Bromide (CTAB) – Specifications
Synonyms
• Hexadecyltrimethylammonium bromide
• Cetrimonium bromide
• C16 surfactant
Chemical Identity
| Property | Specification |
|---|---|
| Molecular formula | C₁₉H₄₂BrN |
| Molecular weight | ~364.45 g/mol |
| CAS Number | 57-09-0 |
| EC Number | 200-311-3 |
| IUPAC name | Hexadecyl(trimethyl)azanium bromide |
Physical & Chemical Properties
| Property | Details |
|---|---|
| Appearance | White, waxy solid or crystalline powder |
| Odor | Faint, characteristic |
| Solubility | Soluble in water (warm), alcohols |
| Critical micelle concentration (CMC) | ~0.9 mM (at 25°C) |
| Melting point | 242–247°C (decomposes) |
| pH (1% solution) | 6–8 |
| Surface charge | Cationic |
Purity Grades (common)
• ≥ 98% (standard laboratory grade)
• ≥ 99% (molecular biology grade)
• Low-endotoxin grades available for DNA extraction
Functions / Applications
• Surfactant and cationic detergent
• CTAB-based buffer for DNA/RNA extraction (precipitates polysaccharides)
• Disinfectant, emulsifier, antiseptic
• Used in nanoparticle synthesis (e.g., gold nanorods)
• Quaternary ammonium compound (quats family)
Storage & Stability
• Store tightly closed, dry, at room temperature (15–30°C)
• Hygroscopic; keep away from moisture
• Stable under normal lab conditions
• Protect from strong oxidizers
Safety Snapshot
• Corrosive to skin and eyes
• Toxic if ingested or inhaled
• Strong irritant; handle in a fume hood with PPE
• GHS classification:
∘ Skin Corr. 1B, Acute Tox. 4 (oral), Aquatic Acute 1
Regulatory
• UN number: Not usually assigned
• Hazard codes: H302, H314, H400
• Waste disposal: As hazardous chemical waste
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