2% CTAB extraction buffer (plant DNA) recipe
Extracts DNA from polysaccharide-rich plant and fungal tissue: 2% CTAB, 100 mM Tris pH 8.0, 20 mM EDTA, 1.4 M NaCl, 0.2% β-ME.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| CTAB (cetyltrimethylammonium bromide) | 2 g | 2% |
| 1 M Tris-HCl (pH 8.0) | 10 mL | 100 mM |
| 0.5 M EDTA (pH 8.0) | 4 mL | 20 mM |
| NaCl | 8.18 g | 1.4 M |
| β-mercaptoethanol (add fresh) | 200 µL | 0.2% |
| Water (distilled) | to final volume |
Steps
- Dissolve Tris, EDTA and NaCl, add CTAB and stir at 60 °C until dissolved.
- Bring to volume and store at room temperature.
- Just before use add β-ME, warm to 65 °C and add to ground tissue.
Good to know
- For polyphenol-rich plants add 1–2% PVP to keep DNA from browning.
- Follow with chloroform:isoamyl alcohol (24:1) extraction and isopropanol precipitation.
⚠ Safety CTAB powder is irritant and β-ME is toxic — use a fume hood.
FAQ
The CTAB set solid in the cold.
Normal — it precipitates below ~15 °C; warm it to redissolve.
This is a widely used standard composition. Amounts depend on the hydrate form and purity of your reagents — check the formula weight (FW) on the bottle and follow your institution's safety rules and the manufacturers' instructions.