3 M sodium acetate (pH 5.2) recipe
The salt added at 1/10 volume for ethanol precipitation of DNA and RNA, adjusted to pH 5.2 with acetic acid.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| Sodium acetate trihydrate | 40.82 g | 3 M |
| Glacial acetic acid | as needed | to pH 5.2 |
| Water (distilled) | to final volume |
Steps
- Dissolve sodium acetate in about 70% of the final volume of water (it cools as it dissolves).
- Adjust to pH 5.2 with glacial acetic acid.
- Bring to the final volume with water.
- Autoclave (121 °C, 20 min) and store at room temperature.
Good to know
- With anhydrous sodium acetate use 246.1 g/L.
- Precipitation: nucleic acid + 1/10 vol 3 M NaOAc + 2–2.5 vol cold 100% ethanol.
FAQ
Can I use it with samples containing SDS?
Yes. Some prefer NaCl (0.2 M final) when SDS is present, since SDS then stays soluble in ethanol.
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.