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Herman Lab

Ethanol Precipitation

1.Add sodium acetate to 0.3M

2. Add two volumes 100% ethanol
3. Mix; spin 30 minutes at 4°C (optional)

4. Remove supernatant carefully; save to be safe (at least until you quantify to ensure that you didn’t lose too much).

5. Fill tube halfway with 70% ethanol; spin 2 minutes (this is a wash).

6. Repeat wash.

7. Carefully pipet out or decant supernatant. There will be a clear pellet on the bottom. It may be difficult to see. 

8. Dry the pellet by placing the tube upside down on a rack. It shouldn’t take longer than 30 minutes – just until all residual ethanol has evaporated.

9. Dissolve pellet in appropriate amount of TE or desired buffer or water, depending on application.

*If, after quantifying DNA solution, the concentration is lower than you expected, spin down the saved supernatant from step 4 again, starting at step 3.