Ethanol
Precipitation
1.Add sodium acetate to 0.3M
2. Add two volumes 100% ethano
l
3. Mix; spin 30 minutes at 4C
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.
*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.
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