<select Language> bio:エタノール沈殿|Japanese bio:en:Ethanol precipitation|English </select>

Ethanol precipitation

Precipitation of polynucleotide such as DNA and RNA with ethanol aqueous solution to purify the polynucleotide.


  1. Add 1/10 volume of 3M AcONa.
  2. Add 2x volume of cold 100% EtOH.
  3. Incubate for 20 min at r.t.
  4. Centrifuge at 4 ºC, 15000rpm for 10 - 15 min.
  5. Remove EtOH by pippetting or decantation.
  6. Add cold 70% EtOH aq. and mix.
  7. Centrifuge for 5 - 10 min.
  8. If necessary, dry by using centrifuging evaporator.


  • To prepare dried DNA.
  • To remove excess salt from the solution.
  • To purify DNA from the solution after Ph/Chl protein precipitation.

70% EtOH aq.

-precipitatessolutes (removable)
nucleicacidsDNA, RNAdNTP, NTP
salts-salts in the solution
solvents-organic solvents
(phenol and chloroform)

100% EtOH

-precipitatessolutes (removable)
nucleicacidsDNA, RNA
dNTP, NTP(high conc.)
saltssalts in the solution
(high conc.)
solvents-organic solvents
(phenol and chloroform)