 In a last step, the nucleic acids are recovered from the aqueous phase by precipitation with 2-propanol.The 2-propanol is then washed with ethanol and the pellet briefly air-dried and dissolved in TE buffer or RNAse free water.Guanidinium thiocyanate denatures proteins, including RNases, and separates rRNA from ribosomal proteins, while phenol, isopropanol and water are solvents with poor solubility.