- 1 volume of isopropanol or 2.5 volumes of 100% ethanol
- 0.1 volume 5M NaCl (or NaAc to 0.3M)
- one hour at -80oC or O/N at -20oC
- warm to 0oC (on ice; else viscosity impairs spin)
- centrifuge at full speed for 15 minutes
- wash pellet in 70% ethanol (this removes salt more efficiently than isopropanol)
- re-suspend in 10mM Tris, 1mM EDTA, pH 7.5 or in water - may need one hour at 37oC
Remember that isopropanol is a little more efficient (needs less coolth/time to precipitate) but that it precipitates more salt.