Hi!

Usually, just adding cold (-20°C) isopropanol in a large enough ratio (> 3:1 volumes) should already do the trick. If you want to be on the safe side: Add 3M sodium acetate solution (pH 4.8) to a final concentration of 0.3M beforehand. If necessary, wash 1-2 times with 70% ethanol.

Thanks, the latter is what I had in mind but was not sure since I have never attempted to do this before.