To get a good DNA or RNA pellet through precipitation, you first need to choose between using ethanol and isopropanol. A post from Bitesize Bio a little while ago explains the choice — and when one approach is better than the other. However, blogger Suzanne Kennedy adds: “I use ethanol over isopropanol for most cases, but will use isopropanol if I need to make everything fit in one tube.” A follow-up post from John Mackay adds a tip on removing ethanol so you can be sure you got as much out as possible. After removing the 70 percent ethanol, he says to recap the tube and centrifuge it again. “Remove this liquid with a pipette and 200ul tip – you can get right alongside the pellet if visible. Leave the tube open as you move to the next sample,” he writes.