How to precipitate RNA from water - (Jul/02/2012 )

I used the trizol protocol to isolate RNA and have dissolved the RNA in too much water to accurately quantify. How do I precipitate the RNA again from the water?

How much water is that? you can add pure iso-p as much as you can, then centrifuge for 15 min at least, at high speed. Additional iso-p won't harm your RNA.

yes, you can precipitate the diluted RNA with equal volume of isopropanol, incubate at -20 for 15-30 min, pellete down by centrifuging at 10000 g/4C/10 min and dissolve the pellet in the desired volume of water

don't forget to add salt