Extracting precious tissue from too large of volumes of RNAlater - stored tissue in too large of volume of RNAlater, can't recover (Dec/01/2009 )

I am trying to recover very precious FACS samples (approx 8000 cells) that was stored in 2 mL of RNAlater. I am unable to pellet the tissue. I am really hoping there is a way to save the samples! Your advice is very much appreciated!

have you tried diluting the sample so that the solution is less dense?

With only about 8000 cells, you may be sedimenting the cells, but there isn't enough there to form a visible pellet. What do you want to use the cells for now?

This sounds like a job for a microcon filter (Millipore). Although these are mostly for dialysis replacement protein purification, I think there is one with a 0.2 micron cutoff, which would be just the thing for this problem. You invert and spin the filtered product out.

hi dbratt
Cells normally dont pellet effectively in RNAlater. The best way is to just add equal volume of PBS to the solution and spin it...I normally do a 9k rpm for 3 minutes...

Its better to take a maximum of 1 ml per tube during centrifugation, else you end up with some cells over the wall which would be disturbed when pipetting the solution...Just to make sure, keep the supernatent and spin once more

Hope this helps

gfischer on Dec 2 2009, 11:00 AM said: