RNAlater - have you used it? (Jan/26/2005 )
I was recently informed about RNAlater (Ambion product) and was wondering if anyone was using it. If you have, does it seem to improve the quality and quantity of your RNA? AND How do you fit it into your RNA extraction protocol?
YES, i have used it before. RNAlater does't improve your RNA quality or quantity. but it would help to keep your sample (tissue or cell) for a long time without any apparent RNA degradation as long as your sample is kept in RNAlater. i kept my cells in it and stored at 4 centigrade for 3days. if you want to extract RNA, just spin down all the cells at 6000rpm (because cells will become less fragile in RNAlater) and collect your cells, discard RNAlater. then follow the traditional RNA extraction protocol. (i used RNAeasy MINI KIT from QIAGEN).
I use RNAlater when extracting RNA from mouse tissues. As littlecell said above, it does not improve quantity or quality of the RNA but it is really useful if you are working with difficult tissues such as pancreas which has got a lot of RNases. In fact, for me it's the only way to extract good quality RNA from pancreas. I just dissect the tissue, put it in RNAlater and keep it overnight at 4ºC. Then you can take it out from the RNAlater and directly into Trizol, or wathever other method you are using.
Thanks a lot!!
I too found RNA later to be good for working with liver, muscle, brain, fat, and kidney. Storage at 4 degrees for up to two weeks was fine (I didn't try any longer than that).
However, I did notice that it seems to make the tissues tougher to homogenise (using a polytron homogeniser), this is especially a problem for muscles, which are hard enough as it is. I would recommend grinding the tissue in liquid N2 if you are going to be working with muscle.
Bob
Yes, that is true. I'm not sure which is the composition of RNAlater but it seems to have formaldehyde in it (so the RNAses would be fixed and thus inactivated). What I do when storing tissues for some time is keep them in RNAlater at 4ºC overnight and then take them out of the RNAlater and store them at -20ºC for the time being.
FYI- I just found out that there is RNAlater-ICE if your samples are already frozen. The product description states that it's a "reagent for transitioning frozen tissue to a state that can be readily processed by common homogenization methodologies to extract high quality RNA. It circumvents the need to grind frozen tissue into a powder before homogenization, and even makes it possible to further dissect tissues before homogenization without RNA loss or degradation."
I just thought this might be a product you all may be interested in if you rapidly freeze in liquid nitrogen.
It's extremely good and I'd recommend it for long-term storage of whole tissues, cells and especially plant samples - saved me a lot of work when I was doing my Ph.D!