Storing RNA in formamide: The Downside?

David L. Haviland, Ph.D. dhavilan at IMM2.IMM.UTH.TMC.EDU
Wed Mar 19 16:01:16 EST 1997

At 17:25 3/19/97 GMT, Jason Eriksen wrote:
>I was recently browsing across the Paul N. Hengen's  excellent
>Molecular Biology Homepage (,
>and I found a technique used for storing RNA that seems to be greatly
>preventative towards degradation. 
>This technique seems too good to be true; extremely inhibitory to
>RNase activity and no apparent problems with its use, and it. 
>The only thing that make me a cautious about this technique  is that
>not one lab that I know uses it; they all suspend RNA in either DEPC
>or ethanol.
>Has anyone had experience with using the following RNA storage
>technique, and is there something that I should know about before I
>start resuspending my samples this way?


I have stored RNA in formamide.  The problem in the protocol for doing this
is quantitation.  I tried 1:50 and 1:100 but the background of formamide
alone is too high.  To store it as such would prevent degredation and other
than reducing the volume for loading RNA gels, it would be no problem.
However, one would have to bring it up in DEPC water, grab some for
quantitation, then reprecipitate it and bring it up in formamide.  

I thing what started this thread was a comment of diluting an RNA sample at
1:500.  That will likely work if one has enough RNA to dilute it that far.
Most of the times I have conducted a acid phenol RNA extraction, there was
not enough total RNA to do this.  So for me to do it would require
quantitation only to reprecip it all.

Hope this helps,

 David L. Haviland, Ph.D.
 Asst. Prof. Immunology 
 University of Texas - Houston, H.S.C.
 Institute of Molecular Medicine  
 2121 W. Holcombe Blvd.  
 Houston, TX  77030 
 Internet:"dhavilan at" 
 Voice: 713.500.2413  FAX: 713.500.2424
" Sometimes you're the windsheild, sometimes you're the bug."

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