RNA freezing

Andrew Cockburn afc at gnv.ifas.ufl.edu
Mon Sep 12 13:55:26 EST 1994

In article <desrocn.779215499 at alize.ERE.UMontreal.CA>, desrocn at ERE.UMontreal.CA (Desrochers Normand) writes:
> 	Is it really necessary to keep RNA frozen at -70 celsius or is it 
> sufficient to keep it at -20 ?  I use to think that nothing could happen 
> in a frozen solution... Could I be wrong ?
>       ********************* DESROCHERS, Normand **********************
>       **************** desrocn at alize.ere.umontreal.ca ****************
>       ************** dep. Microbiologie et Immunologie ***************
>       ******* Universite de Montreal (514) 343-6111 poste:1432 *******

Fozen at -20 C is *not* the same as frozen at -70 C.  At around -55 C all
available water molecules crystalize; above this temperature water can
still exist in liquid phase if it is suitably stabilized.  Proteins
(RNase, for example) can keep water in liquid phase around them, which means
that your RNA is in trouble.

That is why Forma, SoLow, and Revco can get away with charging us so much
for their -70 C freezers- they are important.

Andrew Cockburn

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