Best way to store DNA?

John Ladasky jladasky at pmgm.Stanford.EDU
Tue Jul 14 22:25:44 EST 1998


In article <6oh6tc$ocj$1 at mark.ucdavis.edu>,
Anne Gillen <ez049617 at dilbert.ucdavis.edu> wrote:
>I would store it as a dry pellet for long term storage.

	For long genomic DNA, this could be a very bad idea.  Have you
ever tried to resuspend genomic DNA that you left on the Speed-Vac for
too long?  If it goes into solution at all, it takes days.

>I do not know if
>it matters what temp a dry pellet is stored at.  Synthesized oligos are
>sent at RT using FedEx.  However, the manufacturer recommeds long term
>storage of dried  oligos at -20C.  DNA in water is subject to acid hydrolysis,
> as well as nuclease activity.  
>
>I always hydrate with TE pH 8. Degradation is TE is slower than water.
>Does anyone know why?  My genomic DNA is just fine at 4C, but I have only
>a little experience with plasmids. 

	You started to explain it above.  DNA in water is subject to acid
hydrolysis.  DNA is acidic, and can catalyze the hydrolysis of its own
purine moieties, albeit rather slowly.  The TE, being buffered to pH 8, 
prevents this acid-mediated hydrolysis.

-- 
Rainforest laid low.
"Wake up and smell the ozone,"
Says man with chainsaw.					- John Ladasky



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