Viability of plasmids at 4 degrees

Ken Howe howe at DARWIN.UCSC.EDU
Thu Dec 14 20:33:43 EST 1995

J. David,

After storage of cut DNA at 4 degrees C, it's very likely that your DNA 
has been chewed up.  If you get nothing at all or a shmear when you run 
your transcriptions on a denaturing gel, then this is the likely 
explanation.  On the other hand, nucleic acids tend to adsorb to the 
sides of tubes thus decreasing their effective concentration in 
solution.  If your reactions are still giving the same (hopefully clean 
and tight) product, it's likely that this is the case. 

Of course, if you're not using fresh reagents, then it could be anything.

Hope this helps.

Ken Howe
"the onions expressed here are my own"

Thu, 14 Dec 1995, J. David Spafford wrote:

> Date: Thu, 14 Dec 95 23:16:07 GMT
> From: J. David Spafford <jspaffor at>
> To: methods-and-reagents at
> Subject: Viability of plasmids at 4 degrees
> Hi,
> We have linearized-plasmids that we have used as templates for transcription
> of ion channel genes.  A year ago, we found that the plasmids gave very good
> expression.  Today, a year later, we are having difficulty getting good
> quality RNA.  The plasmids were kept at 4 C.  Should they still be viable?
> J. David Spafford,
> Department of Biological Sciences, University of Alberta
> jspaffor at

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