Storing dNTPs at -70 or -20?

Andre Hamel ahamel at
Sat Mar 2 13:23:30 EST 2002

  What's the opinion out there regarding storing dNTPs 
at -70 versus -20 (NOT frost free freezers of course)?

  I've been in the mol bio field 20 years now and we have
always stored our stock solutions at -70 (for long term storage).
This had always seemed the "intuitively correct" thing to do.

  The only stocks we ever stored at -20 (NOT frost free) were small 
aliquots of "working" solutions (that is, were used frequently and 
consequently were used up more quickly ... usually within a few weeks).

  I've had far too many occassions when using dNTPs stored in frost free 
freezer (usually by grad students) , only to have sequencing reactions 
fail as result.

  Now the kicker is, I recall having read a paper (BRL Focus?,
showing how dNTPs store better at colder temperatures.

  Can anyone come up with any publications on this topic?

ThanX ... I will post any email responses if they are not posted

Andre Hamel (PCR scientist) Virology Lab, 
Veterinary Services Branch, Manitoba Agriculture
Winnipeg, Manitoba, CANADA
mailto:ahamel at


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