Amp stock survival?
chrisb at hgu.mrc.ac.uk
Thu Sep 26 09:46:55 EST 1996
Trevor Fenning (trevor.fenning at hri.ac.uk) wrote:
: Hi There,
: Not long is the answer - ampicillin goes off very fast indeed (half
: life at 37oC = 18 hours) even without resistant bacteria degrading it,
: so don't kep stocks at room temp, or even in the fridge.
: I keep 1000x stocks made up in 1 ml aliquots at -20 which seem to
: last, although they will deterioate eventually. If you are using it
: to select for transformants, always include controls of
: non-resistant/non transformed cells on the amp media. That way you
: will notice any loss of effectiveness early.
I second all that, and also recommend dissolving Ap in 70% EtOH. This
has the dual benefits of staying liquid at -20 and being less prone to
Chris Boyd | from, | MRC Human Genetics Unit
chrisb at hgu.mrc.ac.uk | not | Western General Hospital
http://www.hgu.mrc.ac.uk/~chrisb | for | Edinburgh EH4 2XU, SCOTLAND
More information about the Methods