frozen competent cells - how to prepare competent cells from frozen bacteria? (Mar/12/2010 )

Dear Drs,

i have competent e-coli top 10, saved in liquid nitrogen from more than a year ago.
i think that it is no longer competent.
is it right?
if so , i will need to make it competent again,
So how can i prepare competent cells from frozen competent cells before a year in LN2?
i only need to to how to right begin.
Thanks a lot .
Aida

aidaelshaer on Mar 12 2010, 03:54 PM said:

I suspect your cells are still highly competent, if they started out being competent.

You can make more by growing up a culture from your existing stock and following the protocol here, which is the one I use, after trying them all:
http://openwetware.org/wiki/TOP10_chemically_competent_cells

in my experience its still working..