Can't freeze my comp cells!

Daniel.Marc marc at
Wed Mar 29 02:06:04 EST 2000

: > should be so easy to freeze and store them. But every time I try to
: > freeze them, the next day the efficiency is below my detection level of
: > 10e6. So whats the secret? 
: > 

I use the "CCMB" method to prepare and store competent cells,
and I am happy with it. It is described in the ref. below ;
Hanahan, Jessee and Bloom (1991) Plasmid transformation of
Escherichia coli and other bacteria.
Methods in Enzymology, vol 204, pp 63-113

Hope it helps.

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