BL21(DE3) and trc promoter
Dr. Duncan Clark
Duncan at nospam.demon.co.uk
Tue Feb 8 07:44:20 EST 2000
In article <Pine.GSO.4.21.0002081427230.4046-100000 at sun3.oulu.fi>, Petri
Kursula <pkursula at cc.oulu.fi> writes
>Confused by all these E.coli genotypes and strains, I would like to know
>if anyone has used BL21(DE3) cells to produce recombinant proteins from a
>vector with the trc promoter, such as pTrc99a. If yes, is this expression
>tightly regulatable by IPTG, or do you get leaky expression?
Probably leaky unless you have a copy of lacI on your vector in order to
make sure you really have enough repressor to switch the trc off.
If you really need tight control maybe an arabinose promoter expression
vector would be better (available from Invitrogen).
The problem with being on the cutting edge is that you occasionally get
sliced from time to time....
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