BL21(DE3) and pTrc

Dr. Peter Gegenheimer PGegen at UKans.nolospamare.edu
Fri Feb 11 20:22:26 EST 2000

On Tue, 8 Feb 2000 12:31:26, Petri Kursula <pkursula at cc.oulu.fi> wrote:

ð Confused by all these E.coli genotypes and strains, I would like to know
ð if anyone has used BL21(DE3) cells to produce recombinant proteins from a
ð vector with the trc promoter, such as pTrc99a. If yes, is this expression
ð tightly regulatable by IPTG, or do you get leaky expression?

BL21(DE3) contains the phage T7 RNA polymerase under lac repression; it's used
to express genes cloned behind a T7 promoter. You cannot transform it with a 
plasmid containing the lac repressor; that induces the T7 polymerase gene and 
the cells stop growing. 
| Dr. Peter Gegenheimer       | Vox: 785-864-3939  FAX: 785-864-5321   |
| Department of               |   PGegen at UKans.nospam.edu              |
|   Molecular Biosciences     |   http://rnaworld.bio.ukans.edu/       |
| University of Kansas        |"When you have excluded the impossible, |
| 2045 Haworth Hall           |  whatever remains, however improbable, |
| Lawrence  KS  66045-2106    |  must be the truth."      S. Holmes    |

More information about the Proteins mailing list

Send comments to us at biosci-help [At] net.bio.net