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.
o----------------------------------------------------------------------o
| 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 |
o_____________________________|________________________________________o
