deusebe at wotan.ens.fr (Danièle EUSEBE) writes:
> I have to induce beta-galactosidase in a liquid culture of E.coli Y1089
> lysogen for a lambda gt11 phage containing a beta-galactosidase-fusion
> protein gene.
> I have read in a protocole to use 10 mM IPTG, which seems to me an
> enormous amount, since I have to make a liter scale culture.
Routinely we use 0.1 mM for the modified promoter (Tac?) in pGEX,
but you should titrate for your application. This is a general rule - always
titrate on a small scale when you do something new.
> Is this concentration required? What is the minimal efficient
> concentration to fully induce beta-galactosidase synthesis?
Isn't b-gal promoter heat-shockable, anyway?
Richard P. Grant MA DPhil rpgrant at molbiol.ox.ac.uk
Nuffield Department of Obstetrics and Gynaecology, University of Oxford.
No wonder I can't go to parties anymore.