On Mon, 12 Aug 96 15:29:06 PST, Email (YourName) wrote:
>Hi there. I want to screen an inducible Arabidopsis cDNA library in yeast.
>Looking through the literature, the promoter (GAL4) is induced in liquid
>culture lacking glucose with 1% galactose. Does anybody have any experience
>in reducing this galactose concentration. How low can I go before the
>promoter is turned off? and what conc of glucose will turn off
>the promoter?? Thanks.
>
My experience has shown that any glucose present at any concentration
will be utilized. I would suggest a broth containing 100 mg/l
glucose and 5 gm galactose to induce the promoter. The glucose will
yield active log growth and will accelerate the conversion. If one
adds a small amount of glucose back into the system (50 mg./l) the
promoter will be momentarily arrested and then "restart" when the
available glucose is metabolized. RR
Robert Randolph
Randolph Biomedical
401-826-1407
rrandy at hotmail.com