protein expression in PLysS
umluther at cc.umanitoba.ca
Sun Mar 28 13:58:21 EST 1999
Anant Patkar wrote:
> We have also observed leaky expression in E. coli BL21(DE3) with
> vector. There was also significant plasmid stability problem. Because
> of the leaky expression, only 60% of the cells would have plasmid after
> reaching stationary phase. Has anyone seen this?
> Anant Patkar
> University of Minnesota
I have seen my expression drop off continually. I have to keep
reclaiming my original transformants from -70 c to get the original
levels. I tried the plasmid stability test in the pET manual and got no
useful information. I have also tried retransforming with the original
plasmid sample, but have not been able to regain suitable expression
Do you do retransformations, and pick clones from a plate for your
cultures or do you keep frozen cell stocks as a source of inoculum?
*University of Manitoba
*Department of Chemistry "Illegitimati non carborundum"
*Winnipeg, Manitoba General Joseph W. Stilwell
* mailto:umluther at cc.umanitoba.ca
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