I'm working with JM109 as a host cell with pKRT2 as the plasmid. pKRT2
has a _lac_ type operon that is inducible by IPTG. The plasmid also
affords the host ampicillin resistance. I'm growing the bacteria up in 2x
YT to an OD of 2.5-2.75 where I add IPTG to a final concentration of 0.5
mM. However, even after waiting 6 hours, SDS-PAGE reveals no significant
difference from uninduced lysate.
Does anyone have an idea that I could try (the protocol is modified from a
protocol submitted by D'Aquila and Summers)? Or does anyone have any
experience with JM109 or could point me to a reference that could tell me
what OD generally would be late log phase - starting of stationary phase?
I could just use any sort of help. Thanks.
Please respond via e-mail and this newsgroup.
Robert T. Love
Undergrad - Texas A&M University -- Dept. of Chemistry
rtlove at tamu.edu