REQ: Info on _E. coli_ JM109

DeRose's Group derose at tamu.edu
Wed Jun 4 20:17:13 EST 1997


Howdy,

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.

P.S.  

Please respond via e-mail and this newsgroup.

Robert T. Love
Undergrad - Texas A&M University -- Dept. of Chemistry
rtlove at tamu.edu



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