Selective media question - (May/30/2008 )
I'm trying to select clones using an auxotrophic E. coli strain, and want to ensure that my carbon source IS the only one used by the organism on solid medium. I've been told that I don't need to worry about bacteria breaking down agar, but I've seen cases where studies have been done and growth was observed on agar (when there should not have been).
Which leads me to my question: What's the best solidifying agent for plates for selective media?
-clone raider-
QUOTE (clone raider @ May 30 2008, 09:26 PM)
I'm trying to select clones using an auxotrophic E. coli strain, and want to ensure that my carbon source IS the only one used by the organism on solid medium. I've been told that I don't need to worry about bacteria breaking down agar, but I've seen cases where studies have been done and growth was observed on agar (when there should not have been).
Which leads me to my question: What's the best solidifying agent for plates for selective media?
Which leads me to my question: What's the best solidifying agent for plates for selective media?
Use Noble Agar. It is extra pure, and will ensure that only nutrients you add will supply the bacteria for growth.
http://www.bd.com/ds/productCenter/214220.asp
-phillyandrew-
Just try it. E. coli does not break down agar and extraneous growth would probably due to carry over of other substrates with inoculum rather than impurities in the agar. If you're so worried use agarose.
-jorge1907-