BL21(DE3) vs contamination - (May/01/2009 )

Hi

I have BL21(DE3) culture (no vector) that has possible contamination. How should I purify and differentiate E. coli from the rest?

Thanks

orang on May 1 2009, 06:44 PM said:

Take a loop and streak the your culture to single colonies. Pick one well isolate colony that has the morphology of an e coli colony. Streak out that colony again to be on the safe side that it is pure. Pick one well isolated colony from this second streaking and plate it out on a nice plate.

But it would probably easier to go back to the frozen stocks for some fresh uncontaminated cells

perneseblue on May 1 2009, 07:47 PM said:

Thank you. I received the small disk from somebody else and when I try to inoculate into LB broth in the laminar hood, the disk fell on table. So basically, I don't have the frozen stock because I was trying to make one. Will try to streak it today and see what happen. Thank you again for suggestion.