Competent Cells - (Sep/28/2009 )
Does anyone know if in the process of purifying competent cells, should the culture be at a specific optical density for the best results?
I didnt get you ...........
Yes! Check out the original paper by Hanahan 1983.
Biochick99 on Sep 28 2009, 10:41 PM said:
yes, the OD600 must be at 0.5 which is the log phase of bacterila growth.
Biochick99 on Sep 28 2009, 01:41 PM said:
They do need to be at a specific OD but that will be different depending on what bacterium you're making competent. They need to be in log phase. If it's E coli that will be ~0.5 - my way of determining this is when you can only vaguely see the lab light thru the culture!
0.3 to 0.6 is fine.
sometimes i just took an overnight, diluted 100 fold in fresh LB and let it grow for 2-3 hours.
Never let me down.