E. coli culture - (Sep/20/2013 )

Hello, everyone.

Today I made a culture of Escherichia coli (I started from OD600=0.1, until OD600=1). When I centrifuged the cells, I noticed some black "impurities" in my culture. Do you have any idea what could this be?

Thank you.

Have a great day!

Cristina

Hi.  I often see small black regions of my cell pellet when collecting overgrown cells and I believe this to be dead bacteria.  Only grown to an OD600 of 1, there shouldn't be dead bacteria from being overgrown but perhaps there was something else going on.  As long as it is a small percentage of the pellet it is not a big deal (in my experience).