Cell culture contamination issue - unable to identify the contamination - (Sep/06/2013 )

Hello,

I have been growing few different cell lines in our cell culture room.

Apparently one of the cells I got from outside carried this contamination (black dots inside the cells and moving)

and it looked like it spread to the other cell lines as well.

We tried to clean out cell culture room by decontaminating cell culture incubator and hood.

We used clean media and tried to culture the cells again but we are still having this problem (as shown in the image - these tiny black dots inside the cells - around the nucleus- are moving!).

We tested for the mycoplasma using mycoalert (from Lonza) but it was negative.

Can someone please identify this contamination and help us out with how to clean/treat cells?

We have been having this problem for almost a month now...

thanks!

Have a look at these threads: http://www.protocol-online.org/forums/topic/21330-black-dots-contaminant-phenonmenon-helpful-paper/

http://www.protocol-online.org/forums/topic/19403-black-dots-in-cell-culture/