Cell culture contamination or not? - (May/31/2014 )

Hi

Does anybody know how to interpret attached picture of murine CT26 colon cancer cell culture? Is it normal appearance of this cell culture? Or not?

Thanks for help

From first glance it looks like you have alot of dead/dying cells forming the big clumps. But after zooming in, I can see regularly sized spherical 'things' which looks too big to be bacteria and too small to be suspended cells (compared to nuclei of the surrounding cell). 

Why do you suspect contamination? How does the media coloration look? Is the media cloudy? How is the growth rate of the cells?