Bacterial contamination in cell culture - (Dec/11/2014 )

Hi,

Iam having bacterial contamination in cell culture. I see these wriggling at high magnification and as black balls at low magnification. My problem is, I see these only after I start splitting the cells. When taken from liq nitrogen, it seems to be fine, but dont know what is happening after that. I tested my medium, by keeping it in the incubator and nothing grew in it even after 4- 5 days. I threw away the old medium, trypsin and everything I use, cleaned the incubator with alcohol, but still not able to get rid of it. Please help me out of this .

Thanks in advance

It sounds like either you are misidentifying contamination, or you have a low level contamination in your cell stocks. Another possibility is that some contaminants won't grow in the absence of cells (e.g. mycoplasma).

If its not bacteria as I thought, what could it be. These are sometime elliptical, or round mass black in color and I also see black dots throughout the medium. I got something like this few months back and after I threw the culture flasks and used new ones, it wasnt present. Now Iam facing it again, but this time more severe.

Have a look at the thread on black dots here. That might give you some ideas. Dots in the culture could be debris from dead/dying cells or debris from the serum in the medium