There is a mystery contamination going on in my lab. We have seen small dots( about 500nm) in our COS-7 and primary macrophage cultures. Those dots are killing our cells. They move pretty fast but not Brownian motion movement. But the culture media would still be clear after overnight culture. We tried DAPI staining, it was inclusive. We tried microplasma detection kit, the results was negative for culture media and cell lysate. I have attached an image of infected COS-7 cell.
Please help.Thank you very much.
Edited by JiaL, 28 June 2011 - 02:37 PM.