mammalian cells invaded by intracellular microbes - how can I decontaminate? (Feb/27/2006 )
My CHO cells looked like they had lots of dark spots within the cytocplasm, and on closer inspection, some cells were lysed. Most of the cells are still there, but growth is stagnant. Can't see any other sign of contamination. The media contains penicillin and streptomycin. Can anyone help with tackling these intracellular invaders? Resistant bacteria? Or something else? Hope there's a drug for it. Thanks.
Throw them away, throw your media, and thaw a new batch of cells out.
I did. But I only have a few tubes of frozen stock. So at some point I need a strategy to see how I can overcome the problem. First step would be to identify the microbe.
OK I understand.
You could try kanamycin (around 100 ug/mL) or gentamicin (around 5 to 50 ug/mL).
you should determine the toxicity of the antibiotic for your cells if you have some other batches of CHO. Try several concentrations in a 96 well plate. Observe signs of toxicity days after days.
Then use the antibiotic at a concentration twice lower than the one which is toxic, for 2-3 passages, then one passage without antibiotic, then again treat your cells for 2-3 passages.
then culture the cells without antibiotic for 4-5 passages and check if the contamination has been eliminated.