Mysterious Contamination Problem - (Oct/15/2012 )

We've been doing cell culture in this lab for quite some time and just recently all of our cells have been getting contaminated. The contamination is odd because it happens on different days for different flasks. Once cells are cultured they look healthy and will remain so for the next few days, sometimes even weeks, then all of a sudden the cells will be dead with a lot of contamination. We have tested all mediums and reagents used, had the hood looked at, experimented to see if it is a problem with technique as well. Our only thought left is that it could be the CO₂ incubator, or the lines going from the tank to the incubator. If anyone has seen this kind of contamination or has any suggestions of what to do please let me know!

Throw away your cells (if possible). Throw away your Medium. Decontaminate your incubator. Usually, incubators have an automatic decontamination routine. If not, see the instructions in the manual how to decontaminate.

If you have done so, then thaw new aliquots of your cells. Also you should use a kind of AntiAnti, Pen-Strep or similar to protect from bacterial and fungal contamination. These don't harm your euk. cells. You should also check for mycoplasma contamination. There are several ways, even possible with a simple PCR.