Our tissue culture incubator smells badly. Can't place it, but its strong and it seems to me that there is a great deal of "warm air" coming from the incubator when it is first opened. We have autoclaved the all the racks and cleaned the inside. Right after, the smell went away and all cells were put back. However, as time has gone by the smell has returned. I have put my cells in non-P/S media to observe them over several days and have not seen bacterial contamination (cloudiness). Though I do see floating cells. Also, I have been more careful with making sure no media sticks to the outside of my plates.
In general, I would think that there would have to be a great deal of contamination to smell like this. Obviously, the more the incubator is opened, the less it smells. Are there any other ideas about what this might be? Could it be mycoplasma? What about filters. Its just that have done TC for numerous years, I think its unlikely that I have grossly contamined everything. I just want to see what other people think before I stop all my experiments and start with all new cells.

Have you cleaned the inside (washed the walls) with bleach? Also, you can try taking apart and cleaning the fan with bleach. If your cells are not contaminated, then the incubator should be fine. I've noticed my own TC incubator sometimes has a slight odor, but any contamination issues I've had, have always been isolated to a single plate or cell line.

Omai

The other thing to look at is if you have either a fungal or a pseudomonas sp. contaminant in any water source associated with the incubator.

This could be a real issue if the incubator has a water jacket.

Cleaning the incubator will help for a short while there but not really eliminate the problem. And if the water jacket is growing "bugs", the chances of contaminating your cultures is low even if the smell is pretty bad; but it would be better to remove the problem. The incubator manual will probably indicate how to clean the water jacket and if there is biocide you can add to help minimize the problem in the future.

Dan