Mold in cell cultures

[LabAsstBeaker]

I have had a mold problem in my cultures for three weeks prior to now.

Last week, after the most recent batches went moldy, I cleaned the incubators. So far, since then, no contamination. My current cultures are clean.

We are trying to figure out where the contamination came from. I believed it was the incubator fans spreading the mold around and then it getting on the culture plates, and handling the culture plates. Another person believes it was the FBS that went into our media.

I'm a tech and never had a class in mycology or anything similar. I don't know if mold can lie dormant for awhile, and/or is triggered by something we do (media change, incubation, etc). I know it is in the air, and I realize that when it is in the cultures, it is perpetuating, especially if it is slow-growing or can be dormant until conditions are right. Can anyone give me a good capsulized education on mold in cultures and how to keep it out, aside from strict technique?

Thanks!