Dear Ciliate Community,

I am struggling with contamination in my Tetrahymena cultures for a while. Routinely used antibiotics (pen-strep, amphotericin) don't work. I  used normocin from Invitrogen in conbination with pen-strep or kanamycin to get rid of them but no success again. Contaminated wells appear whitish and cloudy (Please see attachment). I noticed that this contamination generally occurs after biolistic bombardment. Sterile cabinet was tested for the possible contamination source but it seems OK. I extensively sterilize the inner chamber of the biolistic gun (which is in our sterile cabinet) and other components with alcohol prior to shot but they show up during passaging when I increase the pm concentration for example.

Many thanks in advance for your any kind of suggestions.

Best regards.

Erhan Aslan

Anadolu University 
Graduate School of Sciences
Department of Molecular Biology

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