Some observations on contamination of animal cell cultures by the fungus Aspergillus fumigatus and suggested control measures.

The fungus Aspergillus fumigatus Fres. was found to be a most troublesome contaminant of animal cell cultures (hybridomas). Conditions in a carbon dioxide incubator (37 degrees C; about 100% relative humidity) are very favourable for its growth. Unlike bacteria it spreads by means of passively-released aerial spores and of filaments (mycelium) growing within and between wells of tissue culture vessels. It has the potential to cause mycotic infections and allergic reactions in laboratory workers. Various measures for controlling it in the tissue culture laboratory are briefly discussed, such as use of antifungal antibiotics, fumigation with formaldehyde and heat sterilisation of the incubator.