Impact of the CO2 incubator on contamination

This article was published first in "Inside Cell Culture" , the monthly newsletter for cell culture professionals. Find more interesting articles about CO₂ incubators on our page "FAQs and material on CO₂ incubators" .

Sterility of cultures is a continuous challenge in cell culture. Germs may be transferred involuntarily by many different means:

• Contaminated cell stocks
• Cross contamination of cell stocks in liquid nitrogen
• Errors in aseptic technique
• Lack of strict general hygiene
• Malfunction of equipment
• Non-sterile plastic ware, media and supplements

In addition to these factors, the incubator plays an important role as it may increase or decrease the risk of culture contamination. Even though incubators do not provide a “sterile” environment, one can reduce the risk of contamination when following the below rules:

• Remove contaminated cultures from the incubator immediately
• Keep door opening times as short as possible
• Use incubator with split inner doors
• Immediately clean any spills inside the incubator
• Exchange the water frequently with autoclaved, distilled water
• Clean the incubator thoroughly once a month using an appropriate disinfectant
• Unscrew ventilators and other parts (if your incubator is equipped with) that often hide fungi for cleaning
• When fungal contamination occurs check the incubator thoroughly
• If possible, regularly decontaminate/sterilize using the respective function after cleaning
• Use HEPA filters in the incubator gas inflow if necessary
• Avoid the use of internal, non-sterilizable HEPA-filters