Anyone who has ever worked in a cell culture lab has experienced it—contamination.
Ranging from minor annoyance to major catastrophe, contamination causes loss of time, money, and effort spent in developing cultures and setting up experiments.
Contaminants can affect all cell characteristics (e.g. growth, metabolism, and morphology) and contribute to unreliable or erroneous experimental results. Cell culture contamination will likely create a need for experiments to be repeated, resulting in frustrating time delays and costly reagent wastage. Data derived from undetected contaminated cultures can end up published in scientific journals, allowing others to build hypotheses from dubious results. Cell culture contamination costs millions of dollars every year in the United States alone, and it seems to be only getting worse. While the problem will not and cannot ever be fully defeated, however, it can be fought.
Protect yourself from cell culture contamination
The first step in avoiding cell culture contamination lies in being aware of potential sources, and building practices that reduce the risk of contamination from those sources.
Before being allowed to work in a tissue culture facility, laboratory personnel should be given full practical training in aseptic cell culture techniques by an experienced staff member. While each laboratory will have their own standard operating procedures related to use of incubators, autoclaving, labeling of cultures, media storage, and waste disposal, guidelines typically include the following tips:
1. Select the Right Equipment
- Choose an incubator with that has design features that will help prevent contamination
- Copper housings and parts can fight contamination—choose them when appropriate
- Internal HEPA filters will reduce or eliminate many airborne particles
2. Use Good Aseptic Technique
- Use sealed culture vessels whenever possible
- Avoid pouring media
- Use clean lab coats and restrict them to the cell culture area
- Work with one cell line at a time
- Leave the hood running 24 hrs a day
3. Keep Your Incubator Clean
- Remove humidity pan, shelves, shelf supports, and shields weekly and autoclave all stainless steel parts
- Use disinfectants as appropriate and rinse with fresh distilled water
- Wipe down chamber with disinfectant and allow to dry
- Disinfect all access ports, electrical pass-through, shaft holes etc. and carefully clean around sensors
4. Practice Good Housekeeping
- Dirty water baths can be a source of contamination and generate aerosols
- Waste containers provide a source of heavily contaminated materials and should not be located near the hood
- Pest control—mice, ants, roaches, flies, and mites, can all be sources of contamination. The presence of foodor plants in the lab can attract these undesirable guests
5. Routinely Monitor for Contamination
- Perhaps the best strategy for reducing contamination is to be proactive and routinely monitor for it
- Supplies, media, work areas, and cultures should be routinely tested for contamination
6. Use Antibiotics Sparingly
- Overuse of antibiotics can lead to poor aseptic techniques and resistance
- Use antibiotics only strategically to prevent the loss of critical cultures