Why Is the Mycoplasmal Contamination Rate So High?
1. The absence of visible signs of mycoplasmal contamination including changes in turbidity, cytopathic effect and pH, even in heavily contaminated cultures, leads to a false sense of security. Once present in the laboratory, mycoplasmally infected cultures often cross-contaminate the other cell lines being used. 2. The continuous use of antibiotics which are not usually mycoplasmacidal in long-term cell cultures can mask poor aseptic technique. This leads to accidental introduction of mycoplasmas along with other microorganisms. 3. The lack of simple, easy-to-use and reliable detection methods in the past has resulted in many cell lines being untested. Because of this, many cell lines brought into a lab from outside sources although appearing normal and healthy, are in fact already infected with mycoplasma. 4. Because of their small size and lack of cell wall, mycoplasmas occasionally penetrate the filters used to “sterilize” cell culture media and sera, resulting in low levels of the
