Mycoplasma Testing

Antibiotic-resistant Mycoplasma bacteria.

Mycoplasma contamination is a widespread and reoccurring problem in a wide variety of cell culture systems. Mycoplasma are bacteria that lack a cell wall and are thus not susceptible to penicillins or other antibiotics that act on this structure. Mycoplasma often also show tolerance to many other antibiotics. This allows them to grow to high titers in culture media without exhibiting typical bacterial contamination signs, like turbidity.

They can cause diverse effects on cultured cells including altered metabolism, slowed proliferation, and chromosomal aberrations. In short, mycoplasma contamination compromises the validity of affected cell lines data and resulting for life science research. This makes the maintenance of contamination-free cell cultures fundamental to cell-based research and to manufacturing of goods where consumer health is a major concern.

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Sources of Mycoplasma Bacteria in the Laboratory

Sources of mycoplasma contamination in the laboratory are very challenging to control. Some mycoplasma species are found on human skin and can be introduced to cultures through poor aseptic technique. Additionally, mycoplasma may be introduced via contaminated supplements, such as fetal bovine serum, or most commonly by transmission from other contaminated cell cultures. Once mycoplasma is present in cell cultures, it can quickly spread and contaminate other areas of the lab by aerosols and particulates generated during culture handling. Strict adherence to good laboratory practices, such as good aseptic techniques is key, and routine testing of cultures for mycoplasma is highly recommended for successful control of mycoplasma contamination in manufacturing areas.

Mycoplasma Testing Methods

Bioreactor contamination can lead to significant loss of time, materials and revenue unless identified early in the manufacturing process. It is therefore important to test biopharmaceuticals, vaccines, cell cultures and virus cultures for mycoplasmas at various points during quality control. The three most common test methods are:

  • Mycoplasma culture, where bacterial culture media optimized for mycoplasma is inoculated with test samples
  • DNA staining method, where mycoplasma nuclei are counterstained with Hoechst or DAPI and imaged using fluorescence microscopy
  • PCR (polymerase chain reaction), to amplify the bacterial DNA if mycoplasma are present in culture samples