Mycoplasma contamination is a type of biological contamination; however, it differs from regular bacterial, viral, or fungal contamination because mycoplasma is extremely difficult to detect. Mycoplasma are simple bacteria that lack a cell wall, and they are considered the smallest self-replicating organism. It is because of their extremely small size (typically less than 1 µm), that mycoplasma contamination is difficult to detect until they achieve extremely high densities and cause the cell culture to deteriorate; until then, there are often no visible signs of infection.
Causes of mycoplasma contamination in cell culture
Like other forms of biological contamination, mycoplasma is spread through various channels, usually arising from contaminants already present in your laboratory or working area. Through improper handling or a lack of adherence to aseptic techniques, mycoplasma contamination can be difficult to detect while becoming increasingly pervasive.
Learn more about how to prevent mycoplasma contamination with aseptic techniques
Detecting mycoplasma contamination
Some slow growing mycoplasma may persist in culture without causing cell death, but they can alter the behavior and metabolism of the cells in the culture. Chronic mycoplasma infections might manifest themselves with decreased rate of cell proliferation, reduced saturation density, and agglutination in suspension cultures; however, the only assured way of detecting mycoplasma contamination is by testing the cultures periodically using fluorescent staining, ELISA, PCR, immunostaining, autoradiography, or microbiological assays. |
 |
| Figure 1. Photomicrographs of mycoplasma-free cultured cells (panel A) and cells infected with mycoplasma (panels B and C). The cultures were tested using the MycoFluor Mycoplasma Detection Kit, following the kit protocols. In fixed cells, the MycoFluor reagent has access to the cell nuclei, which are intensely stained with the reagent, but the absence of fluorescent extranuclear objects indicates that the culture is free from mycoplasma contamination (panel A). In fixed cells infected with mycoplasma, the MycoFluor reagent stains both the nuclei and the mycoplasma, but the intense relative fluorescence of the nuclei obscures the mycoplasma on or near the nuclei. However, the mycoplasma separated from the bright nuclei are readily visible (panel B). In live cells, the MycoFluor reagent does not have access to the nuclei, but readily stains the mycoplasma associated with the outside of cells (panel C). The images were obtained using 365 nm excitation and a 100/1.3 Plan Neoflaur® (Zeiss) objective lens coupled with a 450±30 nm bandpass filter. |
Removing mycoplasma from cell cultures
If you detect mycoplasma contamination in a cell culture before it causes cellular deterioration, it can be treated with antibiotics. However, because of their lack of a cell wall, mycoplasma are resistant to common antibiotics that target the area, such as penicillin.
Thermo Fisher Scientific offers several antibiotics suitable for removing mycoplasma from cell cultures. Always use caution when deciding when to use an antibiotic for your cultures as persistent use can result in antibiotic resistant strains.
Preventing mycoplasma contamination
There are many efforts one can take to minimize and prevent mycoplasma contamination within a cell culture lab. Mycoplasma contamination is best prevented by following proper aseptic techniques in the cell culture lab. Through proper sterilization procedures and handling, donning of PPE, and diligent aseptic technique, mycoplasma contamination can be severely limited. Though as a last line of defense, when handling culture media, serum, additives, and buffers, you can also opt for a sterilization filter that has a pore size of 0.1 μm to enable maximum protection.
Resources
Cell Culture & Transfection Learning Center
Access cell culture and transfection educational resources to enable excellent experiment planning and execution.
Gibco Cell Culture Basics
Learn best practices and fundamentals of cell culture. Topics include aseptic technique and methods for the growth and maintenance of cells in culture.
Cell Culture Videos
Explore this collection of cell culture videos providing valuable insights into techniques, resources, and stay up to date with the latest advancements in the field.
Cell Culture Selection Tools
Find the right cell culture products for your research with these selection tools. Search for media, FBS, plastics, transfection reagents, and more.
Support
Cell Culture & Transfection Support Center
Find technical support recommendations for your cell culture and transfection workflows, including tips for experimental setup and in-depth troubleshooting help.
Need technical support?
Contact our expert team for technical and application support of Laboratory Products.
Related products
For Research Use Only. Not for use in diagnostic procedures.