How can we test for mycoplasma and cell culture contamination?

Mycoplasma is a genus of bacteria that lacks a cell wall around its cell membranes, making it resistant to antibiotics that target cell wall synthesis. It is a species that belongs to the mollicutes class, which are all gram-positive. This type of species is widespread in nature as parasites of mammals (humans included), reptiles, insects and plants. They are the smallest and simplest self-replicating prokaryotes.

Where does mycoplasma contamination come from?

Firstly, there are six species of mycoplasma that account for 95% of all detected contaminations in cell line cultures. These are:

  • M. orale
  • M. arginini
  • M. fermentans
  • M. hyorhinis
  • M. hominis
  • A. laidlawii

For cell cultures to become contaminated with mycoplasma, there are numerous routes of contamination that could have occurred. Some of these are:

  • Cross-contamination from other cells – for example, aerosols generated during pipetting.
  • Using the same media bottles.
  • Handling more than one cell type at a time.
  • Direct contamination from the researcher.
  • The use of contaminated materials, such as animal sera.

Cell contamination is a very common issue and is likely to occur. The high risk of mycoplasma contamination shows the importance of always purchasing high-quality cell culture media from reputable manufacturers, such as SwiftDx. Taking the necessary precautions – such as using high-quality media and materials, and conducting your studies in an isolated space – should help to reduce the risk of cross-contamination in cell cultures as much as possible.

What if your cell cultures become contaminated by mycoplasma?

Like all cell culture contaminants, mycoplasma contamination can be problematic. Mycoplasma is very small and replicates at a much slower rate compared to many other bacterial species, which makes it much harder to detect. The presence of mycoplasma in your cell cultures can seriously affect the behaviour of your cells, making your results unreliable, unreproducible and inaccurate.

Should you have a contaminated cell culture, it is best to completely discard this as well as the results and try again. Although this may be frustrating and delay your research, this is the best option as using mycoplasma-contaminated cell cultures will not help you to obtain accurate data and will not be representative of your sample.

You can continue with your experiments from the last negative mycoplasma test and include that cell culture in your findings. Make sure you review all contamination guidelines as well to prevent this occurrence from happening again.

How to prevent mycoplasma contamination

Ways to prevent mycoplasma contamination are:

  • Wearing proper PPE around your cell cultures: clean lab coats, gloves and footwear.
  • Examining your cell line stock for contamination before testing.
  • Using fresh media and materials and keeping them isolated and clean.
  • Fumigating the laminar airflow periodically.

In-lab testing for mycoplasma with SwiftDx

The good news is that testing for mycoplasma is now easier than ever due to modern detection testing kits. Thanks to advancements in science and technology, molecular diagnostic companies, such as SwiftDx, have been able to develop mycoplasma detection kits that provide quick and accurate results.

Designed as lateral flow tests, they are easy to carry out. The use of a mycoplasma detection kit provides rapid results too, unlike swabs that have to be sent off. The kit comes with everything needed to test for mycoplasma, including the lateral flow strips that provide a simple positive or negative result.

SwiftDx’s mycoplasma detection tests

About our kit

Our mycoplasma detection kit uses a modified and highly advanced version of a polymerase chain reaction (PCR) and includes a labelled oligo system that allows mycoplasma PCR products to be detected on a lateral flow device. The kit is designed to detect all mycoplasma species that are usually encountered due to cell culture contamination. This is thanks to the specified primer sets included that are specific to the highly conserved 16S rRNA coding region within the mycoplasma genome.

At SwiftDx, we are always looking to improve our processes, continually testing different species and then adding them to the ‘confirmed detected’ list. Our use of a modified PCR approach ensures that only the necessary, specific 16S rRNA amplicons are detected on the lateral flow test strip. This means that, when you use our kit, only a positive or negative output will be shown to you. This makes it much more straightforward to read the results.

How to use our kit

Our mycoplasma detection kit is straightforward to use. It can be broken down into three steps, which are:

Reaction set-up
  1. Mix 5 ul of Solution I and 5 ul of Solution II
  2. Add 2 ul of cell culture supernatant
  1. Run the 36-cycle thermal cycler programme
  2. Add 10 ul Solution III and place it back in the cycler for a final cycle
Run the sample on the strip
  1. Mix 20 ul of Running Buffer with the PCR reaction
  2. Add 5 ul of this mixture to the Test Strip in a tube or well with 300 ul of Running Buffer
  3. Wait for 10 minutes to pass whilst the test runs. You can then read the result

It is also accompanied by detailed instructions, which you can use alongside the insightful guides available on the SwiftDx website.

For more information about mycoplasma detection tests and how you can use them in your lab, get in touch today!