Mycoplasmas are small (0.2-0.3 m) wall-less bacteria that can grow to very high concentrations in cell cultures. Mycoplasma contamination of cell culture is a common occurrence and diffcult to detect.

PCR Kit such as ATCC Mycoplasma detection kit can be used to detect mycoplasma contamination.

A quick but less sensitive method is to visulize mycoplasma DNA using DAPI or Hoechst dye. Mycoplasma will appear as fluorescent spots in the cytoplasm and on membranes.