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.