Mycoplasma are extremely small bacteria without cell wall around the cell membrane. Not only are mycoplasma undetectable and difficult to destroy with a light microscope, they can quickly infiltrate entire laboratories. In the process of cell culture, the mycoplasma contamination rate reaches more than 60%. When the cells are polluted by mycoplasma, the expression of DNA, RNA and protein in the cells will change. When the pollution is serious, the cell growth will be slow, the cell morphology will change, and cell pathology will appear. Therefore, in the process of cell culture, it is particularly important to regularly detect mycoplasma, remove mycoplasma pollution at the source, and take an effective measure to prevent mycoplasma.