Mycoplasma can be preserved using either glycerol or lyophilized powder. This video demonstrates the most common and convenient glycerol method used in laboratories. Cultured mycoplasmas are then added to 20% glycerol. Alternatively, if the pH of the culture medium is close to the critical value for mycoplasma, an appropriate amount of fresh culture medium can be added before adding glycerol. This method generally allows for storage at low temperatures for six months to a year, but avoid storing at -40°C.