Bacterial Freezing Medium is a glycerol based solution that is designed to protect bacteria stored from temperatures from -20°C to below -130°C liquid nitrogen temperatures. Bacterial Freezing Medium is easy to use. Simply culture your bacteria to mid/late log phase, pellet by centrifugation, decant, and then resuspend the bacteria in an equal volume of Bacterial Freezing Medium. Cultures may also be concentrated or diluted in the medium as well. Available in 500 ml bottles as well.