Freeze-drying (or lyophilization) of bacteria interrupts the metabolism of a bacterial culture, putting it into a dry resting state. Bacteria are revived from the dry state by the addition of water or nutrient media. After lyophilization, bacteria in the dry state may be stored for a long period at room temperature or frozen.
Difficulties in the freeze-drying process lie in removing water while retaining the ability of the bacteria to be revived when rehydrated. Various sugars, proteins, small molecules, polymers and salts are used to formulate and protect the bacteria during the drying process and subsequent rehydration. Equally important are the methods used for freezing and evaporating the water. A well- designed formulation and lyophilization cycle can produce a bacterial product that can be stored and revived on cue.
Bacterial stocks have been formulated and lyophilized as part of our standard operating procedures at List Labs for more than thirty years. Let us put our experience to work in formulating and drying your cell bank or live biotherapeutic.