Freeze-drying of microbial cultures

• One of the best ways to store bacterial, fungal, yeast or other microorganism culture for long periods of time is to use a process called Freeze-Drying or Lyophilization.
• Bacteria are suspended in a suitable protective medium, frozen and exposed to a vacuum.
• After drying the bacteria are stored under vacuum in glass vials, for preservation of culture collection.
• The viability or the colony forming units of the strain are tested before and after the preservation step and, depending from the strain, in certain intervals during the storage period for documentation of viability form.