Bacterial Glycerol Stocks
  1. Put 0.5ml bacterial culture in a sterile eppendorf tube.
  2. Add 0.5ml of sterile 80% (v/v) glycerol soution.
  3. Freeze  on dry ice or directly into 70oc .
  4. Store at 70oC. Cells are best for about 4-6 months, but will probably work ok for a whole year. * DNA rearrangements may occur (this is especially true for bacterial strains used for protein expression). Thus, it is highly recommended to maintain DNA midi or mini preps, that will be used for future transformation in case of activity loss of the glycerol bacterial stock.
To recover the bacteria:
OR
Return the frozen culture to storage at -70oc.