Freeze glycerol stocks of E. coli

To preserve all stocks of each strain derived from a unique colony, we will freeze glycerol stock at -80 C.

1. Put 37.5 µL of warmed glycerol in a pre-labeled sterile 1.5 mL tube.
2. Remove 212.5 µL of your overnight culture and add it to the appropriately labeled tube with glycerol.
3. Close the lid tightly and mix by vortexing.
4. When all 4 tubes are well mixed, give them to your instructor to put in the freezer.