Freezing Bacterial Strains

— Ryla Cantergiani 2020/04/10 23:49

Bacteria can be frozen at -80C, and that stock can be taken at a later date to re-grow up the strain. We freeze down strains that we've created or ordered. A full list of strains can be found in the MM-BACTERIA-STRAINS spreadsheet in the dropbox.

Bacteria need to be flash-frozen using liquid nitrogen or an ethanol and a dry ice bath.

Day 0

1. Overnight your bacterial strains in 3 mL of LB or LB + selection antibiotic (e.g. amp).

Day 1

1. Name each strain with an MM###-B number. Label each tube using the pre-printed 3/8“ printable toughspots that have been made for bacterial strains.
2. One sticker goes on the tub, one on the cap, and one on top of the niblet over the cap.
3. Update the MM-BACTERIA-STRAINS spreadsheet on the dropbox.
4. Pipette 990μL from LB or LB+selection antibiotic overnight culture into freezer tube
5. Add 330μL of 80% Glycerol Stock.
6. Flash freeze using a Dry Ice Ethanol bath.
7. Put in the appropriate MM Bacteria box in the -80C freezer.