====== Freezing Bacterial Strains ======

 --- //[[rylajosephine@gmail.com|Ryla Cantergiani]] 2020/04/10 23:49//

===== Overview =====
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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.

===== Materials=====
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^ Materials               ^  
| test tubes and caps |
| 1.5ml Screw Cap Tubes  |  
| toughspot tube labels (pre-made bacteria labels) |
| [[80_glycerol|80% glycerol]] |
| [[200_proof_ethanol|ethanol]] |
| dry ice |
| ethanol bath metal container |   


=====Procedure=====
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Day 0
  - Overnight your bacterial strains in 3 mL of LB or LB + selection antibiotic (e.g. amp).

Day 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.
   - One sticker goes on the tub, one on the cap, and one on top of the niblet over the cap.
  - Update the MM-BACTERIA-STRAINS spreadsheet on the dropbox.
  - Pipette 990μL from LB or LB+selection antibiotic overnight culture into freezer tube
  - Add 330μL of 80% Glycerol Stock.
  - Flash freeze using a Dry Ice Ethanol bath.
  - Put in the appropriate MM Bacteria box in the -80C freezer.

=====Notes=====
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=====Part Numbers=====
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