Storing Cells Long-Term

 Often, you will want to save a cell sample for use at a later time. Cells will decay in the freezer, so you must use specific techniques to preserve the sample. This is done by storage at -80C.

Materials

    Glycerol
   Deionized water
   Cryovials
   Fresh (<18 hours) liquid culture

Procedure

    1. Create 45% glycerol by mixing 450uL of glycerol and 550uL of distilled water in an epitube. The glycerol is viscous, so place the tip of the micropipette into the container and grab the sample, leaving the tip in the container for at least 30 seconds.
    2. Use a vortex to mix the 45% glycerol until the mixture is homogeneous, you should not be able to see any defined glycerol.
    3. Create a 15% glycerol to store the cells in by mixing 2mL of your liquid culture and 1mL of 45% glycerol into a test tube. Use the 1000uL micropipette for both contents, you will have to pipette twice for the liquid culture.
    4. Put 1mL of the test tube contents into the 1.2mL cryovial.
    5. Add a small amount of liquid nitrogen into a low temperature bucket and drop the cryovial into the bucket. Wait for a minute of longer until the sample is frozen. It will be a slushee-like mixture after frozen.
    6. Place the cryovial in a -80 degC freezer for future use.