DMSO (>99.5% for TC)

Protocols

Typical Protocol

1. (Adherent cells):  Detach cells from the tissue culture vessel according to normal procedure, as gently as possible to minimize damage to the cells, and resuspend the detached cells in the complete growth medium.
2. Determine total cell number and viability percentage, and according to the desired viable cell density, determine the required volume of freezing medium.
3. Centrifuge the cell suspension at approximately 100g–400g for 5-10 minutes (optimum centrifugation speed and duration depends on the cell type). Aseptically withdraw the supernatant (pipet) to the smallest volume without disturbing the cell pellet and discard.
4. Resuspend the cell pellet in cold freezing medium at the recommended viable cell density for the specific cell type.
5. Prepare aliquots of the cell suspension into sterile cryogenic storage vials. Whilst preparing aliquots, mix often but gently the cells to maintain a homogeneous cell suspension.
6. Freeze the cells slowly by reducing the temperature at approximately 1°C per minute using a controlled rate cryo-freezer. Alternatively, place the cryovials containing the cells in an isopropanol chamber and store them at –80°C overnight. Next day, store frozen cells in liquid nitrogen at –135°C.