Daudi cells are slow to recover from cryopreservation. These cells are adapted to a RPMI-1640 medium with high glucose (4.5g/L) such as ATCC® 30-2001 ™ and are known to recover poorly in a low glucose formulation.
The batch specific information should be used to determine the correct volume of medium to achieve a seeding density of 3 X 105 viable cells/mL. Trypan blue viability assays should not be used immediately after thaw because they yield a false indication of low viability due to residual effects of DMSO on the cells upon thawing. The flask containing the medium should first be incubated at 37°C, 5% CO2 for at least 15 minutes so that the medium has adjusted to the proper alkalinity and temperature before adding the cells.
Cultures of Daudi cells can be fed by addition of small amounts of fresh medium to the flask several times each week, transferring to larger flasks (or more flasks) as necessary. Cultures can be also be maintained by centrifugation with re-suspension at 3 - 5 x 105 viable cells/ml. The cells must be diluted with fresh culture medium to lower the cell concentration and provide sufficient nutrients for growth. If the medium is simply replaced (by spinning down and resuspending in the same volume) and the cell density is not decreased, the cells will deplete the medium and die. If the cells are diluted below their minimum density, they may either enter into a lag phase and grow very slowly, or they will die. Therefore it is very important to always maintain the density between 3 X 105 viable cells/ml and 2-3 x 106 viable cells/ml.
|Date Created||02/21/2014 07:26 AM
|Date Updated||02/21/2014 07:27 AM