Cells can be adapted by Sequential or Direct Adaptation. Suggested protocols for each are below, and you can also find more information by searching "Adaptation of Cell Cultures to a Serum-Free Medium" from our website home page.
SEQUENTIAL ADAPTATION
1) Subculture the cells growing in serum-supplemented medium into a 25%:75% mixture of SFM and serum supplemented medium.
2) When the cell density is 5 x 10E5 cells/ml, subculture the cells into a 50%:50% mixture of SFM and serum supplemented medium at a cell density 2.5 x 10E5 to 3 x 10E5 cells/ml.
3) Continue to subculture after the cell density 5 x 10E5 cells/ml in gradually increasing proportions of SFM until the serum is ~0.1% with about 85% cell viability.
4) Subculture the cells into SFM with an innoculum of 2.5 x 10E5 to 3 x 10E5 cells/ml.
5) When the cell density is 1 x 10E6 to 3 x 10E6 cells/ml (4 to 6 days post planting) subculture the cells again.
6) Stock cultures of SFM adapted cells should be subcultured in SFM every 3 to 5 days when the cell density is 1 x 10E6 to 3 x 10E6 cells/ml with 90% viability.
DIRECT ADAPTATION
Some cells can be directly adapted from serum-containing medium to SFM. For direct adaptation, the cell innoculum should be 1.5 x 10E5 to 3 x 10E5 cells/ml.
Cells should be subcultured when the cell density is 1 x 10E6 to 3 x 10E6 cells/ml. Cells are fully adapted to SFM when the cell density is 2 x 10E6 to 4 x 10E6 cells/ml after 4 to 7 days in culture.
Stock cultures of cells adapted to SFM should be subcultured in SFM every 3 to 5 days when the cell density is 1 x 10E6 to 3 x 10E6 cells/ml with 90% viability.
