For one confluent 15ml flask
- Remove media
- Wash with PBS
- Trypsin 4ml for 5min.
- Add 10ml DMEM
- Spin cells at 1K for 2min.
- Remove media
- Resuspend in 6ml: 4.0ml DMEM; 1ml serum; 0.5ml DMSO
- Aliquot 2ml in well-labeled cryovials
- Wrap in paper towel and place in box for slow freezing at -80
- Label and store in liquid nitrogen