1. Remove and discard culture medium.
2. Briefly rinse the cell layer with 0.25% (w/v) Trypsin-0.53mM EDTA solution to remove all traces of serum which contains trypsin inhibitor.
3. Let the culture sit at room temperature or at 37°C until cells detach (about 10 minutes).
   Note: To avoid clumping do not agitate the cells by hitting or shaking the flask while waiting for the cells to detach. Cells that are difficult to detach may be placed at 37°C to facilitate dispersal.
4. Add complete growth medium and aspirate cells by gently pipetting.
5. Add appropriate aliquots of the cell suspension to new culture vessels.
6. Incubate cultures at 37°C.

Subcultivation Ratio: 1:2 to 1:4
Medium Renewal: Every 2 to 3 days

Note: For more information on enzymatic dissociation and subculturing of cell lines consult Chapter 13 in Culture of Animal Cells, a Manual of Basic Technique by R. Ian Freshney,xa05th edition, published by Wiley-Liss, N.Y., 2005.

Complete growth medium described above supplemented with 5% (v/v) DMSO.xa0 Cell culture tested DMSO is available as ATCC Catalog No. 4-X.