Note: For routine culturing of our hNSPCs, we change 50-100% of the media every other day and usually passage them 1:2 once a week. The culture media contains 20% BIT-9500, 1X antibiotic/antimycotic, and growth factors (EGF, FGF, and PDGF each at 40 ng/ml) in DMEM:F12 base media.
Preparing the Coated Flask and Dissociating the Cells
- To prepare new flasks for the passaged cells, coat T25 flasks with 10 µg/ml human fibronectin in EMEM for 4 hours, or overnight, in a 37°C tissue culture incubator. Right before passaging the cells, remove the fibronectin solution and rinse the flasks with PBS.
- Transfer the old "conditioned" media from the cells to be passaged to the new fibronectin-coated flasks (such that half the final volume of media for each flask will be the "conditioned" media). These culturing conditions help keep these cells in their undifferentiated state.
- Once all of the media is removed from the cells to be passaged, rinse the cells once with PBS. Take care to not dry out the cells.
- Add Cell Dissociation Buffer (CDB) directly onto the cells (1.0-1.5 ml for a T25 flask). Incubate cells in the buffer for about 5 minutes at room temperature. Gently tapping the flask will help speed up cell detachment.
Centrifuging, Resuspending, and Plating Cells
- Add serum-containing media (DMEM:F12 with 10% heat-inactivated fetal bovine serum) (use ~3X the volume of CDB) to the flask with detached cells. Remove the media and cells to a 15 ml conical tube. Use a small volume of fresh serum-containing media to rinse the flask and recover residual cells.
- Centrifuge the media and cells at 1000 rpm (~200xg) for 5 minutes.
- Suction off the serum-containing media and resuspend the cells in fresh culture media, pipetting up and down to make a homogeneous cell suspension.
- Transfer half of the resuspended cells into each new flask for a 1:2 split. Note the new passage number on the flask.