Frozen NPC aliquots were retrieved from liquid nitrogen storage and quickly thawed in a 37 °C water bath. NPCs were resuspended in a 15 ml tube containing pre-warmed DMEM and centrifuged (5 min × 1000g). Following aspiration of DMEM, the cell pellet was gently resuspended in NPC medium (Table 1) and seeded onto Matrigel-coated plates. The plate was gently shaken in order to evenly distribute NPCs and returned to the incubator. NPCs were fed every second day until the cell density reached ten to fifteen million NPCs in a single well of the 6-well plate.
