Figure 1.

Schematic of the hypoxic cultivation set up. hNTSCs and a gas-controlling agent were placed in a gas-barrier bag, which was sealed with a clip to lower the oxygen saturation within the bag. The oxygen meter showed an initial oxygen level of 13.4% (left). After 10~20 min, the oxygen meter showed that the desired oxygen level of 5% was achieved (middle). Once reaching 5% oxygen, the gas-controlling agent was isolated from the hypoxic cell cultures using another clip (right).