Looks like maintaining really constant physiological oxygen levels in cell culture will be quite technically challenging. Apparently, the actual O2 levels change a lot in the medium relative to the external O2 content: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2570003/figure/Fig3/

For how many hours were the cells keep at low O2 before analyzing mitochondrial content and potential?

Thanks

NPCs spontaneously differentiate in unfavorable environmental conditions. Were the test NPCs differentiation-competent and able to generate long cytoplasmic extensions? This is significant to the application of the study results in drug screens.