Stem Cell

Oxygen is a fundamental part of the stem cell niche. Physiologic O2 levels are far below those provided in most stem cell experiments (room air - 21% oxygen). In the body, stem cells experience a range of oxygen levels: mesenchymal stem cells (MSCs) range 2-8% O2, hematopoietic stem cells (HSCs) at 1-6% oxygen, and neural stem cells (NSCs) from 1-8% O2. Human development occurs under low oxygen conditions and scientists optimize O2 conditions (2-5% O2) for experiments with embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Multiple benefits are reported for physiologic oxygen in stem cell cultures:

  • increase proliferation
  • maintain pluripotency
  • promote proper phenotype
  • streamline cell reprogramming
  • preserve stemness
  • increase yield
  • diminish spontaneous differentiation
  • decrease doubling time
  • boost self-renewal
  • control lineage commitment
  • modulate quiescence
  • enhance repopulating ability

Researchers are using new tools for culture, handling, and analysis of stem cells under biologically relevant oxygen levels (or physioxia). Upgrading existing CO2 incubators with insertable O2-controlled chambers is an economical approach for optimizing oxygen in stem cell experiments. Even brief interruptions of physiologic O2 during culture maintenance in open hoods/BSCs alter stem cell function. To prevent this, physioxia (or hypoxia) workstations maintain constant control of O2, CO2, and Temp with interconnected incubators and hoods for all steps of cell incubation, handling, and analysis.