Utilizing Low Oxygen Tension to Reduce Hematopoietic Cells in Murine Bone Marrow Stromal Cell Cultures

Currently, there remains a lack of universally accepted markers to prospectively isolate a homogeneous population of skeletal stem cells (SSCs). For this reason, BMSCs, which support hematopoiesis and contribute to all the functions of the skeleton, continue to be widely used to study multipotent mesenchymal progenitors (MMPs) and to infer SSC function. Moreover, given the breadth of transgenic murine models used to study musculoskeletal diseases, the use of BMSCs also serves as a powerful tool to examine the molecular mechanisms regulating MMPs and SSCs. However, common isolation procedures for murine BMSCs result in over 50% of recovered cells being of hematopoietic origins, potentially hindering the interpretation of the data generated during these studies. Here, we describe a method using low oxygen tension or hypoxia for the selective elimination of CD45⁺ cells in BMSC cultures. Importantly, this method can be easily implemented to not only reduce hemopoietic contaminants but to also enhance the percentage of MMPs and putative SSCs in BMSC cultures.