Pluripotent stem cells can develop into various kinds of cells in the body, such as muscle, blood vessels, and bone cells; however, there are several barriers to culturing adult stem cells in a petri dish. It has been especially difficult to generate blood stem cells in the lab without using animal serum, which can carry viruses that interfere with cell reproduction and create other complications.
Schiedlmeier and Klump used mouse embryonic stem cells to grow blood-forming stem cells in low-oxygen conditions in the lab without using any serum or supportive cells known as stroma. When they transplanted the blood-forming cells into mice, they found the cells were capable of rebuilding the mice's blood-forming system.
Their discovery means that scientists may eventually be able to create blood stem cells from transplant patients in a lab rather than using stem cells from unrelated donors, avoiding dangerous "graft versus host" reactions.