Scientists have used embryonic stem cells to generate blood -- a feat that could eventually lead to endless supplies of type O-negative blood, a rare blood type prized by doctors for its versatility.
"We literally generated whole tubes in the lab, from scratch," said Robert Lanza, chief science officer at Advanced Cell Technologies.
People usually require blood transfusions that match their own blood type: A mismatch can be fatal. Type O-negative can be safely transferred into anyone, but is only possessed by about 7 percent of the population, leaving supplies perpetually short.
But because blood cells are short-lived and cannot divide, there's reason to believe that stem cell-derived blood cells could pose fewer complications than other therapeutic stem cells, which can divide unpredictably.
But Lanza said his technique could also work with stem cells produced by de-differentiation, a new and ethically trouble-free process during which adult cells regress into an embryonic state.
De-differentiated cells have a tendency to go cancerous -- but because blood cells are DNA-free, said Lanza, they could be safe in this particular application.