Scientists have manufactured human blood in a laboratory using embryonic stem cells, reports the Los Angeles Times. The project represents a major technical breakthrough in the controversial area of stem cell research. Researchers made significant quantities of several blood types, but still have a number of hurdles ahead before producing blood that could be used in a transfusion.
"People don't usually think about these types of cells when they talk about human embryonic stem cell therapy, but it is important," said a scientists. "There's more infections all the time, and the number of donors is more and more limited."
(Read more human blood stories.)