Blood LustBlood Lust

Only about 7% of humans have O negative blood—the blood type that can be transfused into anyone without causing tissue rejection. The rarity of this blood type poses problems for blood transfusion services, which must rely on a steady-stream of donors to provide a constant supply of fresh blood. But help is on the way.A three-year UK research project will develop the technology for producing unlimited amounts of synthetic human blood from embryonic stem cells. Supported by the National Health Services Blood and Transplant, the Scottish National Blood Transfusion Service, and the Wellcome Trust (the world's largest charity devoted to medical research), researchers will test human embryos left over from in vitro fertilization treatments to single out those embryos that are genetically programmed to develop into O negative blood.Scientists think that O negative blood can be produced in unlimited quantities from embryonic stem cells because the cells can be induced to multiply indefinitely in the laboratory. The aim of the UK project is to stimulate embryonic stem cells to develop into mature, oxygen-carrying red blood cells. In addition to being plentiful, synthetic blood will not be at risk of carrying infectious viruses such HIV and hepatitis.An obvious boon to armies around the world that require large quantities of blood for wounded soldiers, the project will also benefit accident victims and those requiring blood transfusions during surgery. Thus, scientists in several other countries, including Sweden, France, and Australia, are developing similar projects to produce synthetic blood from embryonic stem cells.