British scientists have created human red blood cells from spare embryonic stem cells, a major breakthrough they claim could soon pave the way for production of synthetic ‘O-negative’ blood for medical transfusions. The red blood cells have been produced from stem cells from spare IVF embryos as part of a three-billion-pound project to develop an alternative source of O-negative blood, the universal donor group which can be transfused into people without fear of rejection, ‘The Independent’ reported. In their research, the scientists used more than a 100 spare embryos left over from treatment at fertility clinics to establish several embryonic stem cell “lines”. A line, RC-7, was transformed into blood stem cells before being converted into red cells containing oxygen-carrying haemoglobin. Prof. Marc Turner, the Director of the Scottish National Blood Transfusion Service in Edinburgh and leader of the project, said that synthetic blood made on an industrial scale would overcome the problem of blood shortages and risk of transmitting new infections between donors and recipients. “We’ve proved the principle that from these embryonic stem cell lines we can generate red blood cells. “At the end of this three-year period we would envisage generating up to one unit (a pint) of red cells from embryonic stem cells at clinical grade which fulfil all the in vitro characteristics of red cells,” Prof Turner was quoted as saying.