Scientists from Bristol University have found a way to mass produce blood that is good enough for hospital patients. For many years, they could produce blood in a laboratory. However, the process to do that was very slow and they could not make a lot of blood. The new method means scientists can make an "unlimited supply" of blood. Researcher Dr Jan Frayne said older ways of producing red blood cells used stem cells that could only produce a limited amount of blood. She added: "We have [shown] a [workable] way to sustainably manufacture red cells."

Professor David Anstee, another researcher, told reporters his team now needs the technology to make blood on a large scale – to mass produce it. He said that would be a challenge. He added: "The next phase of our work is to look at methods of [producing more]." He told reporters that at first, they would produce only rare types of blood. He said these are difficult to find with traditional blood donation. He said: "The first…use of [our] red cell product is likely to be for patients with rare blood groups, because suitable…red blood cell donations can be difficult to source."