Scientists have found  to  produce blood. The blood is  enough to give to . The old  of making blood was very slow and . It was difficult to make a . The new way means  can make a lot. They can make as  as they want. They can make "unlimited"  of blood.
A researcher said his  needs the  to mass produce blood. He said it was a . He said his team would make  rare types of blood at . These are  easy to find. Not  people with  blood types donate blood. He said: "Suitable… blood cell  can be difficult to [find]."