A new source of blood could be just around the corner: artificial red blood cells grown from fibroblasts that have been reprogrammed into mature red blood cells in the lab. The blood, developed by researchers at the University of Edinburgh and the Scottish National Blood Transfusion Service (SNBTS), would be Type O negative, also known as universal donor blood, which currently comprises just 7 percent of the blood donor pool.

“We have made red blood cells that are fit to go in a person’s body,” project leader Marc Turner, medical director at SNBTS, told Forbes. “Before now, we haven’t really had that.”

The blood is created by dedifferentiating fibroblasts from an adult donor and reprogramming them into induced pluripotent stem cells (iPSCs), which are then cultured in a bone-marrow-like environment for a month. Blood cells are then extracted from the cell culture. If the technique can be scaled up to industrial levels (which is no trivial task), beyond potentially supplying an endless supply of life-giving blood, the artificial serum would consist entirely of young, healthy, and infection-free cells, avoiding the issues of pathogen contamination that have in the past plagued the donor blood supply.

However, scaling up the process to meet demand will be a challenge, as Prof Turner’s laboratory conditions are not replicable on an industrial scale. “A single unit of blood contains a trillion red blood cells. There are 2 million units of blood transfused in the UK each year,” he said.