Scientists in the UK have announced they will begin human trials on artificial blood grown in a lab from stem cells in the near future.  

“We are confident that by 2017 our team will be ready to carry out the first early-phase clinical trials in human volunteers,” Dr. Nick Watkins, assistant director of research and development at the National Health Service (NHS) Blood and Transplant, told the Daily Mail. “These trials will compare manufactured cells with donated blood. The intention is not to replace blood donation but provide specialist treatment for specific patient groups.”

Researchers created the blood using stem cells taken from umbilical cords and from adult donors, the International Business Times reported. The stem cells were cultured in a solution for three weeks before becoming red blood cells. Researchers reported a 40 to 50 percent success rate in converting the stem cells into red blood cells.

According to the report, this type of treatment would benefit patients with complex blood types and conditions that require frequent transfusions. The number of blood donors in the UK has fallen by 40 percent.