It is the stuff of gothic science fiction: men in white coats in factories of blood and bones.
But the production of blood on an industrial scale could become a reality once a trial is conducted in which artificial blood made from human stem cells is tested in patients for the first time.
It is the latest breakthrough in scientists' efforts to re-engineer the body, which have already resulted in the likes of 3d-printed bones and bionic limbs.
Marc Turner, the principal researcher in the £5 million programme funded by the Wellcome Trust, told The Telegraph that his team had made red blood cells fit for clinical transfusion.
Prof Turner has devised a technique to culture red blood cells from induced pluripotent stem (iPS) cells - cells that have been taken from humans and 'rewound' into stem cells. Biochemical conditions similar to those in the human body are then recreated to induce the iPS cells to mature into red blood cells - of the rare universal blood type O.
"Although similar research has been conducted elsewhere, this is the first time anybody has manufactured blood to the appropriate quality and safety standards for transfusion into a human being," said Prof Turner.
There are plans in place for the trial to be concluded by late 2016 or early 2017, he said. It will most likely involve the treatment of three patients with Thalassaemia, a blood disorder requiring regular transfusions. The behaviour of the manufactured blood cells will then be monitored.
"The cells will be safe," he said, adding that there are processes whereby cells can be removed.
The technique highlights the prospect of a limitless supply of manufactured type-O blood, free of disease and compatible with all patients.
"Although blood banks are well-stocked in the UK and transfusion has been largely safe since the Hepatitis B and HIV infections of the 1970s and 1980s, many parts of the world still have problems with transfusing blood," said Prof Turner.
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.
Currently, it costs approximately £120 to transfuse a single unit of blood. If Prof Turner's technique is scaled up efficiently, it could substantially reduce costs.
Dr Ted Bianco, Director of Technology Transfer at the Wellcome Trust, said: "One should not underestimate the challenge of translating the science into routine procedures for the clinic. Nowhere is this more apparent than in the challenge Professor Turner and colleagues have set out to address, which is to replace the human blood donor as the source of supply for life-saving transfusions."
For the moment, factories of blood remain the stuff of fiction ( via telegraph.co.uk ).