The world's first human trials of synthetic blood will take place in Scotland.
Researchers from the Scottish Centre for Regenerative Medicine in Edinburgh have been granted a licence to make blood from stem cells that can be tested on humans.
The licence from the UK's Medicines and Healthcare Products Regulatory Agency will allow scientists at SCRM to attempt to manufacture blood on an industrial scale.
The research is designed to help to tackle shortages and stop the transfer of infections from blood donors.
The trials on humans will be the first stage in establishing more large-scale clinical trials and could result in regular use of synthetic blood.
Researchers will use stem cells from adult donors - known as induced pluripotent stem cells - as part of this project instead of the more controversial embryotic ones.
Project leader Professor Marc Turner said: "In the first part of the project we used human embryonic stem cell lines,"
He said: "one of the problems with using those lines is you can't choose what the blood group is going to be."
Professor Turner said: "Over the last few years there has been a lot of work on induced pluripotent stem cells and with those an adult can donate a small piece of skin or a blood sample and the technology allows for stem-cell lines to be derived from that sample."
He said: "This makes our life a lot easier in some ways because that means we can identify a person with the specific blood type we want and get them to donate a sample from which we could manufacture the cell lines."
With the licence scientists will also be able to work on stem cell products used to help patients with Parkinson's disease, diabetes, cancer or those who have suffered a stroke.
Other research projects have previously gained licences for human trials of other stem cell products, but this is the first time synthetic blood will be tested on humans.
Prof Turner hopes that the preparations to begin human testing will be completed in the next two to three years.
