British scientists are planning to produce synthetic human blood from embryonic stem cells to be used in infection-free transfusions.
The three-year research project will provide an unlimited supply of blood from the stem cells of spare IVF embryos.
Scientists will test human embryos left over from IVF treatment to find those that are genetically programmed to develop into the rare 'O-negative' blood group, which can be transfused into people with all blood types.
The project aims to develop mature, oxygen-carrying red blood cells that will be free from viruses such as HIV and hepatitis, or the human form of 'mad cow' disease.
This is while many groups believe it is not ethical to destroy embryos for creating stem cells.
"Like so many of the claims associated with embryonic stem cells, this is first steps research rather than a cure around the corner, and just as hypothetical as the rest of the claims which try to justify destroying the human embryo for the benefit of mankind,” BBC quoted Josephine Quintavalle of the public interest group Comment on Reproductive Ethics as saying.
"Associating this controversial research with a National Blood Transfusion service may even end up contaminating the feel-good image of blood banks,” she added.
"Those who donate blood but who defend the right to life of the human embryo may be reluctant to continue giving their blood."