Stem cells from just ten human embryos could theoretically be used to treat more than a third of the UK population, scientists revealed today.
A study paving the way to clinical stem cell banks found that a small subset of potential "super-donors" exists in the population.
Embryonic stem cells from these individuals could be matched to the widest variety of people.
Just ten lines of the cells would provide a top level, or "full", match for 38 per cent of the population, a "favourable" match for more than 60 per cent, or a "beneficial" match for about 80 per cent.
Each step-down in match level requires greater efforts to counter the problems of immune system rejection.
Human embryonic stem cells are "blank slate" cells that can potentially be turned into any kind of human tissue.
Scientists hope that in future the cells will be used to treat a host of diseases including some, such as Parkinson's and diabetes, that are currently incurable.
The cells are obtained from within human embryos. To avoid rejection by the recipient's immune system, it has been suggested that patients can be therapeutically "cloned" to provide embryos containing "perfect match" stem cells.
But many experts believe such an idea to be impracticable and far too expensive.
The first stem cells used in treatments are far more likely to be employed in the same way as current transplants.
They will have to be tissuetyped and matched to recipients, and even those with the best matches will require patients to be given immune system-suppressing drugs.
The big advantage of stem cells is that, once collected, they can be grown in the laboratory and replenished without seeking new donors.
One stem cell line could be used to treat many different patients.
Britain already has a Stem Cell Bank but at present it contains stem cells suitable only for research, not medical treatment.
The UK Stem Cell Initiative is promoting efforts to produce medical-grade stem cells, generated without animal growth mediums and screened for viruses, that would be safe for patients.
Commenting on the research, Dr Justin St John, from the University of Birmingham, said: "We have a starting point on which we can build, and think about how we can populate the Stem Cell Bank in the future."
The research highlighted a serious obstacle in the way of stem cell treatments for people from ethnic minorities in the UK. Full matches could only be found for two per cent of patients from Asian and black communities, who typically have different blood groups from white Caucasians.
The problem could be tackled by international cooperation between stem cell banks in different countries.