US scientists for the first time have used a cloning technique to get tailor-made embryonic stem cells to grow in unfertilised human egg cells, a landmark finding and a potential new flashpoint for opponents of stem cell research.
The researchers were trying to prove it is possible to use a cloning technology called somatic cell nuclear transfer, or SCNT, to make embryonic stem cells that match a patient's DNA.
The achievement, published in the journal Nature, is significant because such patient-specific cells potentially can be transplanted to replace damaged cells in people with diabetes and other diseases without rejection by the immune system.
This could ignite new controversy because some opponents consider the technique to be cloning, which they fiercely oppose.
"This paper will be seen as significant both by those who are trying to use SCNT to produce human patient-specific embryonic stem cell lines and by those who oppose human 'cloning' experiments," said Professor Robin Lovell-Badge, a division head at Britain's National Institute for Medical Research.
Stem cells are the body's master cells, the source material for all other cells.
Proponents of embryonic stem cells say they could transform medicine, providing treatments for blindness, juvenile diabetes or severe injuries.