Human embryonic stem cells copied successfully
Courtesy of M. Tachibana
With a tweak to the technique that cloned a sheep in 1996, scientists have generated stem cells in the lab that genetically match those found in human embryos.
The feat pumps life into a sputtering field. Until now, researchers had to harvest the cells from embryos left over from in vitro fertilization, or tinker with ways to turn adult cells into embryonic ones, a task riddled with technical challenges.
Embryonic stem cells are so prized because they can transform into any type of cell in the body. This boundless potential carries the promise of personalized medicine: Doctors could one day dose patients with new, healthy cells made from patients’ own bodies. Though scientists had previously cloned cells from frogs, sheep and even monkeys, no one had figured out how to