By Nathan Seppa
A South Korean scientist who claimed to have cloned the first human embryonic stem cell is now requesting that some of his published work be retracted. But as Science News went to press, it was still unclear whether the abrupt turnaround arose from scientific fraud, a laboratory mistake, or both.
Either way, the fiasco is a setback for stem cell research, other scientists say.
In the March 12, 2004 Science, Woo Suk Hwang of Seoul National University and his team reported that they had removed DNA from a human egg, replaced it with DNA from a mature cell, and then grown the altered egg into a cluster of cells. It appeared that the researchers had thus cloned human stem cells, with the potential to develop into any cell in the body (SN: 2/14/04, p. 99: Tailoring Therapies: Cloned human embryo provides stem cells).