Harvard University (search) scientists have asked the university's ethical review board for permission to produce cloned human embryos for disease research, potentially becoming the first researchers in the nation to wade into a divisive area of study that has become a presidential campaign issue.

"We want to find new ways to study and hopefully cure diseases," said Harvard biologist Douglas Melton (search), a senior researcher who, along with a colleague, has applied for permission to do the work.

Embryonic stem cells are master cells that can form into any tissue of the body. Many scientists believe harnessing them might one day allow tissue regeneration to treat numerous diseases.

Harvesting stem cells from embryos kills the embryo, and some argue that it is tantamount to taking a life. President Bush (search) has signed an executive order limiting federal help to all but existing stem cell lines.

Democratic challenger John Kerry supports widespread stem cell research.

The research group asking for a green light to advance its work is one of two teams affiliated with the Harvard Stem Cell Institute, a facility set up earlier this year to fund such research.

The university is considering all of the ethical and other issues of embryonic stem cell cloning, said Provost Dr. Steven E. Hyman, although he did not know when the university would reach a decision. "We are being extremely careful about this," he told The Boston Globe for a story in Wednesday's editions.

None of the proposed experiments involves attempts to produce a cloned person.

So far, only a South Korean team has successfully performed nuclear transfer with human cells. British scientists also have been granted permission to conduct experiments.