President George W. Bush's policy on embryonic stem-cell research has long been too restrictive. News that stem-cell lines available for...

President George W. Bush’s policy on embryonic stem-cell research has long been too restrictive. News that stem-cell lines available for federally funded research are contaminated makes his approach indefensible.

A study published in the online journal Nature Medicine says the stem-cell lines are contaminated with a non-human molecule that may make them risky for use in medical therapies.
Three years ago, Bush said federal funds could be used for research only on a limited number of stem-cell lines already in existence. That allowed research to continue and enabled the president to assure social conservatives that no new embryos would be destroyed in the process.

If few or none of the stem cells in the federally approved batch remain uncontaminated, Bush is wasting precious time. To people suffering from Parkinson’s, Alzheimer’s, diabetes and other ailments, the president’s policy is a failure because it impedes progress.

The cells were contaminated because of the manner in which they are processed. Researchers grow the cells in petri dishes lined with cells from mice and bathed in serum derived from calves and other animals.

There is a chance the stem cells eventually could be cleared of the contaminants. But even the most optimistic scientists say it will take a year or two, if it is possible at all, to salvage existing stem cells by cleaning mouse molecules from them.

The best course is for scientists to create new, uncontaminated stem-cell lines.

New lines for federally funded research could come from embryos typically left over from fertility clinics. Some private research is proceeding with stem cells processed differently to avoid the contamination problem. Several other countries are conducting stem-cell research in a much-less-restrictive environment.

Scientists consider stem cells one of the most powerful new tools in modern medicine. No one knows for sure all that can be accomplished by them, but they could aid people suffering from numerous ailments.

It would be politically challenging but scientifically rational for the federal government to allow new embryos to be used. The research could save some lives and improve many others.