More oversight is needed to ensure that research using stem cells (search) culled from human embryos (search) is done under strict ethical standards, a government advisory group said Tuesday in proposing national guidelines for the controversial field.

Strict limits on taxpayer-funded research using human embryonic stem cells means most of the work in this growing scientific field today is done with private funding -- and little federal oversight.

So the new report recommends a set of standards for U.S. scientists to follow, in how researchers cull, store, distribute and use the valuable cells.

"Heightened oversight is essential to assure the public that stem cell research is being carried out in an ethical manner," said Jonathan Moreno, a biomedical ethicist at the University of Virginia who co-wrote the report for the National Research Council and Institute of Medicine. "The oversight we call for will in many instances set a higher standard than required by existing laws or regulations."

The independent organizations are chartered by Congress to advise the government on scientific matters.

Embryonic stem cells form in the first few days of a developing embryo and are capable of becoming any type of cell in the body. Researchers hope they can find ways to use these cells to cure a variety of illnesses, but the research has been controversial because the embryo is destroyed in collecting the cells.

President Bush banned federal funding for stem cell research except for already existing cell lines, but private funding is continuing some new research.

The new report urged that new stem cell oversight committees be established in addition to other institutional review boards, which also review stem cell research.

In addition to experts in biology and stem cell research, the committees should include legal and ethical experts as well as representatives of the public, the report said.

Among the recommended guidelines:

--Donors must give their consent before their embryo could be used to produce stem cells and they should be told they have the right to withdraw their consent at any time before a stem cell line is derived. In addition, donors should not be paid.

--Consent forms should inform the donor that embryos will be destroyed in the process of deriving stem cells and that the resulting cell lines may be kept for many years.

--Donors should be told that research involving their stem cells may have commercial potential, but they will not share in any financial benefit.

--An oversight committee should keep a registry of stem cell lines banked at an institution, which should include a proof of informed consent, a medical history of the donors, and a characterization of any genetic markers on the cell lines.

--Repositories of stem cell lines need a secure coding system to protect donors' identities.

--No animal embryonic stem cells should be transplanted into a human embryo, and approval by a review committee should be secured before any human embryonic stem cells are put into an animal. No human embryonic stem cells should be put into nonhuman primates.

The report also called for a national independent organization to periodically review stem cell research and determine whether guidelines need to be updated.

The report was funded by the National Academies with additional support from the Ellison Medical Foundation (search) and the Greenwall Foundation (search).