The National Institutes of Health (NIH) today released draft guidelines that permit federal funding for research on stem cells from human embryos set to be discarded by fertility clinics.

Under the new regs, the agency would fund studies on embryos created in test tubes — but no longer needed — for reproductive purposes, adult stem cells and induced pluripotent stem cells (skin or other adult cells that are nudged back into their pluripotent state, when they have the potential to become any cell type). Fertility patients would have to consent to their leftover embryos being donated for research.

The rules bar funding for research on embryos created expressly for stem-cell studies; ditto for studies involving embryos derived from somatic cell nuclear transfer (replacing the nucleus of an unfertilized egg with genetic material from another body cell and stimulating it to divide) or parthenogenesis (reproduction without fertilization).

"This is an incredible opportunity for the scientific community and the health of the people [who may benefit] by what we learn from this additional science," Raynard Kington, NIH's acting director, said during a teleconference with reporters today. Scientists believe that embryonic stem cells, which have the ability to morph into any type of tissue in the human body, could one day be used to treat conditions such as diabetes and Parkinson's disease.

Former President George W. Bush banned federally funded research on embryonic stem-cell lines created after Aug. 9, 2001. On March 9, President Obama lifted the ban and gave the NIH 120 days to craft guidelines governing such research. Scientists complained that Bush's ban limited research to about two dozen stem-cell lines of varying quality. But there may now be some 700 embyronic stem-cell lines that would qualify for federal funding under the new guidelines, Kington said. (Congress passed legislation twice calling for the limit to be lifted on stem cell research, but Bush vetoed both bills.)

The proposed new regs disappointed some who said the prohibition on funding of embryos created specifically for research could hamper the creation of treatments such as organ tissue genetically matched to prospective transplant recipients, the New York Times notes.

"The proposed guidelines limit some very promising avenues of current research and limit the genetic diversity of the stem cell lines that will be eligible for federal funding," Susan Solomon, CEO of the nonprofit New York Stem Cell Foundation, said in a statement. "This is a very young field, with the promise to combat the most deadly diseases of our time. Scientists need to be able to deploy a full arsenal, one that encompasses what may be possible in the future."

Two colonies of human embryonic stem cells carrying the mutation causing Marfan syndrome, derived from a donated IVF blastocyst/Lab of Julie Baker, Stanford University School of Medicine courtesy of California Institute for Regenerative Medicine