Enlarge By Stem Cell Program, Children's Hospital Boston This photo shows a colony of human embryonic stem cells growing on mouse feeder cells. This cell line (CHB-1) was established at Children's Hospital Boston. Health officials Wednesday gave the green light to federally funded research on 13 human embryonic stem cell lines, the first approved since the Bush administration imposed limits eight years ago. "What we are announcing today is just the beginning," Francis Collins, National Institutes of Health director, said Wednesday. Approval was "open and shut," he said, because the lines met requirements of new Obama administration guidelines for informed consent of embryo donors. An embryonic stem cell line is a colony of cells grown from one embryo, which is destroyed in the process. The cells can grow into every type of body tissue. Collins and others propose using the cells to study embryonic development, screen drugs and perhaps grow rejection-free replacement organs. "It's very exciting," says George Daley of Children's Hospital Boston, whose lab submitted 11 of the 13 approved lines. The other two lines belong to Ali Brivanlou at Rockefeller University in New York. The NIH will allow researchers, whose 31 grants for using such cells had awaited the announcement, to now proceed with the 13 lines. "Eventually, the new guidelines will open up several hundred lines," says Dartmouth bioethicist Ronald Green. "Researchers need to be patient." In July, the NIH answered President Obama's call for new federal funding rules for human embryonic stem cell research, overturning Aug. 9, 2001, Bush administration rules that limited funding to 21 lines created before that date. Richard Doerflinger of the U.S. Conference of Catholic Bishops, which opposes embryonic cell research, called the announcement "a political event, but the science is all moving in the other direction," toward "induced" stem cells, which are grown from skin cells but with the tissue-growing potential of embryonic cells. But Collins said the embryonic stem cells possess unique potential and also will illuminate induced cell line research. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more