The announcement on Sunday of an experiment to clone a human embryo has sparked debate in Northwestern’s biological sciences community about the test’s significance and ethical ramifications.

“What they are doing is potentially very important,” said Rex Chisholm, director of the Center for Genetic Medicine at the Medical School. “It’s just too early to say.”

Advanced Cell Technology, a small biotechnology company in Worcester, Mass., announced that it tried to produce the first human embryos through cloning. Advanced Cell did not plan to clone an entire human being but rather would have used the embryo’s cloned stem cells for therapeutic purposes — growing different tissues that potentially could treat diseases.

But Chisholm and other scientists around the country argue that the experiments did not result in actual cloning. In the most successful experiment, the cells divided a couple of times.

“In order to clone an embryo, the dividing would have to go on,” said Chisholm, a professor of cell and molecular biology. “It’s a long shot to call this cloning. It is inconclusive.”

In the experiment, scientists inserted adult human DNA into an unfertilized human egg. Chisholm said signals present in the human eggs could have caused them to divide several times even without the DNA nucleus.

“No data says the nucleus they added was driving that division,” Chisholm said. “What they have done is a technique called somatic nuclear transfer — and that isn’t cloning a human.”

Chisholm’s lab isn’t interested in cloning human beings so much as using stem cells for its current research with growing mouse tissue. Although many scientists are comfortable with using therapeutic cloning to produce stem cells, others, including politicians and lobbyists, rail against what they call the “slippery slope” of bioethics.

President Bush sounded off Monday about the controversial experiments.

“The breakthrough was morally wrong, in my opinion,” Bush said. “We should not, as a society, grow life to destroy it.”

Although Bush decided in August not to allocate federal funds to create new embryos for stem cell research, University President Henry Bienen said he hopes to increase the university’s presence in the field. NU currently does not have any stem cell lines.

“I think we will make a big push in stem cell research,” Bienen told The Daily on Nov. 15. “We are going to do a lot of new work in the Medical School and in medical research.”

Some fear that research with stem cells will soon transfer to cloning humans, even though research currently is far from producing a cloned embryo that develops into a human fetus, said Neena Schwartz, director of NU’s Center for Reproductive Science.

“Therapeutic cloning, if you could control it … isn’t inherently controversial,” said Schwartz, a professor emeritus who has served on several national bioethics committees. “But two years from now, we might be able to use a similar technology to clone a human. Then it really becomes an ethical issue.”

Schwartz also said religious beliefs affect whether or not someone approves of cloning even for therapeutic purposes. Religions that dictate human life begins at fertilization also believe that destroying a fertilized egg to harvest its stem cells is unacceptable.

Schwartz agreed with Chisholm that most scientists want to use stem cells only to cure diseases but feared that some would try to create cloned human beings.

“If one scientist thinks it would be neat to make a human clone, it would be very difficult to stop it,” Schwartz said. “While 99 percent of people are ethical, there is always that 1 percent that isn’t. This is a hot-button issue.”

The Associated Press contributed to this report.