Religion and biology professors this week greeted with skepticism an announcement that scientists have developed a procedure that allows parents to choose their baby's sex.

The In Vitro Fertilization Institute of Fairfax, VA announced earlier this month that it has successfully sorted sperm by staining it with a fluorescent dye which helps differentiate male- and female-producing sperm.

According to The London Independent, a British couple has conceived a female baby using the treatment.

But some Harvard professors--like Jay M. Harris, Wolfson professor of Jewish studies--question the morality of what they deemed "tantamount to playing God."

Harris says he does not think the discovery could have any positive impact on society.

"It necessarily gives people the opportunity to value one form of human being over another," he says. "In my mind, this procedure can only make people more ethically callous."

Harris also says he fears that science will use the procedure "in an ethically negative way."

Most Western religions are likely to discourage followers from using the new technology, he adds.

"[Religious leaders] will recognize that this encourages humans to actively value one form of human life over another, and this should offend against the ethical missions of these faiths," he says.

"I suspect that we'll reject it, just as most of us have rejected cloning, which to my mind is much less objectionable."

Yet scientists pointed out some possible positive uses for the procedure.

William D. Fixsen, senior lecturer on molecular and cellular biology, says choosing a baby's sex would enable parents to "weed out genetic diseases" that often target only one sex.

Still, Fixsen does not whole-heartedly endorse the procedure either.

"I'm uneasy about why one would want to create a process like that," he says. "It seems an unnecessary technique."

William M. Gelbart, professor of molecular and cellular biology, says he does not want to judge the issue as ethical or unethical.

"Whether it's ethical for others, I have no idea," he says. "For myself, I kind of like the mystery."

Neither Fixsen nor Gelbart hails the new procedure as a major scientific achievement. Another method of sex selection--through in vitro fertilization--is available for parents who want to choose the sex of their child.

"It's not news," Fixsen says. "I don't consider it to be a step forwards but maybe a step backwards."

Gelbart says the concept is very old.

"In the context of some cultures where there's such severe gender discrimination, it might be used," he says. "It's been used through selective abortion for a long time."

"Is it better to have a technique?" he asks. "I don't know."