Human embryonic stem cells are derived from surplus embryos generated at in vitro fertilization clinics.

"If we follow scientific protocol it could take 5 to 10 years before in vitro fertilization clinics add human cloning to their repertoires."

They had gone to a well-known, highly regarded in vitro fertilization clinic in Boulder.

"I've got all the facilities of a fertilization clinic."

It seems more respectful to use donated embryos from in vitro fertilization clinics than simply to discard them.

Let's stick with exploring stem cells from adults and embryos already in in-vitro fertilization clinics not used for reproduction.

"He's the head of the in vitro fertilization clinic at Boulder," I muttered to myself.

I remembered that Jilly was a pediatric nurse, and worked at the hospital's in vitro fertilization clinic.

Thus, rather than fighting to secure funds for therapeutic cloning, we should stop the practice of producing "surplus embryos" at in vitro fertilization clinics.

But critics of the research object that the cells are harvested by destroying embryos, which come from in vitro fertilization clinics.