You run into moral problems doing research on a woman's body and a human embryo.

"It is even hard to keep on the table the idea that human embryos are more than research material," she said.

"There's a significant weight to the decision to use human embryos," he says.

Finally, and not for the first time, I want to express my concern about research on human embryos.

I believe so, but again, not at the expense of human embryos.

At no stage of the process, as it has been described, would a human embryo be created.

Does not the eye of the human embryo predict the light?

To develop the method, research with human embryos was required.

That does not mean no scientist has ever worked on human embryos.

In some countries, it is illegal to develop a human embryo for more than 14 days outside a woman's body.