Fear of the clone word

These fertilised embryos generally have the capacity to develop to term.

Nuclear-transfer embryos have little or no capacity to develop to term (fewer than

one per cent are able to and most are abnormal) but are able to form embryonic stem cells.

The reasons for this difference are complex and not well understood.

If we are agreeable to use "normal" IVF embryos for research, why are there more concerns for using nuclear-transfer embryos?

Strongly stated opposition to nuclear transfer to form disease and patient-specific stem cells must then arise from those who also oppose IVF, to be logical.

This is a minority of the community.

The opposition to forming embryos for research is not really relevant because there is no combination of sperm and egg involved.

Since nuclear-transfer embryos cannot ever be placed in the body of a woman, they are not formed with reproductive intention - they are formed to understand and possibly treat severe disease and injury.

Hence both by nature and intent they are not embryos in the usual understanding of this term.

Scientists are unanimous in their opposition to reproductive cloning and support strict regulation and community involvement in the monitoring of research on human embryonic stem cells.

Nuclear-transfer methods offer new research opportunities for conditions with few or no treatment options.