Cloning Breakthrough

Updated: August 12, 2010

Click on the gallery to see how stem cells are extracted from a cloned human embryo.

In a scientific breakthrough, researchers in South Korea have become the first to successfully clone human embryos and extract stem cells from them. The scientists said their goal was to further understanding of the causes and treatment of disease, and not for reproductive purposes.

But the achievement, published in this month's journal Science, raises the possibility of making a cloned human baby more feasible. The development rekindles the debate about whether all human cloning should be banned, even if it were strictly for medical purposes. Cloning to create babies has been banned in numerous countries, including South Korea, but "therapeutic cloning" for stem cells could potentially lead to cures for crippling diseases and is still being considered by many governments.

Embryonic stem cells hold great promise for medical research, as they can be manipulated into many other human cells that may provide cures for conditions such as Parkinson's, Alzheimer's, diabetes, heart disease and spinal cord injuries. But some critics say that using stem cells from embryos, even those newly created in a petri dish, is equivalent to taking human life, since embryos are destroyed when stem cells are removed.