For those of us who object to embryonic stem cell research because it destroys human life, this is a real breathrough: removing a single cell from an embyro. The embryo is apparently unharmed, and the single cell can be used for stem cells.
Right now, my biggest objection is changing apparently unharmed into definitely not harmed. Since the procedure of removing a cell has already been performed on many people who started life in vitro, I'm hoping that they can be studied to determine the safety of the procedure.
There is the concern as well that this involves experimentation without consent. One answer is that it is already being performed, so we aren't talking about something new. But more fully, the question is one of safety. Unlike cloning , where animal clonings have shown real problems and for which I would have big concerns for that reason, this method has been used for testing purposes on people and again apparently isn't a big problem. If there are problems, then I would object that it is experimentation without consent.
As to the claim that you could, through further manipulation, create a clone embryo and thus human life this way, I'm not impressed. The possibility exists that someday any cell may be turned into an embryo via manipulation, but I'm not going to stop brushing my teeth because I knock a few cells loose from my cheeks and flush them down drain when doing so.
I have to guard my optimism because medicine is a field that over announces breakthroughs -- but tends to deliver improvements.
