Chris, he must think you're actually Cindy, and with the "cp" in your ID it's an easy mistake to make… :-[
LOL – I wish!
I must admit that embryonic stem cells are not my area of expertise. However, non-embryonic stem cells are only just coming nto use. They took a long while to develop, because adult stem cells are, I believe, programmed to a degree. Embryonics are not. Certainly, if a line is even slightly contaminated with foreign DNA, it's next to useless. It's like PCR, which I have used – RNA or DNA samples must be as close to 100% pure as possible, because, with the enormous levels of amplification, a small impurity ends-up being a big problem. As far as embryonic cells are concerned, there is a simple choice – do it properly and accept the moral implications, or wait until other techniques are developed, with the understanding that you're delaying development of treatments for some unpleasant diseases so that many wil suffer who might not. Neither way is ideal, ut that's just tough – somethings got to give. :-
