At what stage are stem cells removed from the developing “embryo” - is it at the 4 cell, 8 cell, 300 cell stage or what?
Of the 90 existing lines, at what stages were the embryos destroyed?
I have not seen this information anywhere, and it is relevant for the various debates on the issue.
But, in your answer, PLEASE PLEASE do not get into the debates. I want only accurate information and sources, if possible.
Please, please no debates here. We can do that elsewhere.
Try searching for “stem cell” in the search engine.
Okay, but only if you say “please”.
In this thread where we are tossing GQs about stem cells around, I suggested that everybody check out the stem cell primer. The answer depends on which kind of stem cells you want, and whether or not you want them supersized.
Totipotent stem cells (the most useful) can be obtained from a fertilized egg almost immediately and up until several cycles of cell division (about 4 days), at which time the totipotent cells begin to specialize and become a blastocyst.
Pluripotent stem cells are almost as useful as totipotent, the principal difference being that they cannot develop into a human like the totipotent cells can.
Multipotent stem cells results from pluripotent stem cells that have undergone development into further stages of specialization. These stem cells can give rise only to cells which have only one function, e.g. blood stem cells give rise only to red blood cells.
So it would seem that if you like your stem cells totipotent (and who doesn’t?), you’d better get them as early in the developmental stage as possible. So those first four days look like the cheese.
I’m not sure this will make much of a difference to the anti-abortion group, because (I think) they draw their line at conception anyway. Whether you take your cells at day 4 or day 40, it’s still “murder”.