I don't think there's any reason that a blastocyst couldn't survive cell removal just as well as these earlier embryos
The issue isn't blastocyst survival but subsequent developmental progrsm being effected. I'd think there is a good reason to think this may be effected, but both of you have provided info that empirically it doesn't seem to.
Interestingly, it may be that later manipulation would be more deleterious than at this very early pre-implantation stage before any obvious differentiation and before pattern formation begins.
Very true. There's just so much self-malleability built into these early embryonic cells that they can compensate for a heck of a lot. This is why researchers are so fascinated with the potential of embryonic cells.
Malleability seems to decrease gradually as an organism differentiates and grows. Weird little factoid: in the handful of cases where abdominal/thoracic surgery has been done on fetuses in utero, to correct defects that would likely be fatal before birth if they went uncorrected, the incisions in the embryos heal without scars. Surgery even shortly after birth (and probably in very late stage fetuses) leaves scars. Somewhere along the line, some switch seems to get flipped in all the skin cells, from "heal wounds with normal skin cells" to "heal wounds with scar-type skin cells". If they ever figure out how to flip that switch back without causing other serious harm, the implications for victims of disfiguring injuries and burns would be immense.
You are welcome. I am not convinced that this is a viable option for the research, but time will tell. I am hopeful that this research can bridge the gap between the potential of embryonic stem cells and the right to life for the innocent embryo. I have a grandfather suffering from Alzheimers, so I have been very interested in the potential of both adult and embryonic stem cells. Any benefits will be too late to help him, but I would love to keep others from the same fate.
I just can't see taking an innocent life as justifiable for any reason. This research at least indicates that we are working toward the right goal.