No, I don't think there is a human spirit in an embryo. I don't need to deal with the more difficult question of when the spirit comes alive, because we're just talking about an embryo.
If you're so upset about this, then why is your anger directed at stem cell research? Shouldn't you be attacking the whole concept of creating and destroying embryos? Your approach is sort of like being opposed to murder, but only if it occurs during a liquor store robbery.
You nor I can prove when the spirit takes up residence (you're still dodging answering whether you even believe there is a human spirit), but the Bible indicates that God gives the spriit to the little ones and that happens sometime during the nine months from conception to birth.
A person selfish enough to kill because of expedience and utilitarian application of the corpse doesn't want to seek the truth because it might conflict with the selfish desire. But then, you're only talking about an embryo-aged being and you've decided that such a young one is not yet a human being. Circular reasoning, that.