Stem cells from abortion are not a preferred source. Procedures necessary to induce abortion compromise the quality and viability of cells obtained by that method.

"Stem-like" cells, as described in the article on umbilical blood may be usable for some purposes, but often would be "too advanced" in their cellular development and thus not as versatile for the kinds of research that could be most promising.

The preferred source for stem cells is from fertilized ova prepared for artificial insemination, and "abandoned" because they're "in excess" of what's needed for that procedure. The only alternatives to using them for stem cell development are to keep them perpetually frozen with no possibility of ever being used for anything, or to toss them in the incinerator. While I fail to see the moral or ethical problem with using these cells for research that may benefit others, some people do seem to have a problem with it.

John