Adult stem cell is cited as possible and viable alternative when a ban on embryonic stem cell is asked. It is true that re adult stem cells have the potential and area morally less problematic alternative.
But there are a lot of possible problems. First is that human adult stem cells are rare, of few types and difficult to isolate.
Most of these are difficult to grow in culture. Much of the work on human adult cells is of hematopoietic stem cells an results of this work can not be generalized to other types.
However, adult stem cells if they can be harnesses have potential to produce histocompatible transplant which would not trigger immunological responses.
