On Stem Cells – Web Resource Center
Feb 18th, 2010 | By Wilfried F. VossMost of the controversy surrounding stem cells is focussed on the use of human embryonic stem cells, because the harvesting of embryonic stem cells requires the destruction of a human embryo. Embryonic stem cells are retrieved from embryos approximately four to five days old. These cells can divide further into more stem cells. Alternatively, they can specialize and become a particular type of body cell. These attributes give embryonic stem cells the highest potential for medical benefit.

