Human embryonic stem cell research: An ethical controversy in the US & Germany

Stem cells refer to a broad class of cells with potential for prolonged self-renewal and the potential to differentiate. Human embryonic stem (ES) cells are derived from a fertilized human egg, before it has been implanted into a womb. Recently published research has used human embryos, produced by in-vitro fertilization for clinical purposes, to develop lines of pluripotent human ES cells. This review discusses the legal status and ethical implications of ES cell research with special attention paid to the situation in the USA and Germany.