A stem cell is a primitive type of cell that can be induced to develop into most of the different types of cells found in the human body (blood cells, heart cells, brain cells, etc).
Stem cells can be extracted from adult tissue without causing any harm to the subject, but researchers agree that adult stem cells are limited in usefulness as they are sparse and can only produce a few of the 220 human cells.
Stem cells can also now be grown in the laboratory, which means that some research can be done using existing stem cells. However, such stem cell lines gradually degrade and become useless for research.
The most prolific source of stem cells has been found to be human embryos. Researchers can use surplus frozen embryos left over from in-vitro fertilization (IVF) procedures at fertility clinics.
However, research on human embryonic stem cells is controversial, as extracting its stem cells kills the embryo. Many pro-life organisations therefore consider such an act to be murder.
Backers of research on human embryos argue that stem-cell research could allow scientists to find cures for diseases such as Parkinson’s, diabetes and heart failure.
According to the results of a Eurobarometer survey on biotechnology and life sciences published in June 2006, a majority of European citizens are in favour of stem cell research, with 59% saying they approve such research, although most of these would prefer tighter regulation. Only 9% of the population said it does not approve stem cell research under any circumstances (See EurActiv 21 June 2006).



