Embryonic Stem Cells
- Almost unlimited growth potential.
- Can differentiate into any type in the body.
- More risk of becoming tumour cells than with adult stem cells, including teratomas that contain different tissue types.
- Less chance of genetic damage due to the accumulation of mutations than with adult stem cells.
- Likely to be genetically different from an adult patient receiving the tissue.
- Removal of cells from the embryo kills it, unless only one or two cells are taken.
- Easily obtained and stored.
- Commercial collection and storage services already available.
- Fully compatible with the tissues of the adult that grows from the baby, so no rejection problems occur.
- Limited capacity to differentiate into different cell types - only naturally develop into blood cells, but research may lead to production of other types.
- Limited quantities of stem cells from one baby's cord.
- The umbilical cord is discarded whether or not stem cells are taken from it.
- Difficult to obtain as there are very few of them and they are buried deep in tissues.
- Less growth potential than embryonic stem cells.
- Less chance of malignant tumours developing than from embryonic stem cells.
- Limited capacity to differentiate into different cell types.
- Fully compatible with the adult's tissues, so rejection problems do not occur.
- Removal of stem cells does not kill the adult from which the cells are taken.