Stem cells

Find out where stem cells come from and how they are used in humans and plants

Stem cells in humans

Stem cells are cells that have not undergone differentiation. A cell which has not yet become specialised is called undifferentiated.

An embryo develops from a fertilised egg. Cells at the early stages in the development of the embryo are stem cells.

If cells are removed from the embryo - called embryonic stem cells - they will differentiate into any cell type.

Some stem cells remain in the bodies of adults - adult stem cells. Adult stem cells are found in limited numbers at certain locations in the body.

Adult stem cells can be found in several regions of the body, including the:

  • brain
  • eyes
  • blood
  • heart
  • liver
  • bone marrow
  • skin
  • muscle

Adult stem cells can differentiate into related cell types only, for instance, bone marrow cells can differentiate into blood cells and cells of the immune system but not other cell types.