Micro No. 21
by David Mack - © Corbis. All Rights Reserved. - © David Mack/Science Photo Library/Corbis
Stem cells
12 May 2009 --- Stem cells, computer artwork. Stem cells are undifferentiated cells that can produce other types of cell when they divide. Medical researchers believe that eventually it will be possible to manufacture new tissues and organs from stem cells. There are three main types of mammalian stem cell: embryonic stem cells, derived from blastocysts; adult stem cells, which are found in adult tissues; and cord blood stem cells, which are found in the umbilical cord. --- Image by © David Mack/Science Photo Library/Corbis