Stem Cells: The Building Blocks of Life

Embryonic Stem Cells

 

What are they?

     Embryonic stem cells are derived from 3-5 day old human embryos during the blastocyst phase of development. These stem cells are pluripotent, meaning they are able to differentiate into any type of cell in the human body. In fact, they have the potential to differentiate into over two hundred cells.

 

How can they be used?

     Proliferating without limit, embryonic stem cells are easily cultivated in laboratories. Therefore, they are beneficial for developing replacement organs and treating a variety of diseases. 

 

What are the challenges or risks?

     Since human embryos are destroyed when their embryonic stem cells are harvested, the use of embryonic stem cells is still being debated. 

 

 

Non-embryonic Stem Cells 

(Adult or Somatic Stem Cells)

 

What are they?

     Also known as "adult" stem cells or somatic stem cells, these mature stem cells reside in specialized tissue in the human body. For example, the brain, blood, liver, and intestine all have their own stem cells. These stem cells replace dying or damaged cells in the body. Unlike embryonic stem cells, which are pluripotent, non-embryonic stem cells are multipotent, capable of differentiating into only a limited selection of cell types. Non-embryonic stem cells have limited proliferation and are only activated when the tissue in which they reside has been damaged.

 

How can they be used?

     Although less versatile than embryonic stem cells, non-embryonic stem cells, are less likely to be rejected by a patient. The non-embryonic stem cells used for treatment can be derived from the patient, so they are less likely to be attacked by the patient's immune system. 

 

What are the challenges or risks?

     Non-embryonic stem cells do not proliferate profusively after they are removed from the mature tissue so scientists have difficulty cultivating these stem cells in laboratories.