• What are Stem Cells?

• Types of Stem Cells
• Embryonic Stem Cells
• Embryonic Germ Cells
• Cord Blood Stem Cells
• Adult Stem Cells
• What is the Potential?

• Research in Australia
• The Stem Cell Debate
• FAQs
• Glossary
• Links
• Patient Information

Types of Stem Cells

There are three main types of stem cells that are being investigated for their potential use in research and medicine. They differ in their degree of differentiation and ability to self-renew. In the human:

• Embryonic stem cells come from a four to seven-day-old embryo. They have the ability to form virtually any type of cell found in the human body, but are not capable of developing into a whole new organism.
• Embryonic germ cells are derived from the part of a human embryo or fetus that will ultimately produce eggs or sperm (gametes).This called the gonadal ridge found at six to nine weeks of gestation when the embryo is developing into a fetus. Little research is now performed using this type of cells because they do not appear to be as versatile as embryonic stem cells.
• Adult stem cells are more specialised than embryonic stem cells. They are found in the majority of tissues and organs in our body and generate the mature cell types within that tissue or organ. They have a restricted ability to produce different cell types and to self-renew.

Stem cells that have the potential to develop into any of the cell types found in an adult organism are called pluripotent. Embryonic stem cells and embryonic germ cells are pluripotent.

Stems cells that only have the potential to make a few cell types in the body are called multipotent. Adult stem cells are multipotent.

Cells that are capable of forming a completely new embryo that can develop into a new organism are called totipotent. A fertilised egg cell is totipotent as it has the potential to develop into a new organism.