Embryonic stem cells are derived from early stage embryos (called
blastocysts) that are five to seven days old. In Australia these
blastocysts are donated for research with consent from patients who have
completed treatment for infertility, and have surplus embryos. The
embryos donated and used in research would otherwise be discarded. At
this stage of development the blastocyst is a hollow ball of about 150
cells and no bigger than a pinhead. The blastocyst is a unique stage of
development, as there are two different types of cells, an outer layer
called the trophectoderm, and a small group of approximately 30 cells
called the inner cell mass. The inner cell mass is what ultimately
becomes the embryo, and the trophectoderm becomes the placenta.
Embryonic stem cells are isolated from the blastocyst when the inner
cell mass is removed and cultured in the laboratory. During this process
the blastocyst is destroyed. Once the cells have been isolated they can
be grown continuously in a laboratory culture dish that contains a
nutrient-rich culture medium. As the stem cells divide and spread over
the surface of the dish some are removed to populate fresh subcultures
to form a stem cell line. Because these cells have the ability to keep
dividing (self-renewing), large numbers of embryonic stem cells can be
grown in the laboratory and also frozen for future use. As a result,
established embryonic stem cell lines can be maintained in laboratories
for research, shared between researchers and maybe ultimately used in
It has been legal to use human embryos for stem cell research in
Australia since 2002 but only where scientists meet strict regulatory
requirements such as obtaining a licence for the creation of the human
embryonic stem cells.
To learn more about embryonic stem cells watch Creation of human embryonic stem cell lines
in our video library.
To learn more about the Australian laws that regulate this area of science watch The Stem Cell Debate
or visit Is stem cell research legal in Australia?