Tuesday, February 05, 2008
Above image from here.
Stem cells are primative, undifferentiated cells that have the capacity to proliferate and differentiate into more mature types of cells.
Some forms of tissue regeneration require stem cells.
You can go here to see animations about stem cells (you need Flash Player installed).
There is also stem cell information in lay terms at the NIH Stem Cell Information website.
Embryonic stem cells are obtained from human fertilized eggs called blastocysts. These stem cells are often refered to as "totipotent stem cells".
You can view an animated tutorial on human embryonic stem cells at this website and also at this website.
Adult stem cells are multipotent and are normally obtained from the bone marrow. A bone marrow transplant can be considered a stem cell transplant.
More recently, stem cells have been obtained from umbilical cords of recently born babies.
Stem cells were first cultured at my Alma Mater, The University of Wisconsin by James Thomson (paper cited above). Lots of stem cell info at this UW website.