Re: How are stem cells harvested and grown? How are stem cells use in the lab?

Dear Shelby,

There are many different types of stem cell and they are isolated from 
different areas of the body (e.g. haematopoietic stem cells are isolated 
from the blood/bone marrow). I work with embryonic stem (ES) cells which 
are harvested from the inner cell mass of preimplanation embryos.

To enable ES cells to grow outside of the embryo they have to be cultured 
in the presence of embryonic fibroblasts, which provide nutrients to keep 
the ES cells in an undifferentiated state. In this state the cells can 
grow indefinately. When these cells are removed from the fibroblasts (or 
medium which has been conditioned by these cells) the ES cells 
spontaneously differentiate into a range of cell types. In theory, ES 
cells can form into any of the cells within the body. However, in practice 
only a few pure cell types have been produced (e.g. neuronal and blood). 

At the moment, research is mainly focused on the conditions required to 
form pure cell types from undifferentiated ES cells so they can be used 
for cell replacement therapies. It is highly likely that in the next few 
years many more cell types will be able to be made from ES cells. 

However, ES cells are also a useful tool for studying how ES cells form 
into other cell types (i.e. a model of human development). Understanding 
how this process works may enable treatment of certain diseases without 
the need to use cell therapy. Also, because ES cells grow like cancer 
cells (they continually divide) studies on ES cells may enable a greater 
understanding of the process of cancer.

I hope I have answered your question.
Chris