Embryonic stem cells originate from the inner mass blastocyst. They are pluripotent and capable of forming any organ in the body.

Adult stem cells from the blood, bone marrow, brain, eye, muscle, gastrointestinal tract, pancreas, liver, skin form progenitor cells that can differentiate and form specific tissues.

Adult stem cells from one organ are capable of forming tissue from another organ , a condition which is called plasticity. Adult stem cells derived from adipose tissue or umbilical cord blood have the capacity to form many types of differentiated cells such as neuron stem cells, pancreatic stem cells, cardiomyocytes, blood and bone cells.

Research done in animal models and clinical trials on humans show that stem cells are capable in differentiating into specific tissue such as heart muscle, pancreatic islets that produce insulin, neurons that would be capable of transplantation into patients that have damaged organs.

Adult stem cells are capable of being transferred into any one single organ of the body. Stem cells from the bone marrow form hematopoietic cells which produce blood ,immunological cells, neurons, oligodendrocytes, astrocytes (brain cells), liver and stromal cells that form heart, skeletal muscle fat, cartilage and bone.

Umbilical cord blood is also a source of stem cells capable of differentiating into many different organ tissues.

Isolating adult stem cells from the bone marrow and umbilical cord blood require special laboratory techniques to isolate them and expand their numbers in culture. Various agents are used to take the stem cells and differentiate them into specialized tissues.

The methods of isolating these stem cells; differentiating them and then using transplantation methods into the blood stream or directly into the damaged organs is an ever growing field of research.