Stem Cell

Stem cells are unique in that they are undifferentiated cells that can differentiate to become virtually any type of cell in the body (totipotent). They therefore represent an ongoing source of the specialized cells that make up the tissues and organs. There is great interest in stem cells because they have potential to replace defective or damaged cells resulting from a variety of disorders and injuries, leading to a range of new regenerative therapies.

Stem cells also have value as a research tool, as their in vitro study would allow scientists to learn more about the function of various organs and the development of particular diseases; stem cells may also eventually permit drug developers to test emerging therapies on diseased cells.

Cells must meet very specific criteria in order to be termed stem cells. They must: produce copies themselves; proliferate at a rapid rate; and display certain proteins on their surface that indicate a capacity to differentiate into other tissues, such as bone and cartilage. A stem cell line is a group of cells that all descend from a single original stem cell. Symmetric division gives rise to two identical daughter cells both endowed with stem cell properties. Asymmetric division produces only one stem cell and a progenitor cell with limited self-renewal potential.