Definition

Stem cells are undifferentiated or generic cells that can manufacture exact copies of themselves, but some can also develop into cells that form blood, organs and tissue. They also contribute to the immune system.

Types

Pluripotent stem cells can multiply for long periods of time and can turn into all types of cells the body needs. Two examples are the embryonic stem cell and the (umbilical) cord blood stem cell. Pluripotent stem cells have also been produced from adult skin cells. Fetal stem cells can be taken from various parts of a developing human fetus, and tend to have only the characteristics of the tissue from which they are extracted. Adult blood stem cells can be extracted from various parts of the human body, such as the bone marrow, and can treat some blood diseases.

Use

Stem cells are used in genetic research to learn how diseases affect the body and to study human development. Blood stem cells can be used to treat leukemia and other blood diseases. Research into using stem cells to treat severe heart disease and to learn how cancer cells develop is underway.

Collection

Stem cells can be harvested surgically from bone marrow, can be collected from human fetuses, and collected from infant umbilical cord blood and the placenta. Cord blood stem cells can be used immediately or stored for future transplantation into compatible recipients.

Controversy

Some people object to the use of embryonic stem cells out of concern that the practice will encourage people to sacrifice human embryos for their stem cells rather than allowing them to fully develop and be born.

Source:

International Society for Stem Cell Research