Embryonic (or fetal) Germ Cells (EGCs)
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These pluripotent stem cells are derived from primordial germ cells, which give rise to the gametes (sperm & eggs) in adults. They are found in a 5 to 9 week old embryo/fetus in the area that is destined to become either the testicles or the ovaries. Like the embryonic stem cells, primordial germ cells too are transferred into a specially treated culture dish to form germ cell colonies. Deriving stem cells through this process is controversial since the embryo or the fetuses from which the germ cells are obtained are destroyed. The embryo or the fetuses, even though not fully formed, are considered 'human' in many cultures and hence their destruction leads to ethical dilemmas. Such a dilemma exists even if the embryonic germ cells are derived from a fetus that is obtained as a result of a miscarriage or abortion. |
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Menstrual Blood Stem Cells
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| Exciting new research shows that menstrual fluid contains self-renewing stem cells. A woman's menstrual blood includes tissue shed from the endometrial lining of the uterus which potentially contains hundreds of millions of rich and abundant stem cells which could possibly serve as a source for a wide range of regenerative therapies. These menstrual stem cells are unique because they have many properties and characteristics similar to both bone marrow and embryonic stem cells; they multiply rapidly and can differentiate into many other types of stem cells such as neural, cardiac, bone, fat, cartilage and possibly others; demonstrating great promise for future use in clinical regenerative medical therapies. |
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Peripheral Blood Stem Cells
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Stem cells, in limited quantities, can also be found in the peripheral blood circulation. Peripheral blood stem cells are easier to obtain than bone marrow as they can be drawn from blood. Some studies have shown that these stem cells engraft faster than bone marrow stem cells. |
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