Stem Cell Terms

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Allogeneic Transplant:

The hematopoietic stem cell donor is not the same person as the recipient.

Autologous Transplant:

The hematopoietic stem cell donor and the recipient are the same person. The patient’s own stem cells are used in the transplant.

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A structure consisting of DNA and regulatory proteins found in the nucleus of the cell. The DNA in the nucleus is usually divided up among several chromosomes. The number of chromosomes in the nucleus varies depending on the species of the organism. Humans have 46 chromosomes.

Cell-based Therapies:

Treatment in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cells or tissues.

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Deoxyribonucleic acid, a chemical found primarily in the nucleus of cells. DNA carries the instructions or blueprint for making all the structures and materials the body needs to function. DNA consists of both genes and nongene DNA in between the genes.

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The outermost germ layer of cells derived from the inner cell mass of the blastocyst; gives rise to the nervous system, sensory organs, skin, and related structures.


The innermost layer of the cells derived from the inner cell mass of the blastocyst; it gives rise to lungs, other respiratory structures, and digestive organs, or generally “the gut”.


The process of transplanted stem cells reproducing new cells.

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A functional unit of heredity that is a segment of DNA found on chromosomes in the nucleus of a cell. Genes direct the formation of an enzyme or other protein.

Graft vs. Host Disease (GVHD):

GVHD occurs when the recipient host seeks to destroy the donor cells just as it would seek to destroy germs. Umbilical cord blood transplants have a reduced incidence and severity of GVHD because of the relative immaturity of its immune cells.

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Hematopoietic Stem Cell:

A stem cell that gives rise to all red and white blood cells and platelets.

Hematopoietic Stem Cell Transplant:

A transplant of stem cells derived from cord blood, placenta, peripheral blood or bone marrow.

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Long-Term Self-Renewal:

The ability of stem cells to renew themselves by dividing into the same non-specialized cell type over long periods (many months to years) depending on the specific type of stem cell.

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Mesenchymal Stem Cells:

A term that is currently used to define non-blood adult stem cells from a variety of tissues, although it is not clear that mesenchymal stem cells from different tissues are the same.


Middle layer of a group of cells derived from the inner cell mass of the blastocyst; it gives rise to bone, muscle, connective tissue, kidneys, and related structures.


The molecules and compounds such as nutrients and growth factors in the fluid surrounding a cell in an organism or in the laboratory, which play an important role in determining the characteristics of the cell.


The type of cell division that allows a population of cells to increase its numbers or to maintain its numbers. The number of chromosomes remains the same in this type of cell division.


Having the ability to develop into more than one cell type of the body.

Neural Stem Cell:

A stem cell found in adult neural tissue that can give rise to neurons and glial (supporting) cells. Examples of glial cells include astrocytes and oligodendrocytes.

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Nerve cells, the principal functional units of the nervous system. A neuron consists of a cell body and its processes—an axon and one or more dendrites. Neurons transmit information to other neurons or cells by releasing neurotransmitters at synapses.

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A supporting cell that provides insulation to nerve cells by forming a myelin sheath (a fatty layer) around axons.

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Related Allogeneic Transplant:

The hematopoietic stem cell donor is a related family member of the recipient.

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Internal and external factors that control changes in cell structure and function. They can be chemical or physical in nature.

Somatic (Adult) Stem Cell:

A relatively rare undifferentiated cell found in many organs and differentiated tissues with a limited capacity for both self renewal (in the laboratory) and differentiation. Such cells vary in their differentiation capacity, but it is usually limited to cell types in the organ of origin. This is an active area of investigation.

Stem Cells:

Cells with the ability to divide for indefinite periods in culture and to give rise to specialized cells.

Stromal Cells:

Connective tissue cells found in virtually every organ. In bone marrow, stromal cells support blood formation.


Transferring cultured cells, with or without dilution, from oneculture vessel to another.

Surface Markers:

Proteins on the outside surface of a cell that are unique to certain cell types and that can be visualized using antibodies or other detection methods.

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The process by which stem cells from one tissue differentiate into cells of another tissue.

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Umbilical Cord Blood Stem Cells:

Stem cells collected from the umbilical cord at birth that can produce all of the blood cells in the body (hematopoietic). Cord blood is currently used to treat patients who have undergone chemotherapy to destroy their bone marrow due to cancer or other blood-related disorders.


A cell that has not yet developed into a specialized cell type.

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Wharton’s Jelly:

A substance that surrounds the blood vessels in the umbilical cord. Contains a high concentration of Mesenchymal Cells.

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