Glossary
Adult stem cell—An undifferentiated cell found in a differentiated tissue that can renew itself and differentiate to give rise to all the specialized cell types of the tissue from which it originated.
Cell culture—Growth of cells in vitro in an artificial culture medium for experimental research.
Cord blood—Contains hematopoietic stem cells collected from the umbilical cord at birth that can produce all of the blood cells in the body. 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.
Culture medium—The liquid that covers cells in a culture dish and contains nutrients to feed the cells. Medium may also include other growth factors added to produce desired changes in the cells.
Differentiation—The act of a less mature cell type, like a stem cell, turning into a more mature or specialized cell type, like a neuron.
Embryonic stem cells—(also known as ESCs)—A type of pluripotent cell that is derived from an embryo and has the potential to become a wide variety of specialized cell types.
Embryonic stem cell line—Embryonic stem cells, which have been cultured under in vitro conditions that allow proliferation without differentiation for months to years.
Ex vivo—Treatments or experiments performed in or on living tissue in an environment outside the organism.
Gene—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.
Genetic reprogamming—The forced expression of genes either on viruses, plasmids or other genetic material to turn a mature, differentiated adult cell into an iPS cell
Hematopoietic stem cell—A stem cell that gives rise to all red and white blood cells and platelets.
Induced pluripotent stem cells—(also known as iPS cells or iPSCs)—Adult cells reprogrammed to an embryonic stem cell–like state by being forced to express factors important for maintaining the "stemness" of embryonic stem cells (ESCs).
In vitro—Latin for "in glass"; in a laboratory dish or test tube.
In vivo—Takes place inside an organism.
Pathways—Pathway is short for signaling pathway. A signal, often from the outside, approaches a cell to tell it to perform a specific action.
Personalized cell replacement therapies—Treatment in which stem cells are created to genetically match a patient to reduce the risk of immune rejection and then induced to differentiate into a specific cell type ex vivo. These cells are then transplanted into the patient to repair damaged or destroyed cells or tissues.
Pluripotency—Ability of a single stem cell to give rise to all of the various cell types that make up the body.
Preclinical Testing—Laboratory tests of a new drug or a new medical device to determine the toxicity and pharmacokinetics in order to gather evidence to support a clinical trial in humans.
Programming—The term which encompasses both reprogramming, differentiation and transdifferentiation.
Proliferation—Expansion of cells by the continuous division of single cells into two identical daughter cells.
Reprogramming—Turning a fully mature adult cell, like a skin cell, into a stem-like cell, called an induced pluripotent stem (iPS) cell.
Regenerative medicine—A treatment in which stem cells are induced to repair damaged or destroyed cell populations or tissues.
Signals—Internal and external factors that control changes in cell structure and function.
Specialized cells—Also known as differentiated, mature or adult cells. Cells
Stem cells—Cells with the ability to differentiate to give rise to specialized cells.
Transdifferentiation—The process by which stem cells from one tissue differentiate into cells of another tissue.
Undifferentiated—A cell that has not yet become committed to a specialized cell type, such as a neuron or liver cell.
For more, please visit the NIH’s glossary of stem cell terms and definitions.
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