Monoclonal antibody
Say it: mon-oh-KLOH-nul AN-tih-bod-ee
A monoclonal antibody is one of a set of identical antibodies made by clones of a single B cell, so that all of them bind the same site on one antigen.
Also: monoclonal antibodies, mAb
Definition
What is a monoclonal antibody?
A monoclonal antibody (mAb) is an antibody produced by a single clone of cells, so every molecule is identical and recognizes the same epitope, a single spot on one antigen. Polyclonal antibodies, by contrast, are a mixture made by many different B cells that bind many epitopes.
The classic way to make them is the hybridoma method, developed in the 1970s. A mouse is immunized with the antigen, and antibody-producing B cells from its spleen are fused with myeloma cells, cancerous B cells that keep dividing indefinitely. The fused hybridoma cells are grown in a medium in which unfused cells die, and those making the wanted antibody are picked out and cultured, giving a steady, uniform supply. Mouse antibodies provoke an immune response in people, so antibodies meant for treatment are engineered to be chimeric, humanized or fully human.
Monoclonal antibodies are central tools in both the laboratory and the clinic. They are the detecting reagents in ELISA, flow cytometry, western blots and home pregnancy tests. As drugs, which have names ending in -mab, they can block a receptor or signaling molecule, mark cancer cells for attack by the immune system, deliver a toxic drug to a target, or neutralize a virus or toxin. They are used against many cancers, autoimmune diseases such as rheumatoid arthritis, and some infections.
Word parts
Where does the term “monoclonal antibody” come from?
- mono-
- single, oneGreek monos
- clon-
- twig (a cutting grown into an identical plant)Greek klon
- anti-
- againstGreek anti
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Terms that go with it
- AntibodyAn antibody is a Y-shaped protein made by B cells and plasma cells that binds tightly to one specific antigen and helps the body destroy it.
- AntigenAn antigen is any molecule the immune system can recognize as a target, especially one that prompts antibodies or T cells to respond against it.
- B cellA B cell is a lymphocyte, a kind of white blood cell, that produces antibodies and forms a key part of the adaptive immune system.
- ImmunotherapyImmunotherapy is treatment that works by boosting, steering or suppressing the immune system, best known as a way to help it attack cancer.
- ELISAELISA is a lab test that uses enzyme-linked antibodies to detect and measure a specific antigen or antibody in a sample through a color change.
- Flow cytometryFlow cytometry is a laboratory technique for measuring the size, inner complexity and fluorescent labels of single cells as thousands stream past a laser.
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Checked against
Written for biofideX in plain words, after checking these references:
- OpenStax Microbiology, 20.1 Polyclonal and Monoclonal Antibody Production
- NCI Dictionary of Cancer Terms: monoclonal antibody
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