monoclonal antibody

monoclonal antibody A specific antibody produced by one of numerous identical cells derived from a single parent cell. (The population of these cells comprises a clone and each cell is said to be monoclonal.) The parent cell is obtained by the fusion of a normal antibody-producing cell (a lymphocyte) with a cell derived from a malignant tumour of lymphoid tissue of a mouse (see cell fusion). The resulting hybridoma cell then multiplies rapidly and yields large amounts of antibody. Monoclonal antibodies are used to identify a particular antigen within a mixture and can therefore be used for identifying blood groups; they also enable the production of highly specific, and therefore effective, vaccines. Above all, they have transformed medical and biological diagnostics by ushering in a huge range of cheap and convenient kits for identifying and quantifying biological materials (see immunoassay).