monoclonal antibody, an antibody that is mass produced in the laboratory from a single clone and that recognizes only one antigen. Monoclonal antibodies are typically made by fusing a normally short-lived, antibody-producing B cell (see immunity) to a fast-growing cell, such as a cancer cell (sometimes referred to as an
cell). The resulting hybrid cell, or hybridoma, multiplies rapidly, creating a clone that produces large quantities of the antibody.
Monoclonal antibodies engendered much excitement in the medical world and in the financial world in the 1980s, especially as potential cures for cancer. They have been used in laboratory research and in medical tests since the mid-1970s, but their effectiveness in disease treatment has been limited. By the mid-1990s, however, some of the technical problems had been overcome. Experimental cancer therapies have used drugs, radioactive materials, or immune killer cells attached to monoclonal antibodies that, when injected into patients, home in on antigens that grow only on the surface of cancer cells.