Students should be able to describe some of the ways in which monoclonal antibodies can be used. Some examples include: for diagnosis such as in pregnancy tests; in laboratories to measure the levels of hormones and other chemicals in blood, or to detect pathogens; in research to locate or identify specific molecules in a cell or tissue by binding to them with a fluorescent dye; to treat some diseases: for cancer the monoclonal antibody can be bound to a radioactive substance, a toxic drug or a chemical which stops cells growing and dividing. It delivers the substance to the cancer cells without harming other cells in the body. • Monoclonal antibodies create more side effects than expected. They are not yet as widely used as everyone hoped when they were first developed.