A monoclonal antibody is a type of antibody that is made from a single clone of cells and is specific to a single antigen. Monoclonal antibodies are used in medical research and in the treatment of various diseases, such as cancer and autoimmune disorders. They are produced by fusing a single B-cell with a myeloma cell, which results in a hybrid cell that produces a single type of antibody. Monoclonal antibodies can be used to target specific antigens on cells, allowing researchers to study the function of the antigen and its role in disease. They can also be used to deliver drugs or toxins to specific cells, making them useful in cancer treatments.