This document discusses monoclonal antibodies, including their structure, types, methods of preparation, applications, and marketed products. Monoclonal antibodies are homogeneous antibodies produced by identical immune cells that are clones of a single parent cell. They are prepared using the hybridoma technology which involves immunizing an animal, fusing immune cells with myeloma cells to form hybridomas, screening and selecting hybridomas that produce the desired monoclonal antibody. Monoclonal antibodies have various therapeutic applications in areas such as cancer, autoimmune diseases, organ transplants, and infections. They are also used for diagnostic purposes.