How are monoclonal antibodies produced?

All antibodies are produced by (B) lymphocytes, which are the cells of the immune system. They are produced as a response to special proteins (antigens) on the surface of pathogen cells; they are made to match the shape of the antigen. Monoclonal just means many copies of the same antibody, so they are also produced by lymphocytes.Lymphocytes from mice are stimulated to produce antibodies by a particular antigen (eg. by injecting the antigen into the mouse). The lymphocytes are then combined with a kind of tumour cell. The combination forms a special cell called a hybridoma, which can produce antibodies (because of the lymphocyte) and reproduce very quickly (because of the tumour cell). The hybridoma can clone itself rapidly to form lots of cells all producing the same antibody. The identical antibodies (monoclonal) can then be collected.