Monoclonal antibody

Monoclonal antibody is a highly specific antibody from ONE B cell line, against a specific epitope on a specific antigen. It is produced by fusing B cells with myeloma cells, then selecting for the fused cells. At this point you have polyclonal antibody being made, so you clone them such that you separate out the particular B cell line making the specific Ab you need. These homogenous antibodies are used as reagents for diagnostic tests, as "magic bullets" in experimental treatment protocols, etc.