A hybridoma is a hybrid cell produced by injecting a specific antigen into a mouse, collecting an antibody-producing cell from the mouse's spleen, and fusing it with a long-lived cancerous immune cell called a myeloma cell. Individual hybridoma cells are cloned and tested to find those that produce the desired antibody. Their many identical daughter clones will secrete, over a long period of time, millions of identical copies of made-to-order "monoclonal" antibodies.

Thanks to hybridoma technology, scientists are now able to make large quantities of specific antibodies.