What are Monoclonal Antibodies?

Monoclonal antibodies are antibodies which are identical because they are produced by specialized cells which have been cloned. There are a number of uses for monoclonal antibodies, ranging from drug testing to cancer treatment, and they are produced in labs all over the world. Like many medical discoveries, monoclonal antibodies are also accompanied with some controversy, because they are produced in mice and there is no logistical way to make them from human cells.

Antibodies are developed by the body when it is exposed to foreign substances. They linger in the body, conferring immune resistance long after the exposure is over, and they are also highly refined, designed to distinguish between very similar foreign substances. The precise targeting of antibodies became a topic of interest in the 20th century, and in the 1970s, the first monoclonal antibodies were developed, allowing researchers to produce large numbers of pure antibodies in a lab setting.

To make these antibodies, a mouse is exposed to an antigen, and cells are collected from the spleen. These cells are cultured with cells from a myeloma, a cancer of the plasma cells, to create a hybridoma which will endlessly replicate itself. The replications can be tested to find the cells which are producing the desired antibody or antibodies, and these cells can be cloned and used to develop a large store of monoclonal antibodies. The resulting antibodies are pure, without any other substances, which makes them superior to antiserum, and they will continue to reproduce indefinitely, thanks to the immortal nature of the tumor cells used to make the hybridoma.

Once produced, monoclonal antibodies can be used in screening tests. For example, a doctor testing for drugs or the presence of a disease could expose a patient's blood sample to monoclonal antibodies which will react with the antigen in question if it is present, alerting the doctor to the presence of whatever he or she is testing for. Monoclonal antibodies can also be modified so that they can be used in purification, by binding to a particular antigen and allowing all other substances in a sample to be washed away.

For cancer treatment, monoclonal antibodies have tremendous potential, because they can be blended with radioactive agents or other compounds and introduced in the body, targeting the cancer cells and the cancer cells alone. Products used in medical treatment all have names which end in -mab, for “monoclonal antibody.

Researchers are reluctant to develop these special antibodies with human cells because they believe that it is not ethical to expose humans to antigens. Some researchers have suggested that advances in the biosciences will make the production of monoclonal antibodies in vitro possible, thereby allowing researchers to avoid using live animals or people.