How Are Secondary Antibodies Produced?

Secondary antibodies bind to primary antibodies or antibody fragments.

Secondary antibodies are formed by the immune systems of a vertebrate upon detection of antibodies belonging to a foreign species within the blood stream. They are produced by injecting one organism with the harvested antibodies of another organism.

Production of Primary Antibodies

Secondary antibodies act as indicators for an immune reaction for a specific target molecule within a particular target species of vertebrate. The production of secondary antibodies first requires the production of primary antibodies on which the secondary antibodies can be based. Production begins by injecting the target species with a sample of the target molecule. This causes an immune response in which the immune system of the animal produces unique antibody proteins tailored to identify and bind to the target molecule. These are the primary antibodies.

Production of Secondary Antibodies

Once a sufficiently strong immune response has occurred, the primary antibodies from the target species are harvested from the fluids of an animal through a purification process, often a type of affinity chromatography procedure. They are then injected into a second, different vertebrate species. The primary antibodies are treated as foreign invaders by the immune system of the second animal, which then produces a second set of unique antibody proteins tailored to identify and bind to the primary antibodies. These are the secondary antibodies. They are then harvested from the second animal through a process similar to that used with the primary antibodies in the first animal.

Applications

The presence of secondary antibodies in an animal of the target species indicates that the animal is experiencing an immune response to the target molecule.Thus, secondary antibodies have a wide range of uses within medical trials and molecular biology research. The secondary antibody molecules are often labeled with colorimetric or fluorescent chemicals to enhance their ease of detection. Most common methods of secondary antibody detection include Western blot, immunohistochemistry, immunocytochemistry and Enzyme-linked immunosorbent assay.

References

• Labome: Secondary Antibody Review
• Vector Laboratories: Secondary Antibodies
• Sigma Aldrich: Secondary Antibodies