Monoclonal antibodies
Monoclonal antibodies are monospecific antibodies
Monospecific antibody
Monospecific antibodies are antibodies that all have affinity for the same antigen. Monoclonal antibodies are monospecific, but monospecific antibodies may also be produced by other means than producing them from a common germ cell.-Hybridoma cell:...

 that are the same because they are made by identical immune cells
White blood cell
White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...

 that are all clones
Cloning in biology is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or...

 of a unique parent cell.

Given almost any substance, it is possible to produce monoclonal antibodies that specifically bind to that substance; they can then serve to detect or purify that substance. This has become an important tool in biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...

, molecular biology
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...

 and medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

. When used as medications, the non-proprietary drug name ends in -mab (see "Nomenclature of monoclonal antibodies
Nomenclature of monoclonal antibodies
The nomenclature of monoclonal antibodies is a naming scheme for assigning generic, or nonproprietary, names to monoclonal antibodies. An antibody is a protein that is produced in B cells and used by the immune system of humans and other vertebrate animals to identify a specific foreign object like...

The idea of a "magic bullet" was first proposed by Paul Ehrlich
Paul Ehrlich
Paul Ehrlich was a German scientist in the fields of hematology, immunology, and chemotherapy, and Nobel laureate. He is noted for curing syphilis and for his research in autoimmunity, calling it "horror autotoxicus"...

, who, at the beginning of the 20th century, postulated that, if a compound could be made that selectively targeted a disease-causing organism, then a toxin for that organism could be delivered along with the agent of selectivity.