In 1975 George Köhler and César Milstein working in the Laboratory of Molecular Biology in Cambridge described a technique to produce endless quantities of antibodies of defined and predictable specificity. This technique has revolutionized the study and practice of immunology as well as providing tools of immense value in many areas of biology and medicine. It must be understood from the outset that monoclonal antibodies (MCA's) do not differ structurally from other antibodies found under natural conditions. The property which makes MCA's unique is that all the molecules in any single preparation are identical. Their reaction with any defined antigen--the opposite partner in the fundamental reaction of immunology--must also be exactly the same each time. It is this constancy in preparation and in effect that makes them so useful. Immunologically complex structures such as cell surfaces may be dissected at a molecular level and studied, piece by piece. The knowledge so gained will have a tremendous impact on our understanding of many diseases and the way in which they are treated.
