LONDON — The immunologist César Milstein died in Cambridge, UK, on 24 March aged 74. Milstein, who was born in Argentina, devoted most of his career to studying the structure of antibodies and the mechanism by which antibody diversity is generated. He was awarded the Nobel Prize in Physiology or Medicine in 1984 with Georges Köhler, for developing the hybridoma technique for the production of monoclonal antibodies. This was the discovery that allowed the exploitation of antibodies in science and medicine and is now the basis of a multi billion pound industry. Milstein himself went on to develop monoclonal antibodies as markers for particular cell types. He is said to have regretted the fact that the UK government had failed to patent the hybridoma technology.

Milstein joined the Medical Research Council's Laboratory of Molecular Biology in Cambridge in 1963, shortly after it opened. The Chief Executive of the MRC, Sir George Radda, said "No other MRC scientist has made such an outstanding contribution to Britain's science, health and wealth creation. MRC awarded its first Millennium Medal to César in 2000 in recognition of his ground-breaking work."

In recent years, Milstein focussed on characterizing the somatic hypermutation of immunoglobulin genes that allows the production of higher affinity antibodies in the course of an immune response. He submitted a manuscript on this topic less than a week before he died.

In addition to his contributions to antibody research, Milstein worked hard to improve the lot of scientists in less well-developed countries. César Milstein's death follows the death last month of fellow LMB Nobel laureate, Max Perutz.