This section documents Milstein's scientific research from the early 1950s at the University of Buenos Aires, Argentina, the Department of Biochemistry in Cambridge and his brief return to Argentina in 1961-1962, to his career at the Medical Research Council Laboratory of Molecular Biology, Cambridge up and well beyond official retirement. It spans some fifty years of research in enzymology and molecular biology.The material mostly comprises bound notebooks and, generally later in date, the contents of MRC ringbinders kept as laboratory notebooks and so styled. A very high proportion of the material is in the hands of Milstein's researchers and collaborators, especially J.M. Jarvis, Milstein's laboratory technician/research officer from the mid-1960s, and S.C. Howe, technician 1972-1977.There is documentation of administration of research in the form of records of the distribution worldwide of cell line samples from Milstein's laboratory and a little material relating to grant applications. There is also material relating to patents, including correspondence relating to the failure to patent monoclonal antibodies in the mid 1970s.