This series contains correspondence between the directors and scientists and staff working at the Unit, scientists working elsewhere in the UK and abroad, the Medical Research Council (MRC) and various government bodies. The subject matter includes research projects and proposals, careers of scientific researchers, security clearance and general personnel matters. There is a small amount of personal correspondence. The series also contains administrative files relating to the premises at 15 Chaucer Road, staff recruitment, and Unit procedures.
The series is loosely arranged by director and period of directorship, although there are obvious areas of overlap in this arrangement. Some files have access restrictions - see individual catalogue entries for details.