Collection encompasses Delbruck's entire lifetime, and chronicles his role in the development of molecular biology. It includes personal and professional correspondence both incoming and outgoing copies, lectures, manuscripts, biographical material, festschrift, technical files and research papers, and publications. Some of the topics include: his immigration as a German scientist during the early years of World War II, biophysics, his work with the Phage Information Service; his teaching and collaboration with students, Cold Spring Harbor, Among the correspondents are: Niels Bohr, Seymour Benzer, Albert Einstein, Emory Ellis, Werner Heisenberg, A. D. Hershey, S. E. Luria, James Watson.