INSTITUTIONEN FOR CELLFORSKNING MEDICINSKA NOBELINSTITUTET Stockholm, December 2. 1960. KAROLINSKA INSTITUTET STOCKHOLM 60 Telefon 23 54 80 INSTITUTE FOR CELL RESEARCH KAROLINSKA INSTITUTET STOCKHOLM 60 Professor J. Lederberg Stanford University Medical Center Department of Genetics Palo Alto, California Dear Professor Lederberg: Thank you as well for the discussion we had in San Francisco as for your letter of November 8, I recently came back to Sweden from Japan. This is to assure you that I am very interested in your project and that we will start taking ultraviolet spectra as soon as it can be arranged. At present the best machine for that work happens to be at an exposition arranged by the Karolinska Institute because of its 150-year anniversary which is being celebrated these days. In two weeks the instrument will be back again and we will start the bacterial measurements, I am also working on the plans we made in our discussion that I should come to Stanford in February or March and spend a week or so for discussions of the technical problems. With kindest personal regards to you and Mrs. Lederberg. Sincerely yours, Torbjérn Caspérsson Professor