Madison, September 24, 1952

Dr. C. A. Elias
458, Av. Pasteur
Instituto de Bilofisica
Rio de Janeiro, Brasil
Dear Dr. Elias:

I am enclosing herewith subcultures of K-12 and its lambda-sensitive
“mutant”, W-1485, as reqaausted in your letter of August 30. Stocks
of the free lambda can be conveniently prepared by cultivating filtrates
of K-12 + W-1485 on the latter, or better, by the UV~induction of
suspensions of K-12 in nutrient~yeast extract broth (Lwoff effect).

I hopa the delay ig my response has not inconvenienced you, but

I was away and have only just sst my laboratory in crder again. Please

let me know if I can be of any further services.
Yours sincerely,

Jodi ua Lederberg a
Associate Professor of Genetics