AMERICAN (yanamid COMPANY

7
1937 WEST MAIN ST. TELEPHONE
STAMFORD, CONN. STAMFORD 4-614I

January 11, 1952

Dr. Joshua Lederberg
Department of Genetics
University of Wisconsin
College of Agriculture
Madison 6, Wisconsin

Dear Josh:

During a visit to our laboratories several
months ago, Rernard Davis mentioned the fact that you had
developed a method of preserving bacterial cultures using
silica gel, which appesrs to be much more convenient than
the usual method of freeze-drying.

We would appreciate any information you
could give us concerning the details of your method and
experiences relating to the probable life of the preserved
cultures.

With best regards,

Sincerely yours,
R. R. Roepke
RRR:mmn Chemotherapy Division

GENERAL OFFICES: 30 ROCKEFELLER PLAZA- NEW YORK 20-N-Y-