PETER BENT BRIGHAM HOSPITAL

NORBERT A. WILHELM, M. OD. 721 HUNTINGTON AVENUE FRANCIS 0D. MOORE, M. D.
DIRECTOR SURGEON-IN-CHIEF
BOSTON 183, MASS.

GEORGE W. THORN. M. D. MERRILL CC. SOSMAN. M. OD. GUSTAVE J. DAMMIN, M. D.
PHYSICIAN-IN-CHIEF RADIOLOGIST PATHOLOGIST-IN-CHIEF

October 2, 1956

Dr. Joshua Lederberg
Department of Genetics
University of Wisconsin
Madison, Wisconsin

Dear Dr. Lederberg:

In connection with our work in disinfection, we would like to test several
of your F # and F— strains of Escherichia coli.

We would appreciate it, if you could arrange to send us four strains, two F-+-
and two F=. In order to avoid additional variables, it would be desirable
to have all four prototroph strains.

Please send us also a reprint of your article entitled 'Sex Compatibility
in Escherichia coli" which appeared in Genetics, Vol. 37, 1952.

Very sincerely,

}

/ eee L / Cord pew

(Mrs.) Ruth Kundsin,

Bacteriologist to Dr. Carl W. Walter
ne,