Yuji Hasaka
Jujin Hospital
1-14 Shiba, Shinbashi,
Minato-ku, Tokyo. Japan,
Dr. Josima Lederberg, 25th June,1958,
Department of Genetics, College of Agriculture,
University of Wisconsin,Madison, Wisconsin,
U. S. A.

Dear Dr. Joshua Lederberg,

Please excuse my writing you w ithout an introduction. I
am very well acquainted with your excellent work through the Journa 1 of Bacteriology
andi other literatures. After reading "Isolation and Characerization of Biochemical
Mutants of Bacteria", I have also used T.T.C instead of E.M.B. agar, and also made
experiments using T.T.C. in Casaminoacid-galactose in Minimal Medium. I have also used
T.T.C. with galactose = phosphate buffer (Ph 5,6,7,8) in studying fermenters and none
fermenters. However the results obtained differ very mech from yours, i.e. the fermenters
showed red and the non-fermenters white, This discrepancy may be due to the method
employed in preparing the medium, so would you please enlighten me as to the exact
method for preparing the medium, and also if there is a literature regarding prpparation
of the medium, I shall be very much obliged if you would kindly let me know the number.

n I shall be most gratefu 1 if you will kindly give me an early reply.

Yours faithfully

fi ilatc ks

Y. Hasaka

P.S. If you happen to have a reprint of your "Replica Plating and Indirect Selection of
Bacterial Mutants" (J, Bacteriol. 63, 1952) and "Isolation of Pre-adaptive Mutants in
Bacteria by Sib Selection" (Genetics 41, 1956), I shall be tery mich obliged if you would

_kindly send me copy of each.

(| POA,

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