March 13, 1948.

Dr, C. ud. oCloskey,
Department of Organic Shenistry,
State University of Iowa,
Iowa City,
Dear Dr. “4eCloskey,

I found your 1945 paper in Proc. Soc. , "Utilization of certain rare sugars
by microorganisms" of considerable interest, because we are sngaged here in
a atudy of the specificity and genetics of fermentative mitations in E. coli.
I wonder whether you have sufficient supplies of the following to permit you
to send samples for investigation. Minimum 200 mg., we could use profitably at
least a} gram of any comphund. The substrates in which I would be particulatty
4nterested include: b,b (iao-) trehalose, tagatose, turanose, neclactose, and
4-p-d-glucosyl-d-mannosédg. Your cooperation would be greatly appreciated.

Yours sincerely,

Joshua Lederberg
Assistant Professor of Genetics.