UNITED STATES DEPARTMENT OF AGRICULTURE

AGRICULTURAL. RESEARCH ADMINISTRATION

BUREAU OF AGRICULTURAL AND INDUSTRIAL CHEMISTRY
PEORIA 5, ILLINOIS

April 19, 1949

Dr. Joshua Lederberg
Department of Genetics

The University of Wisconsin
Madison 6, Wisconsin

Dear Joshua:

In answer to your request of April 15, I am sending you two
samples of calcium lactobionate for your interesting work on
adaptation. One of the samples (NRRL 2378-7-A; 500 mg.) is

the same as you received previously. It was purified by way of
the basic calcium salt which should remove lactose. The other
sample (NRRL 2512~42-A; 20 grams) contains 0.52 percent lactose
and was found to be 93.7 percent vure based on galactose
determination after hydrolysis. Based on calcium analysis, it
was 96.7 percent pure. The loss on drying to constant weight
at 100° is 10.0 percent.

If you can establish without question the results you describe,
it would appear that you have made a valuable contribution to
your field. Although I don't know too much about it, it would
seam to me that the whole experiment hinges on whether or not
you have lactose-free calcium lactobionate. If I am right, how
do you go about proving that you have such a lactobionate? I
certainly wouldn't want to be quoted as saying that any of the
samples I sent you fulfill the requirements of your experiment
as I view it. Let me hear from you on this point,

IT know of only two good ways of replacing calcium by Na* or H.
The first is by removal of the calcium with amberlite ITR-100
and the other is by the addition of slightly less than the
calecvlated amount of sodium oxalate,

Let me hear from you soon, and keep up the good work.

Sincerely yours,

Yeon,

Frank H. Stodola, In Charge
Chemistry Section

Fermentation Division

Northern Regional Research Laboratory