EXECUTIVE COMMITTEE BIOLOGICAL STAIN COMMISSION

H. J. CONN, PRESIDENT
P. O. Box 269, GENEVA, N. ¥.
8. 1. KORNHAUSER, SECRETARY
101 W. CHESTNUT ST., LOUISVILLE 2, Ky.
E. H. STOTZ, TREASURER
UNIV. OF ROCHESTER, ROCHESTER 7, N. Y.

 

GENEVA, N. Y.

July 5, 1949

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

Dear Dr, Lederberg:

I have your letter of the 1st about eosin, NE-23,
and its failure to behave in the EMB agar,

We do not test eosin in this medium, for the simple
reason that to give best results a batch of it has to
be combined with the right batch of methylene blue;
unless proverly paired with the correct lot of the latter
dye, you cannot exnect ontimum results. That may vossibly
be your trouble.

On the other hand, NE-23 is apnarently an abnormal
batch, It was vassed by our regular collaborators, and
hénce certified; but after the batch had been comoletely
sold out, complaints beg@én to come in about it either
to the manufacturer or to us. We have no idea what the
trouble is, but we realize that something must be the
matter with 1t; so do the menufecturers. Accordingly
they always stand ready to renlace lots of this batch
returned to them; and I know you will receive courteous
treatment from them if you return your sample for
revlecement to:

Pharmaceutical Department

National Aniline Division

Allied Chemical and Dye Corporation
LO Rector Street

New York 6, New York

You might mention that you are doing so on my instructions,
I am not certain their current batch would be better in
the EMB agar, however, for the reasons given in the first
paragraph of this letter. .

Sincerely,yours,
Ce AM,
H. J.. Conn

HJC: bs