PUBLIC HEALTH LABORATORY SERVICE
(Directed by the Medical Research Council for the Ministry of Health)
, Central Enteric Reference Laboratory and
e -Centrat—Pusrre—Heatti-baporeterr, Bureau,
COLINDALE AVENUE,
LONDON, N.W.9,

  

Telephone : COLINDALE 6041 & 4081.
Telegrams : DEFENDER, HyDE, LONDON.

26th November, 1951.

Dear Dr. Lederberg,

In response to your post card of the 9th November, addressed to my
co-worker Dr. «1.5, Anderson, I am sending you under separate cover a
collection of reprints of papers published from my laboratory, some recently
and others long ago.

Of course, we are following here with the greatest interest your
recent work on genetic recombination, I noticed from the reprint of your
paper in Science, July 20, 1951, p.68, which you were good enough to send me,
that you are now employing serological metnods and also the acriflavine test
in connection with your experiments. For this reason I have added the reprint
of an old paper by one of my previous co-workers, W. Hirsch, which deals with
a source of error in the acriflavine test that is not generally known, It is
possible that a similar source of error may be operating also in Escherichia
coli, since many strains of this group of organisms possess antigens of the
type of the typhoid Vi antigen, to which Kauffmann has given a variety of
designations. I thought, therefore, this paper might be of interest to you.

I shall be glad if you will place my name, too, on your regular
mailing list.

Yours sincerely,

J. =
Dr. Joshua Lederberg, rei
Department of Genetics,
University of Wisconsin,
Madison 6,

Wisconsin, U.S.A.