April 16, 1952

Dr. I. N. Asheshov
New York Botanical Gardsn
Bronx Park, New York 58, N.Y.

Dear Dr. Asheshov:

I have your letter of the i4th. Your position with regard to
the distribution of your antibiotics is quite uuderstandabls.

We will be very happy to send you %-1485 (our best indicator
for lambda}, and its immediate parsnt, the lysogenic K-12? strain.

Fortunately, Mr. Norton Zinder will be visiting New York next
week, wr. cinder is just now completing nis Ph.5. dissertation on
genetic exchange in Salmonella typhimurium. This hus turned out to
be very much a phage problem, and he shares my interest in therapy.
I have askednhim to try to arrange an appointasnt with you, which he
would be greatly interested to do. He will try to telephone you
when he arrives in New York, Friday, April 25, IE would appreciate
aby couréésies you extend to him. In addition to his own immedtate
problem, he is aiso cognizant of the work Jirs. Lederberg and I are
doing with 2. coll, and I am sure he could raise the same questions
and report your remarks as if I were able to join you in pergon,

Mr, Zinder will also transmit the cultures. The best method of
securing high titer lambda 18 by JV “induction” (efter Lwoff) cof
the 1tysogenic bacteria; it can also ve grown on the sensitive, from
direct filtrates of K-12. in the usual way.

To answer your final question, we are deeply involved now in these
two systems (E. coli and Salmonella. I would hesitate to contemplate
taking on still another system, for the present, even for this very
interest question of lysogenic therapy. This means, I suppose, that
we will have to depend on luck that some of your agents act oh our
phages. ”

I must confess to only a vague apprehension of your recent studies
with antivirotics. Can you refer me to any publications as yet?

Yours sincerely,

Joshua Lederberg