February 10, 1958

Dr. Armin C, Braun

The Rockefeller Institute for Medical Ressarch
66th Street and York avenue

New York 21, New York

Dear Dr. Braun:

To your letter of February 6: I ama little abashed to have to
tell you how little we actually did with Agrobacterium tumefaciens.
A few cagual experinents were done which were not very promising and
then for reasons I won't go into here the project was not properly
pursued,

To your second question, ay assessment of this work has depended
in part by my understanding that Klein had quite falled to repeat his
experiments in your own laboratory. I have been rather hoping that
some more definite statement might be forthcoming from you. I was not
at all impressed by ths initial publication, espscielly with regard to
the rigor with which surviving bacteria were excluded from the DNA
preparations. All in all it has seemed to me a very messy businesa
and I was waiting all this time to hear what the specialists in agro-
bacterium, like yourself, thought about it.

I will say that I am rather better impressed by the perhaps re-
lated studies by Bulassa on the transduction of streptomycin resistance
in rhizobium. However, here too, I'll have to maintain a reserved
reaction until some confirmation is forthcoming.

While we are on the subject, may I take the opportunity to make
an earnest request for your more genefial papers on the biology of the
crown-gall phenomenon?

Yours sincerely,

Joshua Lederberg
Professor of Medical Genetics

JL/ew