October 14, 1958

Dr. J. A. Ki tchener

Department of Chemistry

Imperial College of Science and Technology
University of Lendon

Lenden $.W.7. England

Bear Or. Kitchener;

Thank you very much for your letter of the 9th, which has a number of very
useful leads. {t would be difficult to summarize what I'm after and ft is an
improbable gamble In any case. if you do have concrete references to any
examples of amphoteric resins, @.g., the mixed nuclear NH, / COOH, | would
be esvecially pleased to have them, as this is the sort of thing I'm loeking
for. In the long run, 1 will have to have a controlled sequence of the two
residues and this is the main reason | was looking to condensation processes.
ft may be that my product would have to be primarily a linear polymer made
insoluble by some secondary trick, (as suggested in your fast paragraph) so
your reference to Or. Gregor may be particularly useful.

Yeurs sincerely,

Jeshua Lederberg
Professor of Medical Genetics

JL/Jp