Columbia Gnibersity
College of Physicians and Surgeons

630 WEST 168TH STREET
NEW YORK 32, N. Y.

DEPARTMENT OF BIOCHEMISTRY

CELL CHEMISTRY LABORATORY December 10, 1957 OFFICE: ROOM 12-201
TEL, WADSWORTH 3-2500
EXT. 7479

Professor J. Lederb
Department of Medical” Genetics

Genetics Building

The University of Wisconsin
School of Medicine

Madison 6, Wisce

Dear Joshua:

You were marked down for receiving immediately a reprint of the
NATURE paper, but it is only yesterday that they were received. To
make up, I am sending you not only this article, but also a bunch of
other recent ones. You will see that you are being thanked profusely
in our paper.

Have you got on anything new in the way of media or other things
connected with the production of protoplasts or their growing back?
A synthetic medium would be highly useful for chemical work. Also,
do you know anything concerning the permeability properties of the
“penicillin protoplasts" as compared with the other brands?

Best wishes and kindest regards,

sincerely,

Erwin Chargaff: eb