Columbia Qnibersity
College of Bbhpsicians and Surgeons

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

DEPARTMENT OF BIOCHEMISTRY

CELL CHEMISTRY LABORATORY July 23, 1956 OFFICE: ROOM 12-201
TEL. WADSWORTH 3-2500
EXT. 7479

Avi 4 = 1956
Dr. Joshua Lederberg
Department of Genetics
University of Wisconsin
Madison, Wisc.

Dear Josh:

Recently in Ann Arbor I heard wonders about the various ways of
getting protoplasts from E. coli of which you seem to be the prime
perpetrator. We are very interested in trying out such methods in
connection with our attempts to get bacterial micleoproteins.

I understand some procedures made use of lysozyme (with or without
versene), others of penicillin. If your method is Not classified,
could you give me the recipe, if possible so foolproof that even I
could do it? For certain purposes we should like to isolate the proto-—
plasts, for others this is not so important: what has been so nicely
called a shockate would do. There are two difficulties to consider:
(a) our work being preparatory we have to be able to handle large quan-
tities of cells; (b) we are lousy bacteriologists, not even deserving
of this proud name.

With kindest regards,

sincerely yours,

Erwin Chargaffi eb