THE UNIVERSITY OF WISCONSIN
COLLEGE OF AGRICULTURAL AND LIFE SCIENCES

1630 Linden Drive Madison, Wisconsin 53706

DEPARTMENT OF PLANT PATHOLOGY February 25, 1969

Dr. Joshua Lederberg

Department of Genetics

Stanford University School of Medicine
Palo Alto, California 94304

Dear Dr. Lederberg:

Thank you for your recent letter, copies of your papers, and your
expression of interest in our work with higher plant cell protoplasts.
We have just submitted two papers on this subject to the Canadian
Journal of Botany and the Plant Disease Reporter. Also, we plan to
present papers on the subject at the Tissue Culture Association
meetings in June at Detroit and at the XI International Botanical
Congress in Seattle.

Briefly stated, it has been possible to produce protoplasts from
tissue cultured cells of the 19 species of plants we routinely main-
tain in this laboratory for this and other studies. This has been
done with a purified commercial cellulase. Some protoplasts survive
only a few hours, but peanut protoplasts have survived 15 days or
more. The process was followed with phase microscopy in the living
unstained cells growing in a microscope slide microculture. This
protoplast formation we consider the first step in our goal of
producing somatic hybrids. A second step was recently achieved when
we were able to obtain protoplast fusions of peanut. These remained
alive only a short while, but we are encouraged.

Under separate cover I am sending several reprints that you may not
have seen that provide some background and encouragement for our
common interests.

Best wishes from Madison.

Sincerely yours,

[s2.0_32 Nord

A. C. Hildebrandt
ACH ms Professor

4: Schenk, frp

WW Laayy ad 2dtH