UNIVERSITY OF CALIFORNIA

DEPARTMENT OF BACTERIOLOGY October 23, 1950
BERKELEY 4, CALIFORNIA AIR MAIL

Dr, Joshua Lederberg
Department of Genetics
University of Wisconsin
Madison, Wisconsin

Dear Josh,

I would like to plan a simple recombination experiment for our class
in advanced microbiology, Since I have forgotten the specific details of
doing such an experiment and since both Roger and I have appeared to have
lost the mimeographed directions that you had given us, I wonder if you
could send me such directions by return air mail and a couple of good stable
mitants which give a striking differentiation in a fermentation character
of the recombined prototroph, I will leave it to you to choose lactose or
maltose as the differential character,

I am gradually becoming adjusted to living in America in the second
year of the oath, The fortunate action of the faculty in damming the
majority of the Regents has created sufficient feeling of solidarity to
prevent some of the decomposition that was going on in the faculty. I am
happy to say that Roger has decided to remain with us and this makes a preat
deal of difference for my future plans,

Rita and Roger join me in sending Esther and yourself our warmest re-
gards,

Sincerely yours,
Michael Doudoroff _
MD:his