I am writing to you now simply to tell you that I am now located here at the University of Wisconsin, where I am trying to
organize a laboratory for research on genetics of microorganisms. As soon as possible I hope to take up again the problem
of directing mutations of biochemical mutant strains of C1 and C2. While still at Yale, Tatum and I obtained several such
mutants which, I trust, Dr. Tatum will send to you as soon as convenient.
Also at Yale, I tested the fermentation characteristics of c1 and c2, particularly with respect to sucrose. In my hands,
I find that on "EMB-sucrose" agar, neither C1-S nor C-2S attacks sucrose to any appreciable extant. There was some
indicaiton, however, that a very small proportion of the cells in a culture might "revert" or otherwise become sucrose+.
In tests on liquid medium, the sucrose+ variants would probably outgrow the culture if they occurred and give the impression
of a positive test. This is in agreement with your statements as to the spontaneous variation in fermentative ability of
I have not been able to pick out a suitable C2-E strain with which to duplicate your experiments. Since this should be our
first step in confirming your work, I would appreciate it very much if you could send me a transfer of a C1-r or C2-r strain
which you have found satisfactory. On the other hand, as I told you at Cold Spring Harbor, our first experiments on the directed
mutation of an anaerogenic mutant to the aerogenic type were very encouraging, although I am not now entirely satisfied with
our control experiments.
You may be interested that Dr. A Hershey of Washington University, St. Louis, Mo., has written to me that C1 and C2 are susceptible
to the bacteriophages: T2, T3, T4, T5, T6 and T7, but not to T1. He was also able to obtain resistant mutants very easily.
These should be useful markers. If you are interested in having these phage strains let me know, or else write to Hershey
or to Luria.
My colleagues at this University have expressed a deep interest in your work, as I have. Be assured of my sincerest respects.