December 1, 1952

Dr. L. Dienea

Bacteriology Dept.
Maecachusetts Genera Hoepita:
Boston, Mase.

Dear Dr. Dienes:

I was about to write to you a few days age with dilecouraging
news. However, juet during the peat couple of days, one of the
broth tubes tnat I nad inoculated with the danpie of Pibuteus L
thet you had given me finally decided to grew out, in the charac-
teristic surface film. I had been afraid that the vibration of
the airolane had so euuldifies the vial of l-grovth that I would
not achieve a successful transfer, but this is very encouraging.

from rroteus 52

Meanwhile, alao, I have ebtained L-type growth/in penicillin-
nutrient-agar (without horse serum) and have made one transfer to
the same medium, using a maceive agar inoculum. No bacterialforms
are evident, and I am now trying to propagate this in broth. I am
therefore hopeful that I may eventually learn how to handle these
queur beests. Unleas we are very lucky, however, I doubt that thers
is much we can do by way of genetic experinents with Proteus. Have
you nanaged to re-Leolate L-type from your Salmonelia strain, and
have you dacided how 4¢ may be pessible for you to send this’

Under separate cover, I am sending #-1657, which is the same ss
"Ee coli 204" described by Klieneberger. Actually, it looks more like
Aerobacter than coli. Microseovically it appears to coneist primerily
of vesicles, but I have not noticed any prominent granular phase. I
will be perfeotly happy to send you our Salmonell« essay strain, W-435,
but will remind you that thie le now cuite far removed from ite ori-
ginal isolation. Actually, for the genetic experiments I discusced
with you, it is preferable to obtain the L-type growth from a wild-
type Salmonella, and to experiment on combinations of this with the
mutant bacterial forus.

Let me take this cecasion to thank you for your gracious hospitality
during my very profitable visit.

Yours sincerely, -

Joshua’ Lederberg
PS. Ife just as well I got to the airport early the day I left.
New York was closed by fog, but I found another flight direct to Chi-
Cagos ,
JL