Louls Denes
MEH

October 9, 1346,
Dear Dr, Dienes, |
Please acce,t my thenks at the outset for the hospitality
with which I was rected Upon my abrupt visit to your Laboratory.
The prec-aretions were very impressive indeed. - LY
Oe of our graduate students, ‘a Yr, Cart Been, is devoting his :
time to the ‘securing of mutants of Proteus, Acting on your sug- |
gestion, chloral hydrate has been tried for the suppression of
sworming, ami <;pesrs to be quite setisfactory in concentrations
of ,901 % or tess, without much inhibition of growth. I think we
can anthoipate fairly rapid progress now. We sheil of course be | -
interested to learn the results of your serol-gical tests along the
sane lines, . .
A culture of F, coli, strain K-12 is being sent under separate
cover. Since 612 mutants derived from this strain snow genetio
"evidence of recombination, the structures in which this takes
place should be present. The genetic data suggest as thease struc~'
tures may. be present in & proportion of perhaps 1; 198 in cultures
off 4-8 hours in liquid medium (nutrient broth will do; Yeast Beef
Broth is probably better. ) this low figure may not be entirely hope-
less if the ‘gygote' {3 morphologically distinctive. Ye appreciate
very much your examination of this matter, however cursory. I need
hardly Suggest that ‘ler,e Bodies! may not be «he only distinctive
structure, Along these lines, has Br. Smith been continuing becterlo-—
logical investigetions? . : vs
Antiglpating the Opportunity to return your hospitality, I remain, .
vinoerely yours, Son

Joshua Lederberg,