September 16, 1958

Dear Lou:

Thanks for the culture of TM: ETS-9 s‘, which arrived in perfect time. As
1 told you our main objective would be to isolate an Hfr recombinant if possible
to repeat the analysis of phase variation, and it would be neatest If we could
have this ready before Nancy Atkinson arrives. We will certainly let you know
how this works out and send you any material thereform that might be useful
to you.

Mainly for symmetry, could | ask you for the original ETS-9 culture, notwith-

standing Its poor fertility? There's no hurry about this and | could easily pick
It up from you at the meeting in BeGhesda.

tn any case, see you there,
Yours sincerely,

Joshua Lederberg