Esportezione

Copier mm Us0;
A.B. C. Sem. & 6rg. Epition
Benriry’s
Rupotr Mossz

Sstituto veroterapico SWilanese Serafino Delfanti

Milano - via Darwin n. 20
Telefoni NM. 30640 30677 - 31757 - 32823 - 33917 WMileno, 19 J31/. BO nnn

Dear Dr. Vogt,

. Thank you for your letter of Oct 3rd. I am very
pleased that ytw. intend to try the Hfr strain. Lederberg has
both the original strain,which is a derivative of 58-161 ( B-
M-) after selection £2 nitrogen mustard resistance, and some
derivatives of it ,which he has made himself for selection of
recombinants by means of fermentative markers in complete media,
May I suggest that you test single colony isolates for Hfr
behaviourm, since it tends to revert,especially if the strain is
kept at room temperature.

Please give my wishes to Dr. Delbruck.
Yours sincerely

bite Goat

+