HAYYHO-H3CIENOBATEICKK MHCTUTYT 3A JbPIKABEH KOHTPON HA JIEKAPCTBEHM CPEJICTBA
Oy. ,,3anmos 26, Codnn

FOCYJAPCTBEHHbIA HAYYHbIA KOHTPOJbHbIM HHCTHTYT JIEKAPCTBEHHDIX CPEJICTB
Oya. ,,daumos 26, Copua — Boarapaa

RESEARCH INSTITUTE FOR STATE CONTROL OF MEDICAL PREPARATIONS
bul. ,,Zaimov" 26, Sofia — Bulgaria

Sofia, 8.3.i196D.

Ue lssther Lederberg

Department of Geneties,Calit.,USA.

Dear Collegue,

we address ourselves to You with the request to send us,if
possible,the strains: E.coli B ( W 4576 ) thimin deficient and

Hecoli B radioresistent.
thanking You in advance for Your kindness,we beg You to ace

cept our best regards.

Trouly Yours,

Director: }. ;

(prof Sv.Bardarott Drem.)

7 W456 Ech Shar, thy ~ | |
(Medi - a Ten re |

Selection 4 Hye Stohr’ ims ) .

JK los