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CENTRO GE INVESTIGACION Y DE ESTUDIOS AVANZADOS HANS

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INSTITUTO POLITECNICO NACIONAL
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APARTADO POSTAL 14-740
OIRECCION CABLEGAAFICA: POLINVEST

Departamento de Bioquimica

December 30, 1965

Dr. Joshne Lederberg

Department of Genetics

Stanford University School of Medicine
Palo Alto, California

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Dear Dr. Lederberg:

In our laboratory we are working with
some mutants of Salmonella typhimurium LT-2 and we would
like to do some conjugation experiments using as donors
some of the strains of S. abony Hfr that were derived in
your laboratory.

I should be extremely thankful if you were
kind enough as for sending us the following strains:

Salmonella abony

SW 1403 Hfr met” avo™ str™

SW 1418 Hfr pro~ str™

SW 1444 (or S¥ 1391) Her met™ ayo” str™
SW 1446 Her str®

SW1452 Hr gal str®

SW 1462 Her str®

rlease accept my best wishes for a fruitful
1966 and my thanks for your attention.

Truhy yours,

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