November 3, 1959

Dr. $. Schafler

Institutul De Microblologle,
Parazitologle Si Eptdemiologle
Bucharest, Romania

Dear Dr. Schafler:
Thank you for your letter just received.

With reference to the last paragraph of your letter, may,! refer
you to a paper by S. Banic (Banc, S. 1958. Isolation of lac’ mutants
from a lac strain of Escherichia colli, by the replica plating technique.
J. gen. Microbiol. 18, 566-590.). Dr. Banic's address Is:

Institute of Microblology, Medical Faculty, Ljubljana, Yugoslavia.
While Dr. Banic has not carried out precisely the protocol you
indicated, there should be no difficulty In extending his experiment
by observing the induction of B-galactosidase with meliblose In the
strain which Dr. Banic has selected in the absence of lactose.

Yours cordially,

Joshua Lederberg
Professor of Genetics

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