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4
Ministére de !'Instruction publique

UNIVERSITE DE LIEGE

Liége, le February, 4, 1958

1, rue des Bonnes-Villes

Microbiologie et Hygiéne

 

Prof. P. Fredericq

 

Prof,J. Lederberg
Department of Genetics
University of Wisoonsin
Madison 6 Wisconsin
USA

Dear Professor Lederberg,

Thank you very much for your proposal for a lec-
ture in Madison. I shall be very glad to do it. I think that
I shall come to Madison around June 9 but my travel program is
not yet definitely settled, I hope that the date will suit you,

IT am sorry to have made a distinction between
*‘virus-like" and”“plasmid-like", I really had overlooked the full
meaning of the term plasmide

a I am sending by the same mail phage BF.25 which
is useful reagent to distinguish resistance and immunity to
colicin E, Its host~strain is E.coli B that,I am sure,you have.
I include also a new sample of strain TR.27 as you did find
the previous one to be streptomycin sensitive, This one is at
least qualitatively resistant,;for if you cross-streak it on a
streak of streptomycin 10.000 ¥/m1 , there is no inhibition,

I am very sincerely yours,

GA fool

Prof.P.Fredericq