UNIVERSITY OF CALIFORNIA

DEPARTMENT OF BIOCHEMISTRY

BERKELEY 4, CALIFORNIA January 31, 1958

Professor Joshua Lederberg
Genetics Building
University of Wisconsin
Madison 6, Wisconsin

Dear Josh:

We do not know the nutritional requirements of Hemophilus
influenzae. We have never tried to culture it, but have assumed
(perhaps without reason) that its nutrition might be similar to
that of Hemophilus parainfluenza.

Metzler and I were able to get rather good growth of
one of Davis! Be-requiring mutants of E. coli in the absence of vita-
min Bg if the medium contained a complete assortment of amino acids
and vitamins. The medium was that listed as Medium B in the
Journal of Biological Chemistry, Vol. 198, page 363 (1952).

Cordially yours,

Cons d ,

Esmond &. Snell