2

amary 5, 1959 4

Cag

Dirsotor of LaLuraboriss
Untardio Depurtuent of Health
Torontc, Ontario

Attention: Vere i. Crossley
Dear Ur. Crossieys

This enquiry concerns the paper "On the use of soluble starch medium in the
preparation of saaphh “C"’ Salmonella antigens", which appeared in the Journal
of Baclericivgy in 1946.

van you wl ue whether you have had any further experience with this pro-
cedure, or ddtether it has been repeated in other laboratories? I could not be
sure from the text, in the absance of arglutinin-absorntion testa, whether the
starch media improves ine Ceaggiutinability of strains whieh have become par-
tiaily rough, whether it aelects for the smoothest component of rough~smooth
iaixiures, of whether it actually restoras the somatic antigen to cultures from
which this has been essentially coapletely lost, If your experiance vermits,
I wWoulu app teclaw your cuaieit on these details.

Finaily, aight i ask for a reprint, Af any should still ba avallable.
{ e Your's aingsrely,

i Joshua Lederberg
Associate Profeasor of Genetics