August 24, 1955

De. Lou 8. Heren

Dept. Bacterial Phyalology
Immunology Division

AMS Graduate School
Washington 12, 0.¢.

Dear Lou:

I found your letter of July 30 won returning from a trip to the SAB
meotings.

Thanke for the informetion on the Es coli cultures: we're glad to have
them. There was no letter with then-- you can imagine how mystifying they
were.

Larry Weed did arrange to have sent the cultures we wanted fron hin.
Unfortumately, we s¢i11 havwenot duplicated hie reeulte. I have no idea
what's wrong.

Concerning the two Be coli oultures which react with Salmonella IX
do you have eny further information on theér oultural or serological behavior. —
Do they have XII? De they have recognizable H antigens?

Can I eek one more question? In your note in Proc Seo on the transductions
with Vi phage, there's a linger graph relating number of transductions to
aanount cf phege. The latter 1s, however, on auxexpmmeutiuixeraiy 2 logerithsic
acale. Do you attach any special signiffeance to this relationship?

¥e have lately looked over the paratyphi 8 typing phagee for traneducing
activity. The 8.A.0eR, typing phage worked very much like PLT22, but has,
unfortunately a much narrower host range, though not confined to paratyphi 5.
This observation ie not likely to be of much use. Have you tried any of the
experiments wa diecussed anent selection for Vie, eegs, sase of the selective
agglutination poselbilities? 0.0. Spicer hae had some favorable results in
reoonstruction experinents in the separation of various somatic antigen types
by such methods.

Youre singérely,

Jo afns Lederberg