Merton

teveaber 21, 1946.

Cear
,faan sending the following, as requested:

Sieh. Se Yyphimrlua, aonophasio I, .an Leclcusine-valinelese mitant. |
tysogente for ;

SY-36 3. gallinaran. (. sanguinarium). Can be grown with thiwain or
iB thiazole gupplezxent.

Lysogenicity is conveniently tested for elther with almple filtrates of
Sf=13 grown alone, or better, with SY-36 in broth. For large scule teste
for this property, SY-36 can be plated on synthetic agar with B,, and
single colonies of SN-13 picked to the pre-soread vletes. Due the
matritional deficlency, the Si-]3 does oot grow, bat if it carries phege,
ths lysis of thc indiester is apparent. Sevetal hunired colonies of
Sie-13 from washed suspensions, and following various traataents, Cog.
heavy UV troatrent, cultivation in Phoephine CAN, or in arsenite, have

all bean lysogenic. It should be possible to set up tests where eoveral —
hundred colonies of S%=-13 oan bea allowedd to form on a plate, and use the
ving of lysis around the colony for large scale testing.

Sincerely,

dJoshuy Lederberg

CG: Luria
Hershey