(rp ewer . 3 * asa
"Dear Tom, O . .
. Joshua gave me your request for K-12; which with the majokrity of ite de-
. Fivatives, carries the phage we cali lambda. An appropriate sensitive, W-1293, and
K-12 are being matled to you. Both of these strains are haploid. The same systea
can be obtained -in the dinloid, but these ars unstable unless constantly cheaked

for ‘a variety of genetic factors. Particularly as there is no relati-nahip between |
ploidy and lysoganicity the dipioids would not be sspecially useful to you.

Dr. Paul Kaesberg has taken a few preliminary electronmiorographe of lambda
for us and they seen to hzve a nice tuil. We ar» very happy to see you try your
hand with this material.

Yith best regards,

Esther M. Lederberg
aerate
2d

 
  
   
   
 
  

(Up hnwnr March 25, 1952
Dear Tom, 4 . ce
_ doshua gave me your request for K-12; which with the majozrity of its dew.
_ pdvatives, carries the phage wo call lambda. An appropriate sensitive, We1293,; and
K-12 are being mailed to you. Both of these strains are haploid. The same system -
can be obtained-in ths diploid, but these are unstable unless constantly checked -:

for ‘a variety of genetic Cactors. Particularly ag there is no relati-nship. between
_ ploidy and lysogenicity the diploids would not be especially useful to you.

Dr. Paul Kaesberg has taken a few preliminary electronmicrographs of lambda”
for us and they seen to hive a nice tuil. We are very happy to see you try your —
hand with this material.

ith vest regards,

A}

‘ 7 Esther M. Lederberg _

 

uN

twee chow

7 vivi , . re ~S wees 2aguurs qd Seog .
nutrition. various phages ang those senting sensi. —
nev reqvuirements." But ¢ ermining
er developed and he theme was

To my sorrow,

your diploid K-12
heard that tt : coli, particularly since I have

of K~12 and a host for the phage? Me a slant

Best regards,
a
a OP De
Thomas F. Anderson