oY
a
© .
‘Maroh 24, 1949.
. Dr. 4akton Novick,
Institute of fiadLobioLogy & Blophysice,
University of Chicago,
. Chicago 37, filinoia.
. Lear Aart,
Thanke very much for ‘the cultures. They have already bean put to ~
use. But 7 think I must have written a confusing letter. I already
; had B/1,t and u/i,5; would like to get just plain B..,., and B/r if
, ‘ _you have them around. Meanwhile » i've gotten st least one new phage,
mo ply, which has a of the properties I'm looking for. Stocks which

are aroun on SLB (Lambdienegative ) five titers of 109 on 513, and
oniy about 10> 108 onsbammcikives on “811 (516 with Lamida). I don't
know whether this is a mutant or just "Low platime efficiency", probably
the iatter, and tu trit extant, neb veov subisfactory for. my papposes.
. Perhaps Chicago sewage will do better. Are there postal regulations
covering thet sort of thing?(How du you: suppose fec:1 samples are

: _ Malled?) pl9 does give a mutant (about 107° of the nuriicles) which -
attacks B strains: ply seems to be distinct from the T phazes, but
i haven't been uble to obtain any decent resistant mutants fron B or
heiid (viieh gives mooids), so it probably is no great help.

a3 for the tryptophane mutints—— Tpit just seat allt had to
Danny Harris. ‘iould you be abiea to vet them from hin Ltd just have
to dig out ay notes and the buried stocks again, while he probably
has then live. If ha doesn't alre: ady have am same, heSll likely be
vsking you for 3/1,% ag 4 strain blucked batzaen indole ind tryptophane.

| That's a fine electromatis you're typing on, but itds doing things
to your literary style,

Sincerely.