The idea of picking up deficient mutants is very good, and I'm glad to hear the preliminary results are encouraging.
N. Fries used a similar technique (but on minimal agar) for the preliminary screening of Ophiostoma x-ray biochemical mutants
-- fairly successfully.
Regarding the effect of time of incubation on appearance of mutations, I think its [sic] still worth doing, even if Demerec
has done the equivalent (paper just submitted to PNAS) with x-rayed coli; plated immediately, and sprayed, after incubation
1, 2, 3, 4 etc. [ . . . ], with virus. With both x and u.v. "ray direction [?]" there is a definite lag in appearance
of resistant mutants. For biochemicals, incubation would have to be prior to plating.
Dr. Sinnatt assures me that the tower room will be available in March -- rent free -- for the entire term of your stay if
I'll be in N.Y. this week-end -- and will give you a ring when I have time -- or will leave word with the Ryans. (I just
realized you can't get this till Mon.!)