UNIVERSITY of PENNSYLVANIA

PHILADELPHIA 4

The School of Medicine

 

DEPARTMENT OF DERMATOLOGY AND SYPHILOLOGY March 13, 19 53
AND
DrpaRTMENT OF MICROBIOLOGY

Epwarp D. DeLamater, M.D.
Research Professor

Dr. Joshua Lederberg
Department of Genetics
University of Wisconsin
Madison 6, Wis.

Dear Josh:

Thanks for your notes of March 8. I am very sorry
that you don't feel that you would have enough to say, but
suspect that your invited speech will prove to contain a great
deal. I am looking forward to hearing it.

Sorry I forgot about the wire concerning recombination
in megatherium. Three individuals have now produced evidence
for recombination in megatherium, Szybalski at Cold Spring
Harbor, who did this wht Te working with us on a joint project,
Yaverbaum of my own laboratory, and Hunter of my own labora-
tory. The work is progressing nicely, although at the present
time is still preliminary. I feel, however, that the proof
is there,with high recombinant counts under certain biochemical
conditions. All this for the future, At the present time
we are working on the proper technique for handling the recome-
binant material cytologically, and hope to have enough to
present at least preliminary comments at both Lake Como and
Rome.

We are looking forward to seeing you. Best personal
regards to you and your wife and Jim Crow.

As ever,

, ard D. DeLamater, M. D.
EDD:aj Research Professor
THE BIOLOGICAL LABORATORY en
Cold Spring Harbor, New York

During the summer of 1952 four courses will be given, designed to acquaint the
student with some of the techniques used in bacteriophage research, bacterial
genetics, microbial cytology, and population genetics, and with the recent results
of such work. The courses will consist of intensive laboratory and discussion
periods, and may be expected to occupy the student's full time.

(1) Bacterial Viruses.«-June 23 to July 12. Dr. A. H. Doermann, Oak Ridge
National Laboratory. Limited to 14 students. Fee, $70,

Isolation, preparation, and assay of phage; microscopic observation of lysis;
specific antisera reactions; resistance patterns of bacterial mutants; one-step
growth; single-cell bursts; mixed multiple infection; the mutual-exclusion effect;
exchange of genetic characters; ultraviolet irradiation and photoreactivation,

(2) Bacterial Genetics.--July 16 to August 5. #8. M. Witkin, v. Bryson, M. Demerec,
and staff. Limited to 14 students. Fee, $70.

Isolation and analysis of mutants resistant to phages, radiation, and anti-
biotics, fermentation mutants, and nutritional-deficiency mutants; proof of muta-
tional origin of variants; measurement of spontaneous-mutation rates by several
methods, including use of chemostat; induction of mutations by radiation and
chemicals; study of sexual recombination; study of cross-resistance to antibiotics.

(3) Cytology of Microorganisms .--August 11 to August 30. Dr. EB. D. DeLamater,
University of Pennsylvania. Limited to 10 students, Fee, $70.

 

Staining of bacteria, yeasts, fungi (Neurospora), and blue-green algae for
nuclear structure and for mitochondria, using various methods (Feulgen, Piekarski-
Robinow, DeLamater, aceto-orcein); study of mitosis in bacteria (B. megatheriun,
M. cryophilus); use of tetrazoles for study of mitochondria in bacteria and yeast;
phase-contrast microscopy for the study of microorganisms.

Students should bring their own research microscopes, with light and filters.
Limited number of microscopes available for rent at #15.

(4) Population Genetics.--June 23 to July 31. Dr. R. P. Levine, Amherst College.
Limited to 10 students. Fee, $80.

Population-cage techniques for study of the action of selection in Drosophila
populations; sexual isolation; frequency of lethal genes and their allelism in
Drosophila; cytological techniques; representative species of Drosophila groups;
factors affecting fertility, fecundity, and longevity; building up of marker stocks;
analysis of natural hybridization (field trips to study certain plant material.
Some time will be available for the student to carry out or continue an individual
research problem.

Students should bring their own dissecting microscopes. Limited number for
rent at $15,

Address: Biological Laboratory
Cold Spring Harbor, L.I.
New York