THE GEORGE WASHINGTON UNIVERSITY

SCHOOL OF MEDICINE
1335 H STREET, WASHINGTON 5, D. C.

BACTERIOLOGY, HYGIENE
AND PREVENTIVE MEDICINE October 17, 1949

Dr. Joshua Lederberg

Assistant Professor of Genetics
College of Agriculture

The University of Wisconsin
Madison 6, Wises

Dear Dr. Lederberg:

I am happy to find I do have the culture you are looking for, as
mentioned in your letter of October 13, I enclose with this letter
two ampules of Garrett strain. These cultures were put away more
than ten years ago, and I can only hope they are still satisfactory.

You will notice in each of the ampules a small amount of white chemi-
cal which moves freely end a deposit which is on the sides and bottom
of the tubes. This white chemical is a drying agent and is to be dis-
carded when the tube is opened. To culture them from these cesiccated
Materials, one carefully cleans the tapering end of the ampule and,
after flaming it to render it sterile, breaks ite The loose desiccat-
ing agent can then be shaken out. Next, I have usually taken a sterile
straight needle dipped in sterile broth and introduced it into the
tube, taking up some of the deposit which adheres to the sides and
bottom. This, when transferred to a tube of nutrient broth, should
result in good growth within twenty-four hours. I am sending you two
of these because I can do so, although I suppose that in your exper-
ienced hands if one does not grow, neither will the other.

I have not opened any of these desiccated tubes for two or three years,
but I have reason to hope they are all still vieble, since the desicca-
tion was done by a very able worker, the late Dr. Alden Roe, and since

the tubes have been kept continuously at low temperature.

I sincerely regret I have not had time for several years to do active
bacteriological work but I remain, nevertheless, much interested in
these problems, and I hope indeed our understanding of the fermente-
tion of lactose by the coléform bacteria can be made more clear. I
hope you may send me reports of your work from time to time, for I

am interested in the genetics of microbes. In fact, I want to go on
record as having had a very small part in the development of this sub-
ject in this country. I organized and presided at a round table on
Dr. Joshua Lederberg ~2= October 17, 1949

this subject at the annual meeting of the S.AeBe. in Baltimore in
1941. Of course, those in the field who are now working on the
genetics of microbes have gone very far, so mech so that my earlier
contributions amount to very little. However, it gives one consider-
able satisfaction to feel a field in which he was once interested has
importance, and I am glad indeed I happen to have the culture you
asked fore I hope it is still satisfactory.

Cordially yours,

dbo ty lor, @A

Leland We Parr
Professor of Bacteriology

LWP :ms