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The Joshua Lederberg Papers

Letter from Jacqueline St. Clair to Joshua Lederberg pdf (110,911 Bytes) transcript of pdf
Letter from Jacqueline St. Clair to Joshua Lederberg
Item is handwritten.
Number of Image Pages:
2 (110,911 Bytes)
1957-03-18 (March 18, 1957)
St. Clair, Jacqueline
Lederberg, Joshua
Reproduced with permission of Jacqueline St. Clair.
Lederberg Grouping: No Epoch
Box Number: 72
Folder Number: 36
Unique Identifier:
Accession Number:
Document Type:
Letters (correspondence)
Physical Condition:
Series: Research
SubSeries: Genetics
SubSubSeries: University of Wisconsin
SubSubSubSeries: Research Reports
Folder: St. Clair, Jacqueline, 1957
March 18, 1957
Dear Josh,
On the enclosed sheet are a few series of shots taken with oil immersion, Micro-file film, low intensity of light, 4 second exposure. The prints are sloppy and unenlarged, but you can get the general idea from them. The cells sprouted so fast during certain periods that critical pictures are missing. Will try to focus attention upon fewer cells and telescope observations. A few of them are 400x and labeled High Dry.
Spent -- rather wasted -- a couple of days trying to follow cells that progressed no farther than number 1 on other sheet. Then theorized that perhaps combination of brighter light via oil condenser plus concentration of rays by immersion oil produced too much heat (or light???), because preps prepared at same time and with same ingredients grew well either when left alone or observed with high dry. Longer exposure with less light (field poorly visible to eye) allows normal growth and also gives better pictures.
I believe that these pictures, at least when printed properly, are about as well as we can do with 35 mm setup. Perhaps we would not have to sacrifice depth of focus by using plates or larger film with 400x scope magnification.
Ran a large number of platings of Y10 with 50 units of penicillin, and after 6 days of incubation there are a few suspicious looking colonies, but I refuse to become excited till the acid test. Also ran some reconstruction plates containing 1:1000 DAP minus; only a small percent came through (assuming fully viable initial population), but they are detectable. New crosses are being run. Bessie stopped in last Friday and said the electron micrograph specimens look fine -- plan to devote this week to them.
News Briefs: Alan won NSF Fellowship. Wolfram's daughter has measles. No news (that I know of) from Orskovs. 3" of snow so far today. Lab running smoothly.
Persistent Assistant
P.S. Hi, Esther.
Thanks for cards. We all envy you, especially at the moment, with the sudden reappearance of Jack Frost.
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