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The Oswald T. Avery Collection

Desoxy--Saline Extract of Heated Type III Cells
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A page from a lab notebook with first line reading: "Repeat of exp. of Mar. 11 -- using desoxy -- saline extract of heat-killed cells." Caption by Maclyn McCarty: "Experiment carried out by Avery in March 1941 in search for a procedure that would avoid the losses of activity of the transforming substance that were being experienced on extracting live organisms by lysis with bile salts [sodium desoxycholate]. His modification was to heat kill the organisms at 65 degrees at the outset. The organisms were then no longer susceptible to lysis with bile salt, but he reasoned that active material could be extracted by shaking the organisms in saline containing a higher concentration of desoxycholate. After some further trials, which MacLeod also participated in, this proved successful. The old method, which was essentially that devised by [Lionel] Alloway in 1934, was abandoned from then on, with the result that extracts were consistently obtained with higher activity than had ever been encountered in the past."
Item is handwritten.
Number of Image Pages:
1 (147,348 Bytes)
1941-03-18 (March 18, 1941)
[Avery, Oswald T.]
MacLeod, Colin M.
Courtesy of Maclyn McCarty.
Exhibit Category:
DNA as the "Stuff of Genes": The Discovery of the Transforming Principle, 1940-1944
Box Number: 1
Folder Number: 4
Unique Identifier:
Document Type:
Laboratory notes
Physical Condition:
Series: Research and Discovery of the Transforming Principle, 1912-1999
SubSeries: Preliminary Research
Folder: Laboratory Notes, 1940-1946
Metadata Last Modified Date:
Linked Data:
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