Title:

Desoxy--Saline Extract of Heated Type III Cells

Creator:

Avery, Oswald Theodore, 1877-1955

Contributor:

MacLeod, Colin M. (Colin Munro), 1909-1972

Date:

18 March 1941

Description:

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."

Location:

Box: 1. Folder: 4

Rights:

Courtesy of Maclyn McCarty.

Genre:

Laboratory notes

Format:

Still Image

Extent:

1 pages

Language:

English

Legacy ID:

CCAACM

NLM ID:

101584575X54

Profiles Collection:

The Oswald T. Avery Collection

Shareable Link:

https://profiles.nlm.nih.gov/101584575X54

Story Section:

DNA as the "Stuff of Genes": The Discovery of the Transforming Principle, 1940-1944