Desoxy--Saline Extract of Heated Type III Cells Desoxy--Saline Extract of Heated Type III Cells

Contributor(s): Avery, Oswald Theodore, 1877-1955 MacLeod, Colin M. (Colin Munro), 1909-1972 Publication: Produced: 18 March 1941 Language(s): English Format: Still image Genre(s): Archival Materials Laboratory notes Abstract: 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." Copyright: This item may be under copyright protection; contact the copyright owner for permission before re-use. Extent: 1 pages NLM Unique ID: 101584575X54 (See in Profiles in Science) Profiles in Science ID: CCAACM Permanent Link: http://resource.nlm.nih.gov/101584575X54 Archival Collection: The Oswald T. Avery Collection (Profiles in Science)