Molceular homogeneity of the deoxyribinucleic acid of phage T2

Hershey, Alfred Day, Burgi, Elizabeth (1960) Molceular homogeneity of the deoxyribinucleic acid of phage T2. Journal of Molecular Biology, 2. pp. 143-152.

Abstract

Chromatographic analysis by means of a column of basic protein is used to measure the breakage of T2 DNA by stirring. Broken molecules elute from the column at lower salt concentrations than do the original molecules. At a critical low speed of stirring, one can produce single breaks near the centers of the molecules, as shown by the all-or-none character of the initial change in chromatographic behavior, and by the survival of unbroken molecules according to an exponential function of time of stirring. In an analogous way, one can produce fragments resulting from three breaks per molecule, and in general stirring for a long time at a given speed produces a moderately homogeneous collection of fragments whose mean size is smaller, the higher the speed of stirring. The sensitivity of the DNA to breakage by stirring is strongly dependent on the concentration of DNA, being greater the lower the concentration. This self-protective action is greatly reduced when the DNA is broken by stirring. By chromatographic refractionation of the fragments produced by initial breaks, it can be shown that the fragments are not identical in chromatographic properties, presumably because of a continuous distribution of lengths centered about the mean half-length. Unbroken DNA, on the contrary, is homogeneous in chromatographic properties, therefore presumably homogeneous in molecular length. We conclude that DNA can be extracted from T2 by phenol without manipulative breakage, and that it exists in the phage particle in the form of one or more molecules of identical length.

Item Type: Paper
Subjects: organs, tissues, organelles, cell types and functions > cell types and functions > cell types > bacteriophage
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > bacteriophage
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > bacteriophage
CSHL Authors:
Communities: The Carnegie Institution Department of Genetics
Depositing User: Matt Covey
Date: 1960
Date Deposited: 19 Apr 2017 19:40
Last Modified: 19 Apr 2017 19:40
PMCID: .
URI: https://repository.cshl.edu/id/eprint/34507

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