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Matching of single‐strand breaks to form double‐strand breaks in DNA
Author(s) -
Freifelder David,
Trumbo Bruce
Publication year - 1969
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1969.360070506
Subject(s) - ionic strength , breakage , chemistry , dna , double strand , single strand , range (aeronautics) , ionic bonding , crystallography , molecular physics , chemical physics , biophysics , dna damage , ion , biochemistry , materials science , composite material , organic chemistry , aqueous solution , biology
Single‐strand breaks (ssb) in opposite strands of DNA can be sufficiently near that a double‐strand break (dsb) results. A theory is presented by which the maximum number h of base pairs which cannot prevent double‐strand breakage can be determined from the rates of production of ssb and dsb. The assumptions required to derive the necessary equations as well as the range of validity of the equations are discussed in detail. In the experiments ssb and dsb were produced by x‐irradiation in buffers which do not eliminate indirect effects and were measured by analytical ultracentrifugation. Values of h have been determined in low and high ionic strength and in low ionic strength over a range of temperatures. The values, 2.64 and 15.8, were obtained for high and low ionic strength, respectively.