Double strand breaks induced by low doses of {gamma} rays or heavy ions: Quantitation in nonradioactive human DNA

Journal Article · Mon Jul 15 04:00:00 EDT 1996 · Analytical Biochemistry

DOI:https://doi.org/10.1006/abio.1996.0290· OSTI ID:508282

Sutherland, B M; Bennett, P V; Sutherland, J C ^[1]

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1. Brookhaven National Lab., Upton, NY (United States)

We have developed a method of quantitating low frequencies (0-30 sites/10{sup 9} base pairs) of double strand breaks in {approximately}1 {mu}g of nonradioactive human DNA. Unirradiated or irradiated DNA is digested with the restriction endonuclease NotI, producing cleavage fragments that include a major group centered at {approximately}1.2-1.3 Mbp. The DNA molecules are separated as a function of size by transverse alternating field electrophoresis. The frequency of double strand breaks is computed directly from the decrease in number average molecular length induced in the 1.2 to 1.3-Mbp cleavage fragment group by {sup 137}Cs {gamma} or Fe{sup 26+} (1.1 GeV/nucleon) irradiation vs the corresponding unirradiated DNA samples. The double strand break frequency can be quantitated easily in the dose range of 0-10 cGy of {gamma} rays. The frequency of breaks per unit dose calculated for {gamma} irradiation of DNA in human cells ({approximately}4.6 double strand breaks/10{sup 9} bp/Gy) who used methods requiring higher doses. 55 refs., 4 figs.

• OSTI ID: 508282
• Journal Information: Analytical Biochemistry, Journal Name: Analytical Biochemistry Journal Issue: 1 Vol. 239; ISSN ANBCA2; ISSN 0003-2697
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL RADIATION EFFECTS
CLEAVAGE
DNA
ELECTROPHORESIS
HEAVY IONS
IRRADIATION
STRAND BREAKS