Abstract
We have developed a method of quantitating low frequencies (0-30 sites/108 base pairs) of double strand breaks in ~1 μg 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 ~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 137Cs γ or Fe26 (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 γ rays. The frequency of breaks per unit dose calculated for γ irradiation of DNA in human cells (~4.6 double strand breaks/109 bp/Gy) is within the range of values obtained by others (2-8 sites/109 bp/Gy) who used methods requiring higher doses.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 53-60 |
| Number of pages | 8 |
| Journal | Analytical Biochemistry |
| Volume | 239 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jul 15 1996 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology
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Double strand breaks induced by low doses of γ rays or heavy ions : Quantitation in nonradioactive human DNA. / Sutherland, Betsy M.; Bennett, Paula V.; Sutherland, John C.
In: Analytical Biochemistry, Vol. 239, No. 1, 15.07.1996, p. 53-60.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Double strand breaks induced by low doses of γ rays or heavy ions
T2 - Quantitation in nonradioactive human DNA
AU - Sutherland, Betsy M.
AU - Bennett, Paula V.
AU - Sutherland, John C.
PY - 1996/7/15
Y1 - 1996/7/15
N2 - We have developed a method of quantitating low frequencies (0-30 sites/108 base pairs) of double strand breaks in ~1 μg 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 ~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 137Cs γ or Fe26 (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 γ rays. The frequency of breaks per unit dose calculated for γ irradiation of DNA in human cells (~4.6 double strand breaks/109 bp/Gy) is within the range of values obtained by others (2-8 sites/109 bp/Gy) who used methods requiring higher doses.
AB - We have developed a method of quantitating low frequencies (0-30 sites/108 base pairs) of double strand breaks in ~1 μg 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 ~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 137Cs γ or Fe26 (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 γ rays. The frequency of breaks per unit dose calculated for γ irradiation of DNA in human cells (~4.6 double strand breaks/109 bp/Gy) is within the range of values obtained by others (2-8 sites/109 bp/Gy) who used methods requiring higher doses.
UR - http://www.scopus.com/inward/record.url?scp=0030586296&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030586296&partnerID=8YFLogxK
U2 - 10.1006/abio.1996.0290
DO - 10.1006/abio.1996.0290
M3 - Article
C2 - 8660625
AN - SCOPUS:0030586296
VL - 239
SP - 53
EP - 60
JO - Analytical Biochemistry
JF - Analytical Biochemistry
SN - 0003-2697
IS - 1
ER -