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Combined high-performance liquid chromatography/ sup 32 P-postlabeling assay of N7-methyldeoxyguanosine

Journal Article · · Cancer Research; (USA)
OSTI ID:6284167
; ; ; ;  [1]
  1. National Cancer Institute, NIH, Bethesda, MD (USA)
A highly sensitive and specific assay for the detection of N7-methyl-2{prime}-deoxyguanosine (N7methyldG) has been developed by combining high-performance liquid chromatography, {sup 32}P-postlabeling, and nucleotide chromatography. Separation of normal nucleotides and adducts by high-performance liquid chromatography and then combining a portion of 2{prime}-deoxyguanosine to the N7methyldG allows for quantitation using an internal standard. The directly determined molar ratio is not subject to errors in digestion, variable ATP-specific activity, or assumptions in relative adduct-labeling efficiency. The detection limit was one N7methyldG adduct in 10(7) unmodified 2{prime}-deoxyguanosine bases. N7methyldG adducts have been detected in 5 human lung samples in which O6-methyl-2{prime}-deoxyguanosine adducts had been previously determined. The mean ratio of N7methyldG to O6-methyl-2{prime}-deoxyguanosine was determined to be approximately 10. The current assay complements the high-performance liquid chromatography/{sup 32}P-postlabeling assay for O6-methyl-2{prime}-deoxyguanosine and increases the detection sensitivity of DNA methylated by exogenous alkylating agents.
OSTI ID:
6284167
Journal Information:
Cancer Research; (USA), Journal Name: Cancer Research; (USA) Vol. 50:20; ISSN 0008-5472; ISSN CNREA
Country of Publication:
United States
Language:
English