A 32P-postlabeling method for detecting unstable N-7-substituted deoxyguanosine adducts in DNA

UMMS Affiliation

Department of Pharmacology and Molecular Toxicology

Publication Date


Document Type



Animals; Cattle; Chromatography, High Pressure Liquid; DNA; DNA Damage; Deoxyguanosine; Genetic Techniques; Phosphorus Radioisotopes


Life Sciences | Medicine and Health Sciences


Many antitumor agents, including the mustards, form N-7 deoxyguanosine adducts in DNA that are difficult to quantitate by the 32P-postlabeling procedure because of their instability. We have developed a method that is successful for the analysis of such adducts using, as a prototype mustard, 14C-labeled bis(2-chloroethyl)sulfide. This agent forms the unstable product 7-hydroxyethylthioethyldeoxyguanosine in DNA. By performing enzymatic digestions to 3'-deoxynucleotides at 10 degrees C, including a second N-7-substituted guanine deoxynucleotide as an internal standard, removing most of the unmodified nucleotides and [32P]ATP on disposable anion columns, and measuring the labeled products after separation on a C18 column, we are able to detect 1 unstable N-7 deoxyguanosine adduct in 10(7) normal nucleotides with good precision.


Proc Natl Acad Sci U S A. 1994 Jul 19;91(15):7232-6.

Journal/Book/Conference Title

Proceedings of the National Academy of Sciences of the United States of America

Related Resources

Link to Article in PubMed

PubMed ID