7,8-DIHYDRO-8-OXO-2'-DEOXYGUANOSINE PRESENT IN DNA IS NOT SIMPLY AN ARTIFACT OF ISOLATION

7,8-Dihydro-8-oxo-2'-deoxyguanosine (8-oxodG) is present in DNA isolat ed from human and murine cells. Other studies have reported artificial ly elevated levels in DNA extracted using phenol-based methods. This r eport shows that DNA, isolated by different methods, with or without t he use of a phenol reagent, contains similar levels of 8-oxodG. This, taken with other studies of human tissues which show varying levels of 8-oxodG, indicates that, with due care in the extraction procedure, b iologically significant amounts of this altered base are present in ma mmalian DNA.