DNA supercoil introduced to directly visualize individual plectonemes along supercoiled DNA which would further allow to study the interactions of DNA processing proteins with supercoiled DNA. In that study, Sytox Orange (an intercalating dye), has been used to induce supercoiling on surface tethered DNA molecules. DNA supercoiling is important for DNA packaging within all cells. Because the length of DNA can be thousands of times that of a cell, packaging this genetic material into the cell or nucleus (in eukaryotes) is a difficult feat. Supercoiling of DNA reduces the space and allows for DNA to be packaged. In prokaryotes, plectonemic supercoils are
DNA oxidation a half-life of 11 minutes. Steady-state levels of endogenous DNA damages represent the balance between formation and repair. Swenberg et al. measured average amounts of steady state endogenous DNA damages in mammalian cells. The seven most common damages they found are shown in Table 1. Only one directly oxidized base, 8-hydroxyguanine, at about 2,400 8-OH-G per cell, was among the most frequent DNA damages present in the steady-state. As reviewed by Valavanidis et al. increased levels of 8-oxo-dG in a tissue can serve as a biomarker of oxidative stress. They also noted that increased levels of 8-oxo-dG are frequently found