Understanding the photoprotection mechanisms in DNA requires, in a bottom-up approach, a detailed understanding of the electronic and structural properties of their basic constituents, namely the (oligo)nucleotides, and of the dissociation mechanisms involved after radiation damage. Activating them with UV, VUV or X-rays helps us gain more insight into these intrinsic properties. In particular, soft X-ray absorption being element specific makes it ideal to probe the different absorption edges and study the resonant photo-absorption in the C, N, O and P inner shells. It is important to understand the role that charge states can have on nucleotides and whether they influence the charge and energy transfer processes within the molecular ion. When developing an overall picture of the system, it is equally important to describe the role of the sugar and phosphate moieties and whether their presence near the nucleobases affects the photoabsorption and the stability of the system.
