TY - JOUR T1 - Effect of X-ray irradiation on ancient DNA in sub-fossil bones – Guidelines for safe X-ray imaging JF - bioRxiv DO - 10.1101/057786 SP - 057786 AU - Alexander Immel AU - Adeline Le Cabec AU - Marion Bonazzi AU - Alexander Herbig AU - Heiko Temming AU - Verena J. Schuenemann AU - Kirsten I. Bos AU - Frauke Langbein AU - Katerina Harvati AU - Anne Bridault AU - Gilbert Pion AU - Marie-Anne Julien AU - Oleksandra Krotova AU - Nicholas J. Conard AU - Susanne C. Muenzel AU - Dorothée G. Drucker AU - Bence Viola AU - Jean-Jacques Hublin AU - Paul Tafforeau AU - Paul Tafforeau Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/06/08/057786.abstract N2 - Sub-fossilised remains may still contain highly degraded ancient DNA (aDNA) useful for palaeogenetic investigations. Whether X-ray computed [micro-] tomography ([μ]CT) imaging of these fossils may further damage aDNA remains debated. Although the effect of X-ray on DNA in living organisms is well documented, its impact on aDNA molecules is unexplored.Here we investigate the effects of synchrotron X-ray irradiation on aDNA from Pleistocene bones. A clear correlation appears between decreasing aDNA quantities and accumulating X-ray dose-levels above 2000 Gray (Gy). We further find that strong X-ray irradiation reduces the amount of nucleotide misincorporations at the aDNA molecule ends. No representative effect can be detected for doses below 200 Gy. Dosimetry shows that conventional μCT usually does not reach the risky dose level, while classical synchrotron imaging can degrade aDNA significantly. Optimised synchrotron protocols and simple rules introduced here are sufficient to ensure that fossils can be scanned without impairing future aDNA studies. ER -