Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 19: Poster Session 1 (joint session with BP)

CPP 19.17: Poster

Dienstag, 1. April 2014, 09:30–13:00, P1

Quantification of DNA Damage by ROS using AFM Tapping Mode — •Florian Berg¹, Janine Wilken¹, Stephan Block², and Christiane A. Helm¹ — ¹Inst. f. Physik, Uni Greifswald, 17487 Greifswald, Germany — ²Chalmers University of Technology, Gothenburg, Sweden

During times of environmental stress (e.g., UV or heat exposure), levels of reactive oxygen species (ROS) can increase dramatically. This may result in significant damage to cell structures. Here we focus on the effects of ROS on DNA.

The plasmid pBR322 (E. coli cloning vector) is attacked by free hydroxyl radicals in liquid surroundings. ROS are produced by Fenton's reaction. DNA damage is assessed by AFM Tapping Mode imaging of the plasmids in air (after adsorption onto PAH-functionalized mica). As damaged DNA strands (height 0.1 nm) are much smaller than intact DNA strands (height 0.35 nm), DNA damage can be quantified based on height distribution histograms. The amount of damaged DNA strands increases with increasing strength of radical attack, and decreases if ROS scavengers like sodium acetate are added.