Dresden 2006 – scientific programme

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AKB: Biologische Physik

AKB 30: Poster Session I

AKB 30.3: Poster

Monday, March 27, 2006, 15:30–18:00, P1

High resolution imaging of dsDNA by means of scanning tunneling microscopy — •Mihail Brezeanu, Frank Hubenthal, and Frank Träger — Institut für Physik and Center for Interdisciplinary Nanostructure Science and Technology - CINSaT, Universität Kassel, Germany

Scanning probe microscopies (SPM) are versatile tools to image the structure of biomolecules, but only scanning tunneling microscopy (STM) provides the possibility of achieving molecular resolution. In recent years, progress has been made to develop new preparation methods for visualizing DNA molecules with high resolution. However, successful imaging of the molecular structure of DNA has remained a challenge. In this contribution we present our latest results of high resolution imaging of DNA molecules by means of STM, the motivation being to visualize DNA damage induced by heavy ion bombardment for cancer treatment. For this purpose, linear double stranded DNA (dsDNA) with 280 base pairs (bp) has been deposited on highly oriented pyrolytic graphite (HOPG) and subsequently investigated with our CP-R Scanning Probe Microscope. The measurements were carried out under ambient conditions at a humidity of 50% to increase the conductivity. Our images show very clearly the helical turns of the DNA molecules, having a smaller height and larger width than usual. Nevertheless, the calculated circumference agrees well with the parameters normal DNA. Further analysis of DNA on different substrates, as well as further improvement of the resolution are in progress.