Introduction

Since the advent of the Scanning Tunneling Microscope scientist have been able to image a wide variety of surfaces. From the simple hexagonal structure of graphite to large organic molecules, the STM has been able to resolve surface structures down to the very atom. Furthermore, the STM is able to produce these images in the open laboratory and with minimal sample preparation. This features makes the STM an excellent tool for surface analysis of various molecules, large or small, given limited time and facilities.

In this experiment, the STM was used to image linear DNA on a highly ordered pyrolytic graphite substrate. The experiment mimicked previous studies that analyzed the structure of DNA using the STM in the open laboratory with only slight modifications.^1,2 By constructing a suitable tip, preparing a sample, and imaging with the STM, measurements for the width, and major/minor groove separations were obtained.