Observation of DNA molecules using fluorescence microscopy and atomic force microscopy

This article describes a series of lab experiments that allow students to observe single dsDNA molecules. Visualization of these biologically important molecules enhances student interest in the laboratory, as supported by comments from students who have performed this experiment. In addition, the experiments are suitable for teaching the chemical and physical properties of dsDNA as well as the methods of fluorescence microscopy and AFM. While the focus here is on dsDNA imaging, the experiments can also be expanded in other directions, including metal nanowire synthesis on the stretched DNA molecules (17). These experiments would be also applicable to introductory graduate-level laboratory courses and would be especially valuable to students employing these microscopic methods in their graduate research. © Division of Chemical Education.