Date of Graduation
Bachelor of Science in Mechanical Engineering
This report explores dry and wet scanning of a surface and DNA pickup using an AFM, as well as fluorescent staining of DNA. Dry and wet scans of DNA were obtained using a cantilever AFM tip in tapping mode. Dry scans were found to be clearer than wet scans; however, the drying process was found to decrease the thickness of DNA 2–4 times less than its original thickness. Alternately, wet scans were found to be less clear than dry scans and introduced more noise into the images obtained. Additionally, DNA kept its initial thickness during wet scanning. DNA was capable of being picked up using an AFM tip in contact mode, and force curves were produced that signified pickup, as supported by theoretical predictions. Fluorescent DNA staining and visualization were attempted using DAPI nucleic acid stain and a fluorescent microscope. No significant results were found using restricted protocols as a result of an unfortunate time constraint. The DAPI stain was, however, confirmed to react to fluorescent exposure. Fluorescent imaging was attempted for stained DNA both as a solution between glass slides and as a dried sample bound to mica. Through the combination of the processes explored in this experiment (i.e. AFM scanning, DNA pickup, and fluorescent microscopy), future research may be able to explicitly prove that DNA can be picked up and transported via AFM.
Creighton, Drew, "Atomic Force Microscopy Based DNA Analysis" (2016). Mechanical Engineering Undergraduate Honors Theses. 53.