We examined the adsorption of single YOYO-1-labeled -DNA molecules at glass surfaces after treatment with various chemical cleaning methods by using total internal reflection fluorescence microscopy (TIRFM). The characteristics of these surfaces were further assessed using contact angle (CA) measurements and atomic force microscopy (AFM). By recording the real-time dynamic motion of DNA molecules at the liquid/solid interface, subtle differences in adsorption affinities were revealed. The results indicate that the driving force for adsorption of DNA molecules on glass surfaces is mainly hydrophobic interaction.We also found that surface topography plays a role in the adsorption dynamics.

Keywords:Single-molecule imaging   Total internal reflection  fluorescence microscopy λ-DNA             Adsorption     Glass surfaces