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Updated: Aug 18, 2026

Atomic Force Microscopy Investigations of DNA Lesion Recognition in Nucleotide Excision Repair
Published on: May 24, 2017
Quantitative characterization of DNA films by X-ray photoelectron spectroscopy
Dmitri Y Petrovykh1, Hiromi Kimura-Suda, Michael J Tarlov
1Physics Department, University of Maryland, College Park, Maryland 20742, USA. dmitri.petrovykh@nrl.navy.mil
Abstract:
We describe the use of self-assembled films of thiolated (dT)25 single-stranded DNA (ssDNA) on gold as a model system for quantitative characterization of DNA films by X-ray photoelectron spectroscopy (XPS). We evaluate the applicability of a uniform and homogeneous overlayer-substrate model for data analysis, examine model parameters used to describe DNA films (e.g., density and electron attenuation length), and validate the results. The model is used to obtain quantitative composition and coverage information as a function of immobilization time. We find that when the electron attenuation effects are properly included in the XPS data analysis, excellent agreement is obtained with Fourier transform infrared (FTIR) measurements for relative values of the DNA coverage, and the calculated absolute coverage is consistent with a previous radiolabeling study. Based on the effectiveness of the analysis procedure for model (dT)25 ssDNA films, it should be generally valid for direct quantitative comparison of DNA films prepared under widely varying conditions.
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