Nanodissection of single- and double-stranded DNA by atomic force microscopy

Area of Science:

• Biophysics
• Materials Science
• Molecular Biology

Background:

• Atomic Force Microscopy (AFM) is a powerful tool for manipulating and analyzing nanoscale materials.
• Understanding the mechanical properties of DNA is crucial for various biological and technological applications.
• Previous studies have explored DNA-protein interactions and DNA elasticity, but direct nanodissection comparisons are less common.

Purpose of the Study:

• To investigate the nanodissection of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) using AFM.
• To compare the mechanical stability and dissection characteristics of ssDNA versus dsDNA.
• To determine the influence of applied load on DNA strand dissection.

Main Methods:

• Utilized Atomic Force Microscopy (AFM) to perform nanodissection experiments on both ssDNA and dsDNA.
• Applied controlled forces with the AFM tip to repeatedly dissect DNA strands.
• Measured the time required for dissection under consistent load conditions for comparative analysis.

Main Results:

• Both ssDNA and dsDNA were successfully and repeatedly dissected by the AFM tip.
• ssDNA exhibited greater susceptibility to breakage by the AFM tip compared to dsDNA.
• The time required to break ssDNA was consistently shorter than for dsDNA under identical experimental conditions.

Conclusions:

• Nanodissection via AFM is feasible for both ssDNA and dsDNA.
• ssDNA demonstrates lower mechanical robustness than dsDNA when subjected to AFM-tip-induced forces.
• DNA dissection is highly sensitive to applied load, with minor load variations significantly impacting outcomes.