Electron microscopic visualization of complementary labeled DNA with platinum-containing guanine derivative

Area of Science:

• Molecular Biology
• Biophysics
• Electron Microscopy

Background:

• Visualizing DNA at the molecular level is crucial for understanding genetic processes.
• Conventional transmission electron microscopy (TEM) often lacks the resolution for atom-by-atom DNA analysis.
• Developing contrast-enhancement techniques is vital for high-resolution imaging of nucleic acids.

Purpose of the Study:

• To develop a novel method for visualizing DNA in TEM.
• To enable base-specific labeling of single-stranded DNA (ssDNA) using a platinum-containing guanine derivative.
• To achieve atom-by-atom visualization of DNA for potential sequencing applications.

Main Methods:

• Obtaining stretched single-stranded DNA (ssDNA) from double-stranded DNA (dsDNA).
• Adsorbing ssDNA onto a hydrophobic carbon support film in an electron microscope grid.
• Complementary labeling of cytosine bases with a platinum-containing guanine derivative.
• Utilizing conventional TEM at 100 kV for high-resolution imaging.

Main Results:

• Successfully visualized base-specifically labeled ssDNA with high contrast.
• The platinum-containing guanine derivative acted as a high-density marker, distinguishable from the carbon background.
• Achieved atom-by-atom analysis of labeled DNA molecules.

Conclusions:

• The developed method provides a powerful tool for visualizing DNA at an unprecedented resolution.
• This technique holds significant promise for future DNA sequencing and molecular diagnostics.
• Enables detailed examination of nucleic acid structures using electron microscopy.