Enhanced DNA imaging using super-resolution microscopy and simultaneous single-molecule orientation measurements.

Area of Science:

• Biophysics
• Molecular Biology
• Materials Science

Background:

• Single-molecule orientation measurements offer deep insights into biological and polymeric systems.
• Existing techniques can be complex and limited in throughput.

Purpose of the Study:

• To introduce a simple, high-throughput method for measuring single fluorescent molecule azimuthal orientation and rotational dynamics.
• To demonstrate the technique's compatibility with localization microscopy for super-resolution imaging.

Main Methods:

• Modulating the polarization of an excitation laser.
• Analyzing emitted intensities and modulation amplitudes from single dye molecules.
• Utilizing intercalating and groove-binding dyes for fluorescence turn-on with DNA binding.

Main Results:

• Achieved super-resolved imaging of stretched DNA strands.
• Obtained thousands of dye molecule orientation measurements.
• Developed a method to probe DNA strand structure and characterize dye-DNA interactions.

Conclusions:

• The developed technique provides a powerful tool for analyzing DNA structure at the single-molecule level.
• It enables characterization of interactions between dyes and DNA.
• This approach shows potential for monitoring DNA conformational changes induced by DNA-binding proteins.