High-throughput smFRET analysis of freely diffusing nucleic acid molecules and associated proteins

Area of Science:

• Biophysics
• Biochemistry
• Analytical Chemistry

Background:

• Single-molecule Förster resonance energy transfer (smFRET) enables nanometer-scale studies of molecular behavior.
• Solution-based smFRET is valuable for investigating molecular conformations and interactions under physiological conditions.
• Traditional single-spot smFRET measurements in solution are limited by slow data acquisition.

Purpose of the Study:

• To develop a high-throughput smFRET approach for faster and more efficient molecular analysis.
• To enhance the temporal resolution of smFRET measurements for kinetic studies.
• To enable powerful molecular screening applications.

Main Methods:

• A multispot confocal geometry was developed, extending traditional single-spot setups.
• Custom silicon single photon avalanche diode (SPAD) arrays were used for enhanced detection.
• Periodic acceptor excitation (PAX) enabled two-color excitation and differentiation of labeled molecules.

Main Results:

• The multispot smFRET setup rapidly and accurately determines FRET efficiencies and population stoichiometries.
• Data pooling from multiple spots enhances throughput and analytical power.
• Temporal resolution for smFRET population characterization was improved from minutes to seconds.

Conclusions:

• The high-throughput multispot smFRET approach significantly accelerates molecular studies.
• This method provides a powerful tool for real-time kinetic studies when combined with microfluidics.
• The developed technique opens avenues for advanced molecular screening applications.