Multipair Förster Resonance Energy Transfer via Spectrally Resolved Single-Molecule Detection

Area of Science:

• Biophysics
• Molecular Biology
• Spectroscopy

Background:

• Förster resonance energy transfer (FRET) is crucial for studying molecular interactions.
• Spectral crosstalk among fluorophores limits FRET for multi-molecule interactions.

Purpose of the Study:

• To develop and demonstrate multispectral FRET (msFRET) for parallel imaging of multiple interaction pairs.
• To overcome limitations of spectral crosstalk in FRET studies.

Main Methods:

• Utilized a dual (positional and spectral) channel wide-field imaging configuration.
• Spectrally resolved single fluorescent molecules to distinguish closely emitting fluorophores (6-10 nm separation).
• Applied msFRET to monitor DNA oligonucleotide hybridization dynamics.

Main Results:

• Successfully distinguished fluorophores with emission maxima as close as 6-10 nm.
• Demonstrated parallel monitoring of 2x2 DNA oligo hybridization dynamics using Cy3/Cy3.5 donors and Cy5/Cy5.5 acceptors.
• Validated msFRET for simultaneous observation of multiple molecular interactions.

Conclusions:

• msFRET provides a powerful method for parallel imaging of multiple molecular interactions.
• This technique enhances the study of complex molecular systems by overcoming spectral crosstalk.
• Potential applications include probing fluorophore photophysics and multiplexed superresolution imaging.