A FLIM Microscopy Based on Acceptor-Detected Förster Resonance Energy Transfer

Area of Science:

• Biophysics
• Microscopy
• Molecular Biology

Background:

• Time-resolved donor-detected Förster resonance energy transfer (trDDFRET) enables observation of molecular interactions within approximately 10-100 Å.
• Time-resolved acceptor-detected FRET (trADFRET) offers potential for observing longer-range interactions due to improved signal/noise ratios.

Purpose of the Study:

• To introduce a novel fluorescence lifetime microscopy technique, FLIM-trADFRET, for observing biological machinery at distances of 100-300 Å in vivo.
• To extend the range of FRET-based molecular interaction studies into a critical, previously less accessible, biological scale.

Main Methods:

• Development of a new methodology based on time-resolved acceptor-detected FRET (trADFRET).
• Integration of trADFRET signals to cancel noise and enhance photon collection.
• Validation using fluorescence lifetime microscopy (FLIM) and well-defined DNA scaffolds for proof of concept.

Main Results:

• Demonstration of a novel FLIM-trADFRET technique capable of observing molecular interactions in the 100-300 Å range in vivo.
• Successful noise cancellation and improved photon collection in the integrated trADFRET signal.
• Proof of concept established using DNA scaffolds, confirming the methodology's efficacy.

Conclusions:

• FLIM-trADFRET represents a significant advancement for in vivo molecular interaction studies at longer ranges.
• The technique opens new avenues for exploring the 'last frontier' in biomolecular medicine by visualizing larger biological assemblies.
• This method enhances FRET microscopy capabilities for studying complex biological machinery.