Biophysical Society Thematic Meeting | Tutzing 2026

Single-Molecule FRET: The Next 30 Years

Poster Abstracts

66-POS Board 34 SINGLE-MOLECULE MICROFLUIDIC DIFFUSIONAL SIZING INTEGRATED WITH FRET Sophie H van den Boom 1 ; Georg Krainer 1 ; 1 University of Graz, Institute of Molecular Biosciences (IMB), Molecular Biophysics, Graz, Austria Biomolecules such as proteins and nucleic acids carry out their biological functions by undergoing conformational changes and interacting with binding partners. These processes are often studied independently, yet a complete mechanistic understanding requires methods that can probe molecular size, interaction state, and structural state simultaneously. Microfluidic diffusional sizing (MDS) enables the determination of hydrodynamic radius, which can report on protein interactions and assembly, while Förster resonance energy transfer (FRET) provides information on conformational states. Both techniques have been adapted for single-molecule measurements, allowing subpopulations to be resolved beyond the limits of ensemble averaging. In this work, we combine single-molecule FRET with MDS to simultaneously yet independently measure hydrodynamic radius and conformational state at the single-molecule level. This approach, termed smMDS-FRET, provides a dual readout of molecular size and conformational state, enabling direct correlations between protein interactions and structural states. Ultimately, this method could support more complete models of protein dynamics, interactions, and assembly.

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