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Updated: Jan 21, 2026
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Method for Measurement of Viral Fusion Kinetics at the Single Particle Level
Published on: September 7, 2009
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Detecting and Controlling Dye Effects in Single-Virus Fusion Experiments
Robert J Rawle1, Ana M Villamil Giraldo2, Steven G Boxer3
1Departments of Molecular Physiology and Biological Physics and of Biomedical Engineering, University of Virginia, Charlottesville, Virginia.
Biophysical Journal
|July 22, 2019
Summary
Fluorescent probes used in membrane fusion studies can alter fusion efficiency and kinetics. Researchers found that R18 dye perturbs influenza virus fusion, highlighting the need for careful probe selection and experimental conditions.
Area of Science:
- Biophysics
- Cell Biology
- Virology
Background:
- Fluorescent dye-dequenching assays are widely used to study membrane fusion.
- These assays monitor lipid mixing in liposomal, viral, and cellular fusion processes.
- However, the fluorescent dyes themselves may interfere with membrane fusion.
Purpose of the Study:
- To investigate whether fluorescent membrane probes perturb influenza virus membrane fusion.
- To determine how dye properties and illumination conditions affect fusion measurements.
- To establish minimally perturbative conditions for studying membrane fusion.
Main Methods:
- Single-virus measurements of influenza membrane fusion.
- Analysis of lipid mixing kinetics using fluorescent probes (R18 and Texas Red).
- Assessment of dye-photoconjugation to viral proteins under illumination.
Main Results:
- Fluorescent membrane probes, particularly R18, alter the efficiency and kinetics of lipid mixing.
- Dye effects are dependent on the specific dye and illumination intensity.
- R18 undergoes photoconjugation to viral proteins, correlating with fusion inactivation.
Conclusions:
- Fluorescent probes can significantly perturb biological measurements of membrane fusion.
- The choice of dye and illumination conditions is critical for accurate fusion studies.
- A method is provided for determining minimally perturbative measurement conditions for membrane fusion assays.
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