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Measuring Diffusion Coefficients via Two-photon Fluorescence Recovery After Photobleaching
Published on: February 26, 2010
Multiphoton fluorescence recovery after photobleaching in bounded systems
Kelley D Sullivan1, Edward B Brown
1Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.
Summary
Multiphoton fluorescence recovery after photobleaching (MP-FRAP) can accurately measure macromolecule diffusion near barriers. New models quantify this effect, defining safe measurement ranges for MP-FRAP in biological systems.
Area of Science:
- Biophysics
- Laser Microscopy
- Macromolecular Diffusion
Background:
- Multiphoton fluorescence recovery after photobleaching (MP-FRAP) measures macromolecule diffusion.
- MP-FRAP offers 3D resolution and depth penetration for in vitro and in vivo studies.
- The impact of confinement by biological barriers on MP-FRAP measurements is unknown.
Purpose of the Study:
- To investigate the effect of barriers on diffusion coefficient measurements using MP-FRAP.
- To determine ranges for accurate MP-FRAP measurements in the presence of barriers.
- To develop new MP-FRAP models for boundary-influenced diffusion.
Main Methods:
- Monte Carlo simulations of diffusion and MP-FRAP.
- Analysis of barrier geometries and positions relative to the focal volume.
- Development of novel computational models for boundary conditions.
Main Results:
- Barriers significantly affect MP-FRAP measurements of diffusion coefficients.
- Defined ranges of barrier positions ensure accurate diffusion measurements.
- New models accurately predict diffusion coefficients with plane boundaries.
Conclusions:
- MP-FRAP can reliably measure diffusion coefficients even with nearby barriers.
- The developed models and defined ranges enhance MP-FRAP's utility in complex biological environments.
- This work provides crucial insights for interpreting MP-FRAP data in confined biological systems.
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