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Published on: June 10, 2014
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Local collective motion analysis for multi-probe dynamic imaging and microrheology.
1Department of Physics and Astronomy and Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095, USA.
Summary
This study introduces Local Collective Motion (LCM) analysis, a new method using just two probes to detect and correct non-Brownian motion in microrheology experiments. This technique accurately reveals underlying Brownian motion, overcoming limitations of existing drift-correction methods.
Area of Science:
- Physics
- Biophysics
- Materials Science
Background:
- Dynamical artifacts like drift and flow disrupt microrheology experiments.
- Existing methods struggle with complex drifts and limited probe data.
- Molecular motors can induce localized non-Brownian probe motion.
Purpose of the Study:
- Develop a robust method for correcting complex spatio-temporal drifts.
- Enable accurate microrheology analysis with few probes.
- Differentiate between Brownian and non-Brownian motion.
Main Methods:
- Local Collective Motion (LCM) analysis using two or more probes.
- Calculating ensemble-averaged, time-dependent LCM mean square displacement (MSD).
- Comparing multi-probe MSD with single-probe MSDs to identify motion regimes.
Main Results:
- LCM analysis effectively detects non-Brownian motion.
- Corrected single-probe trajectories reveal true Brownian motion.
- The method successfully corrects various dynamical artifacts like drifts and flows.
Conclusions:
- LCM analysis offers a significant improvement for microrheology.
- It accurately corrects artifacts and reveals underlying Brownian dynamics.
- This method enhances the reliability of passive particle-tracking experiments.
