Measuring cell displacements in opaque tissues: dynamic light scattering in the multiple scattering regime

Area of Science:

• Biophysics
• Optical Imaging
• Cell Biology

Background:

• Standard imaging techniques struggle to probe deep tissue structures and dynamics.
• Dynamic light scattering and diffusive wave spectroscopy analyze cellular dynamics in thin and thick samples, respectively.
• An intermediate scattering regime remains largely unexplored for quantitative analysis.

Purpose of the Study:

• To develop an analytical framework for light scattering in the intermediate regime.
• To establish a relationship between scattered light fluctuations and cell displacement distributions.
• To characterize cell motility within thick multicellular aggregates.

Main Methods:

• Utilized coherent light scattering to probe biological tissues.
• Developed an analytical model connecting scattered light fluctuations to cellular dynamics.
• Applied the method to analyze cell motility in millimeter-thick multicellular aggregates.

Main Results:

• Established an analytical relationship for the intermediate light scattering regime.
• Quantified cell displacement distributions over time from scattered light.
• Successfully characterized cell motility within 0.5 mm thick multicellular aggregates.

Conclusions:

• The developed method bridges the gap between single and multiple scattering regimes for light.
• Provides a novel approach to study deep tissue cellular dynamics non-invasively.
• Offers a powerful tool for investigating cell motility in complex biological systems.