Estimating single-cell elastic modulus in a serial microfluidic cytometer from time-of-flight and fluorescence...

Area of Science:

• Biophysics
• Cell Biology
• Microfluidics

Background:

• Cellular mechanical properties are crucial for understanding cell function and disease.
• Current methods for measuring these properties face limitations in throughput, property correlation, and measurement uncertainty.

Purpose of the Study:

• To develop a high-throughput method for estimating single-cell mechanical properties (elastic modulus and size).
• To address limitations of current techniques by enabling one-to-one correlations between mechanical and biochemical properties.
• To quantify measurement uncertainty in single-cell mechanical property estimation.

Main Methods:

• Utilized a serial microfluidic cytometer for high-throughput measurements.
• Employed fluorescence signals and time-of-flight (TOF) measurements for particle analysis.
• Developed a combined spectral time-series analysis (STA) and Gaussian-process regression model to decouple size and elasticity effects.

Main Results:

• Achieved high-throughput estimation of elastic modulus and size from cell-like particles.
• Calibrated the model using polyacrylamide microparticles with known properties (8.9-23 μm diameter, 0.1-9.1 kPa stiffness).
• Successfully applied the model to live MG-63 osteosarcoma cells, yielding median diameter of 16.3 μm and elastic modulus of 0.9 kPa, consistent with other methods.
• Maintained high cell viability (>90%) during measurements.

Conclusions:

• The novel microfluidic device and analysis model enable high-throughput, single-cell mechanophenotyping with uncertainty quantification.
• This technique expands mechanophenotyping capabilities and is compatible with fluorescence-based biochemical measurements.
• The approach offers a powerful new tool for dissecting cell mechanics in various biological contexts.