Combined Dielectric-Optical Characterization of Single Cells Using Dielectrophoresis-Imaging Flow Cytometry.

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cell Biology

Background:

• Accurate cell characterization is crucial for biological research and diagnostics.
• Traditional methods often lack the throughput or resolution for complex cell populations.
• Simultaneous analysis of morphology and dielectric properties offers enhanced cell discrimination.

Purpose of the Study:

• To develop a microfluidic flow cytometer for simultaneous imaging and dielectric characterization of individual cells.
• To demonstrate the system's capability in discriminating viable from non-viable cells.
• To establish a multiphysics model correlating cell properties with dielectric response.

Main Methods:

• Integration of dielectrophoresis (DEP) with high-speed imaging in a microfluidic channel.
• Utilizing a coplanar electrode array for frequency-dependent voltage application.
• Employing particle tracking to analyze cell velocity changes induced by DEP.
• Conducting multiphysics electrostatic-fluid dynamics simulations.

Main Results:

• Successful discrimination of viable and non-viable Chinese hamster ovary cells.
• Demonstrated correlation between cell size, DEP response, and physiological state.
• Validated cytometer accuracy using polystyrene microspheres.
• Real-time tracking and analysis of multiple cells in parallel.

Conclusions:

• The developed microfluidic flow cytometer provides a powerful dual-modality tool for cell analysis.
• Combining imaging and DEP enables enhanced characterization and discrimination of cells.
• The system shows potential for evaluating cellular physiological states in heterogeneous populations.