Continuous differential impedance spectroscopy of single cells

Area of Science:

• Biophysics
• Cell Biology
• Analytical Chemistry

Background:

• Continuous monitoring of single-cell biophysical properties is crucial for understanding cellular responses.
• Existing methods often lack the temporal resolution or sensitivity to capture dynamic cellular events.
• Hydrodynamic cell trapping offers a promising platform for precise single-cell analysis.

Purpose of the Study:

• To develop and validate a novel device for continuous differential impedance analysis of single cells.
• To investigate dynamic cellular responses to chemical perturbations using this device.
• To quantify the effects of specific chemical agents on cell membrane integrity and permeability.

Main Methods:

• A device employing hydrodynamic cell trapping to isolate single cells between two electrode pairs.
• Continuous measurement of electrical current to determine differential impedance.
• Application of chemical perturbations (surfactant Tween, bacterial toxin Streptolysin-O) to trapped cells.
• Time-dependent impedance data analysis to assess cellular responses.

Main Results:

• Demonstrated time-dependent impedance measurements of single cells.
• Observed concentration-dependent impedance reduction in HeLa cells treated with Tween, indicating cell membrane lysis.
• Quantified transient exponential impedance decay upon exposure to Streptolysin-O, correlating decay time constants with toxin concentration.

Conclusions:

• The developed device enables real-time, quantitative analysis of single-cell impedance.
• The system can effectively differentiate cellular responses to various chemical agents.
• This technology provides a sensitive platform for studying cell membrane dynamics and integrity.