Dielectrophoretic estimation of resting membrane potential in excitable cells

Area of Science:

• Cell electrophysiology
• Biophysics
• Membrane potential measurement

Background:

• Cell membrane potential (Vm) is critical for excitable cells like muscle and nerve cells.
• Resting membrane potential (RMP) arises from ion diffusion across the cell membrane.
• Previous label-free dielectrophoresis (DEP) methods measured RMP in non-excitable cells.

Purpose of the Study:

• To adapt DEP for measuring Vm in excitable cells.
• To investigate the extracellular component of Vm in excitable cells.
• To validate DEP's accuracy across diverse cell types and ionic conditions.

Main Methods:

• Adapted dielectrophoresis (DEP) model to account for excitable cell Vm mechanisms.
• Measured cell membrane potential (Vm) and ζ-potential in neuroblastoma and cardiomyoblast cell lines.
• Analyzed cardiomyoblasts in varying extracellular ion concentrations.

Main Results:

• Adapted DEP model accurately estimated RMP in excitable cells (-71.8 mV for neuroblastoma, -74.2 mV for cardiomyoblasts).
• Excitable cells exhibit a significant extracellular Vm component measurable as ζ-potential.
• DEP measurements in low-ion media aligned with published myocyte RMP data.

Conclusions:

• Dielectrophoresis (DEP) is a versatile, label-free technique for measuring Vm across all cell types.
• The adapted DEP model successfully incorporates extracellular potential for accurate RMP determination.
• DEP offers a powerful tool for studying ion channel function and Vm dynamics under varying ionic conditions.