Erythrocyte and ghost cytoplasmic resistivity and voltage-dependent apparent size

Area of Science:

• Biophysics
• Cellular Electrophysiology
• Biomedical Engineering

Background:

• Cell resistivity is a key factor in electronic cell sizing and resistive pulse spectroscopy (RPS).
• Cell membrane resistivity decreases significantly at high electric fields due to dielectric breakdown.
• Past dielectric breakdown, cell membrane transparency allows apparent cell size to reflect cytoplasmic resistivity.

Purpose of the Study:

• To investigate the applicability of the Laplace equation for calculating specific cytoplasmic resistivity from RPS measurements at high electric fields.
• To determine voltage-dependent resistivity changes in red blood cell variants post-dielectric breakdown.

Main Methods:

• Utilized electronic cell sizing and resistive pulse spectroscopy (RPS) at high electric field strengths.
• Applied the Laplace equation to relate apparent cell size to cytoplasmic resistivity post-dielectric breakdown.
• Measured resistivity changes in red blood cell ghosts and spherocytes over time in hypotonic medium.

Main Results:

• The Laplace equation remains applicable for calculating specific cytoplasmic resistivity from RPS measurements even at very high electric field strengths.
• A specific cytoplasmic resistivity of 220 omega X cm was determined for discocytes, aligning with previous research.
• The study provides the first explicit calculations of particle resistivity from post-dielectric-breakdown apparent size using conventional electronic sizing.

Conclusions:

• Traditional electronic cell sizing techniques, incorporating the Laplace equation, are effective for quantifying cytoplasmic resistivity post-dielectric breakdown.
• This method enables the study of dynamic changes in cell resistivity under varying conditions.
• The findings offer a novel approach to understanding cell membrane electrophysiology.