Dielectric properties of human B and T lymphocytes at frequencies from 20 kHz to 100 MHz

Area of Science:

• Biophysics
• Cell Biology
• Immunology

Background:

• Understanding the dielectric properties of human lymphocytes is crucial for differentiating cell types and assessing cellular function.
• Previous studies have explored cellular dielectric properties, but specific characterization of human B and T lymphocytes across a broad frequency range is needed.

Purpose of the Study:

• To measure and analyze the dielectric properties of human B and T lymphocytes.
• To determine specific membrane capacitances and relaxation time distributions for these cell types.
• To correlate dielectric parameters with cellular characteristics.

Main Methods:

• Dielectric properties were measured using an end-of-line capacitive sensor and an automatic network analyzer.
• Experiments were conducted over frequencies from 20 kHz to 100 MHz at varying cell concentrations and temperatures (24°C and 37°C).
• Cole-Cole dielectric parameters were fitted using a computer program, and specific membrane capacitances (Cm) were calculated.

Main Results:

• Specific membrane capacitances were determined as 0.77 µF cm⁻² for T lymphocytes and 2.89 µF cm⁻² for B lymphocytes.
• Relaxation time distributions showed differences, with B lymphocytes centered and T lymphocytes shifted towards higher values, correlating with cell size.
• Maxwell-Wagner dispersion models were used to estimate relaxation time distributions reflecting membrane-charging processes.

Conclusions:

• Human B and T lymphocytes exhibit distinct dielectric properties, particularly in membrane capacitance and relaxation time.
• The measured dielectric parameters provide quantitative insights into the biophysical characteristics of lymphocyte membranes.
• These findings can aid in the non-invasive characterization and differentiation of lymphocyte populations based on their electrical behavior.