Theoretical assessment of single-frequency electrical sensors for continuous monitoring of cell lysis in dilute suspensions

Abstract

We analyze the sensitivity of electrical measurements to lysis of biological cells in suspensions. We aim at discerning the electrical parameter and measuring conditions that are more convenient to monitor the kinetics of a lysis process. We consider single-frequency measurements of the capacitance and resistance of an electrical capacitor containing a suspension of biological cells at mid-radiofrequencies. We use well-established models to estimate the relative sensitivities to variations of the volume fraction of cells during a lysis process. Then we estimate values for the resolution in measuring the fraction of cells that have been lysed with commercially available LCR meters. Unexpectedly, our results indicate that, despite the total number of ions in solution remains constant during a lysis process, in general, the electrical resistance provides a more appropriate signal for sensing the evolution of cell lysis than the capacitance. This is contrary to the case when the cell's volume fraction without lysis is to be measured. We predict that, with single-frequency resistance measurements, a resolution better than 0.1% in volume fraction of lysed cells should be attainable without much difficulty. Keywords: Electrical sensing, Biological-cell suspensions, Lysis, Resistance, Capacitance, Effective dielectric function