Bovine red blood cell starvation age discrimination through a glutaraldehyde‐amplified dielectrophoretic approach with buffer selection and membrane cross‐linking

Abstract

We report a novel buffer electric and dielectric relaxation time tuning technique, coupled with a glutaraldehyde (Glt.) cross-linking cell fixation reaction that allows for sensitive dielectrophoretic analysis and discrimination of bovine red blood cells of different starvation age. Guided by a single-shell oblate spheroid model, a zwitterion buffer composition is selected to ensure that two measurable crossover frequencies (cof's) near 500 kHz exist for dielectrophoresis (DEP) within a small range of each other. It is shown that the low cof is sensitive to changes in the cell membrane dielectric constant, in which cross-linking by Glt. reduces the dielectric constant of the cell membrane from 10.5 to 3.8, while the high cof is sensitive to cell cytoplasm conductivity changes. We speculate that this enhanced particle polarizability that results from the cross-linking reaction is because younger (reduced starvation time) cells possess more amino groups that the reaction can release to enhance the cell interior ionic strength. Such sensitive discrimination of cells with different age (surface protein density) by DEP is not possible without the zwitterion buffer and cleavage by Glt. treatment. It is then expected that rapid identification and sorting of healthy from diseased cells can be similarly sensitized.

Estimation of the physical properties of neurons and glial cells using dielectrophoresis crossover frequency

“…The ability to determine cell dielectric properties with DEP has been demonstrated previously by several research groups, such as Mahaworasilpa et al [18], where a dielectrophoretic (DEP) force on single cells in AC electric fields was measured to analyze cell movement. In addition, the measurement of DEP crossover frequency (CF), namely the frequency occurring on the transition between positive DEP (cells attracted to the maximum electric field area) and negative DEP (cells repelled to the minimum electric field area), has been extensively applied by Pethig et al [12,17], Gascoyne et al [19,20], Voldman et al [21,22] and Gagnon et al [15,23], to characterize and separate multiple cell types.…”

Automated electrorotation shows electrokinetic separation of pancreatic cancer cells is robust to acquired chemotherapy resistance, serum starvation, and EMT

“…Wang et al, 41 Shim et al, 8 and Gascoyne et al 42 attribute higher specific membrane capacitances to larger effective membrane areas due to ruffles and folds in the membrane, changing the apparent effective specific capacitance. Alternatively, Gagnon et al 43 FIG. 5.…”

Liposomes as a model for the study of high frequency dielectrophoresis

“…A typical DEP response for a biological cell has two cross-over frequencies-a lower and upper cross-over frequency (LCOF and UCOF, respectively). While the lower cross-over depends primarily upon the dielectric properties of the membrane, the upper cross-over depends upon the dielectric properties, and in particular the conductivity, of the cytoplasm [29][30][31]. This accounts for the shifts in the UCOF in the microalgae, since the nonpolar lipids are much less conductive than the aqueous cytoplasm.…”