Bovine red blood cell starvation age discrimination through a glutaraldehyde-amplified dielectrophoretic approach with buffer selection and membrane cross-linking.
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.
Department of Chemical and Biomolecular Engineering, Center for Microfluidics and Medical Diagnostics, University of Notre Dame, Notre Dame, IN 46556, USA.
Zachary
Z
Gagnon
Jason
J
Gordon
Shramik
S
Sengupta
Hsueh-Chia
HC
Chang
D000818:Animals; D002021:Buffers; D002417:Cattle; D002469:Cell Separation / Q000379:methods*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004553:Electric Conductivity; D004586:Electrophoresis / Q000379:methods*; D004905:Erythrocyte Aging / Q000502:physiology*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000502:physiology*; D004912:Erythrocytes / Q000166:cytology; D005976:Glutaral / Q000494:pharmacology
D002021:Buffers; D003432:Cross-Linking Reagents; D005976:Glutaral