Affiliations: The Dr. Joseph Kaufmann Hematology Laboratory, Physiology Department, Faculty of Health Sciences, Ben‐Gurion University of the Negev, Beer‐Sheva, Israel | Chemistry Department, Faculty of Natural Sciences, Ben‐Gurion University of the Negev, Beer‐Sheva, Israel | Department of Physiology and Biophysics, School of Medicine, University of Southern California, Los Angeles, USA | The College of Judea and Samaria, Ariel, Israel
Note: [] Correspondence to: Dr A. Pribush, Dept. of Physiology, Faculty of Health Sciences, Ben‐Gurion University of the Negev, P.O. Box 653, Beer‐Sheva 84105, Israel. Fax: 972 7 6477628; E‐mail: [email protected].
Abstract: A method based on dielectric properties of dispersed systems was developed to investigate red blood cell (RBC) aggregation in blood and RBC suspensions. Measurements of capacitance and resistance were made in a rectangular channel at low (0.2 MHz) and high (14 MHz) frequencies relative to the mid‐point of the β‐dispersion range. Compared to capacitance, minimal post‐shearing changes of resistance were observed; capacitance changes at 0.2 MHz were two orders of magnitude larger than those at 14 MHz and hence subsequent measurements were carried out at the lower frequency. It is shown that post‐shearing changes in the capacitance are affected by the recovery of RBC shape and relaxation processes at the electrode‐suspension interface. However, the dominant factor contributing to time‐dependent changes in the capacitance is the dynamic process of RBC aggregation. It is experimentally shown that the time record of the capacitance at 0.2 MHz quantitatively reflects the aggregation process in RBC‐plasma suspensions with hematocrit up to 0.56 (v/v) and in suspensions of RBCs in artificial aggregating media. It is concluded that a dielectric approach to the study of RBC aggregation in whole blood offers great potential for basic studies and for diagnostic use.
