Membrane capacitance of thousands of single white blood cells.

Abstract

As label-free biomarkers, the electrical properties of single cells are widely used for cell type classification and cellular status evaluation. However, as intrinsic cellular electrical markers, previously reported membrane capacitances (e.g. specific membrane capacitance <i>C</i>_spec and total membrane capacitance <i>C</i>_mem) of white blood cells were derived from tens of single cells, lacking statistical significance due to low cell numbers. In this study, white blood cells were first separated into granulocytes and lymphocytes by density gradient centrifugation and were then aspirated through a microfluidic constriction channel to characterize both <i>C</i>_spec and <i>C</i>_mem Thousands of granulocytes (<i>n</i>_cell = 3327) and lymphocytes (<i>n</i>_cell = 3302) from 10 healthy blood donors were characterized, resulting in <i>C</i>_spec values of 1.95 ± 0.22 µF cm^-2 versus 2.39 ± 0.39 µF cm^-2 and <i>C</i>_mem values of 6.81 ± 1.09 pF versus 4.63 ± 0.57 pF. Statistically significant differences between granulocytes and lymphocytes were located for both <i>C</i>_spec and <i>C</i>_mem In addition, neural network-based pattern recognition was used to classify white blood cells, producing successful classification rates of 78.1% for <i>C</i>_spec and 91.3% for <i>C</i>_mem, respectively. These results indicate that as intrinsic bioelectrical markers, membrane capacitances may contribute to the classification of white blood cells.