Membrane capacitance of thousands of single white blood cells

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 C_spec and total membrane capacitance C_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 C_spec and C_mem Thousands of granulocytes (n_cell = 3327) and lymphocytes (n_cell = 3302) from 10 healthy blood donors were characterized, resulting in C_spec values of 1.95 ± 0.22 µF cm^-2 versus 2.39 ± 0.39 µF cm^-2 and C_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 C_spec and C_mem In addition, neural network-based pattern recognition was used to classify white blood cells, producing successful classification rates of 78.1% for C_spec and 91.3% for C_mem, respectively. These results indicate that as intrinsic bioelectrical markers, membrane capacitances may contribute to the classification of white blood cells.