Tumor cell characterization and classification based on cellular specific membrane capacitance and cytoplasm conductivity

This paper reports a microfluidic system that enables the characterization of tumor cell electrical properties where cells were aspirated through a constriction channel (cross-section area smaller than that of biological cells) with cellular impedance profiles measured and translated to specific membrane capacitance (C-specific (membrane)) and cytoplasm conductivity (sigma(cytoplasm)). Two batches of H1299 cells were quantified by the microfluidic platform with different constriction channel cross-section areas, recording no differences with statistical significance (p < 0.001) in both C-specific (membrane) (1.63 +/- 0.52 vs. 1.65 +/- 0.43 mu F/cm(2)) and (sigma(cytoplasm) (0.90 +/- 0.19 vs. 0.92 +/- 0.15 S/m), and thus confirming the reliability of the microfluidic platform. For paired high- and low-metastatic carcinoma strains 95D (n(cell)=537) and 95C cells (n(cell)=486), significant differences in both C-specific (membrane) (2.00 +/- 0.43 VS. 1.62 +/- 0.39 mu F/cm(2)) and sigma(cytoplasm) (0.88 +/- 0.46 vs. 1.25 +/- 0.35 S/m) were observed. Statistically significant difference only in C-specific (membrane) (2.00 +/- 0.43 vs. 1.58 +/- 0.30 mu F/cm(2)) was observed for 95D cells (n(cell)=537) and 95D CCNY-KD cells with single oncogene CCNY down regulation (n(cell)=479, CCNY is a membrane-associated protein). In addition, statistically significant difference only in sigma(cytoplasm) (0.73 +/- 0.17 vs. 1.01 +/- 0.17 S/m) was observed for A549 cells (n(cell)=487) and A549 CypA-KD cells with single oncogene CypA down regulation (n(cell)=597, CypA is a cytosolic protein). These results validated the developed microfluidic platform for C-specific (membrane) and sigma(cytoplasm) quantification and confirmed the feasibility of using C-specific (membrane) and sigma(cytoplasm) for tumor cell classification. (c) 2014 Elsevier B.V. All rights reserved.