Glioblastoma multiform is the most aggressive and invasive brain cancer consisting of genetically and phenotypically altering glial cells. It has massive heterogeneity due to its highly complex and dynamic microenvironment. Here, we used dielectrophoresis to measuree electrophysiological properties of glioma cells and quantified population heterogeneity of U87 glioma cell line. We fabricated a gold microelectrode array within a microfluidic channel and applied 3 Vpp and 100 kHz, 200 kHz, 300 kHz, 400 kHz, 500 kHz, 1 MHz, 2 MHz, 5 MHz, and 10 MHz frequencies to monitor behavior of glioma cells under the microscope. We analyzed dielectrophoretic behavior of 500 glioma cells using the acquired images. We revealed that U87 glioma cells has never experienced negative dielectrophoresis and exhibited crossover frequency around 100 kHz -150 kHz. We detected 3 distinct glioma subpopulations by quantifying dielectrophoretic movement of the cells; 50% of the cells experienced positive dielectrophoresis starting from 500 kHz to 10 MHz, 30% of the cells were spread in the microchannel by moderate DEP forces, and other cells were experienced very weak DEP forces. Our results demonstrate the dielectrophoretic spectra of U87 glioma cell line and associates the dielectrophoretic responses of single glioma cells to the population heterogeneity.

Glioblastoma multiforme is the most aggressive malignant primary brain tumor. We need to better understand its microenvironment to design effective treatment strategies. Hence, characterization of glioma cells while providing their genetic and phenotypic stability is crucial. Here, we used dielectrophoresis (DEP) to underline the deformational heterogeneity of U87 glioma cell line. We fabricated a gold microelectrode array within a microfluidic channel and applied 3 V pp and 30 kHz to 10 MHz frequencies to generate DEP forces. We analyzed dielectrophoretic movement and deformation of 100 glioma cells. We observed that U87 glioma cells exhibited crossover frequency around 100 kHz - 200 kHz. The mean dielectrophoretic displacements of glioma cells were significantly different at varying frequencies with the maximum and minimum travel distances of 13.22 µm and 1.37 µm, respectively. The dielectrophoretic deformation indexes of U87 glioma cells altered between 0.027 – 0.040. It was 0.036 in the absence of dielectrophoretic forces. When we applied 3 V pp and 30 kHz to 10 MHz frequencies, the mean deformation indexes of the glioma cells did not significantly vary between 30 kHz - 500 kHz. The mean value of the deformation index was 0.028 under the influences of strong positive DEP forces when 500 kHz to 10 MHz were applied.