Showing papers by "Meltem Elitas published in 2022"
TL;DR: Electrophysiological properties of U87 human glioma cell line were measured based on a dielectrophoresis phenomenon to quantify the population heterogeneity ofglioma cells to link population heterogeneity to membrane properties of gliomas cells rather than their size distribution in the population.
Abstract: Glioblastoma multiforme 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, electrophysiological properties of U87 human glioma cell line were measured based on a dielectrophoresis phenomenon to quantify the population heterogeneity of glioma cells. Dielectrophoretic forces were generated using a gold‐microelectrode array within a microfluidic channel when 3 Vpp and 100, 200, 300, 400, 500 kHz, 1, 2, 5, and 10 MHz frequencies were applied. We analyzed the dielectrophoretic behavior of 500 glioma cells, and revealed that the crossover frequency of glioma cells was around 140 kHz. A quantifying dielectrophoretic movement of the glioma cells exhibited three distinct glioma subpopulations: 50% of the glioma cells experienced strong, 30% of the cells were spread in the microchannel by moderate, and the rest of the cells experienced very weak positive dielectrophoretic forces. Our results demonstrated the dielectrophoretic spectra of U87 glioma cell line. Dielectrophoretic responses of glioma cells linked population heterogeneity to membrane properties of glioma cells rather than their size distribution in the population.
4 citations
TL;DR: In this paper , the authors developed a simple, portable, low-cost, colorimetric, and remotely controllable platform for reliable, high-throughput, and rapid diagnosis using loop-mediated isothermal amplification (LAMP) assays.
Abstract: Transition of rapid, ready-to-use, and low-cost nucleic acid-based detection technologies from laboratories to points of sample collection has drastically accelerated. However, most of these approaches are still incapable of diagnosis starting from sampling through nucleic acid isolation and detection in the field. Here we developed a simple, portable, low-cost, colorimetric, and remotely controllable platform for reliable, high-throughput, and rapid diagnosis using loop-mediated isothermal amplification (LAMP) assays. It consists of a thermally isolated cup, low-cost electronic components, a polydimethylsiloxane sample well, and a fast prototyped case that covers electronic components. The steady-state temperature error of the system is <1%. We performed LAMP, Colony-LAMP, and Colony polymerase chain reactions (PCRs) using the yaiO2 primer set for Escherichia coli and Pseudomonas aeruginosa samples at 65°C and 30 min. We detected the end-point colorimetric readouts by the naked eye under day light. We confirmed the specificity and sensitivity of our approach using pure genomic DNA and crude bacterial colonies. We benchmarked our Colony-LAMP detection against Colony PCR. The number of samples tested can easily be modified for higher throughput in our system. We strongly believe that our platform can greatly contribute rapid and reliable diagnosis in versatile operational environments.
4 citations
DOI•
31 Oct 2022
TL;DR: In this paper , the performance of a microfluidic gold electrode array to determine dielectrophoretic behavior of U87 glioma cells was numerically analyzed, and the influence of medium conductivity, applied electric field strength and frequency on the dielectoretic spectra of the cells was investigated.
Abstract: Dielectrophoresis have been widely used as rapid and label-free cell characterization and separation method in biology. Integration of an electrode array in a microchannel enabled high throughput yet low-cost alternative to conventional cell separation devices. In this study, we numerically analyzed the performance of a microfluidic gold electrode array to determine dielectrophoretic behavior of U87 glioma cells. We investigated the influence of medium conductivity, applied electric field strength and frequency on the dielectrophoretic spectra of U87 glioma cells.
1 citations
TL;DR: In this article , a gold microelectrode array within a microfluidic channel and applied sinusoidal wave AC potential at 3 Vpp, ranging from 30 kHz to 10 MHz frequencies, to generate DEP forces.
DOI•
31 Oct 2022
TL;DR: In this paper, the authors implemented a cloud service to their LAMP-based biosensor and transferred the obtained image and results of the assays through cloud, which simplifies the data processing, it directly digitized the readouts and eliminates the need of data interpretation.
Abstract: Internet-of-Things technology (IoTs) have accelerated biosensor applications in all fields. Loop-mediated isothermal amplification (LAMP)-based biosensor technologies in conjunction with smartphone detection have been adequate to cover the demands of mobile diagnostics. The ease of use, affordability, portability, high sensitivity, flexibility, and specificity demands of point-of-care detection can be achieved by low-cost electronic components, 3-dimensional printing technologies, capturing images of calorimetrically detected readouts made our system a promising approach for real-time point-of-detection in the field. In this study, we implemented a cloud service to our LAMP-based biosensor. We previously performed bacteria detection using colony-based LAMP device and now distributed the optical readouts of the assay using smartphones. We transferred the obtained image and results of the assays through cloud. Our user-friendly interface simplifies the data processing, it directly digitized the readouts and eliminates the need of data interpretation.