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.

Genetically Modified (GM) foods are becoming the future of agriculture on surviving global natural disasters and climate change by their enhanced production efficiency and improved functional properties. On the other hand, their adverse health and environmental effects, ample evidence on transgene leakage of Genetically Modified Organisms (GMOs) to crops have raised questions on their benefits and risks. Consequently, low-cost, reliable, rapid, and practical detection of GMOs have been important. GMO-detection platforms should be capable of stably storing detection reagents for long-delivery distances with varying ambient temperatures. In this study, we developed an event-specific, closed tube colorimetric GMO detection method based on Loop-Mediated Isothermal Amplification (LAMP) technique which can be integrated into GMO-detection platforms. The entire detection process optimized to 30 min and isothermally at 65 °C. The durability of the LAMP mixture in the test tubes showed that the LAMP reaction mixture, in which Bst polymerase and DNA sample was later included, yielded DNA amplicons for 3 days at room temperature, and for 6 days at 4 °C. Simple, stable, and cheap storage method of LAMP reaction mixture for GMO-detection technologies. GMO-detection platforms can stably store detection reagents for long-delivery distances with varying ambient temperatures. Any DNA sample can be used in the field or resource-limited setting by untrained personnel.

Glioblastoma multiforme is one of the most aggressive malignant primary brain tumors. To design effective treatment strategies, we need to better understand the behavior of glioma cells while maintaining their genetic and phenotypic stability. Here, we investigated the deformation and migration profile of U87 Glioma cells under the influence of dielectrophoretic forces. We fabricated 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. We followed the dielectrophoretic movement and deformation changes of 100 glioma cells at each frequency. We observed that the mean dielectrophoretic displacements of glioma cells were significantly different at varying frequencies with the maximum and minimum traveling 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. This approach presents a rapid, robust, and sensitive characterization method for quantifying membrane deformation of glioma cells to determine the state of the cells or efficacy of administrated drugs.

Global climate change has drastically affected agricultural production. Moreover, pandemics, wars, and rapid decreases in natural resources point to the emerging need for famine prevention by increasing smart agriculture and food production and decreasing food loss and waste. To achieve this, plant and food diseases should be detected early and rapidly treated. From this perspective, we focus on recent, simple, and instrument-free, nucleic acid extraction techniques, which are capable of isolating high-quality nucleic acids from plant tissues, to be either easily used in the field or simply integrated into various nucleic acid detection platforms or sensors.

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 less than 1%. We performed LAMP, Colony-LAMP, and Colony PCR reactions 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.

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 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 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.

No abstract

Antibiotic resistance is a global health threat. To combat against infections, we urgently need better strategies. Currently there are limited number of antibiotics in the treatment repertoire of existing bacterial infections. Among them rifampicin is a broad-spectrum antibiotic against various bacterial pathogens. Efficacy of rifampicin decreases by time due to appearance of rifampicin persister or resistant phenotypes in the population. To benefit more from rifampicin, its current standard dosage might be reconsidered and deeply explored using both computational tools and experimental or clinical studies. In this study, we present the mathematical relationship between the concentration of rifampicin and the growth and killing kinetics of Escherichia coli cells. We generated time-killing curves of Escherichia coli cells in the presence of 4 µg/ml, 16 µg/ml, and 32 µg/ml rifampicin exposures. We fitted time-killing curve data using the lsqcurvefit function in MATLAB to model rifampicin responses of Escherichia coli cells.