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Although real‐time quantitative reverse transcription polymerase chain reaction (RT‐qPCR) is the gold standard for detecting the virus severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) and other pathogens, the coronavirus disease 2019 (COVID‐19) pandemic has highlighted the scarcity of instruments, devices, and reagents for polymerase chain reaction (PCR) testing in constrained settings. At least for under‐resourced countries, it has become critical to deploy instruments that can be rapidly constructed and satisfy this demand. Instead of separating the optical system from the thermal module (typical of qPCR thermocyclers), we report a portable Hybrid Opto‐Thermocycler—dubbed HybOT Cycler—that takes advantage of the high‐temperature tolerances (>100 °C) of electronic and optical components to combine thermal control, illumination, and fluorescence detection into a highly integrated hybrid module. This simple configuration allowed us to reduce the overall number of components, thus simplifying its assembly and reducing the instrument size. The HybOT Cycler is wirelessly controlled from an application installed in a tablet. PCR assays are carried out in a bubble‐free microfluidic device that can be easily replicated from an acrylic mold. Using the HybOT Cycler, down to 100 copies/µL of genetic material of the virus SARS‐CoV‐2 with 95% sensitivity and 100% specificity is detected. The HybOT Cycler can assist in diagnosing SARS‐CoV‐2 and other pathogens in resource‐poor settings. [ABSTRACT FROM AUTHOR]

New tools that facilitate the study of cell-to-cell variability could help uncover novel cellular regulation mechanisms. We present an integrated microfluidic platform to analyze a large number of single cells in parallel. To isolate and analyze thousands of individual cells in multiplexed conditions, our platform incorporates arrays of microwells (7 pL each) in a multilayered microfluidic device. The device allows the simultaneous loading of cells into 16 separate chambers, each containing 4640 microwells, for a total of 74 240 wells per device. We characterized different parameters important for the operation of the microfluidic device including flow rate, solution exchange rate in a microchamber, shear stress, and time to fill up a single microwell with molecules of different molecular weight. In general, after ~7.5 min of cell loading our device has an 80% microwell occupancy with 1-4 cells, of which 36% of wells contained a single cell. To test the functionality of our device, we carried out a cell viability assay with adherent and nonadherent cells. We also studied the production of neutrophil extracellular traps (NETs) from single neutrophils isolated from peripheral blood, observing the existence of temporal heterogeneity in NETs production, perhaps having implications in the type of the neutrophil response to an infection or inflammation. We foresee our platform will have a variety of applications in drug discovery and cellular biology by facilitating the characterization of phenotypic differences in a monoclonal cell population. [ABSTRACT FROM AUTHOR]