Optical electrophysiology: Femtosecond laser facilitated electrophysiological measurements from single cells

Summary form only given. One of the indispensable tools of electrophysiology is patch-clamp recording, which enables direct observation of ionic transport through cellular membranes. It is an invaluable research tool, providing experimental information related to cellular electrical metabolism, as well as various pathological conditions. While the inventors of patchclamp recording subsequently became Nobel laurates [1], still it can be considered as one of the most complicated experimental setups, due to the difficulty in puncturing cells using capillary microelectrodes with extreme precision. The throughput of the measurement is also considerably low. Thus, automatized planar patch-clamp systems depending on automatic suction of cells using special chips have emerged, considerably increasing the throughput of electrophysiological measurements for about a decade [2]. However, they are generally restricted to be used only with cultured cells, while they have a poor applicability when isolated cells are considered. Real-time observation of the cells for quality assessment, in terms of the measurement, is also not possible.Here, a novel laser assisted method for performing cellular electrophysiological measurements is suggested and experimentally demonstrated. Femtosecond lasers have previously been used to form nano-sized pores on cell membranes [3], and their effect on membrane electrical polarization was also investigated [4]; however, this study is their very first utilization in electrophysiology. In this study, femtosecond laser pulses, coupled to an optical microscope, are used to first form a micrometer sized pore on a thin polymer membrane separating two electrodes. Afterwards, the nearby cell is sucked on the pore, and a small hole on this cell is formed again with the femtosecond laser, revealing the membrane over the pocket for electrophysiological recording. This method could be utilized to increase the throughput of electrophysiological measurements substantially, while providing ultimate control to the researcher over the experiment, which is non-existent in planar systems

Clinical evaluation of DIAGNOVIR SARS-CoV-2 ultra-rapid antigen test performance compared to PCR-based testing

Coronavirus Disease-19 (COVID-19) is a highly contagious infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The development of rapid antigen tests has contributed to easing the burden on healthcare and lifting restrictions by detecting infected individuals to help prevent further transmission of the virus. We developed a state-of-art rapid antigen testing system, named DIAGNOVIR, based on immune-fluorescence analysis, which can process and give the results in a minute. In our study, we assessed the performance of the DIAGNOVIR and compared the results with those of the qRT-PCR test. Our results demonstrated that the sensitivity and specificity of the DIAGNOVIR were 94% and 99.2%, respectively, with a 100% sensitivity and 96.97% specificity, among asymptomatic patients. In addition, DIAGNOVIR can detect SARS‑CoV‑2 with 100% sensitivity up to 5 days after symptom onset. We observed that the DIAGNOVIR Rapid Antigen Test’s limit of detection (LoD) was not significantly affected by the SARS‑CoV‑2 variants including Wuhan, alpha (B1.1.7), beta (B.1.351), delta (B.1.617.2) and omicron (B.1.1.529) variants, and LoD was calculated as 8 × 102, 6.81 × 101.5, 3.2 × 101.5, 1 × 103, and 1 × 103.5 TCID50/mL, respectively. Our results indicated that DIAGNOVIR can detect all SARS-CoV-2 variants in just seconds with higher sensitivity and specificity lower testing costs and decreased turnover time. © 2023, The Author(s).Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]