Nejvíce citovaný článek - PubMed ID 26753557
Handheld real-time PCR device
PCR has become one of the most valuable techniques currently used in bioscience, diagnostics and forensic science. Here we review the history of PCR development and the technologies that have evolved from the original PCR method. Currently, there are two main areas of PCR utilization in bioscience: high-throughput PCR systems and microfluidics-based PCR devices for point-of-care (POC) applications. We also discuss the commercialization of these techniques and conclude with a look into their modifications and use in innovative areas of biomedicine. For example, real-time reverse transcription PCR is the gold standard for SARS-CoV-2 diagnoses. It could also be used for POC applications, being a key component of the sample-to-answer system.
- Klíčová slova
- COVID-19, PCR, RNA virus diagnoses, digital PCR, microfluidics, point-of-care diagnostics, portable systems, reverse transcription PCR,
- MeSH
- Betacoronavirus genetika izolace a purifikace MeSH
- COVID-19 MeSH
- design vybavení MeSH
- klinické laboratorní techniky přístrojové vybavení metody MeSH
- koronavirové infekce diagnóza virologie MeSH
- lidé MeSH
- mikrofluidní analytické techniky přístrojové vybavení metody MeSH
- pandemie MeSH
- polymerázová řetězová reakce přístrojové vybavení metody MeSH
- SARS-CoV-2 MeSH
- testování na COVID-19 MeSH
- virová pneumonie diagnóza virologie MeSH
- vyšetření u lůžka MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Infectious diseases, such as the most recent case of coronavirus disease 2019, have brought the prospect of point-of-care (POC) diagnostic tests into the spotlight. A rapid, accurate, low-cost, and easy-to-use test in the field could stop epidemics before they develop into full-blown pandemics. Unfortunately, despite all the advances, it still does not exist. Here, we critically review the limited number of prototypes demonstrated to date that is based on a polymerase chain reaction (PCR) and has come close to fulfill this vision. We summarize the requirements for the POC-PCR tests and then go on to discuss the PCR product-detection methods, the integration of their functional components, the potential applications, and other practical issues related to the implementation of lab-on-a-chip technologies. We conclude our review with a discussion of the latest findings on nucleic acid-based diagnosis.
- Klíčová slova
- COVID-19 diagnoses, Future of PCR, Microfluidics, Miniaturization, Point of care, Polymerase chain reaction,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Optofluidic devices combining optics and microfluidics have recently attracted attention for biomolecular analysis due to their high detection sensitivity. Here, we show a silicon chip with tubular microchannels buried inside the substrate featuring temperature gradient (∇T) along the microchannel. We set up an optical fluorescence system consisting of a power-modulated laser light source of 470 nm coupled to the microchannel serving as a light guide via optical fiber. Fluorescence was detected on the other side of the microchannel using a photomultiplier tube connected to an optical fiber via a fluorescein isothiocyanate filter. The PMT output was connected to a lock-in amplifier for signal processing. We performed a melting curve analysis of a short dsDNA - SYBR Green I complex with a known melting temperature (TM) in a flow-through configuration without gradient to verify the functionality of the proposed detection system. We then used the segmented flow configuration and measured the fluorescence amplitude of a droplet exposed to ∇T of ≈ 2.31 °C mm-1, determining the heat transfer time as ≈ 554 ms. The proposed platform can be used as a fast and cost-effective system for performing either MCA of dsDNAs or for measuring protein unfolding for drug-screening applications.
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The global risk of viral disease outbreaks emphasizes the need for rapid, accurate, and sensitive detection techniques to speed up diagnostics allowing early intervention. An emerging field of microfluidics also known as the lab-on-a-chip (LOC) or micro total analysis system includes a wide range of diagnostic devices. This review briefly covers both conventional and microfluidics-based techniques for rapid viral detection. We first describe conventional detection methods such as cell culturing, immunofluorescence or enzyme-linked immunosorbent assay (ELISA), or reverse transcription polymerase chain reaction (RT-PCR). These methods often have limited speed, sensitivity, or specificity and are performed with typically bulky equipment. Here, we discuss some of the LOC technologies that can overcome these demerits, highlighting the latest advances in LOC devices for viral disease diagnosis. We also discuss the fabrication of LOC systems to produce devices for performing either individual steps or virus detection in samples with the sample to answer method. The complete system consists of sample preparation, and ELISA and RT-PCR for viral-antibody and nucleic acid detection, respectively. Finally, we formulate our opinions on these areas for the future development of LOC systems for viral diagnostics.
- Klíčová slova
- Commercialization, Immunoassays, LOC, Microfluidic, Nucleic acid amplification, Viral detection,
- MeSH
- biosenzitivní techniky MeSH
- design vybavení MeSH
- DNA virů analýza MeSH
- ELISA MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- laboratoř na čipu * MeSH
- lidé MeSH
- mikrofluidní analytické techniky přístrojové vybavení MeSH
- nukleové kyseliny analýza MeSH
- virové nemoci diagnóza MeSH
- vyšetření u lůžka MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- DNA virů MeSH
- nukleové kyseliny MeSH
In this work, we demonstrate the simple fabrication process of AlN-based piezoelectric energy harvesters (PEH), which are made of cantilevers consisting of a multilayer ion beam-assisted deposition. The preferentially (001) orientated AlN thin films possess exceptionally high piezoelectric coefficients d33 of (7.33 ± 0.08) pC∙N-1. The fabrication of PEH was completed using just three lithography steps, conventional silicon substrate with full control of the cantilever thickness, in addition to the thickness of the proof mass. As the AlN deposition was conducted at a temperature of ≈330 °C, the process can be implemented into standard complementary metal oxide semiconductor (CMOS) technology, as well as the CMOS wafer post-processing. The PEH cantilever deflection and efficiency were characterized using both laser interferometry, and a vibration shaker, respectively. This technology could become a core feature for future CMOS-based energy harvesters.
This article introduces in archival form the Nanolithography Toolbox, a platform-independent software package for scripted lithography pattern layout generation. The Center for Nanoscale Science and Technology (CNST) at the National Institute of Standards and Technology (NIST) developed the Nanolithography Toolbox to help users of the CNST NanoFab design devices with complex curves and aggressive critical dimensions. Using parameterized shapes as building blocks, the Nanolithography Toolbox allows users to rapidly design and layout nanoscale devices of arbitrary complexity through scripting and programming. The Toolbox offers many parameterized shapes, including structure libraries for micro- and nanoelectromechanical systems (MEMS and NEMS) and nanophotonic devices. Furthermore, the Toolbox allows users to precisely define the number of vertices for each shape or create vectorized shapes using Bezier curves. Parameterized control allows users to design smooth curves with complex shapes. The Toolbox is applicable to a broad range of design tasks in the fabrication of microscale and nanoscale devices.
- Klíčová slova
- CAD, lithography, nanofabrication, nanofluidic, nanophotonic, nanoplasmonic, nanoscale curved features, nanoscale design, nanoscale devices,
- Publikační typ
- časopisecké články MeSH
