A fully automated centrifugal microfluidic system for sample-to-answer viral nucleic acid testing

Abstract

The outbreak of virus-induced infectious diseases poses a global public-health challenge. Nucleic acid amplification testing (NAAT) enables early detection of pandemic viruses and plays a vital role in preventing onward transmission. However, the requirement of skilled operators, expensive instrumentation, and biosafety laboratories has hindered the use of NAAT for screening and diagnosis of suspected patients. Here we report development of a fully automated centrifugal microfluidic system with sample-in-answer-out capability for sensitive, specific, and rapid viral nucleic acid testing. The release of nucleic acids and the subsequent reverse transcription loop-mediated isothermal amplification (RT-LAMP) were integrated into the reaction units of a microfluidic disc. The whole processing steps such as injection of reagents, fluid actuation by rotation, heating and temperature control, and detection of fluorescence signals were carried out automatically by a customized instrument. We validate the centrifugal microfluidic system using oropharyngeal swab samples spiked with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) armored RNA particles. The estimated limit of detection for armored RNA particles is 2 copies per reaction, the throughput is 21 reactions per disc, and the assay sample-to-answer time is approximately 70 min. This enclosed and automated microfluidic system efficiently avoids viral contamination of aerosol, and can be readily adapted for virus detection outside the diagnostic laboratory. Electronic Supplementary Material Supplementary material is available for this article at 10.1007/s11426-020-9800-6 and is accessible for authorized users.

On‐Chip Optical Detection of Viruses: A Review

“…[ 140 ] Take the photonic‐enhanced loop‐mediated isothermal amplification (LAMP) (Figure 9c) as an example, the detection time of infected bacteria DNA was shortened to 40 min from 60 min and the detection limits was about 10 times lower than the standard LAMP. [ 141,142 ] In addition, ring resonator‐based NAAR methods were also reported in multiple and label‐free nucleic acids detection. [ 143–145 ]…”

Rapid diagnostics of novel coronavirus infection by loop-mediated isothermal amplification

“…Опубликован также протокол без предварительного выделения нуклеиновой кислоты, который сохранил отличную специфичность (99,5%), хотя и показал снижение чувствительности (86% для количества циклов ПЦР с превышением порогового значения флюоресценции (Ct) <30) по сравнению с RT-LAMP с предварительной экстракцией РНК. Ещё в одном исследовании выделение нуклеиновых кислот и последующая RT-LAMP были интегрированы в реакционные блоки микрофлюидного диска [57]; единый прибор запускал реакцию вращением последнего, контролировал нагрев до необходимой температуры, выполняя также обнаружение сигнала флуоресценции. Предполагаемый предел обнаружения для РНК вирусных частиц составил 2 копии на реакцию, пропускная способность -21 тест на диске, время анализа от образца до результата -~70 мин.…”

Fully integrated microfluidic devices for qualitative, quantitative and digital nucleic acids testing at point of care

“…With the outbreak and extension of COVID-19 pandemic, the translation of POC NAT devices from academic research into viable products has gained considerable attentions. Meanwhile, a lot of newly-developed POC NAT devices emerge continuously to address new technical challenges caused by the pandemic ( Tian et al, 2020 ; Ye et al, 2020 ; Zhou et al, 2020 ). Although there exist several reviews focusing on microfluidic systems for NAT ( Ahrberg et al, 2016 ; Shrivastava et al, 2020 ; Yin et al, 2019 ; Zhang et al, 2017 ), they mostly focus on the development of nucleic acid amplification technologies, lacking in detailed discussion on translation.…”