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Sensitive extraction-free SARS-CoV-2 RNA virus detection using a chelating resin.

ABSTRACT: Current conventional detection of SARS-CoV-2 involves collection of a patient's sample with a nasopharyngeal swab, storage of the swab during transport in a viral transport medium, extraction of RNA, and quantitative reverse transcription PCR (RT-qPCR). We developed a simplified preparation method using a chelating resin, Chelex, which obviates RNA extraction during viral testing. Direct detection RT-qPCR and digital droplet PCR were compared to the current conventional method with RNA extraction for simulated samples and patient specimens. The heat treatment in the presence of Chelex markedly improved detection sensitivity as compared to heat alone, and lack of RNA extraction shortens the overall diagnostic workflow. Furthermore, the initial sample heating step inactivates SARS-CoV-2 infectivity, thus improving workflow safety. This fast RNA preparation and detection method is versatile for a variety of samples, safe for testing personnel, and suitable for standard clinical collection and testing on high-throughput platforms.

SUBMITTER: Guan B

PROVIDER: S-EPMC8349732 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Sensitive extraction-free SARS-CoV-2 RNA virus detection using a novel RNA preparation method.

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Fast, cheap and sensitive: Homogenizer-based RNA extraction free method for SARS-CoV-2 detection by RT-qPCR.

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A Saliva-Based RNA Extraction-Free Workflow Integrated With Cas13a for SARS-CoV-2 Detection.

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Rapid and extraction-free detection of SARS-CoV-2 from saliva with colorimetric LAMP.

Project description:Rapid, reliable, and widespread testing is required to curtail the ongoing COVID-19 pandemic. Current gold standard diagnostic assays are hampered by supply shortages in critical reagents including nasal swabs, RNA extraction kits, personal protective equipment (PPE), instrumentation, and labor. Here we present an approach to overcome these challenges with the development of a rapid colorimetric assay using reverse-transcription loop-mediated isothermal amplification (RT-LAMP) optimized on human saliva samples without an RNA purification step. We describe our optimizations of the LAMP reaction and saliva pre-treatment protocols that enabled rapid and sensitive detection of < 10^2 viral genomes per reaction in contrived saliva controls. We also observed high performance of this assay on a limited number of clinical saliva samples. While thorough validation on additional clinical samples are needed before such an assay can be widely used, these preliminary results demonstrate a promising approach to overcome the current bottlenecks limiting widespread testing.

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Accuracy of a RT-qPCR SARS-CoV-2 detection assay without prior RNA extraction.

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| S-EPMC7886139 | biostudies-literature

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| S-EPMC8486790 | biostudies-literature

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