scholarly journals SARS-CoV-2 RNA Extraction Using Magnetic Beads for Rapid Large-Scale Testing by RT-qPCR and RT-LAMP

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 863 ◽  
Author(s):  
Steffen Klein ◽  
Thorsten G. Müller ◽  
Dina Khalid ◽  
Vera Sonntag-Buck ◽  
Anke-Mareil Heuser ◽  
...  

Rapid large-scale testing is essential for controlling the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The standard diagnostic pipeline for testing SARS-CoV-2 presence in patients with an ongoing infection is predominantly based on pharyngeal swabs, from which the viral RNA is extracted using commercial kits, followed by reverse transcription and quantitative PCR detection. As a result of the large demand for testing, commercial RNA extraction kits may be limited and, alternatively, non-commercial protocols are needed. Here, we provide a magnetic bead RNA extraction protocol that is predominantly based on in-house made reagents and is performed in 96-well plates supporting large-scale testing. Magnetic bead RNA extraction was benchmarked against the commercial QIAcube extraction platform. Comparable viral RNA detection sensitivity and specificity were obtained by fluorescent and colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) using a primer set targeting the N gene, as well as RT-qPCR using a primer set targeting the E gene, showing that the RNA extraction protocol presented here can be combined with a variety of detection methods at high throughput. Importantly, the presented diagnostic workflow can be quickly set up in a laboratory without access to an automated pipetting robot.

Author(s):  
Steffen Klein ◽  
Thorsten G. Mueller ◽  
Dina Khalid ◽  
Vera Sonntag-Buck ◽  
Anke-Mareil Heuser ◽  
...  

Rapid large-scale testing is essential for controlling the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The standard diagnostic pipeline for testing SARS-CoV-2 presence in patients with an ongoing infection is predominantly based on pharyngeal swabs, from which the viral RNA is extracted using commercial kits followed by reverse transcription and quantitative PCR detection. As a result of the large demand for testing, commercial RNA extraction kits may be limited and alternative, non-commercial protocols are needed. Here, we provide a magnetic bead RNA extraction protocol that is predominantly based on in-house made reagents and is performed in 96-well plates supporting large-scale testing. Magnetic bead RNA extraction was benchmarked against the commercial QIAcube extraction platform. Comparable viral RNA detection sensitivity and specificity were obtained by fluorescent and colorimetric RT-LAMP using N primers, as well as RT-qPCR using E gene primers showing that the here presented RNA extraction protocol can be combined with a variety of detection methods at high throughput. Importantly, the presented diagnostic workflow can be quickly set up in a laboratory without access to an automated pipetting robot.


Author(s):  
Soon Keong Wee ◽  
Suppiah Paramalingam Sivalingam ◽  
Eric Peng Huat Yap

There is an ongoing worldwide coronavirus disease 2019 (Covid-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). At present, confirmatory diagnosis is by reverse transcription polymerase chain reaction (RT-PCR), typically taking several hours and requiring a molecular laboratory to perform. There is an urgent need for rapid, simplified and cost-effective detection methods. We have developed and analytically validated a protocol for direct rapid extraction-free PCR (DIRECT-PCR) detection of SARS-CoV-2 without the need for nucleic acid purification. As few as 6 RNA copies per reaction of viral nucleocapsid (N) gene from respiratory samples such as sputum and nasal exudate can be detected directly using our one-step inhibitor-resistant assay. The performance of this assay was validated on a commercially available portable PCR thermocycler. Viral lysis, reverse transcription, amplification and detection are achieved in a single-tube homogeneous reaction within 36 minutes. This minimized hands-on time, reduces turnaround-time for sample-to-result and obviates the need for RNA purification reagents. It could enable wider use of Covid-19 testing for diagnosis, screening and research in countries and regions where laboratory capabilities are limiting.


Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 664 ◽  
Author(s):  
Soon Keong Wee ◽  
Suppiah Paramalingam Sivalingam ◽  
Eric Peng Huat Yap

There is an ongoing worldwide coronavirus disease 2019 (Covid-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). At present, confirmatory diagnosis is by reverse transcription polymerase chain reaction (RT-PCR), typically taking several hours and requiring a molecular laboratory to perform. There is an urgent need for rapid, simplified, and cost-effective detection methods. We have developed and analytically validated a protocol for direct rapid extraction-free PCR (DIRECT-PCR) detection of SARS-CoV-2 without the need for nucleic acid purification. As few as six RNA copies per reaction of viral nucleocapsid (N) gene from respiratory samples such as sputum and nasal exudate can be detected directly using our one-step inhibitor-resistant assay. The performance of this assay was validated on a commercially available portable PCR thermocycler. Viral lysis, reverse transcription, amplification, and detection are achieved in a single-tube homogeneous reaction within 36 min. This minimizes hands-on time, reduces turnaround-time for sample-to-result, and obviates the need for RNA purification reagents. It could enable wider use of Covid-19 testing for diagnosis, screening, and research in countries and regions where laboratory capabilities are limiting.


Author(s):  
Mahesh K. R. Kalikiri ◽  
Mohammad Rubayet Hasan ◽  
Faheem Mirza ◽  
Thabisile Xaba ◽  
Patrick Tang ◽  
...  

ABSTRACTThe ongoing pandemic of the novel coronavirus, SARS-CoV-2, has led to a global surge in laboratory testing for the virus. The gold standard approach to detecting an active viral infection is the use of RT-qPCR. This approach requires the isolation of viral RNA from respiratory specimens, such as nasopharyngeal swabs.We developed a method using a widely available lysis buffer coupled with solid-phase reverse immobilization (SPRI) beads to extract viral RNA from swabs collected in viral transport medium (VTM) which can be performed manually or on a Hamilton STAR liquid-handling robot. Using a WHO recommended, laboratory-developed RT-qPCR for SARS-CoV-2, we validated this method in a CAP-accredited laboratory, against the IVD-labelled bioMérieux NucliSENS easyMAG automated extraction platform.Our method demonstrates a comparable sensitivity and specificity, making it suitable for large-scale testing and monitoring of suspected COVID-19 cases and health care workers. This is especially important as the world faces critical shortages of viral RNA extraction reagents for the existing commercial extraction systems.


Author(s):  
Monica Sentmanat ◽  
Evguenia Kouranova ◽  
Xiaoxia Cui

ABSTRACTThe global outbreak of coronavirus disease 2019 (COVID-19) has placed an unprecedented burden on healthcare systems as the virus spread from the initial 27 reported cases in the city of Wuhan, China to a global pandemic in under three month[1]. Resources essential to monitoring virus transmission have been challenged with a demand for expanded surveillance. The CDC 2019-nCoV Real-Time Diagnostic Panel uses a real-time reverse transcription polymerase chain reaction (RT-PCR) consisting of two TaqMan probe and primer sets specific for the 2019-nCoV N gene, which codes for the nucleocapsid structural protein that encapsulates viral RNA, for the qualitative detection of 2019-nCoV viral RNA in respiratory samples. To isolate RNA from respiratory samples, the CDC lists RNA extraction kits from four manufacturers. In anticipation of a limited supply chain of RNA extraction kits and the need for test scalability, we sought to identify alternative RNA extraction methods. Here we show that direct lysis of respiratory samples can be used in place of RNA extraction kits to run the CDC 2019-nCoV Real-Time Diagnostic assay with the additional benefits of higher throughput, lower cost, faster turnaround and possibly higher sensitivity and improved safety.


Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 222-226 ◽  
Author(s):  
Donald J. MacKenzie ◽  
Morven A. McLean ◽  
Srima Mukerji ◽  
Margaret Green

An efficient procedure for the extraction of high-quality RNA from woody plants without the use of phenol, organic solvents, or alcohol precipitation is described. The method employs commercially available spin-column matrices and mitigates the inhibitory effects of plant polysaccharides and polyphenolic compounds commonly observed on subsequent polymerase chain reaction amplification when conventional extraction methods are applied to woody plant species. The method described has been successfully used in the development of highly sensitive reverse transcription-polymerase chain reaction (RT-PCR) techniques for the detection of a number of viruses in their woody hosts. The viruses detected included apple stem grooving capillovirus (ASGV), apple stem pitting virus, Prunus necrotic ringspot ilarvirus (PNRSV), grapevine fanleaf and Arabis mosaic nepoviruses, and grapevine leafroll-associated closterovirus type 3. The method described was equally effective for the extraction of viral RNA from either budwood, leaves, or flower blossoms as determined by the equivalent RT-PCR detection of ASGV and PNRSV from these tissues. Detection of viral RNA in samples of total plant RNA prepared using this method was found to be as sensitive as was previously described for the immunocapture RT-PCR technique.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2239
Author(s):  
Zhen Liu ◽  
Zhenfei Dong ◽  
Binhui Zhan ◽  
Shifang Li

Apple (Malus domestica) fruits exhibiting bright stripe symptoms were identified in Weihai City, Shandong Province, China. To investigate the virome in the apple samples, the method of high throughput sequencing (HTS) was used to identify the viruses. It was found that the sequence of citrus concave gum-associated virus (CCGaV) was involved in the apple transcriptome dataset. The full-length genome of the CCGaV-Weihai isolate contained two segments, the RNA1 was 6674 nt in size containing a conserved RNA-dependent RNA polymerase (RdRp), and the RNA2 was ambisense, 2706 nt in length, encoding a movement protein (MP) and a coat protein (CP). Sequence alignment and phylogenetic analyses indicated that CCGaV-Weihai was more closely related to CCGaV-H2799 isolated from the apple host in the United States and distantly related to CCGaV-CGW2 from Citrus sinensis in Italy, indicating a possibly geographical and host differentiation of CCGaV isolates. This was the first identification and characterization of CCGaV infecting apples in China. Additionally, a rapid and sensitive reverse transcription recombinase polymerase amplification (RT-RPA) assay technique was established for CCGaV detection in apple plants. The RT-RPA of CCGaV was not affected by other common viruses in apple plants and is about 10-fold more sensitive than the conventional reverse transcription polymerase chain reaction method, which can be used in large-scale testing.


2020 ◽  
Author(s):  
Makoto Kashima ◽  
Mari Kamitani ◽  
Yasuyuki Nomura ◽  
Hiromi Hirata ◽  
Atsushi J. Nagano

AbstractUsing current mRNA quantification methods such as RT-qPCR and RNA-Seq, it is very difficult to examine thousands of tissue samples due to cost and labor of RNA extraction and quantification steps. Here, we developed Direct-RT buffer in which homogenization of tissue samples and direct-lysate reverse transcription can be conducted without RNA purification. We showed that appreciate concentration of DTT prevented RNA degradation but not RT in the lysates of several plants’ tissues, yeast, and zebrafish larvae. Using the buffer, direct reverse transcription on the lysates could produce comparable amount of cDNA with that synthesized from purified RNA. Furthermore, we established DeLTa-Seq (Direct-Lysate reverse transcription and Targeted RNA-Seq) method. DeLTa-Seq is a cost-effective, high-throughput and highly-precise quantification method for the expressions of hundreds of genes. It enables us to conduct large-scale studies using thousands of samples such as chemical screening, field experiments and studies focusing on individual variability.


2011 ◽  
Vol 15 (6) ◽  
pp. 547-552
Author(s):  
Guilherme Ambrozio Albertoni ◽  
Carine Prisco Arnoni ◽  
Patricia Regina Barboza Araujo ◽  
Sheila Siqueira Andrade ◽  
Fabrício Oliveira Carvalho ◽  
...  

2020 ◽  
Author(s):  
Sunil More ◽  
Sai Narayanan ◽  
Girish Patil ◽  
Parna Ghosh ◽  
Samuel Pushparaj ◽  
...  

The global outbreak and rapid spread of SARS-CoV-2 has created an urgent need for large scale testing of populations. There is a demand for high throughput testing protocols that can be used for efficient and rapid testing of clinical specimens. We evaluated a pooled-PCR protocol for testing nasopharyngeal swabs using known positive/negative and untested clinical samples that were assigned to pools of 5 or 10. Nasopharyngeal swabs were accurately identified as positive or negative for SARS-CoV-2 in pools of 5 (100% sensitivity; 100% specificity). Even though specificity remained unaffected (100%), the detection sensitivity was reduced (66.67%) when 10 samples were pooled together. Pooling of up to 5 samples can be employed in laboratories for the diagnosis of COVID-19 for efficient utilization of resources, rapid screening of a greater number of people, and faster reporting of test results.


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