scholarly journals Engineered CRISPR/Cas12a Enables Rapid SARS-CoV-2 Detection

2020 ◽  
Author(s):  
Long T. Nguyen ◽  
Santosh R. Rananaware ◽  
Brianna L.M. Pizzano ◽  
Brandon T. Stone ◽  
Piyush K. Jain
Keyword(s):  
High Sensitivity ◽  
High Specificity ◽  
Single Copy ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Magnesium Concentration ◽  
Clinical Validation ◽  
Respiratory Pathogens ◽  
Reporter Assay ◽  
Wide Range

ABSTRACTThe coronavirus disease (COVID-19) caused by SARS-CoV-2 has swept through the globe at an unprecedented rate. CRISPR-based detection technologies such as DETECTR, SHERLOCK, and STOPCovid have emerged as a rapid and affordable platform that can shape the future of diagnostics. Recently, we reported engineered crRNAs for Cas12a, called ENHANCE, that enables enhanced detection of nucleic acids. Here we report development, clinical validation, and advancement of ENHANCE platform for detecting SARS-CoV-2. With an RT-LAMP pre-amplification step, ENHANCE detects samples down to a single copy with 95% accuracy and shows high specificity towards various isolates of SARS-CoV-2 against 31 highly similar and common respiratory pathogens. Utilizing LbCas12a-mediated trans-cleavage activity, ENHANCE works robustly in a wide range of magnesium concentration (3 mM-13 mM), allowing for further assay optimization. Additionally, ENHANCEv2 is developed to further improve the previously reported ENHANCE. ENHANCEv2 employs mutated LbCas12aD156R, engineered chimeric DNA-extended crRNA, and a dual reporter for both fluorescence-based reporter assay and lateral flow assay. Both ENHANCE and ENHANCEv2 are validated in 62 clinical nasopharyngeal swabs, showing 60/62 (96.7%) agreement with RT-qPCR results, and using only 5 μL of sample and 20 minutes of CRISPR reaction. Lateral flow assay on paper strips displays 100% agreement with fluorescence-based reporter assay in the clinical validation. Following a 30-minute pre-amplification RT-LAMP step, the lyophilized ENHANCEv2 is shown to achieve high sensitivity and specificity while reducing CRISPR reaction time to as low as 3 minutes and maintaining its detection capability upon storage at room temperature for several weeks.

scholarly journals Engineered CRISPR/Cas12a Enables Rapid SARS-CoV-2 Detection

2021 ◽  
Author(s):  
Long Nguyen ◽  
Santosh Rananaware ◽  
Brianna Pizzano ◽  
Brandon Stone ◽  
Piyush Jain
Keyword(s):  
High Sensitivity ◽  
High Specificity ◽  
Single Copy ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Magnesium Concentration ◽  
Clinical Validation ◽  
Respiratory Pathogens ◽  
Reporter Assay ◽  
Wide Range

Abstract The coronavirus disease (COVID-19) caused by SARS-CoV-2 has swept through the globe at an unprecedented rate. CRISPR-based detection technologies such as DETECTR, SHERLOCK, and others have emerged as a rapid and affordable platform that can shape the future of diagnostics. Recently, we reported engineered crRNAs for Cas12a, called ENHANCE, that enables enhanced detection of nucleic acids. Here we report development, clinical validation, and advancement of ENHANCE platform for detecting SARS-CoV-2. With an RT-LAMP pre-amplification step, ENHANCE detects samples down to a single copy with 95% accuracy and shows high specificity towards various isolates of SARS-CoV-2 against 31 highly similar and common respiratory pathogens. Utilizing LbCas12a-mediated trans-cleavage activity, ENHANCE works robustly in a wide range of magnesium concentration (3 mM-13 mM), allowing for further assay optimization. Additionally, ENHANCEv2 is developed to further improve the previously reported ENHANCE. ENHANCEv2 employs mutated LbCas12aD156R, engineered chimeric DNA-extended crRNA, and a dual reporter for both fluorescence-based reporter assay and lateral flow assay. Both ENHANCE and ENHANCEv2 are validated in 62 clinical nasopharyngeal swabs, showing 60/62 (96.7%) agreement with RT-qPCR results, and using only 5 µL of sample and 20 minutes of CRISPR reaction. Lateral flow assay on paper strips displays 100% agreement with fluorescence-based reporter assay in the clinical validation. Following a 30-minute pre-amplification RT-LAMP step, the lyophilized ENHANCEv2 is shown to achieve high sensitivity and specificity while reducing CRISPR reaction time to as low as 3 minutes and maintaining its detection capability upon storage at room temperature for several weeks.

scholarly journals Clinical validation of engineered CRISPR/Cas12a for rapid SARS-CoV-2 detection

2022 ◽  
Vol 2 (1) ◽  
Author(s):  
Long T. Nguyen ◽  
Santosh R. Rananaware ◽  
Brianna L. M. Pizzano ◽  
Brandon T. Stone ◽  
Piyush K. Jain
Keyword(s):  
High Sensitivity ◽  
High Specificity ◽  
Detection Methods ◽  
Clinical Validation ◽  
Respiratory Pathogens ◽  
Detection Capability ◽  
Guide Rna ◽  
Assay Optimization ◽  
Dual Reporter ◽  
Wide Range

Abstract Background The coronavirus disease (COVID-19) caused by SARS-CoV-2 has swept through the globe at an unprecedented rate. CRISPR-based detection technologies have emerged as a rapid and affordable platform that can shape the future of diagnostics. Methods We developed ENHANCEv2 that is composed of a chimeric guide RNA, a modified LbCas12a enzyme, and a dual reporter construct to improve the previously reported ENHANCE system. We validated both ENHANCE and ENHANCEv2 using 62 nasopharyngeal swabs and compared the results to RT-qPCR. We created a lyophilized version of ENHANCEv2 and characterized its detection capability and stability. Results Here we demonstrate that when coupled with an RT-LAMP step, ENHANCE detects COVID-19 samples down to a few copies with 95% accuracy while maintaining a high specificity towards various isolates of SARS-CoV-2 against 31 highly similar and common respiratory pathogens. ENHANCE works robustly in a wide range of magnesium concentrations (3 mM-13 mM), allowing for further assay optimization. Our clinical validation results for both ENHANCE and ENHANCEv2 show 60/62 (96.7%) sample agreement with RT-qPCR results while only using 5 µL of sample and 20 minutes of CRISPR reaction. We show that the lateral flow assay using paper-based strips displays 100% agreement with the fluorescence-based reporter assay during clinical validation. Finally, we demonstrate that a lyophilized version of ENHANCEv2 shows high sensitivity and specificity for SARS-CoV-2 detection while reducing the CRISPR reaction time to as low as 3 minutes while maintaining its detection capability for several weeks upon storage at room temperature. Conclusions CRISPR-based diagnostic platforms offer many advantages as compared to conventional qPCR-based detection methods. Our work here provides clinical validation of ENHANCE and its improved form ENHANCEv2 for the detection of COVID-19.

Development of recombinase polymerase amplification combined with lateral flow detection assay for rapid and visual detection of Ralstonia solanacearum in tobacco

Plant Disease ◽  
2021 ◽  
Author(s):  
Changfeng Li ◽  
Yuliang Ju ◽  
Xun Wu ◽  
Pengfei Shen ◽  
Le Cao ◽  
...  
Keyword(s):  
Ralstonia Solanacearum ◽  
Visual Detection ◽  
High Sensitivity ◽  
High Specificity ◽  
Lateral Flow ◽  
Recombinase Polymerase Amplification ◽  
Molecular Diagnostic ◽  
Tobacco Stem ◽  
Detection Assay ◽  
Flow Detection

Bacterial wilt caused by Ralstonia solanacearum is a serious soil-borne disease that results in severe losses to tobacco (Nicotiana tabacum) production in China. In this study, a novel RPA-LFD assay for the rapid visual detection of R. solanacearum was established using recombinase polymerase amplification (RPA) and lateral-flow dipstick (LFD). The RPA-LFD assay was performed at 37°C in 30 min without complex equipment. Targeting the sequence of the RipTALI-9 gene, we designed RPA primers (Rs-rpa-F/R) and an LF probe (Rs-LF-probe) that showed high specificity to R. solanacearum. The sensitivity of RPA-LFD assay to R. solanacearum was the same as that in conventional PCR at 1 pg genomic DNA, 102 CFU/g artificially inoculated tobacco stem, and 103 CFU/g artificially inoculated soil. The RPA-LFD assay could also detect R. solanacearum from plant and soil samples collected from naturally infested tobacco fields. These results suggest that the RPA-LFD assay developed in this study is a rapid, accurate molecular diagnostic tool with high sensitivity for the detection of R. solanacearum.

scholarly journals DNA Sequence Signatures for Rapid Detection of Six Target Bacterial Pathogens Using PCR Assays

2015 ◽  
Vol 8 ◽  
pp. MBI.S29736 ◽  
Author(s):  
Kenjiro Nagamine ◽  
Guo-Chiuan Hung ◽  
Bingjie Li ◽  
Shyh-Ching Lo
Keyword(s):  
Safety Concern ◽  
Rapid Development ◽  
High Sensitivity ◽  
High Specificity ◽  
Clostridium Tetani ◽  
Specificity And Sensitivity ◽  
Wide Range ◽  
Pcr Assays ◽  
Primer Sets ◽  
Species Specific

Using Streptococcus pyogenes as a model, we previously established a stepwise computational workflow to effectively identify species-specific DNA signatures that could be used as PCR primer sets to detect target bacteria with high specificity and sensitivity. In this study, we extended the workflow for the rapid development of PCR assays targeting Enterococcus faecalis, Enterococcus faecium, Clostridium perfringens, Clostridium difficile, Clostridium tetani, and Staphylococcus aureus, which are of safety concern for human tissue intended for transplantation. Twenty-one primer sets that had sensitivity of detecting 5–50 fg DNA from target bacteria with high specificity were selected. These selected primer sets can be used in a PCR array for detecting target bacteria with high sensitivity and specificity. The workflow could be widely applicable for the rapid development of PCR-based assays for a wide range of target bacteria, including those of biothreat agents.

scholarly journals A new lateral flow assay to detect sIL-2R during T-cell mediated rejection after kidney transplantation

The Analyst ◽  
2021 ◽  
Author(s):  
Lisa K. Seiler ◽  
Rebecca Jonczyk ◽  
Patrick Lindner ◽  
Ncog Linh Phung ◽  
Christine S. Falk ◽  
...  
Keyword(s):  
Kidney Transplantation ◽  
T Cell ◽  
Point Of Care ◽  
High Specificity ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Point Of Care Test ◽  
Specificity And Sensitivity ◽  
Kidney Rejection ◽  
Acute Kidney Rejection

In this work a novel point of care test to detect sIL-2R during acute kidney rejection with high specificity and sensitivity was developed.

scholarly journals CASLFA: CRISPR/Cas9-mediated lateral flow nucleic acid assay

2019 ◽  
Author(s):  
Xusheng Wang ◽  
Erhu Xiong ◽  
Tian Tian ◽  
Meng Cheng ◽  
Wei Lin ◽  
...  
Keyword(s):  
Genetically Modified Organisms ◽  
African Swine Fever Virus ◽  
Point Of Care ◽  
African Swine Fever ◽  
Analytical Techniques ◽  
High Specificity ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Nucleic Acid Assay ◽  
Ancillary Equipment

AbstractThe lateral flow assay is one of the oldest and most convenient analytical techniques for analyzing the immune response, but its applicability to precise genetic analyses is limited by the tedious and inefficient hybridization steps. Here, we have introduced a new version of the lateral flow assay, termed Cas9-mediated lateral flow nucleic acids assay (CASLFA), to address such issues. In this study, CASLFA is utilized to identify Listeria monocytogenes, genetically modified organisms (GMOs), and African swine fever virus (ASFV) at a sensitivity of hundreds of copies of genome samples with high specificity within 1 h. CASLFA satisfies some of the characteristics of a next-generation molecular diagnostics tool due to its rapidity and accuracy, allowing for point-of-care use without the need for technical expertise and complex ancillary equipment. This method has great potential for analyzing genes in resource-poor or nonlaboratory environments.

An up-converting phosphor technology-based lateral flow assay for point-of-collection detection of morphine and methamphetamine in saliva

The Analyst ◽  
2018 ◽  
Vol 143 (19) ◽  
pp. 4646-4654 ◽  
Author(s):  
Qiushi Hu ◽  
Qiaozhen Wei ◽  
Pingping Zhang ◽  
Shuang Li ◽  
Lei Xue ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Quantitative Detection

Rapid and quantitative detection of morphine and methamphetamine in saliva with high sensitivity and accuracy by an UPT-LFA.

scholarly journals An Enhanced Lateral Flow Assay Based on Aptamer–Magnetic Separation and Multifold AuNPs for Ultrasensitive Detection of Salmonella Typhimurium in Milk

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1605
Author(s):  
Pingping Gao ◽  
Lihan Wang ◽  
Yang He ◽  
Yitian Wang ◽  
Xinyan Yang ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Au Nanoparticles ◽  
Limit Of Detection ◽  
High Specificity ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Nucleic Acid Amplification ◽  
Visual Signal ◽  
Magnetic Capture ◽  
Magnetic Enrichment

In this paper, a novel and ultrasensitive lateral flow assay (LFA) based on aptamer–magnetic separation, and multifold Au nanoparticles (AuNPs) was developed for visual detecting Salmonella enterica ser. Typhimurium (S. Typhimurium). The method realized magnetic enrichment and signal transduction via magnetic separation and achieved signal amplification through hybridizing AuNPs–capture probes and AuNPs–amplification probes to form multifold AuNPs. Two different thiolated single-strand DNA (ssDNA) on the AuNPs–capture probe played different roles. One was combined with the AuNPs–amplification probe on the conjugate pad to achieve enhanced signals. The other was connected to transduction ssDNA1 released by aptamer–magnetic capture of S. Typhimurium, and captured by the T-line, forming a positive signal. This method had an excellent linear relationship ranging from 8.6 × 102 CFU/mL to 8.6 × 107 CFU/mL with the limit of detection (LOD) as low as 8.6 × 100 CFU/mL in pure culture. In actual samples, the visual LOD was 4.1 × 102 CFU/mL, which did not carry out nucleic acid amplification and pre-enrichment, increasing three orders of magnitudes than unenhanced assays with single–dose AuNPs and no magnetic separation. Furthermore, the system showed high specificity, having no reaction with other nontarget strains. This visual signal amplificated system would be a potential platform for ultrasensitive monitoring S. Typhimurium in milk samples.

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