scholarly journals SARS-CoV-2 RNA Detection with Duplex-Specific Nuclease Signal Amplification

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 197
Author(s):  
Meiqing Liu ◽  
Haoran Li ◽  
Yanwei Jia ◽  
Pui-In Mak ◽  
Rui P. Martins

The emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a zoonotic pathogen, has led to the outbreak of coronavirus disease 2019 (COVID-19) pandemic and brought serious threats to public health worldwide. The gold standard method for SARS-CoV-2 detection requires both reverse transcription (RT) of the virus RNA to cDNA and then polymerase chain reaction (PCR) for the cDNA amplification, which involves multiple enzymes, multiple reactions and a complicated assay optimization process. Here, we developed a duplex-specific nuclease (DSN)-based signal amplification method for SARS-CoV-2 detection directly from the virus RNA utilizing two specific DNA probes. These specific DNA probes can hybridize to the target RNA at different locations in the nucleocapsid protein gene (N gene) of SARS-CoV-2 to form a DNA/RNA heteroduplex. DSN cleaves the DNA probe to release fluorescence, while leaving the RNA strand intact to be bound to another available probe molecule for further cleavage and fluorescent signal amplification. The optimized DSN amount, incubation temperature and incubation time were investigated in this work. Proof-of-principle SARS-CoV-2 detection was demonstrated with a detection sensitivity of 500 pM virus RNA. This simple, rapid, and direct RNA detection method is expected to provide a complementary method for the detection of viruses mutated at the PCR primer-binding regions for a more precise detection.

2015 ◽  
Vol 51 (11) ◽  
pp. 2156-2158 ◽  
Author(s):  
Yi Xie ◽  
Xiaoyan Lin ◽  
Yishun Huang ◽  
Rujun Pan ◽  
Zhi Zhu ◽  
...  

Based on the protective properties of polydopamine nanospheres for DNA probes against nuclease digestion, we have developed a DNase I-assisted target recycling signal amplification method for highly sensitive and selective detection of miRNA.


1995 ◽  
Vol 43 (4) ◽  
pp. 347-352 ◽  
Author(s):  
H M Kerstens ◽  
P J Poddighe ◽  
A G Hanselaar

For amplification of in situ hybridization (ISH) signals, we describe a method using catalyzed reporter deposition (CARD). This amplification method is based on the deposition of biotinylated tyramine (BT) at the location of the DNA probe. The BT precipitate can then visualized with fluorochrome- or enzyme-labeled avidin. Both for bright-field ISH (BRISH) and for fluorescence ISH (FISH), the detection limit was highly increased. This method is especially suitable for visualization of very weak ISH signals, such as those obtained by ISH using locus-specific DNA probes. Furthermore, CARD amplification of ISH signals (CARD-ISH) is highly sensitive, rapid, flexible, and easy to implement. Successful application of CARD-ISH with locus-specific DNA probes on histological and cytological samples may improve the determination of structural chromosomal aberrations in archival material.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Hajime Shinoda ◽  
Yuya Taguchi ◽  
Ryoya Nakagawa ◽  
Asami Makino ◽  
Sae Okazaki ◽  
...  

AbstractCRISPR-based nucleic-acid detection is an emerging technology for molecular diagnostics. However, these methods generally require several hours and could cause amplification errors, due to the pre-amplification of target nucleic acids to enhance the detection sensitivity. Here, we developed a platform that allows “CRISPR-based amplification-free digital RNA detection (SATORI)”, by combining CRISPR-Cas13-based RNA detection and microchamber-array technologies. SATORI detected single-stranded RNA targets with maximal sensitivity of ~10 fM in <5 min, with high specificity. Furthermore, the simultaneous use of multiple different guide RNAs enhanced the sensitivity, thereby enabling the detection of the SARS-CoV-2 N-gene RNA at ~5 fM levels. Therefore, we hope SATORI will serve as a powerful class of accurate and rapid diagnostics.


2020 ◽  
Vol 32 (3) ◽  
pp. 394-400
Author(s):  
Giovani Trevisan ◽  
Leticia C. M. Linhares ◽  
Bret Crim ◽  
Poonam Dubey ◽  
Kent J. Schwartz ◽  
...  

We developed a model to predict the cyclic pattern of porcine reproductive and respiratory syndrome virus (PRRSV) RNA detection by reverse-transcription real-time PCR (RT-rtPCR) from 4 major swine-centric veterinary diagnostic laboratories (VDLs) in the United States and to use historical data to forecast the upcoming year’s weekly percentage of positive submissions and issue outbreak signals when the pattern of detection was not as expected. Standardized submission data and test results were used. Historical data (2015–2017) composed of the weekly percentage of PCR-positive submissions were used to fit a cyclic robust regression model. The findings were used to forecast the expected weekly percentage of PCR-positive submissions, with a 95% confidence interval (CI), for 2018. During 2018, the proportion of PRRSV-positive submissions crossed 95% CI boundaries at week 2, 14–25, and 48. The relatively higher detection on week 2 and 48 were mostly from submissions containing samples from wean-to-market pigs, and for week 14–25 originated mostly from samples from adult/sow farms. There was a recurring yearly pattern of detection, wherein an increased proportion of PRRSV RNA detection in submissions originating from wean-to-finish farms was followed by increased detection in samples from adult/sow farms. Results from the model described herein confirm the seasonal cyclic pattern of PRRSV detection using test results consolidated from 4 VDLs. Wave crests occurred consistently during winter, and wave troughs occurred consistently during the summer months. Our model was able to correctly identify statistically significant outbreak signals in PRRSV RNA detection at 3 instances during 2018.


2004 ◽  
Vol 50 (6) ◽  
pp. 415-421 ◽  
Author(s):  
J Guan ◽  
J L Spencer ◽  
M Sampath ◽  
J Devenish

The fate of the genetically modified (GM) Pseudomonas chlororaphis strain 3732 RN-L11 and its transgene (lacZ insert) during composting of chicken manure was studied using plate count and nested polymerase chain reaction (PCR) methods. The detection sensitivity of the nested PCR method was 165 copies of the modified gene per gram of moist compost or soil. Compost microcosms consisted of a 100-g mixture of chicken manure and peat, whereas soil microcosms were 100-g samples of sandy clay loam. Each microcosm was inoculated with 4 × 1010CFU of P. chlororaphis RN-L11. In controlled temperature studies, neither P. chlororaphis RN-L11 nor its transgene could be detected in compost microcosms after incubation temperature was elevated to 45 °C or above for one or more days. In contrast, in the compost microcosms incubated at 23 °C, the target organism was not detected by the plate count method after 6 days, but its transgene was detectable for at least 45 days. In compost bins, the target organism was not recovered from compost microcosms or soil microcosms at different levels in the bins for 29 days. However, the transgene was detected in 8 of the 9 soil microcosms and in only 1 of the 9 compost microcosms. The compost microcosm in which transgene was detected was at the lower level of the bin where temperatures remained below 45 °C. The findings indicated that composting of organic wastes could be used to reduce or degrade heat sensitive GM microorganisms and their transgenes.Key words: composting, genetically modified Pseudomonas strain, transgene, polymerase chain reaction.


2008 ◽  
Vol 120 (49) ◽  
pp. 9660-9663 ◽  
Author(s):  
Jung Rok Lee ◽  
Juhee Lee ◽  
Sang Kyung Kim ◽  
Kwang Pyo Kim ◽  
Hyung Soon Park ◽  
...  

2019 ◽  
Author(s):  
Renjie Liao ◽  
Diego Mastroeni ◽  
Paul D. Coleman ◽  
Jia Guo

AbstractThe ability to perform highly sensitive and multiplexed in situ protein analysis is crucial to advance our understanding of normal physiology and disease pathogenesis. To achieve this goal, here we develop an approach using cleavable biotin conjugated antibodies and cleavable fluorescent streptavidin (CFS). In this approach, protein targets are first recognized by the cleavable biotin labeled antibodies. Subsequently, CFS is applied to stain the protein targets. Though layer-by-layer signal amplification using cleavable biotin conjugated orthogonal antibodies and CSF, the protein detection sensitivity can be enhanced by at least 10 fold, compared with the existing methods. After imaging, the fluorophores and the biotins unbound to streptavidin are removed by chemical cleavage. The leftover streptavidin is blocked by biotin. Upon reiterative analysis cycles, a large number of different proteins with a wide range of expression levels can be unambiguously detected in individual cell in situ.


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