Strand Displacement Amplification Assisted CRISPR-Cas12a Strategy for Colorimetric Analysis of Viral Nucleic Acid

Author(s):  
Shaohua Gong ◽  
Shiqi Zhang ◽  
Xi Wang ◽  
Jingjing Li ◽  
Wei Pan ◽  
...  
2019 ◽  
Vol 7 (16) ◽  
pp. 2608-2612 ◽  
Author(s):  
Xiaoyi Ma ◽  
Peng Miao

DNA tetrahedron-modified silver nanoparticles were constructed for the colorimetric analysis of HIV-related DNA with strand displacement polymerization and nicking endonuclease-aided cycles.


2004 ◽  
Vol 53 (12) ◽  
pp. 1215-1219 ◽  
Author(s):  
T D McHugh ◽  
C F Pope ◽  
C L Ling ◽  
S Patel ◽  
O J Billington ◽  
...  

Nucleic acid amplification techniques (NAATs) have been demonstrated to make significant improvements in the diagnosis of tuberculosis (TB), particularly in the time to diagnosis and the diagnosis of smear-negative TB. The BD ProbeTec strand displacement amplification (SDA) system for the diagnosis of pulmonary and non-pulmonary tuberculosis was evaluated. A total of 689 samples were analysed from patients with clinically suspected TB. Compared with culture, the sensitivity and specificity for pulmonary samples were 98 and 89 %, and against final clinical diagnosis 93 and 92 %, respectively. This assay has undergone limited evaluation for non-respiratory samples and so 331 non-respiratory samples were tested, identifying those specimens that were likely to yield a useful result. These were CSF (n = 104), fine needle aspirates (n = 64) and pus (n = 41). Pleural fluid (n = 47) was identified as a poor specimen. A concern in using the SDA assay was that low-positive samples were difficult to interpret; 7.8 % of specimens fell into this category. Indeed, 64 % of the discrepant results, when compared to final clinical diagnosis, could be assigned as low-positive samples. Specimen type did not predict likelihood of a sample being in the low-positive zone. Although the manufacturers do not describe the concept of a low-positive zone, we have found that it aids clinical diagnosis.


The Analyst ◽  
2015 ◽  
Vol 140 (22) ◽  
pp. 7540-7549 ◽  
Author(s):  
Bhushan J. Toley ◽  
Isabela Covelli ◽  
Yevgeniy Belousov ◽  
Sujatha Ramachandran ◽  
Enos Kline ◽  
...  

A new rapid and sensitive method of isothermal DNA amplification and a simple kinetic model of this reaction network.


2007 ◽  
Vol 18 (8) ◽  
pp. 543-545
Author(s):  
Patricia Rizzo-Price ◽  
Paul D Stamper ◽  
Billie Jo Wood ◽  
Steven J Reynolds ◽  
Thomas C Quinn ◽  
...  

Microbicides may interfere with detection of Chlamydia trachomatis ( Ct) and Neisseria gonorrhoeae ( Ng) in urine samples from women who use microbicides. The inhibitory effects of BufferGel, PRO2000 and PRO2000 placebo, in urine samples, were determined by nucleic acid amplification tests (NAATs). Uninfected urine was inoculated with different concentrations (105–101 organisms/mL); microbicides were added to achieve final concentrations from 5% to 0.1%. Specimens were tested using strand displacement amplification (SDA) for Ct and Ng. Samples with BufferGel demonstrated no inhibition. Samples with PRO2000 showed inhibition at the 5% concentration when tested for Ct, whereas for Ng, PRO2000 showed inhibition at 5%, 2% and some 1% concentrations. The placebo showed no inhibition when detecting Ct, and variable inhibition at the 5% and 2% concentrations for Ng. The potential inhibitory effects of microbicides on the NAATs selected for detection of Ct and Ng should be considered in clinical trials involving topical microbicides.


2014 ◽  
Vol 155 (26) ◽  
pp. 1019-1023
Author(s):  
Judit Gervain

The successful therapy of hepatitis C viral infection requires that the illness is diagnosed before the development of structural changes of the liver. Testing is stepwise consisting of screening, diagnosis, and anti-viral therapy follow-up. For these steps there are different biochemical, serological, histological and molecular biological methods available. For screening, alanine aminotransferase and anti-HCV tests are used. The diagnosis of infection is confirmed using real-time polymerase chain reaction of the viral nucleic acid. Before initiation of the therapy liver biopsy is recommended to determine the level of structural changes in the liver. Alternatively, transient elastography or blood biomarkers may be also used for this purpose. Differential diagnosis should exclude the co-existence of other viral infections and chronic hepatitis due to other origin, with special attention to the presence of autoantibodies. The outcome of the antiviral therapy and the length of treatment are mainly determined by the viral genotype. In Hungary, most patients are infected with genotype 1, subtype b. The polymorphism type that occurs in the single nucleotide located next to the interleukin 28B region in chromosome 19 and the viral polymorphism type Q80K for infection with HCV 1a serve as predictive therapeutic markers. The follow-up of therapy is based on the quantitative determination of viral nucleic acid according to national and international protocols and should use the same method and laboratory throughout the treatment of an individual patient. Orv. Hetil., 2014, 155(26), 1019–1023.


2011 ◽  
Vol 8 (3) ◽  
pp. 235-244 ◽  
Author(s):  
Mahmoud Elsabahy ◽  
Adil Nazarali ◽  
Marianna Foldvari

ACS Nano ◽  
2021 ◽  
Vol 15 (2) ◽  
pp. 3272-3283
Author(s):  
Javier Cabello-Garcia ◽  
Wooli Bae ◽  
Guy-Bart V. Stan ◽  
Thomas E. Ouldridge

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 602
Author(s):  
Sandra Leonardo ◽  
Anna Toldrà ◽  
Mònica Campàs

The easy and rapid spread of bacterial contamination and the risk it poses to human health makes evident the need for analytical methods alternative to conventional time-consuming laboratory-based techniques for bacterial detection. To tackle this demand, biosensors based on isothermal DNA amplification methods have emerged, which avoid the need for thermal cycling, thus facilitating their integration into small and low-cost devices for in situ monitoring. This review focuses on the breakthroughs made on biosensors based on isothermal amplification methods for the detection of bacteria in the field of food safety and environmental monitoring. Optical and electrochemical biosensors based on loop mediated isothermal amplification (LAMP), rolling circle amplification (RCA), recombinase polymerase amplification (RPA), helicase dependent amplification (HDA), strand displacement amplification (SDA), and isothermal strand displacement polymerisation (ISDPR) are described, and an overview of their current advantages and limitations is provided. Although further efforts are required to harness the potential of these emerging analytical techniques, the coalescence of the different isothermal amplification techniques with the wide variety of biosensing detection strategies provides multiple possibilities for the efficient detection of bacteria far beyond the laboratory bench.


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