Fluorogenic bidirectional displacement probe-based real-time isothermal DNA amplification and specific visual detection of products

2016 ◽  
Vol 52 (76) ◽  
pp. 11438-11441 ◽  
Author(s):  
Xiong Ding ◽  
Guoping Wang ◽  
Jingjing Sun ◽  
Tao Zhang ◽  
Ying Mu
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
Visual Detection ◽  
Dna Amplification ◽  
High Sensitivity

We report an easy-to-design probe as both the primer and the indicator to mediate isothermal DNA amplification with high sensitivity and specificity.

scholarly journals Evaluation of the performance of the COVID-19 rapid antigen tests in a tertiary level hospital in Bangladesh.

2021 ◽  
Author(s):  
Mohammad Jahidur Rahman Khan ◽  
Md. Shahadat Hossain ◽  
Samshad Jahan Shumu ◽  
Md. Selim Reza ◽  
Farzana Mim ◽  
...  
Keyword(s):  
Viral Load ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Detection Rate ◽  
High Sensitivity ◽  
Rt Pcr ◽  
College Hospital ◽  
Medical College ◽  
Qrt Pcr ◽  
Antigen Tests

Abstract Background: While the COVID-19 pandemic is a worldwide crisis, tests with high sensitivity and specificity are essential for identifying and managing COVID-19 patients. Globally, several rapid antigen tests RATs for COVID-19 have been developed, but their clinical efficacy has not been well established. This study aimed to evaluate the performance of several rapid antigen tests (RATs) to diagnose SARS-CoV-2 infection.Methods: This prospective observational study was conducted at Shaheed Suhrawardy Medical College hospital from February 2021 to April 2021 in Dhaka, Bangladesh. This study included the patients admitted in this hospital at the COVID-19 isolation unit or referred from the triage facility of the outdoor department of this hospital suspected as COVID-19 case. Two nasopharyngeal samples were collected simultaneously. one sample was used on the spot for the RAT. The other was sent to the adjacent Shaheed Suhrawardy Medical College COVID-19 RT-PCR laboratory for real-time reverse transcription-polymerase chain reaction (qRT-PCR). The performance of the RAT was evaluated using the results of qRT-PCR as a reference.Results: A total of 223 patients were included in this study, and the real-time RT-PCR detected SARS-CoV-2 in 84 (37.7%) patients. Of these 84 patients, 9 (10.7%) were asymptomatic. The overall sensitivity and specificity of RATs were 78.6% and 99.3%, respectively. The sensitivity was 81.3% in symptomatic cases and 55.6% in asymptomatic cases. False-negatives were observed in 18 patients, 3 of whom were asymptomatic and had a low viral load (cycle threshold (Ct) > 30). The detection rate of RATs was 100% when the Ct value was up to 24. The detection rate was 42.3% when the Ct was >29. The detection rate of RATs was 92.3% when the onset of symptoms was within three days. The detection rate was 33.3% when the onset of symptoms was >7 days.Conclusions: RATs for COVID-19 used in this study delivered an acceptable performance in patients with high viral load and within the first week of the onset of symptoms. They can be used as a supplementary method to RT-PCR for the diagnosis of COVID-19 patients.

scholarly journals Comparison of diagnostics of bacterial vaginosis according to clinical signs with results of laboratory investigations

2016 ◽  
Vol 65 (4) ◽  
pp. 76-82
Author(s):  
Elena V. Shipitsina ◽  
Tatyana A. Khusnutdinova ◽  
Olga S. Ryzhkova ◽  
Anna A. Krysanova ◽  
Olga V. Budilovskaya ◽  
...  
Keyword(s):  
Bacterial Vaginosis ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Vaginal Discharge ◽  
Clinical Signs ◽  
High Sensitivity ◽  
Clinical Diagnostics ◽  
Laboratory Diagnostics ◽  
Molecular Method

Introduction. Bacterial vaginosis (BV) is associated with a number of reproductive health disorders, therefore timely and accurate diagnosis of this condition is exceedingly important. Objective.Comparison of effectiveness of clinical and laboratory diagnostics of BV in women with vaginal discharge. Material and methods. In total, 318 patients addressing gynecological clinics with complaints about vaginal discharge participated in the study. Clinical diagnostics of BV was performed in the clinics participating in patient enrollment in accordance with their clinical practice. For laboratory diagnostics, microscopy of Gram stained smears according to the Nugent method and quantitative real-time PCR were used. Sensitivity and specificity of clinical diagnostics of BV and the molecular method were evaluated using the Nugent method as reference standard. Results. With the Nugent method, BV was diagnosed in 27% of women, with real-time PCR — in 37% of women. Using clinical signs of BV, the condition was diagnosed in 91% women. Sensitivity and specificity of the real-time PCR were 97% and 87%, respectively. Sensitivity of clinical diagnostics was 100%, but specificity was only 17%. Conclusions. Diagnostics of BV based only on the presence of vaginal discharge leads to false positive results and requires laboratory confirmation. The molecular method has a high sensitivity and satisfactory specificity for BV diagnosis and can be used as an alternative to the Nugent method.

scholarly journals Real-time RT-PCR diagnostics of virus causing COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 52-63 ◽  
Author(s):  
E. V. Goncharova ◽  
A. E. Donnikov ◽  
V. V. Kadochnikova ◽  
S. A. Morozova ◽  
M. N. Boldyreva ◽  
...  
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
High Sensitivity ◽  
Medical Product ◽  
World Health ◽  
Differential Diagnostics ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Study Results ◽  
Pcr Diagnostics

Aim: the study was aimed to develop a reagent kit for the real-time RT-PCR diagnostics of virus causing COVID-19.Materials and Methods. Three target sites were chosen in the genome SARS-CoV-2. The testing included 220 samples, 48 artificially created positive samples (made from patients’ biomaterial) and 172 clinical samples (scrapes from nasal and pharyngeal cavities, bronchoalveolar lavage, expectoration, endotracheal/nasopharyngeal aspirate, feces, post-mortem material), obtained from two medical centers. Preliminary, the obtained biomaterial was analyzed with a reagent kit of comparison. The evaluation was performed with a confidential interval CI 95%. The calculation of CI for the sensitivity and specificity was made based on the distribution of χ2.Results. The authors developed a technology of novel coronavirus infection (COVID-19) real-time RT-PCR diagnostics for the application in practical healthcare and proposed the variants of testing at all the stages (preanalytical, analytical, and post-analytical, including automated results processing). The proposed reagent kit meets the requirements of the World Health Organization and the Ministry of Healthcare of the Russian Federation. The study results demonstrated high sensitivity and specificity. The sensitivity was 100% (95% CI) 95.6–100%; the specificity was 100% (95% CI) 96.7–100%.Conclusion. The proposed reagent kit was registered in the RF as a medical product; the registration certificate No. RZN 2020/9948 dated 01.04.2020. The application of the reagent kit in network laboratories will provide patients with access to testing for the virus causing COVID-19 and contribute to quick differential diagnostics, improvement of pandemic control, and accurate statistics on the spread of the virus. 

Real-time monitoring AP site incision caused by APE1 using a modified hybridization probe

2016 ◽  
Vol 8 (4) ◽  
pp. 862-868 ◽  
Author(s):  
Bin Liu ◽  
Lan Peng
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
High Sensitivity ◽  
Fluorescence Method ◽  
Real Time Monitoring ◽  
Hybridization Probe ◽  
Linear Probe ◽  
Ap Site

A real time fluorescence method with wide promising applications was developed for APE1 assay with high sensitivity and specificity by using a double-stranded linear probe as a substrate and reporter molecule.

Coupling a novel spiro-rhodamine B lactam derivative to Fe3O4 nanoparticles for visual detection of free copper ions with high sensitivity and specificity

RSC Advances ◽  
2015 ◽  
Vol 5 (57) ◽  
pp. 45847-45852 ◽  
Author(s):  
Hongyan Zhang ◽  
Xiaoxue Zeng ◽  
Danlong Chen ◽  
Ying Guo ◽  
Wenjing Jiang ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Rhodamine B ◽  
Fe3o4 Nanoparticles ◽  
Visual Detection ◽  
Copper Ions ◽  
Tap Water ◽  
High Sensitivity ◽  
Visual Sensor ◽  
Naked Eye

A novel spiro-rhodamine B lactam derivative, which can be coupled to Fe3O4 NPs and act as a Cu2+-selective visual sensor is reported. It can be used to directly detect as little as 50 nM of Cu2+ in river or tap water by only naked-eye observation.

scholarly journals Development of a two-step nucleic acid amplification test for accurate diagnosis of the Mycobacterium tuberculosis complex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chien-Ru Lin ◽  
Hsin-Yao Wang ◽  
Ting-Wei Lin ◽  
Jang-Jih Lu ◽  
Jason Chia-Hsun Hsieh ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nucleic Acid ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Disease Transmission ◽  
High Sensitivity ◽  
Nucleic Acid Amplification ◽  
Amplification Efficiency ◽  
Pcr Assay

AbstractThe Mycobacterium tuberculosis complex (MTBC) remains one of the top 10 leading causes of death globally. The early diagnosis of MTBC can reduce mortality and mitigate disease transmission. However, current nucleic acid amplification diagnostic test methods are generally time-consuming and show suboptimal diagnostic performance, especially in extrapulmonary MTBC samples or acid-fast stain (AFS)-negative cases. Thus, development of an accurate assay for the diagnosis of MTBC is necessary, particularly under the above mentioned conditions. In this study, a single-tube nested real-time PCR assay (N-RTP) was developed and compared with a newly in-house-developed high-sensitivity real-time PCR assay (HS-RTP) using 134 clinical specimens (including 73 pulmonary and 61 extrapulmonary specimens). The amplification efficiency of HS-RTP and N-RTP was 99.8% and 100.7%, respectively. The sensitivity and specificity of HS-RTP and N-RTP for the diagnosis of MTBC in these specimens were 97.5% (77/79) versus 94.9% (75/79) and 80.0% (44/55) versus 89.1% (49/55), respectively. The sensitivity and specificity of HS-RTP and N-RTP for the diagnosis of MTBC in pulmonary specimens were 96.3% (52/54) versus 96.3% (52/54) and 73.7.0% (14/19) versus 89.5% (17/19), respectively; in extrapulmonary specimens, the sensitivity and specificity of HS-RTP and N-RTP were 100% (25/25) versus 92% (23/25) and 83.3% (30/36) versus 88.9% (32/36), respectively. Among the AFS-negative cases, the sensitivity and specificity of HS-RTP and N-RTP were 97.0% (32/33) versus 90.9% (30/33) and 88.0% (44/50) versus 92.0% (46/50), respectively. Overall, the sensitivity of HS-RTP was higher than that of N-RTP, and the performance was not compromised in extrapulmonary specimens and under AFS-negative conditions. In contrast, the specificity of the N-RTP assay was higher than that of the HS-RTP assay in all types of specimens. In conclusion, the HS-RTP assay would be useful for screening patients suspected of exhibiting an MTBC infection due to its higher sensitivity, while the N-RTP assay could be used for confirmation because of its higher specificity. Our results provide a two-step method (screen to confirm) that simultaneously achieves high sensitivity and specificity in the diagnosis of MTBC.

scholarly journals Correction: Fluorogenic bidirectional displacement probe-based real-time isothermal DNA amplification and specific visual detection of products

2016 ◽  
Vol 52 (83) ◽  
pp. 12384-12384
Author(s):  
Xiong Ding ◽  
Guoping Wang ◽  
Jingjing Sun ◽  
Tao Zhang ◽  
Ying Mu
Keyword(s):  
Real Time ◽  
Visual Detection ◽  
Dna Amplification

Correction for ‘Fluorogenic bidirectional displacement probe-based real-time isothermal DNA amplification and specific visual detection of products’ by Xiong Ding et al., Chem. Commun., 2016, 52, 11438–11441.

scholarly journals Rapid diagnostics of genital herpes by loop-mediated isothermal amplification method with fluorescent detection

2019 ◽  
pp. 40-46
Author(s):  
D. I. Smirnova ◽  
O. A. Petrusha ◽  
A. V. Gracheva ◽  
E. A. Volynskaya ◽  
V. V. Zverev ◽  
...  
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
High Efficiency ◽  
High Sensitivity ◽  
Isothermal Amplification ◽  
Fluorescent Detection ◽  
Lamp Method ◽  
Analytical Sensitivity ◽  
Loop Mediated Isothermal Amplification

Introduction. Due to the high clinical significance of herpesvirus diseases, the searching of fast and effective methods for their diagnosis remains relevant.The aim of the study was to evaluate the diagnostic efficiency of the loop-mediated isothermal amplification of DNA with real-time fluorescent detection (RT-LAMP) with SYTO-82 dye on a model of herpes simplex virus (HSV) infection.Materials and methods. A total of 44 urogenital swabs containing type 1 and type 2 HSV DNA and 43 swabs without HSV DNA, including 33 samples containing the DNA of cytomegalovirus, Epstein-Barr virus and herpesvirus type 6, were studied. For RT-LAMP, Bst 2.0 WarmStart DNA polymerase, SYTO-82 dye, LAMP primers were used.Results. The high efficiency of HSV DNA detection in the RT-LAMP reaction with SYTO-82 dye was shown. RT-LAMP in optimal conditions allowed to reduce reaction time for 2-3 times compared to real-time PCR (to 35 minutes). Analytical sensitivity of HSV type 1 and 2 detection in RT-LAMP was 103 copies of DNA/ml. The diagnostic sensitivity and specificity of the RT-LAMP diagnosis of HSV infection were 96% and 100%, respectively.Discussion. RT-LAMP method has a high sensitivity and specificity comparable to RTPCR, while the risk of false positive results obtaining is minimal.Conclusion. Thus, the reaction of RT-LAMP with SYTO-82 dye allows quickly, with high sensitivity and specificity to detect HSV DNA in clinical material and can be considered as a promising point-of-care testing method.

scholarly journals Comparison of an in house and a commercial real-time polymerase chain reaction targeting Toxoplasma gondii RE gene using various samples collected from patients in Turkey

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mert Döşkaya ◽  
Hüsnü Pullukçu ◽  
Muhammet Karakavuk ◽  
Esra Atalay Şahar ◽  
Mehmet Sezai Taşbakan ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Clinical Manifestations ◽  
High Sensitivity ◽  
Buffy Coat ◽  
Rt Pcr ◽  
Chain Reactions ◽  
Polymerase Chain ◽  
Pcr Test

Abstract Background Toxoplasma gondii is an opportunistic protozoan parasite that can infect all warm-blooded animals including humans and cause serious clinical manifestations. Toxoplasmosis can be diagnosed using histological, serological, and molecular methods. In this study, we aimed to detect T. gondii RE gene in various human samples by in house and commercial real time polymerase chain reactions. Methods A total of 38 suspected cases of toxoplasmosis [peripheral blood (n:12), amnion fluid (n:11), tissue (n:9), cerebrospinal fluid (n:5), and intraocular fluid (n:1)] were included to the study. An in house and a commercial RT-PCR were applied to investigate the T. gondii RE gene in these samples. Results The compatibility rate of the two tests was 94.7% (37/38). When the commercial RT-PCR kit was taken as reference, the sensitivity and specificity of in house RT-PCR test was 87.5 and 100%. When the in house RT-PCR test was taken as reference, the commercial RT-PCR kit has 100% sensitivity and 96.8% specificity. Incompatibility was detected in only in a buffy coat sample with high protein content. Conclusions Both the commercial and in house RT-PCR tests can be used to investigate T. gondii RE gene in various clinical specimens with their high sensitivity and specificity. In house RT-PCR assay can be favorable due to cost savings compared to using the commercial test.

scholarly journals Detection of Biological Threat Agents by Real-Time PCR: Comparison of Assay Performance on the R.A.P.I.D., the LightCycler, and the Smart Cycler Platforms

2006 ◽  
Vol 52 (1) ◽  
pp. 141-145 ◽  
Author(s):  
Deanna R Christensen ◽  
Laurie J Hartman ◽  
Bonnie M Loveless ◽  
Melissa S Frye ◽  
Michelle A Shipley ◽  
...  
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Limit Of Detection ◽  
Dna Amplification ◽  
Pcr Primers ◽  
Cross Reactivity ◽  
Dna Templates ◽  
Assay Performance ◽  
Fluorogenic Probes

Abstract Background: Rapid detection of biological threat agents is critical for timely therapeutic administration. Fluorogenic PCR provides a rapid, sensitive, and specific tool for molecular identification of these agents. We compared the performance of assays for 7 biological threat agents on the Idaho Technology, Inc. R.A.P.I.D.®, the Roche LightCycler®, and the Cepheid Smart Cycler®. Methods: Real-time PCR primers and dual-labeled fluorogenic probes were designed to detect Bacillus anthracis, Brucella species, Clostridium botulinum, Coxiella burnetii, Francisella tularensis, Staphylococcus aureus, and Yersinia pestis. DNA amplification assays were optimized by use of Idaho Technology buffers and deoxynucleotide triphosphates supplemented with Invitrogen Platinum® Taq DNA polymerase, and were subsequently tested for sensitivity and specificity on the R.A.P.I.D., the LightCycler, and the Smart Cycler. Results: Limit of detection experiments indicated that assay performance was comparable among the platforms tested. Exclusivity and inclusivity testing with a general bacterial nucleic acid cross-reactivity panel containing 60 DNAs and agent-specific panels containing nearest neighbors for the organisms of interest indicated that all assays were specific for their intended targets. Conclusion: With minor supplementation, such as the addition of Smart Cycler Additive Reagent to the Idaho Technology buffers, assays for DNA templates from biological threat agents demonstrated similar performance, sensitivity, and specificity on all 3 platforms.

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