scholarly journals Rapid point‐of‐care diagnostics for the detection of Chlamydia pecorum in koalas ( Phascolarctos cinereus ) using loop‐mediated isothermal amplification without nucleic acid purification

2019 ◽  
Vol 8 (12) ◽  
Author(s):  
Lyndal S. Hulse ◽  
Sean McDonald ◽  
Stephen D. Johnston ◽  
Kenneth W. Beagley
Keyword(s):  
Nucleic Acid ◽  
Point Of Care ◽  
Isothermal Amplification ◽  
Phascolarctos Cinereus ◽  
Loop Mediated Isothermal Amplification ◽  
Chlamydia Pecorum ◽  
Point Of Care Diagnostics ◽  
Nucleic Acid Purification

scholarly journals Loop-Mediated Isothermal Amplification (LAMP) as a Promising Point-of-Care Diagnostic Strategy in Avian Virus Research

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 76
Author(s):  
Faiz Padzil ◽  
Abdul Razak Mariatulqabtiah ◽  
Wen Siang Tan ◽  
Kok Lian Ho ◽  
Nurulfiza Mat Isa ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Nucleic Acid ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Isothermal Amplification ◽  
Screening Methods ◽  
Diagnostic Strategy ◽  
Chain Reaction ◽  
Loop Mediated Isothermal Amplification ◽  
Polymerase Chain

Over the years, development of molecular diagnostics has evolved significantly in the detection of pathogens within humans and their surroundings. Researchers have discovered new species and strains of viruses, while mitigating the viral infections that occur, owing to the accessibility of nucleic acid screening methods such as polymerase chain reaction (PCR), qualitative (real-time) polymerase chain reaction (qPCR) and reverse-transcription qPCR (RT-qPCR). While such molecular detection methods are widely utilized as the benchmark, the invention of isothermal amplifications has also emerged as a reliable tool to improvise on-field diagnosis without dependence on thermocyclers. Among the established isothermal amplification technologies are loop-mediated isothermal amplification (LAMP), recombinant polymerase amplification (RPA), strand displacement activity (SDA), nucleic acid sequence-based amplification (NASBA), helicase-dependent amplification (HDA) and rolling circle amplification (RCA). This review highlights the past research on and future prospects of LAMP, its principles and applications as a promising point-of-care diagnostic method against avian viruses.

scholarly journals Rapid Point-of-Care Isothermal Amplification Assay for the Detection of Malaria without Nucleic Acid Purification

2016 ◽  
Vol 9 ◽  
pp. IDRT.S32162 ◽  
Author(s):  
Sayli S. Modak ◽  
Cheryl A. Barber ◽  
Eran Geva ◽  
William R. Abrams ◽  
Daniel Malamud ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Point Of Care ◽  
Isothermal Amplification ◽  
Blood Smears ◽  
Circulating Antigen ◽  
Amplification Assay ◽  
Amplification Loop ◽  
Nucleic Acid Purification ◽  
Antigen Tests ◽  
Mitochondrial Cytochrome Oxidase

Malaria remains one of the most prevalent infectious diseases and results in significant mortality. Isothermal amplification (loop-mediated isothermal amplification) is used to detect malarial DNA at levels of ~1 parasite/μL blood in ≥30 minutes without the isolation of parasite nucleic acid from subject's blood or saliva. The technique targets the mitochondrial cytochrome oxidase subunit 1 gene and is capable of distinguishing Plasmodium falciparum from Plasmodium vivax. Malarial diagnosis by the gold standard microscopic examination of blood smears is generally carried out only after moderate-to-severe symptoms appear. Rapid diagnostic antigen tests are available but generally require infection levels in the range of 200–2,000 parasites/μL for a positive diagnosis and cannot distinguish if the disease has been cleared due to the persistence of circulating antigen. This study describes a rapid and simple molecular assay to detect malarial genes directly from whole blood or saliva without DNA isolation.

scholarly journals Developments in integrating nucleic acid isothermal amplification and detection systems for point-of-care diagnostics

2020 ◽  
Vol 170 ◽  
pp. 112674
Author(s):  
Elizabeth A. Pumford ◽  
Jiakun Lu ◽  
Iza Spaczai ◽  
Matthew E. Prasetyo ◽  
Elaine M. Zheng ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Point Of Care ◽  
Isothermal Amplification ◽  
Detection Systems ◽  
Point Of Care Diagnostics

DETECTION METHODS FOR RESULTS OF A LOOP-MEDIATED ISOTHERMAL AMPLIFICATION OF DNA

2020 ◽  
Vol 65 (1) ◽  
pp. 67-72
Author(s):  
Olga A. Petrusha ◽  
E. B. Faizuloev
Keyword(s):  
Gold Nanoparticles ◽  
Real Time ◽  
Fluorescence Detection ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Lamp Reaction ◽  
Isothermal Amplification ◽  
Loop Mediated Isothermal Amplification ◽  
Advantages And Disadvantages ◽  
Point Of Care Diagnostics

The loop mediated isothermal amplification (LAMP) was developed by T. Notomi et al. in 2000. It has become one of the most promising methods for point-of-care diagnostics due to its accuracy, sensitivity and ease of execution. In this review, various methods for detecting the results of the LAMP reaction are considered; their advantages and disadvantages are revealed. Methods for detecting LAMP results can be divided into indirect and direct. Indirect methods aimed at detecting changes in the chemical composition of the reaction mixture include real-time turbidimetry, fluorescence detection with calcein, colorimetric detection with hydroxynaphthol blue, and detection using modified gold nanoparticles. Direct methods based on the detection of accumulation amplicons during the reaction include fluorimetric detection with intercalating dyes, resonance fluorescence energy transfer, enzyme immunoassay, immunochromatography, using cationic polymers and gold nanoparticles. The development in the field of point-of-care diagnostics is characterized by a pronounced tendency to miniaturization, the LAMP reaction on microchips and microfluidic devices with an electrochemical or optical detection method. The most promising for the diagnosis of infectious diseases are turbidimetry methods and the use of intercalating dyes. The development of portable domestic instruments for detecting of LAMP results based on real-time fluorescence detection or turbidimetry will contribute to the widespread introduction of the method into clinical laboratory diagnostic practice. A literature research was conducted in the Pubmed ncbi based on keywords.

scholarly journals Essential properties and pitfalls of colorimetric Reverse Transcription Loop-mediated Isothermal Amplification as a point-of-care test for SARS-CoV-2 diagnosis

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Bruna de Oliveira Coelho ◽  
Heloisa Bruna Soligo Sanchuki ◽  
Dalila Luciola Zanette ◽  
Jeanine Marie Nardin ◽  
Hugo Manuel Paz Morales ◽  
...  
Keyword(s):  
Viral Load ◽  
Internal Control ◽  
Reverse Transcription ◽  
Color Change ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
False Negative ◽  
Isothermal Amplification ◽  
Clinical Samples ◽  
Loop Mediated Isothermal Amplification

Abstract Background SARS-CoV-2 Reverse Transcription Loop-mediated Isothermal Amplification (RT-LAMP) colorimetric detection is a sensitive and specific point-of-care molecular biology technique used to detect the virus in only 30 min. In this manuscript we have described a few nuances of the technique still not properly described in the literature: the presence of three colors clusters; the correlation of the viral load with the color change; and the importance of using an internal control to avoid false-negative results. Methods To achieve these findings, we performed colorimetric RT-LAMP assays of 466 SARS-CoV-2 RT-qPCR validated clinical samples, with color quantification measured at 434 nm and 560 nm. Results First we determinate a sensitivity of 93.8% and specificity of 90.4%. In addition to the pink (negative) and yellow (positive) produced colors, we report for the first time the presence of an orange color cluster that may lead to wrong diagnosis. We also demonstrated using RT-qPCR and RT-LAMP that low viral loads are related to Ct values > 30, resulting in orange colors. We also demonstrated that the diagnosis of COVID-19 by colorimetric RT-LAMP is efficient until the fifth symptoms day when the viral load is still relatively high. Conclusion This study reports properties and indications for colorimetric RT-LAMP as point-of-care for SARS-CoV-2 diagnostic, reducing false results, interpretations and optimizing molecular diagnostics tests application.

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