iso-μmGene: an isothermal amplification-based portable microfluidic system for simple, reliable and flexibly multiplexed genetic identification and quantification

The Analyst ◽  
2020 ◽  
Vol 145 (13) ◽  
pp. 4627-4636
Author(s):  
Runtao Zhong ◽  
Shilin Liu ◽  
Guohao Zhang ◽  
Mengyu Wang ◽  
Yeqing Sun
Keyword(s):  
Genetic Testing ◽  
Point Of Care ◽  
Microfluidic System ◽  
Isothermal Amplification ◽  
Genetic Identification ◽  
Lamp System ◽  
Identification And Quantification

We present a portable microfluidic LAMP system (iso-μmGene) with features of multi-well chips for convenient filling and reliable sealing, flexible detection throughput, and stand-alone and well-performing point of care device for genetic testing.

Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

2017 ◽  
Author(s):  
Bo Tian ◽  
Peter Svedlindh ◽  
Mattias Strömberg ◽  
Erik Wetterskog
Keyword(s):  
Magnetic Nanoparticles ◽  
Ferromagnetic Resonance ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Resonance Field ◽  
Isothermal Amplification ◽  
Detection Sensitivity ◽  
Serum Samples ◽  
Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, <i>i.e.</i>, rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg<sub>2</sub>P<sub>2</sub>O<sub>7</sub> (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.<br>

scholarly journals Design and experimental investigation of a novel spiral microfluidic chip to separate wide size range of micro-particles aimed at cell separation

2021 ◽  
pp. 095441192110297
Author(s):  
Seyed Ali Tabatabaei ◽  
Mohammad Zabetian Targhi
Keyword(s):  
Point Of Care ◽  
Diagnostic System ◽  
Average Diameter ◽  
Microfluidic System ◽  
Microfluidic Chips ◽  
Medical Sciences ◽  
Blood Samples ◽  
Micro Particles ◽  
Monodisperse Polystyrene ◽  
Device Size

Isolation of microparticles and biological cells on microfluidic chips has received considerable attention due to their applications in numerous areas such as medical and engineering fields. Microparticles separation is of great importance in bioassays due to the need for smaller sample and device size and lower manufacturing costs. In this study, we first explain the concepts of separation and microfluidic science along with their applications in the medical sciences, and then, a conceptual design of a novel inertial microfluidic system is proposed and analyzed. The PDMS spiral microfluidic device was fabricated, and its effects on the separation of particles with sizes similar to biological particles were experimentally analyzed. This separation technique can be used to separate cancer cells from the normal ones in the blood samples. These components required for testing were selected, assembled, and finally, a very affordable microfluidic kit was provided. Different experiments were designed, and the results were analyzed using appropriate software and methods. Separator system tests with polydisperse hollow glass particles (diameter 2–20 µm), and monodisperse Polystyrene particles (diameter 5 & 15 µm), and the results exhibit an acceptable chip performance with 86% of efficiency for both monodisperse particles and polydisperse particles. The microchannel collects particles with an average diameter of 15.8, 9.4, and 5.9 μm at the proposed reservoirs. This chip can be integrated into a more extensive point-of-care diagnostic system to test blood samples.

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.

scholarly journals Isothermal Amplification Using a Chemical Heating Device for Point-of-Care Detection of HIV-1

PLoS ONE ◽  
2012 ◽  
Vol 7 (2) ◽  
pp. e31432 ◽  
Author(s):  
Kelly A. Curtis ◽  
Donna L. Rudolph ◽  
Irene Nejad ◽  
Jered Singleton ◽  
Andy Beddoe ◽  
...  
Keyword(s):  
Point Of Care ◽  
Isothermal Amplification ◽  
Heating Device ◽  
Chemical Heating ◽  
Point Of Care Detection ◽  
Hiv 1

scholarly journals The diagnostic accuracy of isothermal nucleic acid point-of-care tests for human coronaviruses: A systematic review and meta-analysis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pakpoom Subsoontorn ◽  
Manupat Lohitnavy ◽  
Chuenjid Kongkaew
Keyword(s):  
Systematic Review ◽  
Diagnostic Accuracy ◽  
Diagnostic Test ◽  
Point Of Care ◽  
Meta Analysis ◽  
Isothermal Amplification ◽  
Diagnostic Test Accuracy ◽  
Test Accuracy ◽  
Index Test ◽  
Point Of Care Tests

AbstractMany recent studies reported coronavirus point-of-care tests (POCTs) based on isothermal amplification. However, the performances of these tests have not been systematically evaluated. Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy was used as a guideline for conducting this systematic review. We searched peer-reviewed and preprint articles in PubMed, BioRxiv and MedRxiv up to 28 September 2020 to identify studies that provide data to calculate sensitivity, specificity and diagnostic odds ratio (DOR). Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) was applied for assessing quality of included studies and Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) was followed for reporting. We included 81 studies from 65 research articles on POCTs of SARS, MERS and COVID-19. Most studies had high risk of patient selection and index test bias but low risk in other domains. Diagnostic specificities were high (> 0.95) for included studies while sensitivities varied depending on type of assays and sample used. Most studies (n = 51) used reverse transcription loop-mediated isothermal amplification (RT-LAMP) to diagnose coronaviruses. RT-LAMP of RNA purified from COVID-19 patient samples had pooled sensitivity at 0.94 (95% CI: 0.90–0.96). RT-LAMP of crude samples had substantially lower sensitivity at 0.78 (95% CI: 0.65–0.87). Abbott ID Now performance was similar to RT-LAMP of crude samples. Diagnostic performances by CRISPR and RT-LAMP on purified RNA were similar. Other diagnostic platforms including RT- recombinase assisted amplification (RT-RAA) and SAMBA-II also offered high sensitivity (> 0.95). Future studies should focus on the use of un-bias patient cohorts, double-blinded index test and detection assays that do not require RNA extraction.

Long-term dry storage of enzyme-based reagents for isothermal nucleic acid amplification in a porous matrix for use in point-of-care diagnostic devices

The Analyst ◽  
2020 ◽  
Vol 145 (21) ◽  
pp. 6875-6886 ◽  
Author(s):  
Sujatha Kumar ◽  
Ryan Gallagher ◽  
Josh Bishop ◽  
Enos Kline ◽  
Joshua Buser ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Glass Fiber ◽  
Point Of Care ◽  
Porous Matrix ◽  
Isothermal Amplification ◽  
Nucleic Acid Amplification ◽  
Isothermal Nucleic Acid Amplification ◽  
Dry Storage

Long-term dry storage of enzyme-based isothermal amplification reagents in glass fiber porous matrix for use in point-of-care devices.

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