Bead-Based Miniature Microfluidic Systems for Rapid RNA Extraction and Reverse Transcription

2008 ◽  
Author(s):  
Kang-Yi Lien ◽  
Chien-Ju Liu ◽  
Jyh-Wei Shin ◽  
Tsuey-Yu Chang ◽  
Gwo-Bin Lee
Keyword(s):  
Magnetic Field ◽  
Reverse Transcription ◽  
Magnetic Beads ◽  
Biomedical Application ◽  
Rna Extraction ◽  
Control Module ◽  
Rna Purification ◽  
Field Temperature ◽  
Rt Process ◽  
Miniature System

The current study presents a new integrated microfluidic chip for rapid ribonucleic acid (RNA) purification, extraction and reverse transcription (RT) in an automatic fashion. The miniature system consists of two individual functional devices including a two-way microfluidic control module and a magnetic field/temperature control module. The functional microfluidic control module can perform pumping, mixing, purification and concentration of the RNA samples by incorporating with the magnetic bio-separator consisting of 2-dimension twisted microcoils. Notably, the magnetic bio-separators are developed either to perform the separation of magnetic beads or to control the temperature field for the subsequent RT process. Experimental results showed that the total RNA was successfully purified and extracted by the magnetic beads, and the subsequent RT process of RNA was completed automatically. As a whole, the developed system may provide a powerful platform for biomedical application and biological analysis.

scholarly journals Development and validation of a one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) for rapid detection of ZIKV in patient samples from Brazil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Severino Jefferson Ribeiro da Silva ◽  
Keith Pardee ◽  
Udeni B. R. Balasuriya ◽  
Lindomar Pena
Keyword(s):  
Reverse Transcription ◽  
Rapid Detection ◽  
Quantitative Polymerase Chain Reaction ◽  
Rna Extraction ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Serum Samples ◽  
Low Resource ◽  
Loop Mediated Isothermal Amplification ◽  
One Step

AbstractWe have previously developed and validated a one-step assay based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) for rapid detection of the Zika virus (ZIKV) from mosquito samples. Patient diagnosis of ZIKV is currently carried out in centralized laboratories using the reverse transcription-quantitative polymerase chain reaction (RT-qPCR), which, while the gold standard molecular method, has several drawbacks for use in remote and low-resource settings, such as high cost and the need of specialized equipment. Point-of-care (POC) diagnostic platforms have the potential to overcome these limitations, especially in low-resource countries where ZIKV is endemic. With this in mind, here we optimized and validated our RT-LAMP assay for rapid detection of ZIKV from patient samples. We found that the assay detected ZIKV from diverse sample types (serum, urine, saliva, and semen) in as little as 20 min, without RNA extraction. The RT-LAMP assay was highly specific and up to 100 times more sensitive than RT-qPCR. We then validated the assay using 100 patient serum samples collected from suspected cases of arbovirus infection in the state of Pernambuco, which was at the epicenter of the last Zika epidemic. Analysis of the results, in comparison to RT-qPCR, found that the ZIKV RT-LAMP assay provided sensitivity of 100%, specificity of 93.75%, and an overall accuracy of 95.00%. Taken together, the RT-LAMP assay provides a straightforward and inexpensive alternative for the diagnosis of ZIKV from patients and has the potential to increase diagnostic capacity in ZIKV-affected areas, particularly in low and middle-income countries.

HIV detection from human serum with paper-based isotachophoretic RNA extraction and reverse transcription recombinase polymerase amplification

The Analyst ◽  
2021 ◽  
Author(s):  
Andrew T. Bender ◽  
Benjamin P. Sullivan ◽  
Jane Zhang ◽  
David C Juergens ◽  
Lorraine Lillis ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Human Serum ◽  
Reverse Transcription ◽  
Rna Extraction ◽  
Recombinase Polymerase Amplification ◽  
People Living With Hiv ◽  
Treatment Regimens ◽  
Living With Hiv

The number of people living with HIV continues to increase with the current total near 38 million, of which about 26 million are receiving antiretroviral therapy (ART). These treatment regimens...

scholarly journals Magnetic hybrid materials interact with biological matrices

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Christine Gräfe ◽  
Elena K. Müller ◽  
Lennart Gresing ◽  
Andreas Weidner ◽  
Patricia Radon ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Gradient ◽  
Hybrid Materials ◽  
Biomedical Application ◽  
Magnetic Field Gradient ◽  
Apical Cell ◽  
Cell Type ◽  
Cell Layers ◽  
Barrier Model

Abstract Magnetic hybrid materials are a promising group of substances. Their interaction with matrices is challenging with regard to the underlying physical and chemical mechanisms. But thinking matrices as biological membranes or even structured cell layers they become interesting with regard to potential biomedical applications. Therefore, we established in vitro blood-organ barrier models to study the interaction and processing of superparamagnetic iron oxide nanoparticles (SPIONs) with these cellular structures in the presence of a magnetic field gradient. A one-cell-type–based blood-brain barrier model was used to investigate the attachment and uptake mechanisms of differentially charged magnetic hybrid materials. Inhibition of clathrin-dependent endocytosis and F-actin depolymerization led to a dramatic reduction of cellular uptake. Furthermore, the subsequent transportation of SPIONs through the barrier and the ability to detect these particles was of interest. Negatively charged SPIONs could be detected behind the barrier as well as in a reporter cell line. These observations could be confirmed with a two-cell-type–based blood-placenta barrier model. While positively charged SPIONs heavily interact with the apical cell layer, neutrally charged SPIONs showed a retarded interaction behavior. Behind the blood-placenta barrier, negatively charged SPIONs could be clearly detected. Finally, the transfer of the in vitro blood-placenta model in a microfluidic biochip allows the integration of shear stress into the system. Even without particle accumulation in a magnetic field gradient, the negatively charged SPIONs were detectable behind the barrier. In conclusion, in vitro blood-organ barrier models allow the broad investigation of magnetic hybrid materials with regard to biocompatibility, cell interaction, and transfer through cell layers on their way to biomedical application.

The Research of a New Method for Manipulating Magnetic Beads through Multi-Layered Flat Micro-Coils Coupled with Permanent Magnet

2013 ◽  
Vol 753-755 ◽  
pp. 1571-1575
Author(s):  
Zhi Hua Liu ◽  
Yu Feng Huang ◽  
Jian Peng Li ◽  
Xin Wei Xu
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Flow Velocity ◽  
Magnetic Beads ◽  
Magnetic Bead ◽  
New Method ◽  
Viscous Resistance ◽  
Main Factors ◽  
The Magnetic Field

Magnetic bead droplet's non-contacted manipulation can be realized in Electromagnetic MEMS, but how to achieve magnetic beads manipulation is the major problem. A new method of multi-layered flat coils coupled with permanent magnet was proposed. Firstly, the theory of magnetic bead manipulation was analyzed and the main factors affected the magnetic beads manipulation was identified; then the magnetic field of multi-layered flat coils and Stokes viscous resistance of magnetic beads were analyzed and simulated quantificationally; finally the magnetic bead capture area was got under different flow velocity. Consequently the feasibility and correctness of this method was verified.

Pressure effect on the magnetic field-temperature phase diagram of

2008 ◽  
Vol 403 (5-9) ◽  
pp. 749-751 ◽  
Author(s):  
Y.J. Jo ◽  
L. Balicas ◽  
C. Capan ◽  
K. Behnia ◽  
P. Lejay ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Pressure Effect ◽  
Temperature Phase ◽  
Field Temperature ◽  
The Magnetic Field ◽  
Temperature Phase Diagram

scholarly journals Robust Saliva-Based RNA Extraction-Free One-Step Nucleic Acid Amplification Test for Mass SARS-CoV-2 Monitoring

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6617
Author(s):  
Eva Rajh ◽  
Tina Šket ◽  
Arne Praznik ◽  
Petra Sušjan ◽  
Alenka Šmid ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Reverse Transcription ◽  
Screening Program ◽  
Quantitative Polymerase Chain Reaction ◽  
Rna Extraction ◽  
Diagnostic Sensitivity ◽  
Nucleic Acid Amplification ◽  
Nasopharyngeal Swab ◽  
Viral Spread ◽  
One Step

Early diagnosis with rapid detection of the virus plays a key role in preventing the spread of infection and in treating patients effectively. In order to address the need for a straightforward detection of SARS-CoV-2 infection and assessment of viral spread, we developed rapid, sensitive, extraction-free one-step reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP) tests for detecting SARS-CoV-2 in saliva. We analyzed over 700 matched pairs of saliva and nasopharyngeal swab (NSB) specimens from asymptomatic and symptomatic individuals. Saliva, as either an oral cavity swab or passive drool, was collected in an RNA stabilization buffer. The stabilized saliva specimens were heat-treated and directly analyzed without RNA extraction. The diagnostic sensitivity of saliva-based RT-qPCR was at least 95% in individuals with subclinical infection and outperformed RT-LAMP, which had at least 70% sensitivity when compared to NSBs analyzed with a clinical RT-qPCR test. The diagnostic sensitivity for passive drool saliva was higher than that of oral cavity swab specimens (95% and 87%, respectively). A rapid, sensitive one-step extraction-free RT-qPCR test for detecting SARS-CoV-2 in passive drool saliva is operationally simple and can be easily implemented using existing testing sites, thus allowing high-throughput, rapid, and repeated testing of large populations. Furthermore, saliva testing is adequate to detect individuals in an asymptomatic screening program and can help improve voluntary screening compliance for those individuals averse to various forms of nasal collections.

SPIN-DEPENDENT BEATS CREATED BY IRRADIATION OF MICROWAVE FIELD THROUGH A QUANTUM DOT

2011 ◽  
Vol 25 (25) ◽  
pp. 2033-2039
Author(s):  
M. BAGHERI TAGANI ◽  
H. RAHIMPOUR SOLEIMANI
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Microwave Field ◽  
Spin Current ◽  
Tunneling Magnetoresistance ◽  
Rate Equations ◽  
Spin Accumulation ◽  
Spin Dependent Transport ◽  
Field Temperature ◽  
Dependent Transport

We study spin-dependent transport through a quantum dot with Zeeman split levels coupled to ferromagnetic leads and under influence of microwave irradiation. Current polarization, spin current, spin accumulation and tunneling magnetoresistance are analyzed using nonequilibrium Green's function formalism and rate equations. Spin-dependent beats in spin resolved currents are observed. The effects of magnetic field, temperature and Coulomb interaction on these beats are studied.

Magnetic field-temperature phase diagrams of multiferroic (Ni0.9Co0.1)3V2O8

2016 ◽  
Vol 94 (17) ◽  
Author(s):  
N. Qureshi ◽  
E. Ressouche ◽  
A. A. Mukhin ◽  
V. Yu. Ivanov ◽  
S. N. Barilo ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagrams ◽  
Temperature Phase ◽  
Field Temperature
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