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Skaltsounis P, Kokkoris G, Papaioannou TG, Tserepi A. Closed-Loop Microreactor on PCB for Ultra-Fast DNA Amplification: Design and Thermal Validation. MICROMACHINES 2023; 14:172. [PMID: 36677232 PMCID: PMC9860919 DOI: 10.3390/mi14010172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/04/2023] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
Polymerase chain reaction (PCR) is the most common method used for nucleic acid (DNA) amplification. The development of PCR-performing microfluidic reactors (μPCRs) has been of major importance, due to their crucial role in pathogen detection applications in medical diagnostics. Closed loop (CL) is an advantageous type of μPCR, which uses a circular microchannel, thus allowing the DNA sample to pass consecutively through the different temperature zones, in order to accomplish a PCR cycle. CL μPCR offers the main advantages of the traditional continuous-flow μPCR, eliminating at the same time most of the disadvantages associated with the long serpentine microchannel. In this work, the performance of three different CL μPCRs designed for fabrication on a printed circuit board (PCB) was evaluated by a computational study in terms of the residence time in each thermal zone. A 3D heat transfer model was used to calculate the temperature distribution in the microreactor, and the residence times were extracted by this distribution. The results of the computational study suggest that for the best-performing microreactor design, a PCR of 30 cycles can be achieved in less than 3 min. Subsequently, a PCB chip was fabricated based on the design that performed best in the computational study. PCB constitutes a great substrate as it allows for integrated microheaters inside the chip, permitting at the same time low-cost, reliable, reproducible, and mass-amenable fabrication. The fabricated chip, which, at the time of this writing, is the first CL μPCR chip fabricated on a PCB, was tested by measuring the temperatures on its surface with a thermal camera. These results were then compared with the ones of the computational study, in order to evaluate the reliability of the latter. The comparison of the calculated temperatures with the measured values verifies the accuracy of the developed model of the microreactor. As a result of that, a total power consumption of 1.521 W was experimentally measured, only ~7.3% larger than the one calculated (1.417 W). Full validation of the realized CL μPCR chip will be demonstrated in future work.
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Affiliation(s)
- Panagiotis Skaltsounis
- Institute of Nanoscience and Nanotechnology, National Center of Scientific Research (NCSR) “Demokritos”, Patr. Gregoriou Ε’ and 27 Neapoleos Str., 15341 Aghia Paraskevi, Greece
- School of Medicine, National and Kapodistrian University of Athens (NKUA), 75 Mikras Asias Str., 11527 Athens, Greece
| | - George Kokkoris
- Institute of Nanoscience and Nanotechnology, National Center of Scientific Research (NCSR) “Demokritos”, Patr. Gregoriou Ε’ and 27 Neapoleos Str., 15341 Aghia Paraskevi, Greece
| | - Theodoros G. Papaioannou
- School of Medicine, National and Kapodistrian University of Athens (NKUA), 75 Mikras Asias Str., 11527 Athens, Greece
| | - Angeliki Tserepi
- Institute of Nanoscience and Nanotechnology, National Center of Scientific Research (NCSR) “Demokritos”, Patr. Gregoriou Ε’ and 27 Neapoleos Str., 15341 Aghia Paraskevi, Greece
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2
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Chen S, Sun Y, Fan F, Chen S, Zhang Y, Zhang Y, Meng X, Lin JM. Present status of microfluidic PCR chip in nucleic acid detection and future perspective. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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3
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Abstract
Using light to manipulate fluids has been a long-sought-after goal for lab-on-a-chip applications to address the size mismatch between bulky external fluid controllers and microfluidic devices. Yet, this goal has remained elusive due to the complexity of thermally driven fluid dynamic phenomena, and the lack of approaches that allow comprehensive multiscale and multiparameter studies. Here, we report an innovative optofluidic platform that fulfills this need by combining digital holographic microscopy with state-of-the-art thermoplasmonics, allowing us to identify the different contributions from thermophoresis, thermo-osmosis, convection, and radiation pressure. In our experiments, we demonstrate that a local thermal perturbation at the microscale can lead to mm-scale changes in both the particle and fluid dynamics, thus achieving long-range transport. Furthermore, thanks to a comprehensive parameter study involving sample geometry, temperature increase, light fluence, and size of the heat source, we showcase an integrated and reconfigurable all-optical control strategy for microfluidic devices, thereby opening new frontiers in fluid actuation technology.
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4
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Gharizadeh B, Yue J, Yu M, Liu Y, Zhou M, Lu D, Zhang J. Navigating the Pandemic Response Life Cycle: Molecular Diagnostics and Immunoassays in the Context of COVID-19 Management. IEEE Rev Biomed Eng 2021; 14:30-47. [PMID: 32356761 DOI: 10.1109/rbme.2020.2991444] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To counter COVID-19 spreading, an infrastructure to provide rapid and thorough molecular diagnostics and serology testing is the cornerstone of outbreak and pandemic management. We hereby review the clinical insights with regard to using molecular tests and immunoassays in the context of COVID-19 management life cycle: the preventive phase, the preparedness phase, the response phase and the recovery phase. The spatial and temporal distribution of viral RNA, antigens and antibodies during human infection is summarized to provide a biological foundation for accurate detection of the disease. We shared the lessons learned and the obstacles encountered during real world high-volume screening programs. Clinical needs are discussed to identify existing technology gaps in these tests. Leverage technologies, such as engineered polymerases, isothermal amplification, and direct amplification from complex matrices may improve the productivity of current infrastructure, while emerging technologies like CRISPR diagnostics, visual end point detection, and PCR free methods for nucleic acid sensing may lead to at-home tests. The lessons learned, and innovations spurred from the COVID-19 pandemic could upgrade our global public health infrastructure to better combat potential outbreaks in the future.
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Tzivelekis C, Sgardelis P, Waldron K, Whalley R, Huo D, Dalgarno K. Fabrication routes via projection stereolithography for 3D-printing of microfluidic geometries for nucleic acid amplification. PLoS One 2020; 15:e0240237. [PMID: 33112867 PMCID: PMC7592796 DOI: 10.1371/journal.pone.0240237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 09/22/2020] [Indexed: 12/19/2022] Open
Abstract
Digital Light Processing (DLP) stereolithography (SLA) as a high-resolution 3D printing process offers a low-cost alternative for prototyping of microfluidic geometries, compared to traditional clean-room and workshop-based methods. Here, we investigate DLP-SLA printing performance for the production of micro-chamber chip geometries suitable for Polymerase Chain Reaction (PCR), a key process in molecular diagnostics to amplify nucleic acid sequences. A DLP-SLA fabrication protocol for printed micro-chamber devices with monolithic micro-channels is developed and evaluated. Printed devices were post-processed with ultraviolet (UV) light and solvent baths to reduce PCR inhibiting residuals and further treated with silane coupling agents to passivate the surface, thereby limiting biomolecular adsorption occurences during the reaction. The printed devices were evaluated on a purpose-built infrared (IR) mediated PCR thermocycler. Amplification of 75 base pair long target sequences from genomic DNA templates on fluorosilane and glass modified chips produced amplicons consistent with the control reactions, unlike the non-silanized chips that produced faint or no amplicon. The results indicated good functionality of the IR thermocycler and good PCR compatibility of the printed and silanized SLA polymer. Based on the proposed methods, various microfluidic designs and ideas can be validated in-house at negligible costs without the requirement of tool manufacturing and workshop or clean-room access. Additionally, the versatile chemistry of 3D printing resins enables customised surface properties adding significant value to the printed prototypes. Considering the low setup and unit cost, design flexibility and flexible resin chemistries, DLP-SLA is anticipated to play a key role in future prototyping of microfluidics, particularly in the fields of research biology and molecular diagnostics. From a system point-of-view, the proposed method of thermocycling shows promise for portability and modular integration of funcitonalitites for diagnostic or research applications that utilize nucleic acid amplification technology.
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Affiliation(s)
| | - Pavlos Sgardelis
- School of Engineering, Newcastle University, Newcastle, United Kingdom
| | - Kevin Waldron
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle, United Kingdom
| | - Richard Whalley
- School of Engineering, Newcastle University, Newcastle, United Kingdom
| | - Dehong Huo
- School of Engineering, Newcastle University, Newcastle, United Kingdom
| | - Kenny Dalgarno
- School of Engineering, Newcastle University, Newcastle, United Kingdom
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6
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Rajendran VK, Bakthavathsalam P, Bergquist PL, Sunna A. Smartphone technology facilitates point-of-care nucleic acid diagnosis: a beginner's guide. Crit Rev Clin Lab Sci 2020; 58:77-100. [PMID: 32609551 DOI: 10.1080/10408363.2020.1781779] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The reliable detection of nucleic acids at low concentrations in clinical samples like blood, urine and saliva, and in food can be achieved by nucleic acid amplification methods. Several portable and hand-held devices have been developed to translate these laboratory-based methods to point-of-care (POC) settings. POC diagnostic devices could potentially play an important role in environmental monitoring, health, and food safety. Use of a smartphone for nucleic acid testing has shown promising progress in endpoint as well as real-time analysis of various disease conditions. The emergence of smartphone-based POC devices together with paper-based sensors, microfluidic chips and digital droplet assays are used currently in many situations to provide quantitative detection of nucleic acid targets. State-of-the-art portable devices are commercially available and rapidly emerging smartphone-based POC devices that allow the performance of laboratory-quality colorimetric, fluorescent and electrochemical detection are described in this review. We present a comprehensive review of smartphone-based POC sensing applications, specifically on microbial diagnostics, assess their performance and propose recommendations for the future.
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Affiliation(s)
| | - Padmavathy Bakthavathsalam
- School of Chemistry and Australian Centre for Nanomedicine, University of New South Wales, Sydney, Australia
| | - Peter L Bergquist
- Department of Molecular Sciences, Macquarie University, Sydney, Australia.,Department of Molecular Medicine & Pathology, University of Auckland, Auckland, New Zealand.,Biomolecular Discovery Research Centre, Macquarie University, Sydney, Australia
| | - Anwar Sunna
- Department of Molecular Sciences, Macquarie University, Sydney, Australia.,Biomolecular Discovery Research Centre, Macquarie University, Sydney, Australia
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7
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Miao G, Zhang L, Zhang J, Ge S, Xia N, Qian S, Yu D, Qiu X. Free convective PCR: From principle study to commercial applications-A critical review. Anal Chim Acta 2020; 1108:177-197. [PMID: 32222239 DOI: 10.1016/j.aca.2020.01.069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 12/11/2022]
Abstract
Polymerase chain reaction (PCR) is an extremely important tool for molecular diagnosis, as it can specifically amplify nucleic acid templates for sensitive detection. As another division of PCR, free convective PCR was invented in 2001, which can be performed in a capillary tube pseudo-isothermally within a significantly short time. Convective PCR thermal cycling is implemented by inducing thermal convection inside the capillary tube, which stratifies the reaction into spatially separate and stable melting, annealing, and extension zones created by the temperature gradient. Convective PCR is a promising tool that can be used for nucleic acid diagnosis as a point-of-care test (POCT) due to the significantly simplified heating strategy, reduced cost, and shortened detection time without sacrificing sensitivity and accuracy. Here, we review the history of free convective PCR from its invention to development and its commercial applications.
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Affiliation(s)
- Guijun Miao
- Institute of Microfluidic Chip Development in Biomedical Engineering, College of Information Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Lulu Zhang
- Institute of Microfluidic Chip Development in Biomedical Engineering, College of Information Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Jing Zhang
- Institute of Microfluidic Chip Development in Biomedical Engineering, College of Information Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Shengxiang Ge
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361005, China.
| | - Ningshao Xia
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361005, China.
| | - Shizhi Qian
- Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, VA, 23529, USA.
| | - Duli Yu
- Institute of Microfluidic Chip Development in Biomedical Engineering, College of Information Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China; Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing, 100029, China.
| | - Xianbo Qiu
- Institute of Microfluidic Chip Development in Biomedical Engineering, College of Information Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
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8
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Kaprou GD, Papadopoulos V, Papageorgiou DP, Kefala I, Papadakis G, Gizeli E, Chatzandroulis S, Kokkoris G, Tserepi A. Ultrafast, low-power, PCB manufacturable, continuous-flow microdevice for DNA amplification. Anal Bioanal Chem 2019; 411:5297-5307. [PMID: 31161322 DOI: 10.1007/s00216-019-01911-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/25/2019] [Accepted: 05/09/2019] [Indexed: 12/12/2022]
Abstract
The design and fabrication of a continuous-flow μPCR device with very short amplification time and low power consumption are presented. Commercially available, 4-layer printed circuit board (PCB) substrates are employed, with in-house designed yet industrially manufactured embedded Cu micro-resistive heaters lying at very close distance from the microfluidic network, where DNA amplification takes place. The 1.9-m-long microchannel in combination with desirably high flow velocities (for fast amplification) challenged the robustness of the sealing that was overcome with the development of a novel bonding method rendering the microdevice robust even at extreme pressure drops (12 bars). The proposed fabrication methods are PCB compatible, allowing for mass and reliable production of the μPCR device in the established PCB industry. The μPCR chip was successfully validated during the amplification of two different DNA fragments (and with different target DNA copies) corresponding to the exon 20 of the BRCA1 gene, and to the plasmid pBR322, a commonly used cloning vector in E. coli. Successful DNA amplification was demonstrated at total reaction times down to 2 min, with a power consumption of 2.7 W, rendering the presented μPCR one of the fastest and lowest power-consuming devices, suitable for implementation in low-resource settings. Detailed numerical calculations of the DNA residence time distributions, within an acceptable temperature range for denaturation, annealing, and extension, performed for the first time in the literature, provide useful information regarding the actual on-chip PCR protocol and justify the maximum volumetric flow rate for successful DNA amplification. The calculations indicate that the shortest amplification time is achieved when the device is operated at its enzyme kinetic limit (i.e., extension rate). Graphical abstract.
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Affiliation(s)
- Georgia D Kaprou
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Patr. Gregoriou E' and 27 Neapoleos Str., PO Box 60037, 15341, Agia Paraskevi, Attica, Greece.,Department of Biology, University of Crete, Voutes, 70013, Heraklion, Greece
| | - Vasileios Papadopoulos
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Patr. Gregoriou E' and 27 Neapoleos Str., PO Box 60037, 15341, Agia Paraskevi, Attica, Greece
| | - Dimitris P Papageorgiou
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Patr. Gregoriou E' and 27 Neapoleos Str., PO Box 60037, 15341, Agia Paraskevi, Attica, Greece.,Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ioanna Kefala
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Patr. Gregoriou E' and 27 Neapoleos Str., PO Box 60037, 15341, Agia Paraskevi, Attica, Greece
| | - George Papadakis
- Institute of Molecular Biology and Biotechnology-FORTH, 100 N. Plastira Str., 70013, Heraklion, Greece
| | - Electra Gizeli
- Department of Biology, University of Crete, Voutes, 70013, Heraklion, Greece.,Institute of Molecular Biology and Biotechnology-FORTH, 100 N. Plastira Str., 70013, Heraklion, Greece
| | - Stavros Chatzandroulis
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Patr. Gregoriou E' and 27 Neapoleos Str., PO Box 60037, 15341, Agia Paraskevi, Attica, Greece
| | - George Kokkoris
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Patr. Gregoriou E' and 27 Neapoleos Str., PO Box 60037, 15341, Agia Paraskevi, Attica, Greece.
| | - Angeliki Tserepi
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Patr. Gregoriou E' and 27 Neapoleos Str., PO Box 60037, 15341, Agia Paraskevi, Attica, Greece.
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9
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Lee NY. A review on microscale polymerase chain reaction based methods in molecular diagnosis, and future prospects for the fabrication of fully integrated portable biomedical devices. Mikrochim Acta 2018; 185:285. [PMID: 29736588 DOI: 10.1007/s00604-018-2791-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 04/05/2018] [Indexed: 02/06/2023]
Abstract
Since the advent of microfabrication technology and soft lithography, the lab-on-a-chip concept has emerged as a state-of-the-art miniaturized tool for conducting the multiple functions associated with micro total analyses of nucleic acids, in series, in a seamless manner with a miniscule volume of sample. The enhanced surface-to-volume ratio inside a microchannel enables fast reactions owing to increased heat dissipation, allowing rapid amplification. For this reason, PCR has been one of the first applications to be miniaturized in a portable format. However, the nature of the basic working principle for microscale PCR, such as the complicated temperature controls and use of a thermal cycler, has hindered its total integration with other components into a micro total analyses systems (μTAS). This review (with 179 references) surveys the diverse forms of PCR microdevices constructed on the basis of different working principles and evaluates their performances. The first two main sections cover the state-of-the-art in chamber-type PCR microdevices and in continuous-flow PCR microdevices. Methods are then discussed that lead to microdevices with upstream sample purification and downstream detection schemes, with a particular focus on rapid on-site detection of foodborne pathogens. Next, the potential for miniaturizing and automating heaters and pumps is examined. The review concludes with sections on aspects of complete functional integration in conjunction with nanomaterial based sensing, a discussion on future prospects, and with conclusions. Graphical abstract In recent years, thermocycler-based PCR systems have been miniaturized to palm-sized, disposable polymer platforms. In addition, operational accessories such as heaters and mechanical pumps have been simplified to realize semi-automatted stand-alone portable biomedical diagnostic microdevices that are directly applicable in the field. This review summarizes the progress made and the current state of this field.
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Affiliation(s)
- Nae Yoon Lee
- Department of BioNano Technology, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si, Gyeonggi-do, 13120, South Korea.
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10
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Mendoza-Gallegos RA, Rios A, Garcia-Cordero JL. An Affordable and Portable Thermocycler for Real-Time PCR Made of 3D-Printed Parts and Off-the-Shelf Electronics. Anal Chem 2018; 90:5563-5568. [DOI: 10.1021/acs.analchem.7b04843] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Roberto A. Mendoza-Gallegos
- Unidad Monterrey, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Parque PIIT, Apodaca, Nuevo León C.P. 66628, Mexico
| | - Amelia Rios
- Unidad Monterrey, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Parque PIIT, Apodaca, Nuevo León C.P. 66628, Mexico
| | - Jose L. Garcia-Cordero
- Unidad Monterrey, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Parque PIIT, Apodaca, Nuevo León C.P. 66628, Mexico
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11
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Morrison J, Watts G, Hobbs G, Dawnay N. Field-based detection of biological samples for forensic analysis: Established techniques, novel tools, and future innovations. Forensic Sci Int 2018. [DOI: 10.1016/j.forsciint.2018.02.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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12
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Saito M, Takahashi K, Kiriyama Y, Espulgar WV, Aso H, Sekiya T, Tanaka Y, Sawazumi T, Furui S, Tamiya E. Centrifugation-Controlled Thermal Convection and Its Application to Rapid Microfluidic Polymerase Chain Reaction Devices. Anal Chem 2017; 89:12797-12804. [DOI: 10.1021/acs.analchem.7b03107] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Masato Saito
- Department
of Applied Physics, Graduate School of Engineering, Osaka University, 2-1,
Yamadaoka, Suita-shi, Osaka 565-0871, Japan
| | - Kazuya Takahashi
- Department
of Applied Physics, Graduate School of Engineering, Osaka University, 2-1,
Yamadaoka, Suita-shi, Osaka 565-0871, Japan
| | - Yuichiro Kiriyama
- Department
of Applied Physics, Graduate School of Engineering, Osaka University, 2-1,
Yamadaoka, Suita-shi, Osaka 565-0871, Japan
| | - Wilfred Villariza Espulgar
- Department
of Applied Physics, Graduate School of Engineering, Osaka University, 2-1,
Yamadaoka, Suita-shi, Osaka 565-0871, Japan
| | - Hiroshi Aso
- Konica Minolta, Inc., JP Tower,
2-7-2 Marunouchi, Chiyoda-ku, Tokyo 100-7015, Japan
| | - Tadanobu Sekiya
- Konica Minolta, Inc., JP Tower,
2-7-2 Marunouchi, Chiyoda-ku, Tokyo 100-7015, Japan
| | - Yoshikazu Tanaka
- Konica Minolta, Inc., JP Tower,
2-7-2 Marunouchi, Chiyoda-ku, Tokyo 100-7015, Japan
| | - Tsuneo Sawazumi
- Konica Minolta, Inc., JP Tower,
2-7-2 Marunouchi, Chiyoda-ku, Tokyo 100-7015, Japan
| | - Satoshi Furui
- Food
Entomology Unit, Food Research Institute, NARO, 2-1-12, Kannondai,
Tsukuba, Ibaraki 305-8642, Japan
| | - Eiichi Tamiya
- Department
of Applied Physics, Graduate School of Engineering, Osaka University, 2-1,
Yamadaoka, Suita-shi, Osaka 565-0871, Japan
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13
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A sample-to-answer, real-time convective polymerase chain reaction system for point-of-care diagnostics. Biosens Bioelectron 2017. [PMID: 28624618 DOI: 10.1016/j.bios.2017.06.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Timely and accurate molecular diagnostics at the point-of-care (POC) level is critical to global health. To this end, we propose a handheld convective-flow real-time polymerase chain reaction (PCR) system capable of direct sample-to-answer genetic analysis for the first time. Such a system mainly consists of a magnetic bead-assisted photothermolysis sample preparation, a closed-loop convective PCR reactor, and a wireless video camera-based real-time fluorescence detection. The sample preparation exploits the dual functionality of vancomycin-modified magnetic beads (VMBs) for bacteria enrichment and photothermal conversion, enabling cell pre-concentration and lysis to be finished in less than 3min. On the presented system, convective thermocycling is driven by a single-heater thermal gradient, and its amplification is monitored in real-time, with an analysis speed of less than 25min, a dynamic linear range from 106 to 101 copies/µL and a detection sensitivity of as little as 1 copies/µL. Additionally, the proposed PCR system is self-contained with a control electronics, pocket-size and battery-powered, providing a low-cost genetic analysis in a portable format. Therefore, we believe that this integrated system may become a potential candidate for fast, accurate and affordable POC molecular diagnostics.
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14
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Development of Capillary Loop Convective Polymerase Chain Reaction Platform with Real-Time Fluorescence Detection. INVENTIONS 2017. [DOI: 10.3390/inventions2010003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Abstract
We have designed a novel convective flow-based thermocycling system capable of performing high-speed DNA amplification via the polymerase chain reaction in a simplified and inexpensive format. Successful amplification of a 191 bp influenza-A target is demonstrated within 25 min using a 10 μL reaction volume with no modification to standard laboratory protocols. The system is simple to assemble and can be readily integrated with existing laboratory instrumentation for automated operation. (JALA 2006;11:217–21)
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16
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Zhang Y, Li Q, Guo L, Huang Q, Shi J, Yang Y, Liu D, Fan C. Ion-Mediated Polymerase Chain Reactions Performed with an Electronically Driven Microfluidic Device. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201606137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Yi Zhang
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
| | - Qian Li
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
| | - Linjie Guo
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
| | - Qing Huang
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
| | - Jiye Shi
- Kellogg College; University of Oxford; Oxford OX2 6PN UK
- UCB Pharma; 208 Bath Road Slough SL1 3WE UK
| | - Yang Yang
- National Center for NanoScience and Technology (NCNST); Beijing 100190 China
| | - Dongsheng Liu
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education; Department of Chemistry; Tsinghua University; Beijing 100084 China
| | - Chunhai Fan
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
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17
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Zhang Y, Li Q, Guo L, Huang Q, Shi J, Yang Y, Liu D, Fan C. Ion-Mediated Polymerase Chain Reactions Performed with an Electronically Driven Microfluidic Device. Angew Chem Int Ed Engl 2016; 55:12450-4. [DOI: 10.1002/anie.201606137] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 07/19/2016] [Indexed: 12/21/2022]
Affiliation(s)
- Yi Zhang
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
| | - Qian Li
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
| | - Linjie Guo
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
| | - Qing Huang
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
| | - Jiye Shi
- Kellogg College; University of Oxford; Oxford OX2 6PN UK
- UCB Pharma; 208 Bath Road Slough SL1 3WE UK
| | - Yang Yang
- National Center for NanoScience and Technology (NCNST); Beijing 100190 China
| | - Dongsheng Liu
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education; Department of Chemistry; Tsinghua University; Beijing 100084 China
| | - Chunhai Fan
- Division of Physical Biology & Bioimaging Center; Shanghai Synchrotron Radiation Facility; CAS Key Laboratory of Interfacial Physics and Technology; Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai 201800 China
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18
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Ugaz VM, Krishnan M. Novel Convective Flow Based Approaches for High-Throughput PCR Thermocycling. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.jala.2004.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A critical need exists for the development of next-generation genomic analysis instrumentation capable of offering significantly higher throughput at a lower cost than current technology. In this paper, we explore the potential of natural convection-based systems to address these issues by providing a thermocycling hardware platform capable of performing rapid polymerase chain reaction (PCR) amplification of DNA. These systems can be arrayed in a multi-well format that is simple to operate, is suitable for integration with high-throughput automated liquid handling systems, and can be easily and inexpensively mass-produced.
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Affiliation(s)
- Victor M. Ugaz
- Department of Chemical Engineering, Texas A&M University, College Station, TX
| | - Madhavi Krishnan
- Institut für Biophysik/BioTec, Technical University, Dresden, Germany
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HE QD, HUANG DP, HUANG G, CHEN ZG. Advance in Research of Microfluidic Polymerase Chain Reaction Chip. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2016. [DOI: 10.1016/s1872-2040(16)60921-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Chan K, Wong PY, Yu P, Hardick J, Wong KY, Wilson SA, Wu T, Hui Z, Gaydos C, Wong SS. A Rapid and Low-Cost PCR Thermal Cycler for Infectious Disease Diagnostics. PLoS One 2016; 11:e0149150. [PMID: 26872358 PMCID: PMC4752298 DOI: 10.1371/journal.pone.0149150] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 01/27/2016] [Indexed: 01/21/2023] Open
Abstract
The ability to make rapid diagnosis of infectious diseases broadly available in a portable, low-cost format would mark a great step forward in global health. Many molecular diagnostic assays are developed based on using thermal cyclers to carry out polymerase chain reaction (PCR) and reverse-transcription PCR for DNA and RNA amplification and detection, respectively. Unfortunately, most commercial thermal cyclers are expensive and need continuous electrical power supply, so they are not suitable for uses in low-resource settings. We have previously reported a low-cost and simple approach to amplify DNA using vacuum insulated stainless steel thermoses food cans, which we have named it thermos thermal cycler or TTC. Here, we describe the use of an improved set up to enable the detection of viral RNA targets by reverse-transcription PCR (RT-PCR), thus expanding the TTC's ability to identify highly infectious, RNA virus-based diseases in low resource settings. The TTC was successful in demonstrating high-speed and sensitive detection of DNA or RNA targets of sexually transmitted diseases, HIV/AIDS, Ebola hemorrhagic fever, and dengue fever. Our innovative TTC costs less than $200 to build and has a capacity of at least eight tubes. In terms of speed, the TTC's performance exceeded that of commercial thermal cyclers tested. When coupled with low-cost endpoint detection technologies such as nucleic acid lateral-flow assay or a cell-phone-based fluorescence detector, the TTC will increase the availability of on-site molecular diagnostics in low-resource settings.
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Affiliation(s)
- Kamfai Chan
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Pui-Yan Wong
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Peter Yu
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Justin Hardick
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Kah-Yat Wong
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Scott A. Wilson
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Tiffany Wu
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Zoe Hui
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Charlotte Gaydos
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Season S. Wong
- AI Biosciences, Inc., College Station, Texas, United States of America
- * E-mail:
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21
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Wong G, Wong I, Chan K, Hsieh Y, Wong S. A Rapid and Low-Cost PCR Thermal Cycler for Low Resource Settings. PLoS One 2015; 10:e0131701. [PMID: 26146999 PMCID: PMC4492969 DOI: 10.1371/journal.pone.0131701] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 06/04/2015] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Many modern molecular diagnostic assays targeting nucleic acids are typically confined to developed countries or to the national reference laboratories of developing-world countries. The ability to make technologies for the rapid diagnosis of infectious diseases broadly available in a portable, low-cost format would mark a revolutionary step forward in global health. Many molecular assays are also developed based on polymerase chain reactions (PCR), which require thermal cyclers that are relatively heavy (>20 pounds) and need continuous electrical power. The temperature ramping speed of most economical thermal cyclers are relatively slow (2 to 3 °C/s) so a polymerase chain reaction can take 1 to 2 hours. Most of all, these thermal cyclers are still too expensive ($2k to $4k) for low-resource setting uses. METHODOLOGY/PRINCIPAL FINDINGS In this article, we demonstrate the development of a low-cost and rapid water bath based thermal cycler that does not require active temperature control or continuous power supply during PCR. This unit costs $130 to build using commercial off-the-shelf items. The use of two or three vacuum-insulated stainless-steel Thermos food jars containing heated water (for denaturation and annealing/extension steps) and a layer of oil on top of the water allow for significantly stabilized temperatures for PCR to take place. Using an Arduino-based microcontroller, we automate the "archaic" method of hand-transferring PCR tubes between water baths. CONCLUSIONS/SIGNIFICANCE We demonstrate that this innovative unit can deliver high speed PCR (17 s per PCR cycle) with the potential to go beyond the 1,522 bp long amplicons tested in this study and can amplify from templates down to at least 20 copies per reaction. The unit also accepts regular PCR tubes and glass capillary tubes. The PCR efficiency of our thermal cycler is not different from other commercial thermal cyclers. When combined with a rapid nucleic acid detection approach, the thermos thermal cycler (TTC) can enable on-site molecular diagnostics in low-resource settings.
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Affiliation(s)
- Grace Wong
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Isaac Wong
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Kamfai Chan
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Yicheng Hsieh
- AI Biosciences, Inc., College Station, Texas, United States of America
| | - Season Wong
- AI Biosciences, Inc., College Station, Texas, United States of America
- * E-mail:
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22
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Phaneuf CR, Pak N, Saunders DC, Holst GL, Birjiniuk J, Nagpal N, Culpepper S, Popler E, Shane AL, Jerris R, Forest CR. Thermally multiplexed polymerase chain reaction. BIOMICROFLUIDICS 2015; 9:044117. [PMID: 26339317 PMCID: PMC4537481 DOI: 10.1063/1.4928486] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 07/31/2015] [Indexed: 05/06/2023]
Abstract
Amplification of multiple unique genetic targets using the polymerase chain reaction (PCR) is commonly required in molecular biology laboratories. Such reactions are typically performed either serially or by multiplex PCR. Serial reactions are time consuming, and multiplex PCR, while powerful and widely used, can be prone to amplification bias, PCR drift, and primer-primer interactions. We present a new thermocycling method, termed thermal multiplexing, in which a single heat source is uniformly distributed and selectively modulated for independent temperature control of an array of PCR reactions. Thermal multiplexing allows amplification of multiple targets simultaneously-each reaction segregated and performed at optimal conditions. We demonstrate the method using a microfluidic system consisting of an infrared laser thermocycler, a polymer microchip featuring 1 μl, oil-encapsulated reactions, and closed-loop pulse-width modulation control. Heat transfer modeling is used to characterize thermal performance limitations of the system. We validate the model and perform two reactions simultaneously with widely varying annealing temperatures (48 °C and 68 °C), demonstrating excellent amplification. In addition, to demonstrate microfluidic infrared PCR using clinical specimens, we successfully amplified and detected both influenza A and B from human nasopharyngeal swabs. Thermal multiplexing is scalable and applicable to challenges such as pathogen detection where patients presenting non-specific symptoms need to be efficiently screened across a viral or bacterial panel.
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Affiliation(s)
- Christopher R Phaneuf
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, USA
| | - Nikita Pak
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, USA
| | - D Curtis Saunders
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, USA
| | - Gregory L Holst
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, USA
| | - Joav Birjiniuk
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, USA
| | - Nikita Nagpal
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, USA
| | - Stephen Culpepper
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, USA
| | | | | | | | - Craig R Forest
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, USA
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23
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Walsh T, Lee J, Park K. Laser-assisted photothermal heating of a plasmonic nanoparticle-suspended droplet in a microchannel. Analyst 2015; 140:1535-42. [DOI: 10.1039/c4an01750a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The present article reports the numerical and experimental investigations on the laser-assisted photothermal heating of a nanoliter-sized droplet in a microchannel when plasmonic particles are suspended in the droplet.
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Affiliation(s)
- Timothy Walsh
- Department of Mechanical
- Industrial and Systems Engineering
- University of Rhode Island
- Kingston
- USA
| | - Jungchul Lee
- Department of Mechanical Engineering
- Sogang University
- Seoul
- South Korea
| | - Keunhan Park
- Department of Mechanical Engineering
- University of Utah
- Salt Lake City
- USA
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24
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Jiang L, Mancuso M, Lu Z, Akar G, Cesarman E, Erickson D. Solar thermal polymerase chain reaction for smartphone-assisted molecular diagnostics. Sci Rep 2014; 4:4137. [PMID: 24553130 PMCID: PMC3929917 DOI: 10.1038/srep04137] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 01/27/2014] [Indexed: 12/19/2022] Open
Abstract
Nucleic acid-based diagnostic techniques such as polymerase chain reaction (PCR) are used extensively in medical diagnostics due to their high sensitivity, specificity and quantification capability. In settings with limited infrastructure and unreliable electricity, however, access to such devices is often limited due to the highly specialized and energy-intensive nature of the thermal cycling process required for nucleic acid amplification. Here we integrate solar heating with microfluidics to eliminate thermal cycling power requirements as well as create a simple device infrastructure for PCR. Tests are completed in less than 30 min, and power consumption is reduced to 80 mW, enabling a standard 5.5 Wh iPhone battery to provide 70 h of power to this system. Additionally, we demonstrate a complete sample-to-answer diagnostic strategy by analyzing human skin biopsies infected with Kaposi's Sarcoma herpesvirus (KSHV/HHV-8) through the combination of solar thermal PCR, HotSHOT DNA extraction and smartphone-based fluorescence detection. We believe that exploiting the ubiquity of solar thermal energy as demonstrated here could facilitate broad availability of nucleic acid-based diagnostics in resource-limited areas.
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Affiliation(s)
- Li Jiang
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14853
| | - Matthew Mancuso
- Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853
| | - Zhengda Lu
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853
| | - Gunkut Akar
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065
| | - Ethel Cesarman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065
| | - David Erickson
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14853
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25
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Hsieh YF, Lee DS, Chen PH, Liao SK, Yeh SH, Chen PJ, Yang AS. A real-time convective PCR machine in a capillary tube instrumented with a CCD-based fluorometer. SENSORS AND ACTUATORS. B, CHEMICAL 2013; 183:434-440. [PMID: 32288243 PMCID: PMC7126760 DOI: 10.1016/j.snb.2013.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/13/2013] [Accepted: 04/04/2013] [Indexed: 05/06/2023]
Abstract
This research reports the design, analysis, integration, and test of a prototype of a real-time convective polymerase chain reaction (RT-cPCR) machine that uses a color charged coupled device (CCD) for detecting the emission of fluorescence intensity from an RT-cPCR mix in a microliter volume glass capillary. Because of its simple mechanism, DNA amplification involves employing the cPCR technique with no need for thermocycling control. The flow pattern and temperature distribution can greatly affect the cPCR process in the capillary tube, a computational fluid dynamics (CFD) simulation was conducted in this study for the first time to estimate the required period of an RT-cPCR cycle. This study also tested the PCR mix containing hepatitis B virus (HBV) plasmid samples by using SYBR Green I fluorescence labeling dye to assess the prototype performance. The measured results from the image-processing scheme indicate that the RT-cPCR prototype with a CCD-based fluorometer can achieve similar DNA quantification reproducibility compared to commercial machines, even when the initial DNA concentration in the test PCR mix is reduced to 10 copies/μL.
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Affiliation(s)
- Yi-Fan Hsieh
- Department of Mechanical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Da-Sheng Lee
- Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology, Taipei 106, Taiwan
| | - Ping-Hei Chen
- Department of Mechanical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Shao-Kai Liao
- Department of Mechanical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Shiou-Hwei Yeh
- Graduate Institute of Microbiology, National Taiwan University, Taipei 106, Taiwan
| | - Pei-Jer Chen
- Graduate Institute of Clinical Medicine, National Taiwan University, Taipei 106, Taiwan
| | - An-Shik Yang
- Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology, Taipei 106, Taiwan
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26
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Recent Progress in Lab-on-a-Chip Technology and Its Potential Application to Clinical Diagnoses. Int Neurourol J 2013; 17:2-10. [PMID: 23610705 PMCID: PMC3627994 DOI: 10.5213/inj.2013.17.1.2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 03/26/2013] [Indexed: 12/02/2022] Open
Abstract
We present the construction of the lab-on-a-chip (LOC) system, a state-of-the-art technology that uses polymer materials (i.e., poly[dimethylsiloxane]) for the miniaturization of conventional laboratory apparatuses, and show the potential use of these microfluidic devices in clinical applications. In particular, we introduce the independent unit components of the LOC system and demonstrate how each component can be functionally integrated into one monolithic system for the realization of a LOC system. In specific, we demonstrate microscale polymerase chain reaction with the use of a single heater, a microscale sample injection device with a disposable plastic syringe and a strategy for device assembly under environmentally mild conditions assisted by surface modification techniques. In this way, we endeavor to construct a totally integrated, disposable microfluidic system operated by a single mode, the pressure, which can be applied on-site with enhanced device portability and disposability and with simple and rapid operation for medical and clinical diagnoses, potentially extending its application to urodynamic studies in molecular level.
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27
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Almassian DR, Cockrell LM, Nelson WM. Portable nucleic acid thermocyclers. Chem Soc Rev 2013; 42:8769-98. [DOI: 10.1039/c3cs60144g] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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28
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Priye A, Hassan YA, Ugaz VM. Education: DNA replication using microscale natural convection. LAB ON A CHIP 2012; 12:4946-54. [PMID: 23044724 DOI: 10.1039/c2lc40760d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
There is a need for innovative educational experiences that unify and reinforce fundamental principles at the interface between the physical, chemical, and life sciences. These experiences empower and excite students by helping them recognize how interdisciplinary knowledge can be applied to develop new products and technologies that benefit society. Microfluidics offers an incredibly versatile tool to address this need. Here we describe our efforts to create innovative hands-on activities that introduce chemical engineering students to molecular biology by challenging them to harness microscale natural convection phenomena to perform DNA replication via the polymerase chain reaction (PCR). Experimentally, we have constructed convective PCR stations incorporating a simple design for loading and mounting cylindrical microfluidic reactors between independently controlled thermal plates. A portable motion analysis microscope enables flow patterns inside the convective reactors to be directly visualized using fluorescent bead tracers. We have also developed a hands-on computational fluid dynamics (CFD) exercise based on modeling microscale thermal convection to identify optimal geometries for DNA replication. A cognitive assessment reveals that these activities strongly impact student learning in a positive way.
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Affiliation(s)
- Aashish Priye
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843-3122, USA
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29
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Pak N, Saunders DC, Phaneuf CR, Forest CR. Plug-and-play, infrared, laser-mediated PCR in a microfluidic chip. Biomed Microdevices 2012; 14:427-33. [PMID: 22218821 DOI: 10.1007/s10544-011-9619-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microfluidic polymerase chain reaction (PCR) systems have set milestones for small volume (100 nL-5 μL), amplification speed (100-400 s), and on-chip integration of upstream and downstream sample handling including purification and electrophoretic separation functionality. In practice, the microfluidic chips in these systems require either insertion of thermocouples or calibration prior to every amplification. These factors can offset the speed advantages of microfluidic PCR and have likely hindered commercialization. We present an infrared, laser-mediated, PCR system that features a single calibration, accurate and repeatable precision alignment, and systematic thermal modeling and management for reproducible, open-loop control of PCR in 1 μL chambers of a polymer microfluidic chip. Total cycle time is less than 12 min: 1 min to fill and seal, 10 min to amplify, and 1 min to recover the sample. We describe the design, basis for its operation, and the precision engineering in the system and microfluidic chip. From a single calibration, we demonstrate PCR amplification of a 500 bp amplicon from λ-phage DNA in multiple consecutive trials on the same instrument as well as multiple identical instruments. This simple, relatively low-cost plug-and-play design is thus accessible to persons who may not be skilled in assembly and engineering.
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Affiliation(s)
- Nikita Pak
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Room 2103, 315 Ferst Drive, Atlanta, GA, USA.
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30
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Tsai YL, Lin YC, Chou PH, Teng PH, Lee PY. Detection of white spot syndrome virus by polymerase chain reaction performed under insulated isothermal conditions. J Virol Methods 2012; 181:134-7. [DOI: 10.1016/j.jviromet.2012.01.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 01/16/2012] [Accepted: 01/18/2012] [Indexed: 10/14/2022]
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31
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Wu W, Trinh KTL, Lee NY. Hand-held syringe as a portable plastic pump for on-chip continuous-flow PCR: miniaturization of sample injection device. Analyst 2012; 137:983-90. [DOI: 10.1039/c2an15860d] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Chou WP, Chen PH, Miao M, Kuo LS, Yeh SH, Chen PJ. Rapid DNA amplification in a capillary tube by natural convection with a single isothermal heater. Biotechniques 2011; 50:52-7. [PMID: 21231923 DOI: 10.2144/000113589] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Herein we describe a simple platform for rapid DNA amplification using convection. Capillary convective PCR (CCPCR) heats the bottom of a capillary tube using a dry bath maintained at a fixed temperature of 95°C. The tube is then cooled by the surrounding air, creating a temperature gradient in which a sample can undergo PCR amplification by natural convection through reagent circulation. We demonstrate that altering the melting temperature of the primers relative to the lowest temperature in the tube affects amplification efficiency; adjusting the denaturation temperature of the amplicon relative to the highest temperature in the tube affects maximum amplicon size, with amplicon lengths of ≤500 bp possible. Based on these criteria, we successfully amplified DNA sequences from three different viral genomes in 30 min using CCPCR, with a sensitivity of ~30 copies per reaction.
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Affiliation(s)
- Wen Pin Chou
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
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34
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Abstract
The hallmark of living matter is the replication of genetic molecules and their active storage against diffusion. We implement both in the simple nonequilibrium environment of a temperature gradient. Convective flow both drives the DNA replicating polymerase chain reaction while concurrent thermophoresis accumulates the replicated 143 base pair DNA in bulk solution. The time constant for accumulation is 92 s while DNA is doubled every 50 s. The experiments explore conditions in pores of hydrothermal rock which can serve as a model environment for the origin of life.
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Affiliation(s)
- Christof B Mast
- Systems Biophysics, Physics Department, Center for Nanoscience, Ludwig Maximilians Universität München, Amalienstrasse 54, 80799 München, Germany
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35
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Chung KH, Park SH, Choi YH. A palmtop PCR system with a disposable polymer chip operated by the thermosiphon effect. LAB ON A CHIP 2010; 10:202-10. [PMID: 20066248 DOI: 10.1039/b915022f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A small thermocyling system to perform DNA amplification by polymerase chain reaction (PCR) is presented in this report. PCR reactants are convected along a triangular closed-loop channel in a polymer chip by the thermosiphon effect. In an effort to develop a convection-based PCR for real application, we adopted a molded channel to define the flow path inside the chip, so that the chip may be suitable for disposability together with the merits of LOC; mass production, versatile integration and facile handling. We developed the geometry of the flow loop that made it easier to load the PCR reactants without air pockets inside. Based on systematic simulations and theoretical considerations of buoyant flows, the loop channel was designed to acquire an optimized flow for PCR. A PCR sample was dropped on a chip to fill the loop channel, and the chip was inserted into a slot of a heating block unit that was composed of three metal blocks with different temperatures. The temperature differences within the closed loop gave rise to buoyancy differences and the liquid reactant continuously circulated along the closed loop by the thermosiphon effect. Because there was no loss of time among the temperature shifts in the reaction steps, approximately 10 min were sufficient for the detectable amplification of 127 bp target gene from 10 pg microl(-1) of PCR fragments. In addition, it took 20 min for the mass amplification of 470 bp gene from PCR fragments or genomic DNA. The entire PCR system is compact enough even to be palmtop because it requires only a tiny temperature controller for a self-actuated thermosiphon flow. This thermocycling system would be a prototypical model for the field application of PCR.
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Affiliation(s)
- Kwang Hyo Chung
- BioMEMS Team, Electronics and Telecommunications Research Institute (ETRI), 138 Gajeong-no, Yuseong-gu, Daejeon, 305-700, Republic of Korea
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36
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Xu ZR, Wang X, Fan XF, Wang JH. An extrusion fluidic driving method for continuous-flow polymerase chain reaction on a microfluidic chip. Mikrochim Acta 2009. [DOI: 10.1007/s00604-009-0262-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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37
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Duwensee H, Mix M, Stubbe M, Gimsa J, Adler M, Flechsig GU. Electrochemical product detection of an asymmetric convective polymerase chain reaction. Biosens Bioelectron 2009; 25:400-5. [DOI: 10.1016/j.bios.2009.07.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 07/16/2009] [Accepted: 07/23/2009] [Indexed: 10/20/2022]
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38
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Kim SJ, Wang F, Burns MA, Kurabayashi K. Temperature-programmed natural convection for micromixing and biochemical reaction in a single microfluidic chamber. Anal Chem 2009; 81:4510-6. [PMID: 19419189 PMCID: PMC2727855 DOI: 10.1021/ac900512x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Micromixing is a crucial step for biochemical reactions in microfluidic networks. A critical challenge is that the system containing micromixers needs numerous pumps, chambers, and channels not only for the micromixing but also for the biochemical reactions and detections. Thus, a simple and compatible design of the micromixer element for the system is essential. Here, we propose a simple, yet effective, scheme that enables micromixing and a biochemical reaction in a single microfluidic chamber without using any pumps. We accomplish this process by using natural convection in conjunction with alternating heating of two heaters for efficient micromixing, and by regulating capillarity for sample transport. As a model application, we demonstrate micromixing and subsequent polymerase chain reaction (PCR) for an influenza viral DNA fragment. This process is achieved in a platform of a microfluidic cartridge and a microfabricated heating-instrument with a fast thermal response. Our results will significantly simplify micromixing and a subsequent biochemical reaction that involves reagent heating in microfluidic networks.
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Affiliation(s)
- Sung-Jin Kim
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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39
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Zhang C, Xing D. Parallel DNA amplification by convective polymerase chain reaction with various annealing temperatures on a thermal gradient device. Anal Biochem 2009; 387:102-12. [DOI: 10.1016/j.ab.2009.01.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 12/11/2022]
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40
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The Grand Point-of-Care Challenge. POINT OF CARE 2008. [DOI: 10.1097/poc.0b013e318182f9c4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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41
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Abstract
The authors have designed a novel convective flow-based thermocycling system capable of performing high-speed DNA amplification via the polymerase chain reaction in a simplified and inexpensive format. Successful amplification of a 191 bp influenza-A target is demonstrated within 25 minutes using a 10 muL reaction volume with no modification to standard laboratory protocols. The system is simple to assemble and can be readily integrated with existing laboratory instrumentation for automated operation.
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42
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Wang F, Yang M, Burns MA. Microfabricated valveless devices for thermal bioreactions based on diffusion-limited evaporation. LAB ON A CHIP 2008; 8:88-97. [PMID: 18094766 PMCID: PMC2752386 DOI: 10.1039/b711770a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Microfluidic devices that reduce evaporative loss during thermal bioreactions such as PCR without microvalves have been developed by relying on the principle of diffusion-limited evaporation. Both theoretical and experimental results demonstrate that the sample evaporative loss can be reduced by more than 20 times using long narrow diffusion channels on both sides of the reaction region. In order to further suppress the evaporation, the driving force for liquid evaporation is reduced by two additional techniques: decreasing the interfacial temperature using thermal isolation and reducing the vapor concentration gradient by replenishing water vapor in the diffusion channels. Both thermal isolation and vapor replenishment techniques can limit the sample evaporative loss to approximately 1% of the reaction content.
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Affiliation(s)
- Fang Wang
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109
| | - Ming Yang
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109
| | - Mark A. Burns
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109
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Sun Y, Kwok YC, Nguyen NT. A circular ferrofluid driven microchip for rapid polymerase chain reaction. LAB ON A CHIP 2007; 7:1012-7. [PMID: 17653343 DOI: 10.1039/b700575j] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In the past few years, much attention has been paid to the development of miniaturized polymerase chain reaction (PCR) devices. After a continuous flow (CF) PCR chip was introduced, several CFPCR systems employing various pumping mechanisms were reported. However, the use of pumps increases cost and imposes a high requirement on microchip bonding integrity due to the application of high pressure. Other significant limitations of CFPCR devices include the large footprint of the microchip and the fixed cycle number which is dictated by the channel layout. In this paper, we present a novel circular close-loop ferrofluid driven microchip for rapid PCR. A small ferrofluid plug, containing sub-domain magnetic particles in a liquid carrier, is driven by an external magnet along the circular microchannel, which in turn propels the PCR mixture through three temperature zones. Amplification of a 500 bp lambda DNA fragment has been demonstrated on the polymethyl methacrylate (PMMA) PCR microchip fabricated by CO(2) laser ablation and bonded by a low pressure, high temperature technique. Successful PCR was achieved in less than 4 min. Effects of cycle number and cycle time on PCR products were investigated. Using a magnet as the actuator eliminates the need for expensive pumps and provides advantages of low cost, small power consumption, low requirement on bonding strength and flexible number of PCR cycles. Furthermore, the microchip has a much simpler design and smaller footprint compared to the rectangular serpentine CFPCR devices. To demonstrate its application in forensics, a 16-loci short tandem repeat (STR) sample was successfully amplified using the PCR microchip.
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Affiliation(s)
- Y Sun
- National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616
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44
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45
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Zhong JF, Weiner LP, Burke K, Taylor CR. Viral RNA extraction for in-the-field analysis. J Virol Methods 2007; 144:98-102. [PMID: 17548117 PMCID: PMC3635480 DOI: 10.1016/j.jviromet.2007.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 04/16/2007] [Accepted: 04/25/2007] [Indexed: 11/22/2022]
Abstract
Retroviruses encode their genetic information with RNA molecules, and have a high genomic recombination rate which allows them to mutate more rapidly, thereby posting a higher risk to humans. One important way to help combat a pandemic of viral infectious diseases is early detection before large-scale outbreaks occur. The polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR) have been used to identify precisely different strains of some very closely related pathogens. However, isolation and detection of viral RNA in the field are difficult due to the unstable nature of viral RNA molecules. Consequently, performing in-the-field nucleic acid analysis to monitor the spread of viruses is financially and technologically challenging in remote and underdeveloped regions that are high-risk areas for outbreaks. A simplified rapid viral RNA extraction method is reported to meet the requirements for in-the-field viral RNA extraction and detection. The ability of this device to perform viral RNA extraction with subsequent RT-PCR detection of retrovirus is demonstrated. This inexpensive device has the potential to be distributed on a large scale to underdeveloped regions for early detection of retrovirus, with the possibility of reducing viral pandemic events.
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Affiliation(s)
- Jiang F Zhong
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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46
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Affiliation(s)
- Nitin Agrawal
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA
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47
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Ohashi T, Kuyama H, Hanafusa N, Togawa Y. A simple device using magnetic transportation for droplet-based PCR. Biomed Microdevices 2007; 9:695-702. [PMID: 17505884 DOI: 10.1007/s10544-007-9078-y] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The Polymerase chain reaction (PCR) was successfully and rapidly performed in a simple reaction device devoid of channels, pumps, valves, or other control elements used in conventional lab-on-a-chip technology. The basic concept of this device is the transportation of aqueous droplets containing hydrophilic magnetic beads in a flat-bottomed, tray-type reactor filled with silicone oil. The whole droplets sink to the bottom of the reactor because their specific gravity is greater than that of the silicone oil used here. The droplets follow the movement of a magnet located underneath the reactor. The notable advantage of the droplet-based PCR is the ability to switch rapidly the proposed reaction temperature by moving the droplets to the required temperature zones in the temperature gradient. The droplet-based reciprocative thermal cycling was performed by moving the droplets composed of PCR reaction mixture to the designated temperature zones on a linear temperature gradient from 50 degrees C to 94 degrees C generated on the flat bottom plate of the tray reactor. Using human-derived DNA containing the mitochondria genes as the amplification targets, the droplet-based PCR with magnetic reciprocative thermal cycling successfully provided the five PCR products ranging from 126 to 1,219 bp in 11 min with 30 cycles. More remarkably, the human genomic gene amplification targeting glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was accomplished rapidly in 3.6 min with 40 cycles.
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Affiliation(s)
- Tetsuo Ohashi
- Life Science Laboratory, Analytical and Measuring Instruments Division, Shimadzu Corporation, Kyoto, 604-8511, Japan.
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48
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Xiang Q, Xu B, Li D. Miniature real time PCR on chip with multi-channel fiber optical fluorescence detection module. Biomed Microdevices 2007; 9:443-9. [PMID: 17265146 DOI: 10.1007/s10544-007-9048-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This paper presents the design and implementation of a miniature real time PCR system consisting of a disposable reactor chip, a miniature thermal cycler, and a multi-channel fiber optical fluorescence excitation/detection module. The disposable PCR chip is fabricated by using soft photolithography by PDMS (Polydimethylsiloxane) and glass. The miniature thermal cycler has a thin film heater for heating and a fan for rapid cooling. The fiber optical detection module consists of laser, filter cube, photo-detector and 1x4 fiber optical switch. It is capable of four-well real time PCR analysis. Real-time PCR detection of E. coli stx1 has been demonstrated successfully with this system.
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Affiliation(s)
- Q Xiang
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, M5S 3G8, Canada
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49
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Liu RH, Lee AP. PCR in Integrated Microfluidic Systems. INTEGRATED BIOCHIPS FOR DNA ANALYSIS 2007. [PMCID: PMC7124038 DOI: 10.1007/978-0-387-76759-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Miniaturized integrated DNA analysis systems offer the potential to provide unprecedented advances in cost and speed relative to current benchtop-scale instrumentation by allowing rapid bioanalysis assays to be performed in a portable self contained device format that can be inexpensively mass-produced. The polymerase chain reaction (PCR) has been a natural focus of many of these miniaturization efforts, owing to its capability to efficiently replicate target regions of interest from small quantities template DNA. Scale-down of PCR has proven to be particularly challenging, however, due to an unfavorable combination of relatively severe temperature extremes (resulting in the need to repeatedly heat minute aqueous sample volumes to temperatures in the vicinity of 95°C with minimal evaporation) and high surface area to volume conditions imposed by nanoliter reactor geometries (often leading to inhibition of the reaction by nonspecific adsorption of reagents at the reactor walls). Despite these daunting challenges, considerable progress has been made in the development of microfluidic devices capable of performing increasingly sophisticated PCR-based bioassays. This chapter reviews the progress that has been made to date and assesses the outlook for future advances.
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Affiliation(s)
- Robin Hui Liu
- Osmetech Molecular Diagnostics, Pasadena, California USA
| | - Abraham P. Lee
- University of California at Irvine, Irvine, California USA
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50
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Xiang Q, Xu B, Fu R, Li D. Real time PCR on disposable PDMS chip with a miniaturized thermal cycler. Biomed Microdevices 2006; 7:273-9. [PMID: 16404505 DOI: 10.1007/s10544-005-6069-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This paper presents the design and implementation of a low-cost miniature PCR device consisting of a disposable reactor chip and a miniature thermal cycler. The simple fabrication of the PCR chip by PDMS (Polydimethylsiloxane) does not need micro-machining or photolithography processes. The thermal cycler was built with a thin film heater for heating and a fan for rapid cooling. This device can perform PCR tests in a single well chip or a multiple-well chip. It can run PCR reactions of different volumes to meet specific application requirements. The smallest reaction volume tested in this work is 0.9 microL. In addition, this device fits any standard fluorescence microscope for real time detection, which makes real time PCR affordable for most research labs and clinics with a fluorescence microscope. Real-time PCR of E. coli stx1 has been demonstrated with the device described.
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Affiliation(s)
- Q Xiang
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Canada
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