151
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Damhorst GL, Duarte-Guevara C, Chen W, Ghonge T, Cunningham BT, Bashir R. Smartphone-Imaged HIV-1 Reverse-Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) on a Chip from Whole Blood. ENGINEERING (BEIJING, CHINA) 2015; 1:324-335. [PMID: 26705482 PMCID: PMC4687746 DOI: 10.15302/j-eng-2015072] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Viral load measurements are an essential tool for the long-term clinical care of hum an immunodeficiency virus (HIV)-positive individuals. The gold standards in viral load instrumentation, however, are still too limited by their size, cost, and sophisticated operation for these measurements to be ubiquitous in remote settings with poor healthcare infrastructure, including parts of the world that are disproportionately affected by HIV infection. The challenge of developing a point-of-care platform capable of making viral load more accessible has been frequently approached but no solution has yet emerged that meets the practical requirements of low cost, portability, and ease-of-use. In this paper, we perform reverse-transcription loop-mediated isothermal amplification (RT-LAMP) on minimally processed HIV-spiked whole blood samples with a microfluidic and silicon microchip platform, and perform fluorescence measurements with a consumer smartphone. Our integrated assay shows amplification from as few as three viruses in a ~ 60 nL RT-LAMP droplet, corresponding to a whole blood concentration of 670 viruses per µL of whole blood. The technology contains greater power in a digital RT-LAMP approach that could be scaled up for the determination of viral load from a finger prick of blood in the clinical care of HIV-positive individuals. We demonstrate that all aspects of this viral load approach, from a drop of blood to imaging the RT-LAMP reaction, are compatible with lab-on-a-chip components and mobile instrumentation.
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Affiliation(s)
- Gregory L. Damhorst
- Department of Bioengineering, The University of Illinois at
Urbana-Champaign, Urbana, IL 61801, USA
- Micro and Nanotechnology Laboratory, The University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Carlos Duarte-Guevara
- Micro and Nanotechnology Laboratory, The University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, The
University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Weili Chen
- Micro and Nanotechnology Laboratory, The University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, The
University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Tanmay Ghonge
- Department of Bioengineering, The University of Illinois at
Urbana-Champaign, Urbana, IL 61801, USA
- Micro and Nanotechnology Laboratory, The University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Brian T. Cunningham
- Department of Bioengineering, The University of Illinois at
Urbana-Champaign, Urbana, IL 61801, USA
- Micro and Nanotechnology Laboratory, The University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, The
University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rashid Bashir
- Department of Bioengineering, The University of Illinois at
Urbana-Champaign, Urbana, IL 61801, USA
- Micro and Nanotechnology Laboratory, The University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, The
University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Correspondence author.
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152
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Wang P, Jing F, Li G, Wu Z, Cheng Z, Zhang J, Zhang H, Jia C, Jin Q, Mao H, Zhao J. Absolute quantification of lung cancer related microRNA by droplet digital PCR. Biosens Bioelectron 2015; 74:836-42. [PMID: 26232679 DOI: 10.1016/j.bios.2015.07.048] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/20/2015] [Accepted: 07/21/2015] [Indexed: 11/16/2022]
Abstract
Digital polymerase chain reaction (digital PCR) enables the absolute quantification of nucleic acids through the counting of single molecules, thus eliminating the need for standard curves or endogenous controls. In this study, we developed a droplet digital PCR (ddPCR) system based on an oil saturated PDMS (OSP) microfluidic chip platform for quantification of lung cancer related microRNA (miRNA). The OSP chip was made with PDMS and was oil saturated to constrain oil swallow and maintain the stability of droplets. Two inlets were designed for oil and sample injection with a syringe pump at the outlet. Highly uniform monodisperse water-in-oil emulsion droplets to be used for subsequent detection and analysis were generated at the cross section of the channel. We compared miRNA quantification by the ddPCR system and quantitative real-time PCR (qPCR) to demonstrate that the ddPCR system was superior to qPCR both in its detection limit and smaller fold changes measurement. This droplet PCR system provides new possibilities for highly sensitive and efficient detection of cancer-related genes.
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Affiliation(s)
- Ping Wang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Fengxiang Jing
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China
| | - Gang Li
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China; School of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
| | - Zhenhua Wu
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Zule Cheng
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Jishen Zhang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China
| | - Honglian Zhang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China
| | - Chunping Jia
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China
| | - Qinghui Jin
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China
| | - Hongju Mao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China.
| | - Jianlong Zhao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, China.
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153
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Schuler F, Schwemmer F, Trotter M, Wadle S, Zengerle R, von Stetten F, Paust N. Centrifugal step emulsification applied for absolute quantification of nucleic acids by digital droplet RPA. LAB ON A CHIP 2015; 15:2759-66. [PMID: 25947077 DOI: 10.1039/c5lc00291e] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Aqueous microdroplets provide miniaturized reaction compartments for numerous chemical, biochemical or pharmaceutical applications. We introduce centrifugal step emulsification for the fast and easy production of monodisperse droplets. Homogenous droplets with pre-selectable diameters in a range from 120 μm to 170 μm were generated with coefficients of variation of 2-4% and zero run-in time or dead volume. The droplet diameter depends on the nozzle geometry (depth, width, and step size) and interfacial tensions only. Droplet size is demonstrated to be independent of the dispersed phase flow rate between 0.01 and 1 μl s(-1), proving the robustness of the centrifugal approach. Centrifugal step emulsification can easily be combined with existing centrifugal microfluidic unit operations, is compatible to scalable manufacturing technologies such as thermoforming or injection moulding and enables fast emulsification (>500 droplets per second and nozzle) with minimal handling effort (2-3 pipetting steps). The centrifugal microfluidic droplet generation was used to perform the first digital droplet recombinase polymerase amplification (ddRPA). It was used for absolute quantification of Listeria monocytogenes DNA concentration standards with a total analysis time below 30 min. Compared to digital droplet polymerase chain reaction (ddPCR), with processing times of about 2 hours, the overall processing time of digital analysis was reduced by more than a factor of 4.
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154
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Kistrup K, Poulsen CE, Hansen MF, Wolff A. Ultrasonic welding for fast bonding of self-aligned structures in lab-on-a-chip systems. LAB ON A CHIP 2015; 15:1998-2001. [PMID: 25806857 DOI: 10.1039/c5lc00174a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ultrasonic welding is a rapid, promising bonding method for the bonding of polymer chips; yet its use is still limited. We present two lab-on-a-chip applications where ultrasonic welding can be preferably applied: (1) self-aligned gapless bonding of a two-part chip with a tolerance of 50 μm; (2) bonding of a large area shallow chamber (1.8 cm(2) × 150 μm). Using injection moulding combined with ultrasonic welding we achieved a total production and bonding time of 60 s per chip, and a batch of chips could be produced within a day going from design to finished chips. We believe that the technical solutions offered here can significantly help bridge the gap between academia and industry, where the differences in production methods and materials pose a challenge when transferring technology.
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Affiliation(s)
- K Kistrup
- Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby, Denmark.
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155
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Hess D, Rane A, deMello AJ, Stavrakis S. High-throughput, quantitative enzyme kinetic analysis in microdroplets using stroboscopic epifluorescence imaging. Anal Chem 2015; 87:4965-72. [PMID: 25849725 DOI: 10.1021/acs.analchem.5b00766] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Droplet-based microfluidic systems offer a range of advantageous features for the investigation of enzyme kinetics, including high time resolution and the ability to probe extremely large numbers of discrete reactions while consuming low sample volumes. Kinetic measurements within droplet-based microfluidic systems are conventionally performed using single point detection schemes. Unfortunately, such an approach prohibits the measurement of an individual droplet over an extended period of time. Accordingly, we present a novel approach for the extensive characterization of enzyme-inhibitor reaction kinetics within a single experiment by tracking individual and rapidly moving droplets as they pass through an extended microfluidic channel. A series of heterogeneous and pL-volume droplets, containing varying concentrations of the fluorogenic substrate resorufin β-d-galactopyranoside and a constant amount of the enzyme β-galactosidase, is produced at frequencies in excess of 150 Hz. By stroboscopic manipulation of the excitation laser light and adoption of a dual view detection system, "blur-free" images containing up to 150 clearly distinguishable droplets per frame are extracted, which allow extraction of kinetic data from all formed droplets. The efficiency of this approach is demonstrated via a Michaelis-Menten analysis which yields a Michaelis constant, Km, of 353 μM. Additionally, the dissociation constant for the competitive inhibitor isopropyl β-d-1-thiogalactopyranoside is extracted using the same method.
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Affiliation(s)
- David Hess
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, 8093 Zürich, Switzerland
| | - Anandkumar Rane
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, 8093 Zürich, Switzerland
| | - Andrew J deMello
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, 8093 Zürich, Switzerland
| | - Stavros Stavrakis
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, 8093 Zürich, Switzerland
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156
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Eastburn DJ, Huang Y, Pellegrino M, Sciambi A, Ptáček LJ, Abate AR. Microfluidic droplet enrichment for targeted sequencing. Nucleic Acids Res 2015; 43:e86. [PMID: 25873629 PMCID: PMC4513844 DOI: 10.1093/nar/gkv297] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/26/2015] [Indexed: 02/07/2023] Open
Abstract
Targeted sequence enrichment enables better identification of genetic variation by providing increased sequencing coverage for genomic regions of interest. Here, we report the development of a new target enrichment technology that is highly differentiated from other approaches currently in use. Our method, MESA (Microfluidic droplet Enrichment for Sequence Analysis), isolates genomic DNA fragments in microfluidic droplets and performs TaqMan PCR reactions to identify droplets containing a desired target sequence. The TaqMan positive droplets are subsequently recovered via dielectrophoretic sorting, and the TaqMan amplicons are removed enzymatically prior to sequencing. We demonstrated the utility of this approach by generating an average 31.6-fold sequence enrichment across 250 kb of targeted genomic DNA from five unique genomic loci. Significantly, this enrichment enabled a more comprehensive identification of genetic polymorphisms within the targeted loci. MESA requires low amounts of input DNA, minimal prior locus sequence information and enriches the target region without PCR bias or artifacts. These features make it well suited for the study of genetic variation in a number of research and diagnostic applications.
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Affiliation(s)
- Dennis J Eastburn
- Department of Bioengineering and Therapeutic Sciences, California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158, USA Mission Bio, Inc., San Francisco, CA 94107, USA
| | - Yong Huang
- Department of Neurology and Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | | | - Adam Sciambi
- Department of Bioengineering and Therapeutic Sciences, California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158, USA Mission Bio, Inc., San Francisco, CA 94107, USA
| | - Louis J Ptáček
- Department of Neurology and Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | - Adam R Abate
- Department of Bioengineering and Therapeutic Sciences, California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158, USA
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157
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Abstract
Many methods have been developed for DNA integrity assessment including electrophoresis-based procedures, quantitative PCR, and, more recently, microfluidics-based procedures. DNA integrity evaluation can be employed for characterizing biological samples quality before extensive genomic analysis and also finds applications in reproductive medicine, prenatal diagnostics, or cancer research. In this chapter, we will focus on the assessment of DNA integrity in cancer research. In particular, we will present the application of the determination of DNA integrity for tracking of circulating tumor DNA. Finally, we will conclude by illustrating the potential innovative application of DNA integrity as a biomarker in clinical research, especially for prognostic purposes, patient follow-up, or early diagnosis.
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158
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Kim M, Pan M, Gai Y, Pang S, Han C, Yang C, Tang SKY. Optofluidic ultrahigh-throughput detection of fluorescent drops. LAB ON A CHIP 2015; 15:1417-23. [PMID: 25588522 DOI: 10.1039/c4lc01465k] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
This paper describes an optofluidic droplet interrogation device capable of counting fluorescent drops at a throughput of 254,000 drops per second. To our knowledge, this rate is the highest interrogation rate published thus far. Our device consists of 16 parallel microfluidic channels bonded directly to a filter-coated two-dimensional Complementary Metal-Oxide-Semiconductor (CMOS) sensor array. Fluorescence signals emitted from the drops are collected by the sensor that forms the bottom of the channel. The proximity of the drops to the sensor facilitates efficient collection of fluorescence emission from the drops, and overcomes the trade-off between light collection efficiency and field of view in conventional microscopy. The interrogation rate of our device is currently limited by the acquisition speed of CMOS sensor, and is expected to increase further as high-speed sensors become increasingly available.
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Affiliation(s)
- Minkyu Kim
- Department of Mechanical Engineering, Stanford University, CA 94305, USA.
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159
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Perez-Toralla K, Pekin D, Bartolo JF, Garlan F, Nizard P, Laurent-Puig P, Baret JC, Taly V. PCR digitale en micro-compartiments. Med Sci (Paris) 2015; 31:84-92. [DOI: 10.1051/medsci/20153101017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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160
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Assessment of surfactants for efficient droplet PCR in mineral oil using the pendant drop technique. Colloids Surf B Biointerfaces 2015; 126:489-95. [DOI: 10.1016/j.colsurfb.2015.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 12/11/2014] [Accepted: 01/04/2015] [Indexed: 11/17/2022]
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161
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Dressler OJ, Yang T, Chang SI, Choo J, Wootton RCR, deMello AJ. Continuous and low error-rate passive synchronization of pre-formed droplets. RSC Adv 2015. [DOI: 10.1039/c5ra08044d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A microfluidic droplet-handling architecture for the synchronization of asynchronous, mis-matched, pre-formed droplet streams is demonstrated.
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Affiliation(s)
- O. J. Dressler
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zürich
- 8093 Zürich
- Switzerland
| | - T. Yang
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zürich
- 8093 Zürich
- Switzerland
| | - S.-I. Chang
- Department of Biochemistry
- Chungbuk National University
- Cheongju
- South Korea
| | - J. Choo
- Department of BionanoTechnology
- Hanyang University
- Ansan 426-791
- South Korea
| | - R. C. R. Wootton
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zürich
- 8093 Zürich
- Switzerland
| | - A. J. deMello
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zürich
- 8093 Zürich
- Switzerland
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162
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Ding Y, Casadevall i Solvas X, deMello A. “V-junction”: a novel structure for high-speed generation of bespoke droplet flows. Analyst 2015; 140:414-21. [DOI: 10.1039/c4an01730g] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present the use of microfluidic “V-junctions” as a droplet generation strategy that incorporates enhanced performance characteristics when compared to more traditional “T-junction” formats.
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Affiliation(s)
- Yun Ding
- Department of Chemistry and Applied Biosciences
- Institute for Chemical and Bioengineering
- ETH Zurich
- Zurich
- Switzerland
| | - Xavier Casadevall i Solvas
- Department of Chemistry and Applied Biosciences
- Institute for Chemical and Bioengineering
- ETH Zurich
- Zurich
- Switzerland
| | - Andrew deMello
- Department of Chemistry and Applied Biosciences
- Institute for Chemical and Bioengineering
- ETH Zurich
- Zurich
- Switzerland
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163
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Abstract
Droplet microfluidics may soon change the paradigm of performing chemical analyses and related instrumentation.
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Affiliation(s)
- Evgenia Yu Basova
- Masaryk University
- CEITEC, Central European Institute Technology
- Brno
- Czech Republic
| | - Frantisek Foret
- Masaryk University
- CEITEC, Central European Institute Technology
- Brno
- Czech Republic
- Institute of Analytical Chemistry of the Academy of Sciences of the Czech Republic
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164
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Tangen U, Sharma A, Wagler P, McCaskill JS. On demand nanoliter-scale microfluidic droplet generation, injection, and mixing using a passive microfluidic device. BIOMICROFLUIDICS 2015; 9:014119. [PMID: 25759752 PMCID: PMC4327917 DOI: 10.1063/1.4907895] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 01/29/2015] [Indexed: 05/10/2023]
Abstract
We here present and characterize a programmable nanoliter scale droplet-on-demand device that can be used separately or readily integrated into low cost single layer rapid prototyping microfluidic systems for a wide range of user applications. The passive microfluidic device allows external (off-the-shelf) electronically controlled pinch valves to program the delivery of nanoliter scale aqueous droplets from up to 9 different inputs to a central outlet channel. The inputs can be either continuous aqueous fluid streams or microliter scale aqueous plugs embedded in a carrier fluid, in which case the number of effective input solutions that can be employed in an experiment is no longer strongly constrained (100 s-1000 s). Both nanoliter droplet sequencing output and nanoliter-scale droplet mixing are reported with this device. Optimization of the geometry and pressure relationships in the device was achieved in several hardware iterations with the support of open source microfluidic simulation software and equivalent circuit models. The requisite modular control of pressure relationships within the device is accomplished using hydrodynamic barriers and matched resistance channels with three different channel heights, custom parallel reversible microfluidic I/O connections, low dead-volume pinch valves, and a simply adjustable array of external screw valves. Programmable sequences of droplet mixes or chains of droplets can be achieved with the device at low Hz frequencies, limited by device elasticity, and could be further enhanced by valve integration. The chip has already found use in the characterization of droplet bunching during export and the synthesis of a DNA library.
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Affiliation(s)
- Uwe Tangen
- Faculty of Chemistry and Biochemistry, Microsystems Chemistry and BioIT (BioMIP), Ruhr-University Bochum , 44780 Bochum, Germany
| | - Abhishek Sharma
- Faculty of Chemistry and Biochemistry, Microsystems Chemistry and BioIT (BioMIP), Ruhr-University Bochum , 44780 Bochum, Germany
| | - Patrick Wagler
- Faculty of Chemistry and Biochemistry, Microsystems Chemistry and BioIT (BioMIP), Ruhr-University Bochum , 44780 Bochum, Germany
| | - John S McCaskill
- Faculty of Chemistry and Biochemistry, Microsystems Chemistry and BioIT (BioMIP), Ruhr-University Bochum , 44780 Bochum, Germany
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165
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Muluneh M, Kim B, Buchsbaum G, Issadore D. Miniaturized, multiplexed readout of droplet-based microfluidic assays using time-domain modulation. LAB ON A CHIP 2014; 14:4638-46. [PMID: 25311204 PMCID: PMC4418803 DOI: 10.1039/c4lc00819g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Recent advances in microfluidics to generate and control picoliter emulsions of water in oil have enabled ultra-sensitive assays for small molecules, proteins, nucleic acids, and cells. Unfortunately, the conventional fluorescence detection used to measure the outcome of these droplet-based assays has not proven suited to match the time and space multiplexing capabilities of microfluidic systems. To address this challenge, we developed an in-flow fluorescence detection platform that enables multiple streams of droplets to be monitored using only a single photodetector and no lenses. The key innovation of our technology is the amplitude modulation of the signal from fluorescent droplets using distinct micro-patterned masks for each channel. By taking advantage of the high bandwidth of electronics, our technique enables the velocity-independent recovery of weak fluorescent signals (SNR ≪ 1) using only simple hardware, obviating the need for lasers, bulky detectors, and complex fluid control. We demonstrated a handheld-sized device that simultaneously monitors four independent channels with the capability to be scaled-up to more than sixteen, limited primarily by the droplet density.
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Affiliation(s)
- Melaku Muluneh
- Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bawul Kim
- Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gershon Buchsbaum
- Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - David Issadore
- Bioengineering and Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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166
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Norian H, Field RM, Kymissis I, Shepard KL. An integrated CMOS quantitative-polymerase-chain-reaction lab-on-chip for point-of-care diagnostics. LAB ON A CHIP 2014; 14:4076-84. [PMID: 25177916 DOI: 10.1039/c4lc00443d] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Considerable effort has recently been directed toward the miniaturization of quantitative-polymerase-chain-reaction (qPCR) instrumentation in an effort to reduce both cost and form factor for point-of-care applications. Considerable gains have been made in shrinking the required volumes of PCR reagents, but resultant prototypes retain their bench-top form factor either due to heavy heating plates or cumbersome optical sensing instrumentation. In this paper, we describe the use of complementary-metal-oxide semiconductor (CMOS) integrated circuit (IC) technology to produce a fully integrated qPCR lab-on-chip. Exploiting a 0.35 μm high-voltage CMOS process, the IC contains all of the key components for performing qPCR. Integrated resistive heaters and temperature sensors regulate the surface temperature of the chip to an accuracy of 0.45 °C. Electrowetting-on-dielectric microfluidics are actively driven from the chip surface, allowing for droplet generation and transport down to volumes less than 1.2 nanoliter. Integrated single-photon avalanche diodes (SPADs) are used for fluorescent monitoring of the reaction, allowing for the quantification of target DNA with more than four-orders-of-magnitude of dynamic range and sensitivities down to a single copy per droplet. Using this device, reliable and sensitive real-time proof-of-concept detection of Staphylococcus aureus (S. aureus) is demonstrated.
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Affiliation(s)
- Haig Norian
- Columbia University, Department of Electrical Engineering, 500 W. 120th St., New York, New York 10027, USA.
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167
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Ge S, Liu W, Schlappi T, Ismagilov RF. Digital, Ultrasensitive, End-Point Protein Measurements with Large Dynamic Range via Brownian Trapping with Drift. J Am Chem Soc 2014; 136:14662-5. [DOI: 10.1021/ja507849b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Shencheng Ge
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
| | - Weishan Liu
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
| | - Travis Schlappi
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
| | - Rustem F. Ismagilov
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
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168
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Laurent-Puig P, Pekin D, Normand C, Kotsopoulos SK, Nizard P, Perez-Toralla K, Rowell R, Olson J, Srinivasan P, Le Corre D, Hor T, El Harrak Z, Li X, Link DR, Bouché O, Emile JF, Landi B, Boige V, Hutchison JB, Taly V. Clinical relevance of KRAS-mutated subclones detected with picodroplet digital PCR in advanced colorectal cancer treated with anti-EGFR therapy. Clin Cancer Res 2014; 21:1087-97. [PMID: 25248381 DOI: 10.1158/1078-0432.ccr-14-0983] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE KRAS mutations are predictive of nonresponse to anti-EGFR therapies in metastatic colorectal cancer (mCRC). However, only 50% of nonmutated patients benefit from them. KRAS-mutated subclonal populations nondetectable by conventional methods have been suggested as the cause of early progression. Molecular analysis technology with high sensitivity and precision is required to test this hypothesis. EXPERIMENTAL DESIGN From two cohorts of patients with mCRC, 136 KRAS, NRAS, and BRAF wild-type tumors with sufficient tumor material to perform highly sensitive picodroplet digital PCR (dPCR) and 41 KRAS-mutated tumors were selected. All these patients were treated by anti-EGFR therapy. dPCR was used for KRAS or BRAF mutation screening and compared with qPCR. Progression-free survival (PFS) and overall survival (OS) were analyzed according to the KRAS-mutated allele fraction. RESULTS In addition to the confirmation of the 41 patients with KRAS-mutated tumors, dPCR also identified KRAS mutations in 22 samples considered as KRAS wild-type by qPCR. The fraction of KRAS-mutated allele quantified by dPCR was inversely correlated with anti-EGFR therapy response rate (P < 0.001). In a Cox model, the fraction of KRAS-mutated allele was associated with worse PFS and OS. Patients with less than 1% of mutant KRAS allele have similar PFS and OS than those with wild-type KRAS tumors. CONCLUSIONS This study suggests that patients with mCRC with KRAS-mutated subclones (at least those with a KRAS-mutated subclones fraction lower or equal to 1%) had a benefit from anti-EGFR therapies.
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Affiliation(s)
- Pierre Laurent-Puig
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France. Departement of Biology, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
| | - Deniz Pekin
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France
| | - Corinne Normand
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France
| | | | - Philippe Nizard
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France
| | - Karla Perez-Toralla
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France
| | | | - Jeff Olson
- RainDance Technologies, Billerica, Massachusetts
| | | | - Delphine Le Corre
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France
| | - Thevy Hor
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France
| | - Zakaria El Harrak
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France
| | - Xinyu Li
- RainDance Technologies, Billerica, Massachusetts
| | | | - Olivier Bouché
- Service d'hépatogastroentérologie et de Cancérologie Digestive, CHU de Reims, Hôpital Robert-Debré, Reims, France
| | - Jean-François Emile
- Department of Pathology, Hôpital Ambroise Paré, AP-HP, Université de Versailles St Quentin en Yvelines, Boulogne-Billancourt, France
| | - Bruno Landi
- Department of Oncology, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
| | | | | | - Valerie Taly
- Université Paris Sorbonne Cité; INSERM UMR-S1147; Centre Universitaire des Saints-Pères, Paris, France.
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169
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Yu JQ, Huang W, Chin LK, Lei L, Lin ZP, Ser W, Chen H, Ayi TC, Yap PH, Chen CH, Liu AQ. Droplet optofluidic imaging for λ-bacteriophage detection via co-culture with host cell Escherichia coli. LAB ON A CHIP 2014; 14:3519-24. [PMID: 25008551 DOI: 10.1039/c4lc00042k] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Bacteriophages are considered as attractive indicators for determining drinking water quality since its concentration is strongly correlated with virus concentrations in water samples. Previously, bacteriophage detection was based on a plague assay that required a complicated labelling technique and a time-consuming culture assay. Here, for the first time, a label-free bacteriophage detection is reported by using droplet optofluidic imaging, which uses host-cell-containing microdroplets as reaction carriers for bacteriophage infection due to a higher contact ratio. The optofluidic imaging is based on the effective refractive index changes in the microdroplet correlated with the growth rate of the infected host cells, which is highly sensitive, i.e. can detect one E. coli cell. The droplet optofluidic system is not only used in drinking water quality monitoring, but also has high potential applications for pathogenic bacteria detection in clinical diagnosis and food industry.
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Affiliation(s)
- J Q Yu
- School of Electrical & Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
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170
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Sesen M, Alan T, Neild A. Microfluidic on-demand droplet merging using surface acoustic waves. LAB ON A CHIP 2014; 14:3325-3333. [PMID: 24972001 DOI: 10.1039/c4lc00456f] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Individual droplets can be isolated within microfluidic systems by use of an immiscible carrier layer. This type of two phase systems, often termed "digital microfluidics", find wide ranging applications in chemical synthesis and analysis. To conduct on-chip biochemical analysis, a key step is to be able to merge droplets selectively in order to initiate the required reactions. In this paper, a novel microfluidic chip integrating interdigital transducers is designed to merge multiple droplets on-demand. The approach uses surface acoustic wave induced acoustic radiation forces to immobilize droplets as they pass from a channel into a small expansion chamber, there they can be held until successive droplets arrive. Hence, no requirement is placed on the initial spacing between droplets. When the merged volume reaches a critical size, drag forces exerted by the flowing oil phase act to overcome the retaining acoustic radiation forces, causing the merged volume to exit the chamber. This will occur after a predetermined number of droplets have merged depending on the initial droplet size and selected actuation power.
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Affiliation(s)
- Muhsincan Sesen
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
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171
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Rapid, single-molecule assays in nano/micro-fluidic chips with arrays of closely spaced parallel channels fabricated by femtosecond laser machining. SENSORS 2014; 14:15400-14. [PMID: 25140634 PMCID: PMC4178987 DOI: 10.3390/s140815400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 08/08/2014] [Accepted: 08/18/2014] [Indexed: 12/24/2022]
Abstract
Cost-effective pharmaceutical drug discovery depends on increasing assay throughput while reducing reagent needs. To this end, we are developing an ultrasensitive, fluorescence-based platform that incorporates a nano/micro-fluidic chip with an array of closely spaced channels for parallelized optical readout of single-molecule assays. Here we describe the use of direct femtosecond laser machining to fabricate several hundred closely spaced channels on the surfaces of fused silica substrates. The channels are sealed by bonding to a microscope cover slip spin-coated with a thin film of poly(dimethylsiloxane). Single-molecule detection experiments are conducted using a custom-built, wide-field microscope. The array of channels is epi-illuminated by a line-generating red diode laser, resulting in a line focus just a few microns thick across a 500 micron field of view. A dilute aqueous solution of fluorescently labeled biomolecules is loaded into the device and fluorescence is detected with an electron-multiplying CCD camera, allowing acquisition rates up to 7 kHz for each microchannel. Matched digital filtering based on experimental parameters is used to perform an initial, rapid assessment of detected fluorescence. More detailed analysis is obtained through fluorescence correlation spectroscopy. Simulated fluorescence data is shown to agree well with experimental values.
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172
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Sandoz PA, Chung AJ, Weaver WM, Di Carlo D. Sugar additives improve signal fidelity for implementing two-phase resorufin-based enzyme immunoassays. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:6637-6643. [PMID: 24870310 DOI: 10.1021/la5004484] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Enzymatic signal amplification based on fluorogenic substrates is commonly used for immunoassays; however, when transitioning these assays to a digital format in water-in-mineral oil emulsions, such amplification methods have been limited by the leakage of small reporting fluorescent probes. In the present study, we used a microfluidic system to study leakage from aqueous droplets in a controlled manner and confirmed that the leakage of fluorescent resorufin derivatives is mostly due to the presence of the lipophilic surfactant Span80, which is commonly used to preserve emulsion stability. This leakage can be overcome by the addition of specific sugars that most strongly interfered with the surfactants ability to form micelles in water. The application of the microfluidic system to the quantitative analysis of droplets and the implementation of the described sugar additives would allow for alternatives to fluorinated surfactant-based platforms and improve the signal fidelity in enzyme immunoassays implemented through multiphase microfluidics.
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Affiliation(s)
- Patrick A Sandoz
- Department of Bioengineering, University of California , Los Angeles, California 90095, United States
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173
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Tjhung KF, Burnham S, Anany H, Griffiths MW, Derda R. Rapid enumeration of phage in monodisperse emulsions. Anal Chem 2014; 86:5642-8. [PMID: 24892245 DOI: 10.1021/ac500244g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Phage-based detection assays have been developed for the detection of viable bacteria for applications in clinical diagnosis, monitoring of water quality, and food safety. The majority of these assays deliver a positive readout in the form of newly generated progeny phages by the bacterial host of interest. Progeny phages are often visualized as plaques, or holes, in a lawn of bacteria on an agar-filled Petri dish; however, this rate-limiting step requires up to 12 h of incubation time. We have previously described an amplification of bacteriophages M13 inside droplets of media suspended in perfluorinated oil; a single phage M13 in a droplet yields 10(7) copies in 3-4 h. Here, we describe that encapsulation of reporter phages, both lytic T4-LacZ and nonlytic M13, in monodisperse droplets can also be used for rapid enumeration of phage. Compartmentalization in droplets accelerated the development of the signal from the reporter enzyme; counting of "positive" droplets yields accurate enumeration of phage particles ranging from 10(2) to 10(6) pfu/mL. For enumeration of T4-LacZ phage, the fluorescent signal appeared in as little as 90 min. Unlike bulk assays, quantification in emulsion is robust and insensitive to fluctuations in environmental conditions (e.g., temperature). Power-free emulsification using gravity-driven flow in the absence of syringe pumps and portable fluorescence imaging solutions makes this technology promising for use at the point of care in low-resource environments. This droplet-based phage enumeration method could accelerate and simplify point-of-care detection of the pathogens for which reporter bacteriophages have been developed.
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Affiliation(s)
- Katrina F Tjhung
- Department of Chemistry, University of Alberta , Edmonton, AB T6G 2G2, Canada
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174
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Kang DK, Monsur Ali M, Zhang K, Pone EJ, Zhao W. Droplet microfluidics for single-molecule and single-cell analysis in cancer research, diagnosis and therapy. Trends Analyt Chem 2014. [DOI: 10.1016/j.trac.2014.03.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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175
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Bithi SS, Wang WS, Sun M, Blawzdziewicz J, Vanapalli SA. Coalescing drops in microfluidic parking networks: A multifunctional platform for drop-based microfluidics. BIOMICROFLUIDICS 2014; 8:034118. [PMID: 25379078 PMCID: PMC4162452 DOI: 10.1063/1.4885079] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 06/13/2014] [Indexed: 05/06/2023]
Abstract
Multiwell plate and pipette systems have revolutionized modern biological analysis; however, they have disadvantages because testing in the submicroliter range is challenging, and increasing the number of samples is expensive. We propose a new microfluidic methodology that delivers the functionality of multiwell plates and pipettes at the nanoliter scale by utilizing drop coalescence and confinement-guided breakup in microfluidic parking networks (MPNs). Highly monodisperse arrays of drops obtained using a hydrodynamic self-rectification process are parked at prescribed locations in the device, and our method allows subsequent drop manipulations such as fine-gradation dilutions, reactant addition, and fluid replacement while retaining microparticles contained in the sample. Our devices operate in a quasistatic regime where drop shapes are determined primarily by the channel geometry. Thus, the behavior of parked drops is insensitive to flow conditions. This insensitivity enables highly parallelized manipulation of drop arrays of different composition, without a need for fine-tuning the flow conditions and other system parameters. We also find that drop coalescence can be switched off above a critical capillary number, enabling individual addressability of drops in complex MPNs. The platform demonstrated here is a promising candidate for conducting multistep biological assays in a highly multiplexed manner, using thousands of submicroliter samples.
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Affiliation(s)
- Swastika S Bithi
- Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409-3121, USA
| | - William S Wang
- Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409-3121, USA
| | - Meng Sun
- Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409-3121, USA
| | - Jerzy Blawzdziewicz
- Department of Mechanical Engineering, Texas Tech University , Lubbock, Texas 79401-1021, USA
| | - Siva A Vanapalli
- Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409-3121, USA
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176
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Manoj P. Droplet digital PCR technology promises new applications and research areas. Mitochondrial DNA A DNA Mapp Seq Anal 2014; 27:742-6. [PMID: 24779593 DOI: 10.3109/19401736.2014.913168] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Digital Polymerase Chain Reaction (dPCR) is used to quantify nucleic acids and its applications are in the detection and precise quantification of low-level pathogens, rare genetic sequences, quantification of copy number variants, rare mutations and in relative gene expressions. Here the PCR is performed in large number of reaction chambers or partitions and the reaction is carried out in each partition individually. This separation allows a more reliable collection and sensitive measurement of nucleic acid. Results are calculated by counting amplified target sequence (positive droplets) and the number of partitions in which there is no amplification (negative droplets). The mean number of target sequences was calculated by Poisson Algorithm. Poisson correction compensates the presence of more than one copy of target gene in any droplets. The method provides information with accuracy and precision which is highly reproducible and less susceptible to inhibitors than qPCR. It has been demonstrated in studying variations in gene sequences, such as copy number variants and point mutations, distinguishing differences between expression of nearly identical alleles, assessment of clinically relevant genetic variations and it is routinely used for clonal amplification of samples for NGS methods. dPCR enables more reliable predictors of tumor status and patient prognosis by absolute quantitation using reference normalizations. Rare mitochondrial DNA deletions associated with a range of diseases and disorders as well as aging can be accurately detected with droplet digital PCR.
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Affiliation(s)
- P Manoj
- a Rajiv Gandhi Centre for Biotechnology , Thycaud P.O. , Thiruvananthapuram , Kerala , India
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177
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Jeong HH, Noh YM, Jang SC, Lee CS. Droplet-based Microfluidic Device for High-throughput Screening. KOREAN CHEMICAL ENGINEERING RESEARCH 2014. [DOI: 10.9713/kcer.2014.52.2.141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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178
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Zhu Q, Qiu L, Yu B, Xu Y, Gao Y, Pan T, Tian Q, Song Q, Jin W, Jin Q, Mu Y. Digital PCR on an integrated self-priming compartmentalization chip. LAB ON A CHIP 2014; 14:1176-85. [PMID: 24481046 DOI: 10.1039/c3lc51327k] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
An integrated on-chip valve-free and power-free microfluidic digital PCR device is for the first time developed by making use of a novel self-priming compartmentalization and simple dehydration control to realize 'divide and conquer' for single DNA molecule detection. The high gas solubility of PDMS is exploited to provide the built-in power of self-priming so that the sample and oil are sequentially sucked into the device to realize sample self-compartmentalization based on surface tension. The lifespan of its self-priming capability was about two weeks tested using an air-tight packaging bottle sealed with a small amount of petroleum jelly, which is significant for a practical platform. The SPC chip contains 5120 independent 5 nL microchambers, allowing the samples to be compartmentalized completely. Using this platform, three different abundances of lung cancer related genes are detected to demonstrate the feasibility and flexibility of the microchip for amplifying a single nucleic acid molecule. For maximal accuracy, within less than 5% of the measurement deviation, the optimal number of positive chambers is between 400 and 1250 evaluated by the Poisson distribution, which means one panel can detect an average of 480 to 4804 template molecules. This device without world-to-chip connections eliminates the constraint of the complex pipeline control, and is an integrated on-chip platform, which would be a significant improvement to digital PCR automation and more user-friendly.
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Affiliation(s)
- Qiangyuan Zhu
- Research Center for Analytical Instrumentation, Institute of Cyber-Systems and Control, State Key Laboratory of Industrial Control Technology, Zhejiang University, Hangzhou, PR China.
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179
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Khorshidi MA, Rajeswari PKP, Wählby C, Joensson HN, Andersson Svahn H. Automated analysis of dynamic behavior of single cells in picoliter droplets. LAB ON A CHIP 2014; 14:931-7. [PMID: 24385254 DOI: 10.1039/c3lc51136g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We present a droplet-based microfluidic platform to automatically track and characterize the behavior of single cells over time. This high-throughput assay allows encapsulation of single cells in micro-droplets and traps intact droplets in arrays of miniature wells on a PDMS-glass chip. Automated time-lapse fluorescence imaging and image analysis of the incubated droplets on the chip allows the determination of the viability of individual cells over time. In order to automatically track the droplets containing cells, we developed a simple method based on circular Hough transform to identify droplets in images and quantify the number of live and dead cells in each droplet. Here, we studied the viability of several hundred single isolated HEK293T cells over time and demonstrated a high survival rate of the encapsulated cells for up to 11 hours. The presented platform has a wide range of potential applications for single cell analysis, e.g. monitoring heterogeneity of drug action over time and rapidly assessing the transient behavior of single cells under various conditions and treatments in vitro.
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Affiliation(s)
- Mohammad Ali Khorshidi
- Division of Proteomics and Nanobiotechnology, Science for Life Laboratory, KTH - Royal Institute of Technology, Sweden.
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180
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Khodakov DA, Ellis AV. Recent developments in nucleic acid identification using solid-phase enzymatic assays. Mikrochim Acta 2014. [DOI: 10.1007/s00604-014-1167-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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181
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Wang Y, Wu P, Luo Z, Li Y, Liao M, Li Y, He L. Controllable geometry-mediated droplet fission using “off-the-shelf” capillary microfluidics device. RSC Adv 2014. [DOI: 10.1039/c4ra04569f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We describe a cheap, easily assembled, controllable droplet fission device to obtain a variety of uniform daughter droplets.
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Affiliation(s)
- Yong Wang
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei, China
| | - Ping Wu
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei, China
| | - Zhaofeng Luo
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei, China
| | - Yuting Li
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei, China
| | - Meixiang Liao
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei, China
| | - Yue Li
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei, China
| | - Liqun He
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei, China
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182
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Guan Z, Zou Y, Zhang M, Lv J, Shen H, Yang P, Zhang H, Zhu Z, James Yang C. A highly parallel microfluidic droplet method enabling single-molecule counting for digital enzyme detection. BIOMICROFLUIDICS 2014; 8:014110. [PMID: 24753730 PMCID: PMC3977795 DOI: 10.1063/1.4866766] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/12/2014] [Indexed: 05/07/2023]
Abstract
Although digital detection of nucleic acids has been achieved by amplification of single templates in uniform microfluidic droplets and widely used for genetic analysis, droplet-based digital detection of proteins has rarely been reported, largely due to the lack of an efficient target amplification method for protein in droplets. Here, we report a key step towards digital detection of proteins using a highly parallel microfluidic droplet approach for single enzyme molecule detection in picoliter droplets via enzyme catalyzed signal amplification. An integrated microfluidic chip was designed for high throughput uniform droplet generation, monolayer droplet collection, incubation, detection, and release. Single β-galatosidase (β-Gal) molecules and the fluorogenic substrate fluorescein di-β-D-galactopyranoside were injected from two separated inlets to form uniform 20 μm droplets in fluorinated oil at a frequency of 6.6 kHz. About 200 000 droplets were captured as a monolayer in a capture well on-chip for subsequent imaging detection. A series of β-Gal solutions at different concentrations were analyzed at the single-molecule level. With no enzyme present, no droplets were found to fluoresce, while brightly fluorescent droplets were observed under single-enzyme molecule conditions. Droplet fluorescence intensity distribution analysis showed that the distribution of enzyme molecules under single-molecule conditions matched well with theoretical prediction, further proving the feasibility of detecting single enzyme molecules in emulsion droplets. Moreover, the population of fluorescent droplets increased as the β-Gal concentration increased. Based on a digital counting method, the measured concentrations of the enzyme were found to match well with input enzyme concentration, establishing the accuracy of the digital detection method for the quantification of β-Gal enzyme molecules. The capability of highly parallel detection of single enzyme molecules in uniform picoliter droplets paves the way to microdroplet based digital detection of proteins.
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Affiliation(s)
- Zhichao Guan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, the Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Yuan Zou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, the Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Mingxia Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, the Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Jiangquan Lv
- State Key Laboratory of Physical Chemistry of Solid Surfaces, the Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Huali Shen
- Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433, China
| | - Pengyuan Yang
- Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433, China
| | - Huimin Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, the Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Zhi Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, the Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Chaoyong James Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, the Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
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183
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Yoon DH, Numakunai S, Nakahara A, Sekiguchi T, Shoji S. Hydrodynamic on-rail droplet pass filter for fully passive sorting of droplet-phase samples. RSC Adv 2014. [DOI: 10.1039/c4ra08354g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A hydrodynamic droplet pass filter for droplet-phase sample sorting was developed in this study.
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Affiliation(s)
- Dong Hyun Yoon
- Faculty of Science and Engineering
- Waseda University
- Tokyo, Japan
| | | | - Asahi Nakahara
- Faculty of Science and Engineering
- Waseda University
- Tokyo, Japan
| | - Tetsushi Sekiguchi
- Institute for Nanoscience and Nanoengineering
- Waseda University
- Tokyo, Japan
| | - Shuichi Shoji
- Faculty of Science and Engineering
- Waseda University
- Tokyo, Japan
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184
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Muluneh M, Issadore D. Hybrid soft-lithography/laser machined microchips for the parallel generation of droplets. LAB ON A CHIP 2013; 13:4750-4. [PMID: 24166156 PMCID: PMC4420024 DOI: 10.1039/c3lc50979f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Microfluidic chips have been developed to generate droplets and microparticles with control over size, shape, and composition not possible using conventional methods. However, it has remained a challenge to scale-up production for practical applications due to the inherently limited throughput of micro-scale devices. To address this problem, we have developed a self-contained microchip that integrates many (N = 512) micro-scale droplet makers. This 3 × 3 cm(2) PDMS microchip consists of a two-dimensional array of 32 × 16 flow-focusing droplet makers, a network of flow channels that connect them, and only two inputs and one output. The key innovation of this technology is the hybrid use of both soft-lithography and direct laser-micromachining. The microscale resolution of soft lithography is used to fabricate flow-focusing droplet makers that can produce small and precisely defined droplets. Deeply engraved (h ≈ 500 μm) laser-machined channels are utilized to supply each of the droplet makers with its oil phase, aqueous phase, and access to an output channel. The engraved channels' low hydrodynamic resistance ensures that each droplet maker is driven with the same flow rates for highly uniform droplet formation. To demonstrate the utility of this approach, water droplets (d ≈ 80 μm) were generated in hexadecane on both 8 × 1 and 32 × 16 geometries.
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Affiliation(s)
- M. Muluneh
- Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - D. Issadore
- Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
- Electrical and Systems Engineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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185
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Weaver WM, Tseng P, Kunze A, Masaeli M, Chung AJ, Dudani JS, Kittur H, Kulkarni RP, Di Carlo D. Advances in high-throughput single-cell microtechnologies. Curr Opin Biotechnol 2013; 25:114-23. [PMID: 24484889 DOI: 10.1016/j.copbio.2013.09.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 08/30/2013] [Accepted: 09/08/2013] [Indexed: 12/31/2022]
Abstract
Micro-scale biological tools that have allowed probing of individual cells--from the genetic, to proteomic, to phenotypic level--have revealed important contributions of single cells to direct normal and diseased body processes. In analyzing single cells, sample heterogeneity between and within specific cell types drives the need for high-throughput and quantitative measurement of cellular parameters. In recent years, high-throughput single-cell analysis platforms have revealed rare genetic subpopulations in growing tumors, begun to uncover the mechanisms of antibiotic resistance in bacteria, and described the cell-to-cell variations in stem cell differentiation and immune cell response to activation by pathogens. This review surveys these recent technologies, presenting their strengths and contributions to the field, and identifies needs still unmet toward the development of high-throughput single-cell analysis tools to benefit life science research and clinical diagnostics.
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Affiliation(s)
- Westbrook M Weaver
- Department of Bioengineering, University of California, Los Angeles, United States
| | - Peter Tseng
- Department of Bioengineering, University of California, Los Angeles, United States
| | - Anja Kunze
- Department of Bioengineering, University of California, Los Angeles, United States
| | - Mahdokht Masaeli
- Department of Bioengineering, University of California, Los Angeles, United States
| | - Aram J Chung
- Department of Bioengineering, University of California, Los Angeles, United States
| | - Jaideep S Dudani
- Department of Bioengineering, University of California, Los Angeles, United States
| | - Harsha Kittur
- Department of Bioengineering, University of California, Los Angeles, United States
| | | | - Dino Di Carlo
- Department of Bioengineering, University of California, Los Angeles, United States; California NanoSystems Institute, University of California, Los Angeles, United States.
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186
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Patel A, Schwab R, Liu YT, Bafna V. Amplification and thrifty single-molecule sequencing of recurrent somatic structural variations. Genome Res 2013; 24:318-28. [PMID: 24307551 PMCID: PMC3912422 DOI: 10.1101/gr.161497.113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Deletion of tumor-suppressor genes as well as other genomic rearrangements pervade cancer genomes across numerous types of solid tumor and hematologic malignancies. However, even for a specific rearrangement, the breakpoints may vary between individuals, such as the recurrent CDKN2A deletion. Characterizing the exact breakpoints for structural variants (SVs) is useful for designating patient-specific tumor biomarkers. We propose AmBre (Amplification of Breakpoints), a method to target SV breakpoints occurring in samples composed of heterogeneous tumor and germline DNA. Additionally, AmBre validates SVs called by whole-exome/genome sequencing and hybridization arrays. AmBre involves a PCR-based approach to amplify the DNA segment containing an SV's breakpoint and then confirms breakpoints using sequencing by Pacific Biosciences RS. To amplify breakpoints with PCR, primers tiling specified target regions are carefully selected with a simulated annealing algorithm to minimize off-target amplification and maximize efficiency at capturing all possible breakpoints within the target regions. To confirm correct amplification and obtain breakpoints, PCR amplicons are combined without barcoding and simultaneously long-read sequenced using a single SMRT cell. Our algorithm efficiently separates reads based on breakpoints. Each read group supporting the same breakpoint corresponds with an amplicon and a consensus amplicon sequence is called. AmBre was used to discover CDKN2A deletion breakpoints in cancer cell lines: A549, CEM, Detroit562, MOLT4, MCF7, and T98G. Also, we successfully assayed RUNX1–RUNX1T1 reciprocal translocations by finding both breakpoints in the Kasumi-1 cell line. AmBre successfully targets SVs where DNA harboring the breakpoints are present in 1:1000 mixtures.
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Affiliation(s)
- Anand Patel
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, California 92093, USA
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187
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Fradet E, Abbyad P, Vos MH, Baroud CN. Parallel measurements of reaction kinetics using ultralow-volumes. LAB ON A CHIP 2013; 13:4326-30. [PMID: 24077130 DOI: 10.1039/c3lc50768h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We present a new platform for the production and manipulation of microfluidic droplets in view of measuring the evolution of a chemical reaction. Contrary to existing approaches, our device uses gradients of confinement to produce a single drop on demand and guide it to a pre-determined location. In this way, two nanoliter drops containing different reagents can be placed in contact and merged together, in order to trigger a chemical reaction. The reaction rate is extracted from an analysis of the observed reaction-diffusion front. We show that the results obtained using this platform are in excellent agreement with stopped-flow measurements, while decreasing the sample consumption 5000 fold. We also show how the device operation can be parallelized in order to react an initial sample with a range of compounds or concentrations, on a single integrated chip. This integrated chip thus further reduces sample consumption while reducing the time required for the experimental runs from hours to minutes.
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Affiliation(s)
- Etienne Fradet
- Laboratoire d'Hydrodynamique (LadHyX) and Department of Mechanics, Ecole Polytechnique, CNRS, 91128, Palaiseau, France.
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188
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Abstract
Over the past two decades, the application of microengineered systems in the chemical and biological sciences has transformed the way in which high-throughput experimentation is performed. The ability to fabricate complex microfluidic architectures has allowed scientists to create new experimental formats for processing ultra-small analytical volumes in short periods and with high efficiency. The development of such microfluidic systems has been driven by a range of fundamental features that accompany miniaturization. These include the ability to handle small sample volumes, ultra-low fabrication costs, reduced analysis times, enhanced operational flexibility, facile automation, and the ability to integrate functional components within complex analytical schemes. Herein we discuss the impact of microfluidics in the area of high-throughput screening and drug discovery and highlight some of the most pertinent studies in the recent literature.
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Affiliation(s)
- Oliver J. Dressler
- Department of Chemistry & Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Zürich, Switzerland
| | - Richard M. Maceiczyk
- Department of Chemistry & Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Zürich, Switzerland
| | - Soo-Ik Chang
- Department of Biochemistry, Chungbuk National University, Cheongju, Republic of Korea
| | - Andrew J. deMello
- Department of Chemistry & Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Zürich, Switzerland
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189
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Cho S, Kang DK, Sim S, Geier F, Kim JY, Niu X, Edel JB, Chang SI, Wootton RCR, Elvira KS, deMello AJ. Droplet-Based Microfluidic Platform for High-Throughput, Multi-Parameter Screening of Photosensitizer Activity. Anal Chem 2013; 85:8866-72. [DOI: 10.1021/ac4022067] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Soongwon Cho
- Department
of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Dong-Ku Kang
- Department
of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Steven Sim
- Department
of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Florian Geier
- Department
of Surgery and Cancer, Faculty of Medicine, South Kensington
Campus, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Jin-Young Kim
- Department of Bioengineering, South Kensington Campus, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Xize Niu
- Engineering and the Environment, and Institute for Life Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
| | - Joshua B. Edel
- Department
of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Soo-Ik Chang
- Department
of Biochemistry, Chungbuk National University, Cheongju, Chungbuk, Korea
| | - Robert C. R. Wootton
- Institute
for Chemical and Bioengineering, Department of Chemistry and Applied
Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
| | - Katherine S. Elvira
- Institute
for Chemical and Bioengineering, Department of Chemistry and Applied
Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
| | - Andrew J. deMello
- Institute
for Chemical and Bioengineering, Department of Chemistry and Applied
Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
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190
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Taly V, Pekin D, Benhaim L, Kotsopoulos SK, Le Corre D, Li X, Atochin I, Link DR, Griffiths AD, Pallier K, Blons H, Bouché O, Landi B, Hutchison JB, Laurent-Puig P. Multiplex picodroplet digital PCR to detect KRAS mutations in circulating DNA from the plasma of colorectal cancer patients. Clin Chem 2013; 59:1722-31. [PMID: 23938455 DOI: 10.1373/clinchem.2013.206359] [Citation(s) in RCA: 366] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Multiplex digital PCR (dPCR) enables noninvasive and sensitive detection of circulating tumor DNA with performance unachievable by current molecular-detection approaches. Furthermore, picodroplet dPCR facilitates simultaneous screening for multiple mutations from the same sample. METHODS We investigated the utility of multiplex dPCR to screen for the 7 most common mutations in codons 12 and 13 of the KRAS (Kirsten rat sarcoma viral oncogene homolog) oncogene from plasma samples of patients with metastatic colorectal cancer. Fifty plasma samples were tested from patients for whom the primary tumor biopsy tissue DNA had been characterized by quantitative PCR. RESULTS Tumor characterization revealed that 19 patient tumors had KRAS mutations. Multiplex dPCR analysis of the plasma DNA prepared from these samples identified 14 samples that matched the mutation identified in the tumor, 1 sample contained a different KRAS mutation, and 4 samples had no detectable mutation. Among the tumor samples that were wild type for KRAS, 2 KRAS mutations were identified in the corresponding plasma samples. Duplex dPCR (i.e., wild-type and single-mutation assay) was also used to analyze plasma samples from patients with KRAS-mutated tumors and 5 samples expected to contain the BRAF (v-raf murine sarcoma viral oncogene homolog B) V600E mutation. The results for the duplex analysis matched those for the multiplex analysis for KRAS-mutated samples and, owing to its higher sensitivity, enabled detection of 2 additional samples with low levels of KRAS-mutated DNA. All 5 samples with BRAF mutations were detected. CONCLUSIONS This work demonstrates the clinical utility of multiplex dPCR to screen for multiple mutations simultaneously with a sensitivity sufficient to detect mutations in circulating DNA obtained by noninvasive blood collection.
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Affiliation(s)
- Valerie Taly
- Université Paris Sorbonne Cité, INSERM UMR-S775, Centre Universitaire des Saints-Pères, Paris, France
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191
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Salkin L, Schmit A, Courbin L, Panizza P. Passive breakups of isolated drops and one-dimensional assemblies of drops in microfluidic geometries: experiments and models. LAB ON A CHIP 2013; 13:3022-3032. [PMID: 23743651 DOI: 10.1039/c3lc00040k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Using two different geometries, rectangular obstacles and asymmetric loops, we investigate the breakup dynamics of deformable objects, such as drops and bubbles, confined in microfluidic devices. We thoroughly study two distinct flow configurations that depend on whether object-to-object hydrodynamic interactions are allowed. When such interactions are introduced, we find that the volumes of the daughter objects created after breakup solely depend on the geometrical features of the devices and are not affected by the hydrodynamic and physicochemical variables; these results are in sharp contrast with those obtained for non-interacting objects. For both configurations, we provide simple phenomenological models that capture well the experimental findings and predict the evolution of the volumes of the daughter objects with the controlling dimensionless quantities that are identified. We introduce a mean-field approximation, which permits accounting for the interactions between objects during breakup and we discuss its conditions of validity.
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Affiliation(s)
- Louis Salkin
- IPR, UMR CNRS 6251, Campus Beaulieu, Université Rennes 1, 35042 Rennes, France
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192
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Zhu Y, Fang Q. Analytical detection techniques for droplet microfluidics—A review. Anal Chim Acta 2013; 787:24-35. [DOI: 10.1016/j.aca.2013.04.064] [Citation(s) in RCA: 250] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 04/27/2013] [Accepted: 04/30/2013] [Indexed: 01/26/2023]
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193
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Mazutis L, Gilbert J, Ung WL, Weitz DA, Griffiths AD, Heyman JA. Single-cell analysis and sorting using droplet-based microfluidics. Nat Protoc 2013; 8:870-91. [PMID: 23558786 PMCID: PMC4128248 DOI: 10.1038/nprot.2013.046] [Citation(s) in RCA: 825] [Impact Index Per Article: 75.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We present a droplet-based microfluidics protocol for high-throughput analysis and sorting of single cells. Compartmentalization of single cells in droplets enables the analysis of proteins released from or secreted by cells, thereby overcoming one of the major limitations of traditional flow cytometry and fluorescence-activated cell sorting. As an example of this approach, we detail a binding assay for detecting antibodies secreted from single mouse hybridoma cells. Secreted antibodies are detected after only 15 min by co-compartmentalizing single mouse hybridoma cells, a fluorescent probe and single beads coated with anti-mouse IgG antibodies in 50-pl droplets. The beads capture the secreted antibodies and, when the captured antibodies bind to the probe, the fluorescence becomes localized on the beads, generating a clearly distinguishable fluorescence signal that enables droplet sorting at ∼200 Hz as well as cell enrichment. The microfluidic system described is easily adapted for screening other intracellular, cell-surface or secreted proteins and for quantifying catalytic or regulatory activities. In order to screen ∼1 million cells, the microfluidic operations require 2-6 h; the entire process, including preparation of microfluidic devices and mammalian cells, requires 5-7 d.
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Affiliation(s)
- Linas Mazutis
- School of Engineering and Applied Sciences (SEAS), Harvard University, Cambridge, Massachusetts, USA
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194
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Lim J, Gruner P, Konrad M, Baret JC. Micro-optical lens array for fluorescence detection in droplet-based microfluidics. LAB ON A CHIP 2013; 13:1472-5. [PMID: 23455606 PMCID: PMC3697795 DOI: 10.1039/c3lc41329b] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We demonstrate the design and integration of droplet-based microfluidic devices with microoptical element arrays for enhanced detection of fluorescent signals. We show that the integration of microlenses and mirror surfaces in these devices results in an 8-fold increase in the fluorescence signal and in improved spatial resolution. Using an array of microlenses, massively parallel detection of droplets containing fluorescent dyes was achieved, leading to detection throughputs of about 2000 droplets per second and per lens, parallelized over 625 measurement points.
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Affiliation(s)
- Jiseok Lim
- Max Planck Institute for Dynamics and Self-Organization , Am Fassberg 17 , 37077 Goettingen , Germany .
- Max Planck Institute for Biophysical Chemistry , Am Fassberg 11 , 37077 Goettingen , Germany
| | - Philipp Gruner
- Max Planck Institute for Dynamics and Self-Organization , Am Fassberg 17 , 37077 Goettingen , Germany .
| | - Manfred Konrad
- Max Planck Institute for Biophysical Chemistry , Am Fassberg 11 , 37077 Goettingen , Germany
| | - Jean-Christophe Baret
- Max Planck Institute for Dynamics and Self-Organization , Am Fassberg 17 , 37077 Goettingen , Germany .
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195
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Huggett JF, Foy CA, Benes V, Emslie K, Garson JA, Haynes R, Hellemans J, Kubista M, Mueller RD, Nolan T, Pfaffl MW, Shipley GL, Vandesompele J, Wittwer CT, Bustin SA. The digital MIQE guidelines: Minimum Information for Publication of Quantitative Digital PCR Experiments. Clin Chem 2013; 59:892-902. [PMID: 23570709 DOI: 10.1373/clinchem.2013.206375] [Citation(s) in RCA: 595] [Impact Index Per Article: 54.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
There is growing interest in digital PCR (dPCR) because technological progress makes it a practical and increasingly affordable technology. dPCR allows the precise quantification of nucleic acids, facilitating the measurement of small percentage differences and quantification of rare variants. dPCR may also be more reproducible and less susceptible to inhibition than quantitative real-time PCR (qPCR). Consequently, dPCR has the potential to have a substantial impact on research as well as diagnostic applications. However, as with qPCR, the ability to perform robust meaningful experiments requires careful design and adequate controls. To assist independent evaluation of experimental data, comprehensive disclosure of all relevant experimental details is required. To facilitate this process we present the Minimum Information for Publication of Quantitative Digital PCR Experiments guidelines. This report addresses known requirements for dPCR that have already been identified during this early stage of its development and commercial implementation. Adoption of these guidelines by the scientific community will help to standardize experimental protocols, maximize efficient utilization of resources, and enhance the impact of this promising new technology.
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196
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Schneider T, Kreutz J, Chiu DT. The potential impact of droplet microfluidics in biology. Anal Chem 2013; 85:3476-82. [PMID: 23495853 DOI: 10.1021/ac400257c] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Droplet microfluidics, which involves micrometer-sized emulsion droplets on a microfabricated platform, is an active research endeavor that evolved out of the larger field of microfluidics. Recently, this subfield of microfluidics has started to attract greater interest because researchers have been able to demonstrate applications of droplets as miniaturized laboratories for biological measurements. This perspective explores the recent developments and the potential future biological applications of droplet microfluidics.
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Affiliation(s)
- Thomas Schneider
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
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197
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Abstract
Antimicrobial resistance has emerged as one of the most-significant health care problems of the new millennium, and the clinical microbiology laboratory plays a central role in optimizing the therapeutic management of patients with infection. This minireview explores the potential value of innovative methods for antimicrobial susceptibility testing of microorganisms that could provide valuable alternatives to existing methodologies in the very near future.
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198
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Abstract
The miniaturization of droplet manipulation methods has led to drops being proposed as microreactors in many applications of biology and chemistry. In parallel, microfluidic methods have been applied to generate monodisperse emulsions for applications in the pharmaceuticals, cosmetics, and food industries. To date, microfluidic droplet production has been dominated by a few designs that use hydrodynamic forces, resulting from the flowing fluids, to break drops at a junction. Here we present a platform for droplet generation and manipulation that does not depend on the fluid flows. Instead, we use devices that incorporate height variations to subject the immiscible interfaces to gradients of confinement. The resulting curvature imbalance along the interface causes the detachment of monodisperse droplets, without the need for a flow of the external phase. Once detached, the drops are self-propelled due to the gradient of surface energy. We show that the size of the drops is determined by the device geometry; it is insensitive to the physical fluid properties and depends very weakly on the flow rate of the dispersed phase. This allows us to propose a geometric theoretical model that predicts the dependence of droplet size on the geometric parameters, which is in agreement with experimental measurements. The approach presented here can be applied in a wide range of standard applications, while simplifying the device operations. We demonstrate examples for single-droplet operations and high-throughput generation of emulsions, all of which are performed in simple and inexpensive devices.
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Affiliation(s)
- Rémi Dangla
- Laboratoire d'Hydrodynamique (LadHyX) and Department of Mechanics, Ecole Polytechnique, Centre National de la Recherche Scientifique, 91128 Palaiseau Cedex, France
| | - S. Cagri Kayi
- Laboratoire d'Hydrodynamique (LadHyX) and Department of Mechanics, Ecole Polytechnique, Centre National de la Recherche Scientifique, 91128 Palaiseau Cedex, France
| | - Charles N. Baroud
- Laboratoire d'Hydrodynamique (LadHyX) and Department of Mechanics, Ecole Polytechnique, Centre National de la Recherche Scientifique, 91128 Palaiseau Cedex, France
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199
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Chen F, Zhang Y, Nakagawa Y, Zeng H, Luo C, Nakajima H, Uchiyama K, Lin JM. A piezoelectric drop-on-demand generator for accurate samples in capillary electrophoresis. Talanta 2013; 107:111-7. [PMID: 23598200 DOI: 10.1016/j.talanta.2012.12.058] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 12/30/2012] [Accepted: 12/31/2012] [Indexed: 11/17/2022]
Abstract
In this work, we propose a piezoelectric droplet generator for injection of well-defined amounts of sample in capillary electrophoresis. We demonstrate stable, precise and drop-on-demand droplet formation for various solutions, with precise control of waveform driving piezoelectric crystal inside the ink-jet head. By tuning the waveform, we can also manipulate the droplet size and delivery frequency. This injector was used in sampling for capillary electrophoresis. As a state-of-the-art application, the analysis of theobromine, caffeine and theophiline using micellar electrokinetic chromatography was developed. The volume of sample (single droplet) analyzed in this experiment was 179 pL (RSD=1.2%, n=10). The detection limits for caffeine, theobromine, and theophiline are 0.02, 0.08 and 0.06 mM L(-1), respectively. Compared with conventional methods, the combination of picoliter droplet dispenser with capillary electrophoresis allows precise and accurate sampling, as well as for reduced sample consumption, which will prove to be an efficient tool in quantitative separation and analysis.
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Affiliation(s)
- Fengming Chen
- Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, Minamiohsawa, Hachioji, Tokyo 192-0397, Japan
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200
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Sciambi A, Abate AR. Adding reagent to droplets with controlled rupture of encapsulated double emulsions. BIOMICROFLUIDICS 2013; 7:44112. [PMID: 24404045 PMCID: PMC3751951 DOI: 10.1063/1.4817793] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 07/25/2013] [Indexed: 05/06/2023]
Abstract
We present a method to add reagent to microfluidic droplets by enveloping them as a double emulsions in reagent-filled droplets and then rupturing them with an electric field. When the double emulsions rupture, they release their contents into the enveloping droplets, ensuring mixing with reagent while limiting cross-droplet contamination.
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Affiliation(s)
- Adam Sciambi
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, USA
| | - Adam R Abate
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, USA
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