101
|
Kleinert J, Srinivasan V, Rival A, Delattre C, Velev OD, Pamula VK. The dynamics and stability of lubricating oil films during droplet transport by electrowetting in microfluidic devices. BIOMICROFLUIDICS 2015; 9:034104. [PMID: 26045729 PMCID: PMC4441711 DOI: 10.1063/1.4921489] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 05/11/2015] [Indexed: 05/21/2023]
Abstract
The operation of digital microfluidic devices with water droplets manipulated by electrowetting is critically dependent on the static and dynamic stability and lubrication properties of the oil films that separate the droplets from the solid surfaces. The factors determining the stability of the films and preventing surface fouling in such systems are not yet thoroughly understood and were experimentally investigated in this study. The experiments were performed using a standard digital microfluidic cartridge in which water droplets enclosed in a thin, oil-filled gap were transported over an array of electrodes. Stable, continuous oil films separated the droplets from the surfaces when the droplets were stationary. During droplet transport, capillary waves formed in the films on the electrode surfaces as the oil menisci receded. The waves evolved into dome-shaped oil lenses. Droplet deformation and oil displacement caused the films at the surface opposite the electrode array to transform into dimples of oil trapped over the centers of the droplets. Lower actuation voltages were associated with slower film thinning and formation of fewer, but larger, oil lenses. Lower ac frequencies induced oscillations in the droplets that caused the films to rupture. Films were also destabilized by addition of surfactants to the oil or droplet phases. Such a comprehensive understanding of the oil film behavior will enable more robust electrowetting-actuated lab-on-a-chip devices through prevention of loss of species from droplets and contamination of surfaces at points where films may break.
Collapse
Affiliation(s)
| | - Vijay Srinivasan
- Advanced Liquid Logic, Inc., PO Box 14025, Research Triangle Park , North Carolina 27709, USA
| | - Arnaud Rival
- Advanced Liquid Logic France , MINATEC - BHT - Bat 52, 7 parvis Louis Néel, 38000 Grenoble, France
| | - Cyril Delattre
- Advanced Liquid Logic France , MINATEC - BHT - Bat 52, 7 parvis Louis Néel, 38000 Grenoble, France
| | - Orlin D Velev
- Department of Chemical and Biomolecular Engineering, North Carolina State University , Raleigh, North Carolina 27695-7905, USA
| | - Vamsee K Pamula
- Advanced Liquid Logic, Inc., PO Box 14025, Research Triangle Park , North Carolina 27709, USA
| |
Collapse
|
102
|
Zhang C, Sitt A, Koo HJ, Waynant KV, Hess H, Pate BD, Braun PV. Autonomic Molecular Transport by Polymer Films Containing Programmed Chemical Potential Gradients. J Am Chem Soc 2015; 137:5066-73. [DOI: 10.1021/jacs.5b00240] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Chunjie Zhang
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801, United States
| | - Amit Sitt
- Department
of Biomedical Engineering, Columbia University, 1210 Amsterdam Avenue, New York, New York 10027, United States
| | - Hyung-Jun Koo
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801, United States
- Department of Chemical & Biomolecular Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 139-743, Korea
| | - Kristopher V. Waynant
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801, United States
| | - Henry Hess
- Department
of Biomedical Engineering, Columbia University, 1210 Amsterdam Avenue, New York, New York 10027, United States
| | - Brian D. Pate
- Defense Threat Reduction Agency, Fort Belvoir, Virginia 22060, United States
| | - Paul V. Braun
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
103
|
Bartsch MS, Edwards HS, Lee D, Moseley CE, Tew KE, Renzi RF, Van de Vreugde JL, Kim H, Knight DL, Sinha A, Branda SS, Patel KD. The rotary zone thermal cycler: a low-power system enabling automated rapid PCR. PLoS One 2015; 10:e0118182. [PMID: 25826708 PMCID: PMC4380418 DOI: 10.1371/journal.pone.0118182] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 01/09/2015] [Indexed: 12/17/2022] Open
Abstract
Advances in molecular biology, microfluidics, and laboratory automation continue to expand the accessibility and applicability of these methods beyond the confines of conventional, centralized laboratory facilities and into point of use roles in clinical, military, forensic, and field-deployed applications. As a result, there is a growing need to adapt the unit operations of molecular biology (e.g., aliquoting, centrifuging, mixing, and thermal cycling) to compact, portable, low-power, and automation-ready formats. Here we present one such adaptation, the rotary zone thermal cycler (RZTC), a novel wheel-based device capable of cycling up to four different fixed-temperature blocks into contact with a stationary 4-microliter capillary-bound sample to realize 1-3 second transitions with steady state heater power of less than 10 W. We demonstrate the utility of the RZTC for DNA amplification as part of a highly integrated rotary zone PCR (rzPCR) system that uses low-volume valves and syringe-based fluid handling to automate sample loading and unloading, thermal cycling, and between-run cleaning functionalities in a compact, modular form factor. In addition to characterizing the performance of the RZTC and the efficacy of different online cleaning protocols, we present preliminary results for rapid single-plex PCR, multiplex short tandem repeat (STR) amplification, and second strand cDNA synthesis.
Collapse
Affiliation(s)
- Michael S. Bartsch
- Sandia National Laboratories, Livermore, CA, United States of America
- * E-mail:
| | | | - Daniel Lee
- Sandia National Laboratories, Livermore, CA, United States of America
| | | | - Karen E. Tew
- Sandia National Laboratories, Livermore, CA, United States of America
| | - Ronald F. Renzi
- Sandia National Laboratories, Livermore, CA, United States of America
| | | | - Hanyoup Kim
- Sandia National Laboratories, Livermore, CA, United States of America
| | | | - Anupama Sinha
- Sandia National Laboratories, Livermore, CA, United States of America
| | - Steven S. Branda
- Sandia National Laboratories, Livermore, CA, United States of America
| | - Kamlesh D. Patel
- Sandia National Laboratories, Livermore, CA, United States of America
| |
Collapse
|
104
|
Hong J, Lee SJ. Detaching droplets in immiscible fluids from a solid substrate with the help of electrowetting. LAB ON A CHIP 2015; 15:900-907. [PMID: 25500988 DOI: 10.1039/c4lc01049c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The detachment (or removal) of droplets from a solid surface is an indispensable process in numerous practical applications which utilize digital microfluidics, including cell-based assay, chip cooling, and particle sampling. When a droplet that is fully stretched by impacting or electrowetting is released, the conversion of stored surface energy to kinetic energy can lead to the departure of the droplet from a solid surface. Here we firstly detach sessile droplets in immiscible fluids from a hydrophobic surface by electrowetting. The physical conditions for droplet detachment depend on droplet volume, viscosity of ambient fluid, and applied voltage. Their critical conditions are determined by exploring the retracting dynamics for a wide range of driving voltages and physical properties of fluids. The relationships between physical parameters and dynamic characteristics of retracting and jumping droplets, such as contact time and jumping height, are also established. The threshold voltage for droplet detachment in oil with high viscosity is largely reduced (~70%) by electrowetting actuations with a square pulse. To examine the applicability of three-dimensional digital microfluidic (3D-DMF) platforms to biological applications such as cell culture and cell-based assays, we demonstrate the detachment of droplets containing a mixture of human umbilical vein endothelial cells (HUVECs) and collagen (concentration of 4 × 10(4) cells mL(-1)) in silicone oil with a viscosity of 0.65 cSt. Furthermore, to complement the technical limitations due to the use of a needle electrode and to demonstrate the applicability of the 3D-DMF platform with patterned electrodes to chemical analysis and synthesis, we examine the transport, merging, mixing, and detachment of droplets with different pH values on the platform. Finally, by using DC and AC electrowetting actuations, we demonstrate the detachment of oil droplets with a very low contact angle (<~13°) in water on a hydrophobic surface.
Collapse
Affiliation(s)
- Jiwoo Hong
- Center for Biofluid Flow and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, South Korea.
| | | |
Collapse
|
105
|
Kleiber N, Tromp K, Mooij MG, van de Vathorst S, Tibboel D, de Wildt SN. Ethics of drug research in the pediatric intensive care unit. Paediatr Drugs 2015; 17:43-53. [PMID: 25354987 DOI: 10.1007/s40272-014-0101-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Critical illness and treatment modalities change pharmacokinetics and pharmacodynamics of medications used in critically ill children, in addition to age-related changes in drug disposition and effect. Hence, to ensure effective and safe drug therapy, research in this population is urgently needed. However, conducting research in the vulnerable population of the pediatric intensive care unit (PICU) presents with ethical challenges. This article addresses the main ethical issues specific to drug research in these critically ill children and proposes several solutions. The extraordinary environment of the PICU raises specific challenges to the design and conduct of research. The need for proxy consent of parents (or legal guardians) and the stress-inducing physical environment may threaten informed consent. The informed consent process is challenging because emergency research reduces or even eliminates the time to seek consent. Moreover, parental anxiety may impede adequate understanding and generate misconceptions. Alternative forms of consent have been developed taking into account the unpredictable reality of the acute critical care environment. As with any research in children, the burden and risk should be minimized. Recent developments in sample collection and analysis as well as pharmacokinetic analysis should be considered in the design of studies. Despite the difficulties inherent to drug research in critically ill children, methods are available to conduct ethically sound research resulting in relevant and generalizable data. This should motivate the PICU community to commit to drug research to ultimately provide the right drug at the right dose for every individual child.
Collapse
Affiliation(s)
- Niina Kleiber
- Intensive Care and Department of Pediatric Surgery, Erasmus MC-Sophia Children's Hospital, P.O. Box 2060, 3000 CB, Rotterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
106
|
Hu JB, Chen TR, Chang CH, Cheng JY, Chen YC, Urban PL. A compact 3D-printed interface for coupling open digital microchips with Venturi easy ambient sonic-spray ionization mass spectrometry. Analyst 2015; 140:1495-501. [PMID: 25622965 DOI: 10.1039/c4an02220c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Digital microfluidics (DMF) based on the electrowetting-on-dielectric phenomenon is a convenient way of handling microlitre-volume aliquots of solutions prior to analysis. Although it was shown to be compatible with on-line mass spectrometric detection, due to numerous technical obstacles, the implementation of DMF in conjunction with MS is still beyond the reach of many analytical laboratories. Here we present a facile method for coupling open DMF microchips to mass spectrometers using Venturi easy ambient sonic-spray ionization operated at atmospheric pressure. The proposed interface comprises a 3D-printed body that can easily be "clipped" at the inlet of a standard mass spectrometer. The accessory features all the necessary connections for an open-architecture DMF microchip with T-shaped electrode arrangement, thermostatting of the microchip, purification of air (to prevent accidental contamination of the microchip), a Venturi pump, and two microfluidic pumps to facilitate transfer of samples and reagents onto the microchip. The system also incorporates a touch-screen panel and remote control for user-friendly operation. It is based on the use of popular open-source electronic modules, and can readily be assembled at low expense.
Collapse
Affiliation(s)
- Jie-Bi Hu
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
| | | | | | | | | | | |
Collapse
|
107
|
|
108
|
Jebrail MJ, Renzi RF, Sinha A, Van De Vreugde J, Gondhalekar C, Ambriz C, Meagher RJ, Branda SS. A solvent replenishment solution for managing evaporation of biochemical reactions in air-matrix digital microfluidics devices. LAB ON A CHIP 2015; 15:151-158. [PMID: 25325619 DOI: 10.1039/c4lc00703d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Digital microfluidics (DMF) is a powerful technique for sample preparation and analysis for a broad range of biological and chemical applications. In many cases, it is desirable to carry out DMF on an open surface, such that the matrix surrounding the droplets is ambient air. However, the utility of the air-matrix DMF format has been severely limited by problems with droplet evaporation, especially when the droplet-based biochemical reactions require high temperatures for long periods of time. We present a simple solution for managing evaporation in air-matrix DMF: just-in-time replenishment of the reaction volume using droplets of solvent. We demonstrate that this solution enables DMF-mediated execution of several different biochemical reactions (RNA fragmentation, first-strand cDNA synthesis, and PCR) over a range of temperatures (4-95 °C) and incubation times (up to 1 h or more) without use of oil, humidifying chambers, or off-chip heating modules. Reaction volumes and temperatures were maintained roughly constant over the course of each experiment, such that the reaction kinetics and products generated by the air-matrix DMF device were comparable to those of conventional benchscale reactions. This simple yet effective solution for evaporation management is an important advance in developing air-matrix DMF for a wide variety of new, high-impact applications, particularly in the biomedical sciences.
Collapse
Affiliation(s)
- Mais J Jebrail
- Biotechnology and Bioengineering, Sandia National Laboratories, Livermore, CA, USA.
| | | | | | | | | | | | | | | |
Collapse
|
109
|
Nejad HR, Samiei E, Ahmadi A, Hoorfar M. Gravity-driven hydrodynamic particle separation in digital microfluidic systems. RSC Adv 2015. [DOI: 10.1039/c5ra02068a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the present study, the electrode configuration and actuation scheme are designed in a fashion to implement a gravity-based hydrodynamic particle separation method on digital microfluidic systems.
Collapse
Affiliation(s)
| | | | - Ali Ahmadi
- University of British Columbia
- Kelowna
- Canada
| | | |
Collapse
|
110
|
Xu X, Sun L, Chen L, Zhou Z, Xiao J, Zhang Y. Electrowetting on dielectric device with crescent electrodes for reliable and low-voltage droplet manipulation. BIOMICROFLUIDICS 2014; 8:064107. [PMID: 25553184 PMCID: PMC4247374 DOI: 10.1063/1.4902554] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 11/13/2014] [Indexed: 05/31/2023]
Abstract
Digital microfluidics based on electrowetting on dielectric is an emerging popular technology that manipulates single droplets at the microliter or even the nanoliter level. It has the unique advantages of rapid response, low reagent consumption, and high integration and is mainly applied in the field of biochemical analysis. However, currently, this technology still has a few problems, such as high control voltage, low droplet velocity, and continuity in flow, limiting its application. In this paper, through theoretical analysis and numerical simulation, it is deduced that a drive electrode with a crescent configuration can reduce the driving voltage. The experimental results not only validate this deduction but also indicate that crescent electrode can improve the droplet motion continuity and the success in split rate.
Collapse
Affiliation(s)
- Xiaowei Xu
- College of Mechanical Engineering, Quzhou University , Quzhou 324000, China
| | - Lining Sun
- Robotics and Microsystem Center and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215001, China
| | - Liguo Chen
- Robotics and Microsystem Center and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215001, China
| | - Zhaozhong Zhou
- College of Mechanical Engineering, Quzhou University , Quzhou 324000, China
| | - Junjian Xiao
- College of Mechanical Engineering, Quzhou University , Quzhou 324000, China
| | - Yuliang Zhang
- College of Mechanical Engineering, Quzhou University , Quzhou 324000, China
| |
Collapse
|
111
|
Lapierre F, Harnois M, Coffinier Y, Boukherroub R, Thomy V. Split and flow: reconfigurable capillary connection for digital microfluidic devices. LAB ON A CHIP 2014; 14:3589-3593. [PMID: 25058858 DOI: 10.1039/c4lc00650j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Supplying liquid to droplet-based microfluidic microsystems remains a delicate task facing the problems of coupling continuous to digital or macro- to microfluidic systems. Here, we take advantage of superhydrophobic microgrids to address this problem. Insertion of a capillary tube inside a microgrid aperture leads to a simple and reconfigurable droplet generation setup.
Collapse
Affiliation(s)
- Florian Lapierre
- Institute of Electronics, Microelectronics and Nanotechnology (IEMN), UMR CNRS 8520, University Lille 1, F-59652 Villeneuve d'Ascq, France.
| | | | | | | | | |
Collapse
|
112
|
Björnmalm M, Yan Y, Caruso F. Engineering and evaluating drug delivery particles in microfluidic devices. J Control Release 2014; 190:139-49. [DOI: 10.1016/j.jconrel.2014.04.030] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 03/14/2014] [Accepted: 03/21/2014] [Indexed: 02/03/2023]
|
113
|
Fan SK, Wang FM. Multiphase optofluidics on an electro-microfluidic platform powered by electrowetting and dielectrophoresis. LAB ON A CHIP 2014; 14:2728-38. [PMID: 24899133 DOI: 10.1039/c4lc00317a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
For diverse material phases used on an electro-microfluidic (EMF) platform, exploiting the electro-optical properties of matter in varied phases is essential to reap the benefits of the optofluidic capabilities of that platform. Materials in the four fundamental phases--solid-phase dielectric layer, liquid-phase droplet, gas-phase bubble, and plasma-phase bubble microplasma--have been investigated to offer electrically tunable optical characteristics for the manipulation of fluids on an EMF platform. Here we present an overview of the basic driving mechanisms for electrowetting and dielectrophoresis on the EMF platform. Three optofluidic examples occurring in multiple phases are described: solid optofluidics--liquid and light regulation by electrowetting on a solid polymer dispersed liquid crystal (PDLC) dielectric layer; liquid optofluidics--transmittance and reflectance modulation with formation of particle chains in a liquid droplet; and gas and plasma optofluidics--ignition and manipulation of a bubble microplasma by liquid dielectrophoresis. By combining the various materials possessing diverse electro-optical characteristics in separate phases, the EMF platform becomes an ideal platform for integrated optofluidics.
Collapse
Affiliation(s)
- Shih-Kang Fan
- Department of Mechanical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
| | | |
Collapse
|
114
|
Tsaloglou MN, Jacobs A, Morgan H. A fluorogenic heterogeneous immunoassay for cardiac muscle troponin cTnI on a digital microfluidic device. Anal Bioanal Chem 2014; 406:5967-76. [PMID: 25074544 DOI: 10.1007/s00216-014-7997-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 06/18/2014] [Accepted: 06/24/2014] [Indexed: 11/24/2022]
Abstract
We describe a fluorogenic two-site noncompetitive heterogeneous immunoassay with magnetic beads on a low-voltage digital microfluidic platform using closed electrowetting-on-dielectric (EWOD). All the steps of an enzyme-linked immunosorbent assay (ELISA) were performed on the device using 9H-(1, 3-dichloro-9, 9-dimethylacridin-2-one-7-yl) phosphate as the fluorogenic substrate for the enzyme alkaline phosphatase. The performance of the system was demonstrated with cardiac marker Troponin I (cTnI) as a model analyte in phosphate-buffered saline samples. cTnI was detected within the diagnostically relevant range with a limit of detection of 2.0 ng/mL (CV = 6.47 %). Washing of magnetic beads was achieved by movement through a narrow region of buffer bridging one drop to another with minimal fluid transfer. More than 90 % of the unbound reagents were removed after five washes. Further experiments testing human blood serum on the same platform demonstrated a sample-to-answer time at ∼18.5 min detecting 6.79 ng/mL cTnI.
Collapse
Affiliation(s)
- Maria-Nefeli Tsaloglou
- Electronics and Computer Science and Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, UK,
| | | | | |
Collapse
|
115
|
Huang CJ, Fang WF, Ke MS, Chou HYE, Yang JT. A biocompatible open-surface droplet manipulation platform for detection of multi-nucleotide polymorphism. LAB ON A CHIP 2014; 14:2057-62. [PMID: 24789224 DOI: 10.1039/c4lc00089g] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We present a novel and simple method to manipulate droplets applicable to an open-surface microfluidic platform. The platform comprised a control module for pneumatic droplets and a superhydrophobic polydimethylsiloxane (PDMS) membrane. With pneumatic suction to cause deflection of the flexible PDMS-based superhydrophobic membrane, the sample and reagent droplets on the membrane become transported and mixed. A facile one-step laser micromachining technique serves to fabricate a superhydrophobic surface; a contact angle of 150° and a hysteresis angle of 4° were achieved without chemical modification. Relative to previous open-surface microfluidic systems, this platform is capable of simultaneous and precise delivery of droplets in two-dimensional (2D) manipulation. Droplets were manipulated with suction, which avoided interference from an external driving energy (e.g. heat, light, electricity) to affect the bio-sample inside the droplets. Two common bio-samples, namely protein and DNA, verified the performance of the platform. Based on the experimental results, operations on protein can be implemented without adsorption on the surface of the platform. Another striking result is the visual screening for multi-nucleotide polymorphism with hybridization-mediated growth of gold-nanoparticle (AuNP) probes. The detection results are observable with the naked eye, without the aid of advanced instruments. The entire procedure only takes 5 min from the addition of the sample and reagent to obtaining the results, which is much quicker than the traditional method. The total sample volume consumed in each operation is only 10 μL, which is significantly less than what is required in a large system. According to this approach, the proposed platform is suitable for biological and chemical applications.
Collapse
Affiliation(s)
- C J Huang
- Department of Mechanical Engineering, National Taiwan University, Taipei 106, Taiwan.
| | | | | | | | | |
Collapse
|
116
|
Schultz A, Papautsky I, Heikenfeld J. Investigation of Laplace barriers for arrayed electrowetting lab-on-a-chip. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:5349-5356. [PMID: 24738982 DOI: 10.1021/la500314v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Partial-post Laplace barriers have been postulated as a means to allow electrowetting transport and geometrical reshaping of fluids, followed by the preservation of fluid geometry after the electrowetting voltage is removed. Reported here is the first investigation of Laplace barriers with the arrayed electrodes and splitting/merging transport functions for an electrowetting lab-on-a-chip. Laplace barriers optimized for 500 × 500 μm(2) electrodes and 78 μm channel height are shown to provide geometrical control of fluid shape down to radii of curvature of ~70 μm. The Laplace barriers increase the splitting volume error, but with proper electrical control, the average error in the split volume is reduced to 5%. Improved programmable fluid storage in droplets or reservoirs and continuous channel flow are also shown. This work confirms the potential benefits of Laplace barriers for lab-on-a-chip and also reveals the unique challenges and operation requirements for Laplace barriers in lab-on-a-chip applications.
Collapse
Affiliation(s)
- A Schultz
- Department of Electrical Engineering and Computing Systems, University of Cincinnati , Cincinnati, Ohio 45221, United States
| | | | | |
Collapse
|
117
|
Venancio-Marques A, Baigl D. Digital optofluidics: LED-gated transport and fusion of microliter-sized organic droplets for chemical synthesis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4207-4212. [PMID: 24702022 DOI: 10.1021/la5001254] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Microdroplet-based organic syntheses have been developed as a valuable alternative to traditional bulk-based methods. However, unlike their water counterparts, organic microdroplets can prove challenging to manipulate. Here, we describe the first optical manipulation of discrete, nanoliter- to microliter-sized apolar droplets floating on a liquid surface to induce on-demand droplet fusion for organic synthesis. We demonstrate droplet transport on centimeter-scale distances at speeds of 0.1 to 1 mm·s(-1) with well-programmable, sequential or parallel, fusion events. Because our strategy is compatible with most usual hydrocarbon solvents, such droplets can be used as microcompartments for reagents. Organic reactions readily occur upon droplet fusion, as demonstrated with an ene reaction. With an LED as the sole power source, and without any fabrication step, optical setup, pump or electrode implementation, our method provides a robust and versatile way to place digital organic chemistry under optical control.
Collapse
Affiliation(s)
- Anna Venancio-Marques
- Ecole Normale Supérieure-PSL Research University , Department of Chemistry, 24 rue Lhomond, F-75005 Paris, France
| | | |
Collapse
|
118
|
Peng C, Zhang Z, Kim CJCJ, Ju YS. EWOD (electrowetting on dielectric) digital microfluidics powered by finger actuation. LAB ON A CHIP 2014; 14:1117-22. [PMID: 24452784 DOI: 10.1039/c3lc51223a] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We report finger-actuated digital microfluidics (F-DMF) based on the manipulation of discrete droplets via the electrowetting on dielectric (EWOD) phenomenon. Instead of requiring an external power supply, our F-DMF uses piezoelectric elements to convert mechanical energy produced by human fingers to electric voltage pulses for droplet actuation. Voltage outputs of over 40 V are provided by single piezoelectric elements, which is necessary for oil-free EWOD devices with thin (typically <1 μm) dielectric layers. Higher actuation voltages can be provided using multiple piezoelectric elements connected in series when needed. Using this energy conversion scheme, we confirmed basic modes of EWOD droplet operation, such as droplet transport, splitting and merging. Using two piezoelectric elements in series, we also successfully demonstrated applications of F-DMF for glucose detection and immunoassay. Not requiring power sources, F-DMF offers intriguing paths for various portable and other microfluidic applications.
Collapse
Affiliation(s)
- Cheng Peng
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA, USA.
| | | | | | | |
Collapse
|
119
|
Chen S, Javed MR, Kim HK, Lei J, Lazari M, Shah GJ, van Dam RM, Keng PY, Kim CJCJ. Radiolabelling diverse positron emission tomography (PET) tracers using a single digital microfluidic reactor chip. LAB ON A CHIP 2014; 14:902-910. [PMID: 24352530 DOI: 10.1039/c3lc51195b] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Radiotracer synthesis is an ideal application for microfluidics because only nanogram quantities are needed for positron emission tomography (PET) imaging. Thousands of radiotracers have been developed in research settings but only a few are readily available, severely limiting the biological problems that can be studied in vivo via PET. We report the development of an electrowetting-on-dielectric (EWOD) digital microfluidic chip that can synthesize a variety of (18)F-labeled tracers targeting a range of biological processes by confirming complete syntheses of four radiotracers: a sugar, a DNA nucleoside, a protein labelling compound, and a neurotransmitter. The chip employs concentric multifunctional electrodes that are used for heating, temperature sensing, and EWOD actuation. All of the key synthesis steps for each of the four (18)F-labeled tracers are demonstrated and characterized with the chip: concentration of fluoride ion, solvent exchange, and chemical reactions. The obtained fluorination efficiencies of 90-95% are comparable to, or greater than, those achieved by conventional approaches.
Collapse
Affiliation(s)
- Supin Chen
- Bioengineering Department, University of California, Los Angeles, CA 90095, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
120
|
de Ruiter R, Pit AM, de Oliveira VM, Duits MHG, van den Ende D, Mugele F. Electrostatic potential wells for on-demand drop manipulation in microchannels. LAB ON A CHIP 2014; 14:883-91. [PMID: 24394887 DOI: 10.1039/c3lc51121a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Precise control and manipulation of individual drops are crucial in many lab-on-a-chip applications. We present a novel hybrid concept for channel-based discrete microfluidics with integrated electrowetting functionality by incorporating co-planar electrodes (separated by a narrow gap) in one of the microchannel walls. By combining the high throughput of channel-based microfluidics with the individual drop control achieved using electrical actuation, we acquire the strengths of both worlds. The tunable strength of the electrostatic forces enables a wide range of drop manipulations, such as on-demand trapping and release, guiding, and sorting of drops in the microchannel. In each of these scenarios, the retaining electrostatic force competes with the hydrodynamic drag force. The conditions for trapping can be predicted using a simple model that balances these forces.
Collapse
Affiliation(s)
- Riëlle de Ruiter
- Physics of Complex Fluids and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | | | | | | | | | | |
Collapse
|
121
|
Jebrail MJ, Sinha A, Vellucci S, Renzi RF, Ambriz C, Gondhalekar C, Schoeniger JS, Patel KD, Branda SS. World-to-Digital-Microfluidic Interface Enabling Extraction and Purification of RNA from Human Whole Blood. Anal Chem 2014; 86:3856-62. [DOI: 10.1021/ac404085p] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Mais J. Jebrail
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| | - Anupama Sinha
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| | - Samantha Vellucci
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| | - Ronald F. Renzi
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| | - Cesar Ambriz
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| | - Carmen Gondhalekar
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| | - Joseph S. Schoeniger
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| | - Kamlesh D. Patel
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| | - Steven S. Branda
- Departments of Biotechnology and Bioengineering, ‡Systems Biology, and §Advanced Systems Engineering and
Deployment, Sandia National Laboratories, Livermore, California, United States
| |
Collapse
|
122
|
Karabudak E. Micromachined silicon attenuated total reflectance infrared spectroscopy: An emerging detection method in micro/nanofluidics. Electrophoresis 2013; 35:236-44. [DOI: 10.1002/elps.201300248] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 09/30/2013] [Accepted: 10/01/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Engin Karabudak
- Mesoscale Chemical Systems Group (MCS); MESA+ Institute for Nanotechnology; University of Twente; The Netherlands
| |
Collapse
|
123
|
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.
Collapse
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
| |
Collapse
|
124
|
Choi K, Ng AHC, Fobel R, Chang-Yen DA, Yarnell LE, Pearson EL, Oleksak CM, Fischer AT, Luoma RP, Robinson JM, Audet J, Wheeler AR. Automated Digital Microfluidic Platform for Magnetic-Particle-Based Immunoassays with Optimization by Design of Experiments. Anal Chem 2013; 85:9638-46. [DOI: 10.1021/ac401847x] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Kihwan Choi
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto,
Ontario M5S 3H6, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| | - Alphonsus H. C. Ng
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| | - Ryan Fobel
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| | - David A. Chang-Yen
- AbbVie, 200 Abbott Park Road, Abbott Park,
Illinois 60064, United States
| | - Lyle E. Yarnell
- Abbott Diagnostics, 1921 Hurd Drive, Irving,
Texas 75038, United States
| | - Elroy L. Pearson
- AbbVie, 200 Abbott Park Road, Abbott Park,
Illinois 60064, United States
| | - Carl M. Oleksak
- Abbott Diagnostics, 1921 Hurd Drive, Irving,
Texas 75038, United States
| | - Andrew T. Fischer
- Abbott Diagnostics, 1921 Hurd Drive, Irving,
Texas 75038, United States
| | - Robert P. Luoma
- Abbott Diagnostics, 1921 Hurd Drive, Irving,
Texas 75038, United States
| | - John M. Robinson
- Abbott Diagnostics, 100 Abbott Park Road, Abbott Park,
Illinois 60064, United States
| | - Julie Audet
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| | - Aaron R. Wheeler
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto,
Ontario M5S 3H6, Canada
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| |
Collapse
|
125
|
Sinha A, Jebrail MJ, Kim H, Patel KD, Branda SS. A versatile automated platform for micro-scale cell stimulation experiments. J Vis Exp 2013. [PMID: 23962881 DOI: 10.3791/50597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Study of cells in culture (in vitro analysis) has provided important insight into complex biological systems. Conventional methods and equipment for in vitro analysis are well suited to study of large numbers of cells (≥ 10(5)) in milliliter-scale volumes (≥ 0.1 ml). However, there are many instances in which it is necessary or desirable to scale down culture size to reduce consumption of the cells of interest and/or reagents required for their culture, stimulation, or processing. Unfortunately, conventional approaches do not support precise and reproducible manipulation of micro-scale cultures, and the microfluidics-based automated systems currently available are too complex and specialized for routine use by most laboratories. To address this problem, we have developed a simple and versatile technology platform for automated culture, stimulation, and recovery of small populations of cells (100-2,000 cells) in micro-scale volumes (1-20 μl). The platform consists of a set of fibronectin-coated microcapillaries ("cell perfusion chambers"), within which micro-scale cultures are established, maintained, and stimulated; a digital microfluidics (DMF) device outfitted with "transfer" microcapillaries ("central hub"), which routes cells and reagents to and from the perfusion chambers; a high-precision syringe pump, which powers transport of materials between the perfusion chambers and the central hub; and an electronic interface that provides control over transport of materials, which is coordinated and automated via pre-determined scripts. As an example, we used the platform to facilitate study of transcriptional responses elicited in immune cells upon challenge with bacteria. Use of the platform enabled us to reduce consumption of cells and reagents, minimize experiment-to-experiment variability, and re-direct hands-on labor. Given the advantages that it confers, as well as its accessibility and versatility, our platform should find use in a wide variety of laboratories and applications, and prove especially useful in facilitating analysis of cells and stimuli that are available in only limited quantities.
Collapse
Affiliation(s)
- Anupama Sinha
- Department of Systems Biology, Sandia National Laboratories, USA
| | | | | | | | | |
Collapse
|
126
|
Kim H, Jebrail MJ, Sinha A, Bent ZW, Solberg OD, Williams KP, Langevin SA, Renzi RF, Van De Vreugde JL, Meagher RJ, Schoeniger JS, Lane TW, Branda SS, Bartsch MS, Patel KD. A microfluidic DNA library preparation platform for next-generation sequencing. PLoS One 2013; 8:e68988. [PMID: 23894387 PMCID: PMC3718812 DOI: 10.1371/journal.pone.0068988] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 06/03/2013] [Indexed: 12/13/2022] Open
Abstract
Next-generation sequencing (NGS) is emerging as a powerful tool for elucidating genetic information for a wide range of applications. Unfortunately, the surging popularity of NGS has not yet been accompanied by an improvement in automated techniques for preparing formatted sequencing libraries. To address this challenge, we have developed a prototype microfluidic system for preparing sequencer-ready DNA libraries for analysis by Illumina sequencing. Our system combines droplet-based digital microfluidic (DMF) sample handling with peripheral modules to create a fully-integrated, sample-in library-out platform. In this report, we use our automated system to prepare NGS libraries from samples of human and bacterial genomic DNA. E. coli libraries prepared on-device from 5 ng of total DNA yielded excellent sequence coverage over the entire bacterial genome, with >99% alignment to the reference genome, even genome coverage, and good quality scores. Furthermore, we produced a de novo assembly on a previously unsequenced multi-drug resistant Klebsiella pneumoniae strain BAA-2146 (KpnNDM). The new method described here is fast, robust, scalable, and automated. Our device for library preparation will assist in the integration of NGS technology into a wide variety of laboratories, including small research laboratories and clinical laboratories.
Collapse
Affiliation(s)
- Hanyoup Kim
- Department of Biotechnology and Bioengineering, Sandia National Laboratories, Livermore, California, United States of America
| | - Mais J. Jebrail
- Department of Biotechnology and Bioengineering, Sandia National Laboratories, Livermore, California, United States of America
| | - Anupama Sinha
- Department of Systems Biology, Sandia National Laboratories, Livermore, California, United States of America
| | - Zachary W. Bent
- Department of Systems Biology, Sandia National Laboratories, Livermore, California, United States of America
| | - Owen D. Solberg
- Department of Systems Biology, Sandia National Laboratories, Livermore, California, United States of America
| | - Kelly P. Williams
- Department of Systems Biology, Sandia National Laboratories, Livermore, California, United States of America
| | - Stanley A. Langevin
- Department of Systems Biology, Sandia National Laboratories, Livermore, California, United States of America
| | - Ronald F. Renzi
- Advanced Systems Engineering and Deployment, Sandia National Laboratories, Livermore, California, United States of America
| | - James L. Van De Vreugde
- Advanced Systems Engineering and Deployment, Sandia National Laboratories, Livermore, California, United States of America
| | - Robert J. Meagher
- Department of Biotechnology and Bioengineering, Sandia National Laboratories, Livermore, California, United States of America
| | - Joseph S. Schoeniger
- Department of Systems Biology, Sandia National Laboratories, Livermore, California, United States of America
| | - Todd W. Lane
- Department of Systems Biology, Sandia National Laboratories, Livermore, California, United States of America
| | - Steven S. Branda
- Department of Biotechnology and Bioengineering, Sandia National Laboratories, Livermore, California, United States of America
| | - Michael S. Bartsch
- Advanced Systems Engineering and Deployment, Sandia National Laboratories, Livermore, California, United States of America
| | - Kamlesh D. Patel
- Advanced Systems Engineering and Deployment, Sandia National Laboratories, Livermore, California, United States of America
- * E-mail:
| |
Collapse
|
127
|
Quantitative microfluidic biomolecular analysis for systems biology and medicine. Anal Bioanal Chem 2013; 405:5743-58. [PMID: 23568613 DOI: 10.1007/s00216-013-6930-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/10/2013] [Accepted: 03/19/2013] [Indexed: 12/12/2022]
Abstract
In the postgenome era, biology and medicine are rapidly evolving towards quantitative and systems studies of complex biological systems. Emerging breakthroughs in microfluidic technologies and innovative applications are transforming systems biology by offering new capabilities to address the challenges in many areas, such as single-cell genomics, gene regulation networks, and pathology. In this review, we focus on recent progress in microfluidic technology from the perspective of its applications to promoting quantitative and systems biomolecular analysis in biology and medicine.
Collapse
|
128
|
Im DJ, Yoo BS, Ahn MM, Moon D, Kang IS. Digital Electrophoresis of Charged Droplets. Anal Chem 2013; 85:4038-44. [DOI: 10.1021/ac303778j] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Do Jin Im
- Department of Chemical Engineering, Pohang University of Science and Technology, San31 Hyoja-dong,
Nam-Gu, Pohang, Gyeongbuk, 790-784, South Korea
| | - Byeong Sun Yoo
- Department of Chemical Engineering, Pohang University of Science and Technology, San31 Hyoja-dong,
Nam-Gu, Pohang, Gyeongbuk, 790-784, South Korea
| | - Myung Mo Ahn
- Department of Chemical Engineering, Pohang University of Science and Technology, San31 Hyoja-dong,
Nam-Gu, Pohang, Gyeongbuk, 790-784, South Korea
| | - Dustin Moon
- Department of Chemical Engineering, Pohang University of Science and Technology, San31 Hyoja-dong,
Nam-Gu, Pohang, Gyeongbuk, 790-784, South Korea
| | - In Seok Kang
- Department of Chemical Engineering, Pohang University of Science and Technology, San31 Hyoja-dong,
Nam-Gu, Pohang, Gyeongbuk, 790-784, South Korea
| |
Collapse
|
129
|
Mawatari K, Kubota S, Xu Y, Priest C, Sedev R, Ralston J, Kitamori T. Femtoliter droplet handling in nanofluidic channels: a Laplace nanovalve. Anal Chem 2012; 84:10812-6. [PMID: 23214507 DOI: 10.1021/ac3028905] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Analytical technologies of ultrasmall volume liquid, in particular femtoliter to attoliter liquid, is essential for single-cell and single-molecule analysis, which is becoming highly important in biology and medical diagnosis. Nanofluidic chips will be a powerful tool to realize chemical processes for such a small volume sample. However, a technical challenge exists in fluidic control, which is femtoliter to attoliter liquid generation in air and handling for further chemical analysis. Integrating mechanical valves fabricated by MEMS (microelectric mechanical systems) technology into nanofluidic channels is difficult. Here, we propose a nonmechanical valve, which is a Laplace nanovalve. For this purpose, a nanopillar array was embedded in a nanochannel using a two-step electron beam lithography and dry-etching process. The nanostructure allowed precise wettability patterning with a resolution below 100 nm, which was difficult by photochemical wettability patterning due to the optical diffraction. The basic principle of the Laplace nanovalve was verified, and a 1.7 fL droplet (water in air) was successfully generated and handled for the first time.
Collapse
Affiliation(s)
- Kazuma Mawatari
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
| | | | | | | | | | | | | |
Collapse
|
130
|
Thaitrong N, Kim H, Renzi RF, Bartsch MS, Meagher RJ, Patel KD. Quality control of next-generation sequencing library through an integrative digital microfluidic platform. Electrophoresis 2012; 33:3506-13. [PMID: 23135807 DOI: 10.1002/elps.201200441] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/06/2012] [Accepted: 09/08/2012] [Indexed: 11/12/2022]
Abstract
We have developed an automated quality control (QC) platform for next-generation sequencing (NGS) library characterization by integrating a droplet-based digital microfluidic (DMF) system with a capillary-based reagent delivery unit and a quantitative CE module. Using an in-plane capillary-DMF interface, a prepared sample droplet was actuated into position between the ground electrode and the inlet of the separation capillary to complete the circuit for an electrokinetic injection. Using a DNA ladder as an internal standard, the CE module with a compact LIF detector was capable of detecting dsDNA in the range of 5-100 pg/μL, suitable for the amount of DNA required by the Illumina Genome Analyzer sequencing platform. This DMF-CE platform consumes tenfold less sample volume than the current Agilent BioAnalyzer QC technique, preserving precious sample while providing necessary sensitivity and accuracy for optimal sequencing performance. The ability of this microfluidic system to validate NGS library preparation was demonstrated by examining the effects of limited-cycle PCR amplification on the size distribution and the yield of Illumina-compatible libraries, demonstrating that as few as ten cycles of PCR bias the size distribution of the library toward undesirable larger fragments.
Collapse
Affiliation(s)
- Numrin Thaitrong
- Biotechnology and Bioengineering Department, Sandia National Laboratories, Livermore, CA 94550, USA
| | | | | | | | | | | |
Collapse
|
131
|
Jebrail MJ, Assem N, Mudrik JM, Dryden MD, Lin K, Yudin AK, Wheeler AR. Combinatorial Synthesis of Peptidomimetics Using Digital Microfluidics. J Flow Chem 2012. [DOI: 10.1556/jfc-d-12-00012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
132
|
Gorbatsova J, Borissova M, Kaljurand M. Electrowetting on dielectric actuation of droplets with capillary electrophoretic zones for MALDI mass spectrometric analysis. Electrophoresis 2012; 33:2682-8. [DOI: 10.1002/elps.201200096] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|