Embodiments of the present invention provide improved microfluidic devices and related apparatus, systems, and methods. Methods are provided for reducing mixing times during use of microfluidic devices. Microfluidic devices and related methods of manufacturing are provided with increased manufacturing yield rates. Improved apparatus and related systems are provided for supplying controlled pressure to microfluidic devices. Methods and related microfluidic devices are provided for reducing dehydration of microfluidic devices during use. Microfluidic devices and related methods are provided with improved sample to reagent mixture ratio control. Microfluidic devices and systems are provided with improved resistance to compression fixture pressure induced failures. Methods and systems for conducting temperature controlled reactions using microfluidic devices are provided that reduce condensation levels within the microfluidic device. Methods and systems are provided for improved fluorescent imaging of
Microfluidic devices have a wide variety of biological applications. My Ph.D. dissertation focuses on three major projects. A) culturing a non-adherent immortal cell line within a microfluidic device under static and dynamic media flow conditions; B) designing and fabricating novel microfluidic devices for electrokinetic injecting analytes from a hydrodynamic fluid; and C) using this novel injection method to lyse single non-adherent cells by applying a high electric field across the cell at a microfluidic channel intersection. There are several potential advantages to the use of microfluidic devices for the analysis of single cells: First, cells can be handled with care and precision while being transported in the microfluidic channels. Second, cell culturing, handling, and analysis can be integrated together in a single, compact microfluidic device. Third, cell culturing and analysis in microfluidic devices uses only extremely small volumes of culturing media and analysis buffer. In this ...
TY - GEN. T1 - Microfluidic technology. T2 - new opportunities to develop physiologically relevant in vitro models integrated microfluidic platform for the in vitro pre-implantation culture of individual mammalian embryos and their in situ characterization. AU - le Gac, Severine PY - 2017/9/11. Y1 - 2017/9/11. U2 - 10.1109/ESSDERC.2017.8066641. DO - 10.1109/ESSDERC.2017.8066641. M3 - Conference contribution. SN - 978-1-5090-5979-9. SP - 260. EP - 263. BT - 47th European Solid-State Device Research Conference (ESSDERC 2017). PB - IEEE. CY - Piscataway, NJ. ER - ...
Droplet-based microfluidics has been used to facilitate high throughput analysis of individual prokaryote and mammalian cells. However, there is a scarcity of similar workflows applicable to rapid phenotyping of plant systems. We report on-chip encapsulation and analysis of protoplasts isolated from the emergent plant model Marchantia polymorpha at processing rates of ,100,000 protoplasts per hour. We use our microfluidic system to quantify the stochastic properties of a heat-inducible promoter across a population of transgenic protoplasts to demonstrate that it has the potential to assess gene expression activity in response to environmental conditions. We further demonstrate on-chip sorting of droplets containing YFP-expressing protoplasts from wild type cells using dielectrophoresis force. This work opens the door to droplet-based microfluidic analysis of plant cells for applications ranging from high-throughput characterisation of DNA parts to single-cell genomics ...
The use of microfluidic systems for screening of aptamers and their biomedical applications are reviewed in this paper. Aptamers with different nucleic acid sequences have been extensively studied and the results demonstrated a strong binding affinity to target molecules such that they can be used as promising candidate biomarkers for diagnosis and therapeutics. Recently, the aptamer screening protocol has been conducted with microfluidic-based devices. Furthermore, aptamer affinity screening by a microfluidic-based method has demonstrated remarkable advantages over competing traditional methods. In this paper, we first reviewed microfluidic systems which demonstrated efficient and rapid screening of a specific aptamer. Then, the clinical applications of screened aptamers, also performed by microfluidic systems, are further reviewed. These automated microfluidic systems can provide advantages over their conventional counterparts including more compactness, faster analysis, less sample/reagent
The market study on Global Microfluidic Devices Market 2017 Research Report studies current as well as future aspects of the Microfluidic Devices Market primarily based upon factors on which the companies compete in the market, key trends and segmentation analysis. This report covers each side of the worldwide market, ranging from the fundamental market info and advancing more to varied important criteria, based on that, the Microfluidic Devices market is segmented. Microfluidic Devices industry research report analyzes, tracks, and presents the global market size of the major players in every region around the world. Furthermore, the report provides data of the leading market players in the Microfluidic Devices market.. This report studies Microfluidic Devices in Global market, especially in North America, China, Europe, Southeast Asia, Japan and India, with production, revenue, consumption, import and export in these regions, from 2012 to 2017, and forecast to 2022.. Request for FREE Sample ...
misc{8894052, abstract = {Microfluidic applications nowadays have become of great interest due to their broad compatibility especially in biological applications, and one of them being droplet-based cell encapsulation. Cell encapsulation in droplets is carried out by discretising an aqueous phase (i.e. cell suspension) and including them into a continuous oil phase. This methodology is a potential gateway to high throughput droplet-based cell fusion (e.g. for the production of hybridomas). The challenge here is to achieve a high efficiency of correctly paired cells in a droplet to overcome the random fusion pairing during bulk cell fusion. As such, droplet microfluidics can be used to co-encapsulate a single cell A and a single cell B cells in one droplet or encapsulate cells separately and merge droplets with desired cell number and type subsequently with other droplet manipulations. In this study, separate encapsulation studies of human B lymphocytes and mouse embryonic stem cells were ...
Laboratory of microfluidic technologies for biomedicine: MicroRNA, miRNA, organ-on-chip, microfluidics, toxin, viscumin, ricin, laminin, placenta, intestine, gut, liver, brain, blood-brain barrier, cancer, tumor
Microfluidic devices are analogous to circuit boards, and they can be programmed to perform all kinds of laboratory tasks on a small scale. They have the potential to perform all kinds of medical tests involving body fluids in a short time and using very small samples.. While circuit boards pass electricity, which can be abstracted and quantified as bits, microfluidic devices tend to work with liquids that can mix with one another and contaminate each other. For microfluidic devices to approach the logic abilities of circuit boards, the fluids within have to somehow be perfectly separated from each other until the time that theyre expected to mix. Conventional microfluidic gates and valves arent adequate in this context, so researchers at Duke University have now developed a way to keep individual droplets from touching each other while moving them around using sound waves inside a microfluidic device.. Scaling up this approach could lead to programmable and rewritable microfluidics that can ...
A system and method for integrating microfluidic components in a microfluidic system enables the microfluidic system to perform a selected microfluidic function. A capping module includes a microfluidic element for performing a microfluidic function. The capping module is stacked on a microfluidic substrate having microfluidic plumbing to incorporate the microfluidic function into the system. The microfluidic element may comprise a matrix having an affinity for selected molecules in a sample. The matrix binds, reacts with and/or retains the selected molecules without affecting other molecules in the sample.
A system and method for integrating microfluidic components in a microfluidic system enables the microfluidic system to perform a selected microfluidic function. A capping module includes a microfluidic element for performing a microfluidic function. The capping module is stacked on a microfluidic substrate having microfluidic plumbing to incorporate the microfluidic function into the system. The microfluidic element may comprise a matrix having an affinity for selected molecules in a sample. The matrix binds, reacts with and/or retains the selected molecules without affecting other molecules in the sample.
Optical coherence tomography (OCT) angiography (OCTA) has been actively studied as a noninvasive imaging technology to generate retinal blood vessel network maps for the diagnoses of retinal diseases. Given that the uses of OCT and OCTA have increased in the field of ophthalmology, it is necessary to develop retinal phantoms for clinical OCT for product development, performance evaluation, calibration, certification, medical device licensing, and production processes. We developed a retinal layer-mimicking phantom with microfluidic channels based on microfluidic fabrication technology using polydimethylsiloxane (PDMS) and titanium dioxide (TiO2) powder. We implemented superficial and deep retinal vessels using microfluidic channels. In addition, multilayered thin films were synthesized with multiple spin-coating processes that comprised layers that corresponded to the retinal layers, including the ganglion cell layer (GCL), inner plexiform layer (IPL), and inner nuclear layer (INL). The phantom ...
Agave BioSystems proposes to develop and demonstrate an innovative Organic Thin Film Transistor (OTFT) to detect cell characteristics without the need for cell labeling for use in microfluidic flow cytometers. This sensor would be able to detect count all cells, whether the cells are fluorescently labeled or not. This device would easily be able to detect the presence of cells within the channel as well as give information about the cell size and even the DNA content or intactness of the cell. The fact that cells will not need to be fluorescently labeled for detection is one of the major advantages of this device, since it can be used to measure live, unperturbed cells. Microfabrication of the OTFTs and microfluidic components will allow development of inexpensive, self-contained, disposable, high-throughput devices for screening of combinatorial chemical, biochemical or biological libraries. Assisting in this project will be Prof. George Malliaras of the Department of Materials Science and ...
Microfluidic gradient generators are used to study the movement of living cells, lipid vesicles, and colloidal particles in response to spatial variations in their local chemical environment. Such gradient driven motions are often slow (less than 1 μm s−1) and therefore influenced or disrupted by fluid flows Lab on a Chip Emerging Investigators Lab on a Chip Recent HOT Articles
A variety of pulmonary diseases such as COPD, asthma, ARDS are profoundly associated with the surfactant dysfunction that leads to liquid plug formation across the airway lumen [19]. Several animal model studies have shown during such lung disorders severe tissue-level damage to the distal lung airways due to repeated closure and reopening process [4]. To mimic exactly the in vivo conditions, Huh et al. [20] developed a compartmentalized microfluidic airway models and demonstrated that the reopening of occluded microfluidic airway causes severe injury of pulmonary epithelial cells [20]. In the lung airways, rupturing of the liquid plugs leads to abnormal breath sounds known as crackles. To simulate this scenario, a three-dimensional (3D) microfluidic device was developed to detect acoustically the crackling sound and it was demonstrated that there is a higher risk of cell injury when liquid plugs become very thin. They demonstrated cellular level of lung injury under flow condition using this ...
We have developed a microfluidic flow cell where stepwise enzymatic digestion is performed on immobilized proteoliposomes and the resulting cleaved peptides are analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The flow cell channels consist of two parallel gold surfaces mounted face to face with a thin spacer and feature an inlet and an outlet port. Proteoliposomes (50-150 nm in diameter) obtained from red blood cells (RBC), or Chinese hamster ovary (CHO) cells, were immobilized on the inside of the flow cell channel, thus forming a stationary phase of proteoliposomes. The rate of proteoliposome immobilization was determined using a quartz crystal microbalance with dissipation monitoring (QCM-D) which showed that 95% of the proteoliposomes bind within 5 min. The flow cell was found to bind a maximum of 1 μg proteoliposomes/cm2, and a minimum proteoliposome concentration required for saturation of the flow cell was determined to be 500 μg/mL. Atomic force microscopy (AFM)
The hanging drops are connected through 200μm-wide channels (Image: Chemistry World) Scientists in Switzerland have incorporated pulsing human heart tissue into a microfluidic device to make a miniscule model of a living system that could be used to test new drugs.. Microfluidic technology manipulates tiny volumes of liquid. One of its most exciting applications lies in building models of the human body - so-called body-on-a-chip or microphysiological systems. Many microphysiological systems already allow small human tissue samples, which approximate the behaviour of whole organs, to be tested under different conditions. Models of multi-organ systems are linked by slender liquid channels, and the flow of liquid and metabolites from one sample to the next can be controlled with pumps and valves. However, a huge challenge for the concept is that - after the attritive processes of extraction, culturing and insertion into a microfluidic environment - the samples often behave quite differently to ...
Developing blood-based tests is appealing for non-invasive disease diagnosis, especially when biopsy is difficult, costly, and sometimes not even an option. Tumor-derived exosomes have attracted increasing interest in non-invasive cancer diagnosis and monitoring of treatment response. However, the biology and clinical value of exosomes remains largely unknown due in part to current technical challenges in rapid isolation, molecular classification and comprehensive analysis of exosomes. Here we developed a new microfluidic approach to streamline and expedite the exosome analysis pipeline by integrating specific immunoisolation and targeted protein analysis of circulating exosomes. Compared to the conventional methods, our approach enables selective subpopulation isolation and quantitative detection of surface and intravesicular biomarkers directly from a minimally invasive amount of plasma samples (30 μL) within ~100 min with markedly improved detection sensitivity. Using this device, we ...
TY - JOUR. T1 - An integrated microfluidic device for monitoring changes in nitric oxide production in single T-lymphocyte (Jurkat) cells. AU - Metto, Eve C.. AU - Evans, Karsten. AU - Barney, Patrick. AU - Culbertson, Anne H.. AU - Gunasekara, Dulan B.. AU - Caruso, Giuseppe. AU - Hulvey, Matthew K.. AU - Fracassi Da Silva, Jose Alberto. AU - Lunte, Susan M.. AU - Culbertson, Christopher T.. PY - 2013/11/5. Y1 - 2013/11/5. N2 - A considerable amount of attention has been focused on the analysis of single cells in an effort to better understand cell heterogeneity in cancer and neurodegenerative diseases. Although microfluidic devices have several advantages for single cell analysis, few papers have actually demonstrated the ability of these devices to monitor chemical changes in perturbed biological systems. In this paper, a new microfluidic channel manifold is described that integrates cell transport, lysis, injection, electrophoretic separation, and fluorescence detection into a single device, ...
Microfluidic devices offer the chance to manipulate and analyze fluids including bioassays and chemical reactions. In this study, a method to develop a microfluidic analysis system is proposed for detection of nanotubes by a Raman acquisition setup. Microchannels where fabricated in sodalime glass substrate by MeV ion beam lithography or electron beam lithography and wet etching. Fusion bonding (550 °C) was used to seal the microchannels. As a result a prototype microfluidic device with 1.6 µm deep channel that exhibit efficient sealing and suitable channel geometry was obtained. The microfluidic device was tested in a Raman spectroscopy detection system and the collected spectra showed the presence of carbon nanotubes within the channel with clear RBM and G-band peaks. By this approach a practical and simple fabrication technique for microfluidic devices combined with Raman spectroscopy was done. This device can be enhanced to perform concentration maps within the channel and further research ...
Electrophoretic separation in nanofluidic channels exhibits significant differences with microfluidics. We discuss a theoretical / experimental collaboration investigating particle separation by electropohoresis in nanochannels. Recent experimental results in the laboratory of our collaborator Dr. Pennathur (UCSB, Dept. ME) indicate that increased fidelity can be achieved in separating particles by size and charge when using channels with cross sections of nanometer dimensions (100nm x 1000nm), as opposed to larger microfluidic channels. For short double-strands of DNA (10 - 100 base pairs) it is found that separation in microfluidic channels produces electropherograms with only one lumped peak. However, for nanofluidic channels several clearly distinct peaks are observed. Given the small dimensions of the nanofluidic channel, it is expected that new effects which were relatively weak in microfluidic channels play an important role. Identifying how these underlying mechanisms augment electrophoretic
Advances in cell biology, quantification, and identification procedures are essential to develop novel particle characterization tools on the diagnostics, biotechnology, pharmaceutical industry, and material science. Flow cytometry is a pivotal technology and meets the need for almost a century. Increase in todays demand for fast, precise, accurate, and low-cost point-of-care diagnostic tools and cell counting technologies necessitate further improvements for state-of-the-art flow cytometry platforms. These improvements are achievable using novel and precise particle focusing techniques, multiple detection methods, integrated fluidic, optical, and electronic units in the same workflow. Thanks to its indisputable advantages in such integrities, microfluidic flow cytometry platforms are attractive and promising tool for the future of next-generation flow cytometry technologies. In this thesis, we developed viscoelastic focusing technique compatible with optical, impedimetric, and imaging-based ...
A variable, closed-loop apparatus for regulating a microfluidic flow that employs a low-power deflection assembly, which is surface-mounted over a flexible membrane overlying a chamber integrated into a microfabricated platform. A flexible membrane, moveable between two positions, sealingly overlies the chamber. One of the positions of the membrane restricts the flow through the chamber to a greater degree than the other position. A deflection assembly disposed on the substrate over the membrane unidirectionally deflects the membrane, thereby regulating the flow through the chamber.
Culturing Pancreatic Islets in Microfluidic Flow Enhances Morphology of the Associated Endothelial Cells. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Nowadays, many researchers in the field of gene delivery are focused on develop methods to produce nanoparticles with physicochemical characteristics in reproducible, con..
Circular dichroism (CD) is the differential absorption of left- and right-handed circularly polarized light. It is a form of spectroscopy used to determine the optical isomerism and secondary structure of molecules, and to study a wide variety of chiral materials in solution, particularly biologically important molecules such as proteins, nucleic acids, carbohydrates, lipids and drugs. The benefit of carrying out such experiments using synchrotron radiation is that the light available is several orders of magnitude higher in intensity than that available using conventional CD instruments, thereby providing a much higher signal-to-noise ratio over a wide wavelength range (140-700 nm). This paper will detail the development of a technique for rapidly producing 3D printed microfluidic channels in transparent polymer flow cells that enables the rapid and low-cost evaluation and iteration of microfluidic channel geometries. Permitting the flow through novel microfluidic devices to be interrogated thoroughly
TY - JOUR. T1 - Detection of culture-negative sepsis in clinical blood samples using a microfluidic assay for combined CD64 and CD69 cell capture. AU - Zhou, Yun. AU - Zhang, Ye. AU - Johnson, Amanda. AU - Venable, Amanda. AU - Griswold, John. AU - Pappas, Dimitri. PY - 2019/7/25. Y1 - 2019/7/25. N2 - Sepsis is a life-threatening disease that affects millions of people every year. Rapid detection of sepsis assists clinicians to initiate timely antibiotic therapy and to reduce mortality. At the same time, accurate point-of-care detection is needed to reduce unnecessary use of antibiotics. One of the principal challenges in sepsis diagnosis is that many sepsis cases do not result in positive blood cultures. These so-called culture-negative cases present a significant health threat. In this work, we present a microfluidic cells separation system for the detection of sepsis in both culture-positive and culture-negative cases. Leukocytes were captured in several affinity separation zones of a ...
The main aim of this project was to develop novel concepts for miniaturization of bioanalytical techniques for investigating biomolecular interactions. We used optical tweezers to selectively address individual biological objects in microfluidic channels. A general introduction of applications of optical tweezers and microfluidics is given in chapter 1. Theoretical concepts related to optical trapping and microfluidics are reviewed in chapter 2, followed by a detailed description of the instrumentation in chapter 3. In chapter 4, ligand-receptor interactions are studied under physiological conditions: whole cells or native vesicles carrying in their membrane the protein of interest are immobilized first in the laser trap inside a microfluidic channel, then the reaction is initiated by changing the solution in the region around the trap. In chapter 5 and chapter 6 respectively, surface-modified polystyrene beads are used to study ligand-receptor interactions and DNA hybridization. The examples of ...
The purpose of this thesis is to study the crystallization in a microfluidic device of an active pharmaceutical ingredient which is (2S)-2-[(4R)-2-oxo- 4-propylpyrrolidin-1-yl] butanamide, with product name Brivaracetam. This molecule is manufactured by the Belgian pharmaceutical industry UCB, and a better understanding of its crystallization in the microscopic scale, and especially its polymorphism, would lead to new possibilities in order to develop a future industrial continuous crystallizer based in the microfluidic technology. For this purpose, several experiments have been run, both in the macroscopic scale and using the microfluidics technology. The solubility curve for the system was determined, and also a cluster formation was analysed using volumes around 10ml of solution. Several crystallizations were done also with solutions of this volume to first understand the polymorphism that the solute presents. For the micro-scale crystallizations, the microfluidic device used was a system ...
TY - JOUR. T1 - Compartmentalized 3D Tissue Culture Arrays under Controlled Microfluidic Delivery. AU - Gümüscü, B.. AU - Albers, Hugo J.. AU - Van Den Berg, Albert. AU - Eijkel, Jan C.T.. AU - Van Der Meer, Andries D.. PY - 2017/12/1. Y1 - 2017/12/1. N2 - We demonstrate an in vitro microfluidic cell culture platform that consists of periodic 3D hydrogel compartments with controllable shapes. The microchip is composed of approximately 500 discontinuous collagen gel compartments locally patterned in between PDMS pillars, separated by microfluidic channels. The typical volume of each compartment is 7.5 nanoliters. The compartmentalized design of the microchip and continuous fluid delivery enable long-Term culturing of Caco-2 human intestine cells. We found that the cells started to spontaneously grow into 3D folds on day 3 of the culture. On day 8, Caco-2 cells were co-cultured for 36 hours under microfluidic perfusion with intestinal bacteria (E. coli) which did not overgrow in the system, and ...
TY - JOUR. T1 - DNA aptamer-based sandwich microfluidic assays for dual quantification and multi-glycan profiling of cancer biomarkers. AU - Jolly, Pawan. AU - Damborsky, P.. AU - Madaboosi, N.. AU - Soares, R.R.G.. AU - Chu, V.. AU - Conde, J.P.. AU - Katrlik, J.. AU - Estrela, Pedro. PY - 2016/5/16. Y1 - 2016/5/16. N2 - Two novel sandwich-based immunoassays for prostate cancer (PCa) diagnosis are reported, in which the primary antibody for capture is replaced by a DNA aptamer. The assays, which can be performed in parallel, were developed in a microfluidic device and tested for the detection of free Prostate Specific Antigen (fPSA). A secondary antibody (Aptamer-Antibody Assay) or a lectin (Aptamer-Lectin Assay) is used to quantify, by chemiluminescence, both the amount of fPSA and its glycosylation levels. The use of aptamers enables a more reliable, selective and controlled sensing of the analyte. The dual approach provides sensitive detection of fPSA along with selective fPSA ...
Accurate analysis at the single-cell level has become a highly attractive tool for investigating cellular content. An electroosmotic-driven microfluidic chip with arrays of 30-µm-diameter microwells was developed for single-cell electric lysis in the present study. The cellular occupancy in the microwells when the applied voltage was 5 V (82.4%) was slightly higher than that at an applied voltage of 10 V (81.8%). When the applied voltage was increased to 15 V, the cellular occupancy in the microwells dropped to 64.3%. More than 50% of the occupied microwells contain individual cells. The results of electric lysis experiments at the single-cell level indicate that the cells were gradually lysed as the DC voltage of 30 V was applied; the cell was fully lysed after 25 s. Single-cell electric lysis was demonstrated in the proposed microfluidic chip, which is suitable for high-throughput cell lysis.
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A microsystem integrating electrochemical detection for the simultaneous detection of protein markers of breast cancer is reported. The microfluidic platform was realized by high precision milling of polycarbonate sheets and features two well distinguishable sections: a detection zone incorporating the elect
This paper reports on the electrochemical characterization and comparison of printable silver inks for the fabrication of planar electrodes to integrate in a microfluidic platform for in situ desalination of seawater prior to detection of nutrients in marine environment. Screen printing and inkjet printing were investigated to overcome limitations of more conventional deposition techniques. The screen printed ink DuPont 5064H was chosen for the fabrication of the desalination platform as it displayed the best properties in terms of oxidation ability (15.5 mC/mm(2)) and absence of sample contamination. The platform was tested at different oxidation conditions; the optimum potential for desalination was found to be +0.9 V. The device desalination performance was then evaluated through conductivity measurements of the treated sample and a proof-of-concept was achieved: for a potential of +0.9 V, conductivity (hence concentration) could be lowered from an initial value of 42.13 mS (0.6 M) to 20.36 ...
Video articles in JoVE about microfabrication include Microfabrication of Nanoporous Gold Patterns for Cell-material Interaction Studies, Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation, Ordering Single Cells and Single Embryos in 3D Confinement: A New Device for High Content Screening, Experimental Methods for Trapping Ions Using Microfabricated Surface Ion Traps, Image-guided, Laser-based Fabrication of Vascular-derived Microfluidic Networks, A Microfluidic System with Surface Patterning for Investigating Cavitation Bubble(s)-Cell Interaction and the Resultant Bioeffects at the Single-cell Level, Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles, Soft Lithographic Procedure for Producing Plastic Microfluidic Devices with View-ports Transparent to Visible and Infrared Light, A Microfluidic Platform for Precision Small-volume Sample Processing and Its Use to Size Separate Biological
Here a new approach to perform patch-clamp investigations under anoxic and normoxic conditions on nerve cells from Sprague Dawley rats is presented. A patch-clamp micropipette is integrated within a poly-methyl methacrylate (PMMA) based microchip giving optimal control over the oxygen content and the biochemical environment. Nerve cells were trapped by optical tweezers and steered towards the patch-clamp micropipette within the micro-channels. Several experiments were performed to show proof of principle. The oxygen content within the microfluidic chamber was measured to 0.5-1.5 %. The photo-induced effect of the optical tweezers on the nerve cells was investigated in an open Petri dish. The optical trapping did not influence measurements. The microfluidic system was further tested in patch-clamp experiments. This approach showed significant advantages regarding the tuning of the oxygen content and may be used in various electrophysiological investigations of single cells demanding optimal ...
Microfluidic devices can be used for many applications, including the formation of well-controlled emulsions. In this study, the capability to continuously create mono-disperse droplets in a microfluidic device is used to form calcium-alginate capsules through chemical crosslinking from aqueous droplets of calcium chloride and sodium alginate suspended in an oil solution. Calcium-alginate capsules have many potential uses, such as immunoisolation of cells, microencapsulation of active drug ingredients, and encapsulation of bitter agents in food or beverage products. Capsule formation is accomplished through fusion of a sodium alginate droplet and a calcium chloride droplet. The high surface tension between the droplet of calcium chloride and sodium alginate necessitates the use of the surfactant sodium dodecyl sulfate (SDS) and a device with a judiciously designed geometry. After creating the capsules, it is necessary to separate them out of the oil solution and into an aqueous solution. A ...
Microfluidic fluorescence assay devices show great promise as preclinical and clinical diagnostic instruments. Normally, fluorescence signals from microfluidic chips are quantified by analysis of images obtained with a commercial fluorescence microscope. This method is unnecessarily expensive, time consuming, and requires significant operator training, particularly when considering future clinical translation of the technology. In this work, we developed a dedicated low cost fluorescence microfluidic device reader (FMDR) to read sandwich immunofluorescence assay (sIFA) devices configured to detect vascular endothelial growth factor ligand concentrations in ocular fluid samples. Using a series of sIFA calibration standards and a limited set of human ocular fluid samples, we demonstrated that our FMDR reader has similar sensitivity and accuracy to a fluorescence microscope for this task, with significantly lower total cost and reduced reading time. We anticipate that the reader could be used with ...
In order to overcome these challenges, we aim to develop a novel breast cancer model that incorporates the relevant properties of the three-dimensional microenvironment. For this purpose, we use microfluidic technology, which enables us to manipulate and control fluids at the small scale. Cell encapsulation is used to first generate soft, cell-containing beads that mimic the basement membrane. These beads are then embedded in a more fibrous matrix that mimics the stromal ECM, completing the tissue model.
The ability to control the deposition and location of adherent and non-adherent cells within microfluidic devices is beneficial for the development of micro-scale bioanalytical tools and high-throughput screening systems. Here, we introduce a simple technique to fabricate poly(ethylene glycol) (PEG) microstructures within microfluidic channels that can be used to dock cells within pre-defined locations. Microstructures of various shapes were used to capture and shear-protect cells despite medium flow in the channel. Using this approach, PEG microwells were fabricated either with exposed or non-exposed substrates. Proteins and cells adhered within microwells with exposed substrates, while non-exposed substrates prevented protein and cell adhesion (although the cells were captured inside the features). Furthermore, immobilized cells remained viable and were stained for cell surface receptors by sequential flow of antibodies and secondary fluorescent probes. With its unique strengths in utility and ...
Microlytic was founded in 2006 with the intention to use microfluidic technology to help solve the major problems in structural biology. Microlytic sought to develop and produce microfluidic chips that offered a high probability of crystallizing target proteins with a set-up that is simple and easy to use.. Microlytic developed microfluidic chips to let users grow crystals large enough to be used immediately for X-ray diffraction, plus give users direct access to the crystals themselves. These goals were realized with the development of the Crystal Former - the first microfluidic platform to allow users to go from crystallization screen to structure using a single device.. The advantages of the Crystal Former are ...
Fabrication of conductive pathways, microcircuits and microstructures in microfluidic networks - Disclosed herein are a variety of microfluidic devices and solid, typically electrically conductive devices that can be formed using such devices as molds. In certain embodiments, the devices that are formed comprise conductive pathways formed by solidifying a liquid metal present in one or more microfluidic channels (such devices hereinafter referred to as microsolidic devices). In certain such devices, in which electrical connections can be formed and/or reformed between regions in a microfluidic structure; in some cases, the devices/circuits formed may be flexible and/or involve flexible electrical components. In certain embodiments, the solid metal wires/conductive pathways formed in microfluidic channel(s) may remain contained within the microfluidic structure. In certain such embodiments, the conductive pathways formed may be located in proximity to other microfluidic channel(s) of the ...
The invention provides a microfluidic device having a plurality of chambers each containing separately deposited reagents. The invention also provides an efficient PCR-based method for producing a linear expression template. The invention also provides methods for analyzing interactions between molecules, involving flow-deposition of expression templates on the substrate of chambers in a microfluidic device, and expressing proteins from the templates.
TY - JOUR. T1 - Ranking migration cue contributions to guiding individual fibroblasts faced with a directional decision in simple microfluidic bifurcations. AU - Pham, Quang Long. AU - Tong, Anh. AU - Rodrigues, Lydia N.. AU - Zhao, Yang. AU - Surblyte, Migle. AU - Ramos, Diomar. AU - Brito, John. AU - Rahematpura, Adwik. AU - Voronov, Roman S.. PY - 2019/5/1. Y1 - 2019/5/1. N2 - Directed cell migration in complex micro-environments, such as in vivo pores, is important for predicting locations of artificial tissue growth and optimizing scaffold architectures. Yet, the directional decisions of cells facing multiple physiochemical cues have not been characterized. Hence, we aim to provide a ranking of the relative importance of the following cues to the decision-making of individual fibroblast cells: chemoattractant concentration gradient, channel width, mitosis, and contact-guidance. In this study, bifurcated micro-channels with branches of different widths were created. Fibroblasts were then ...
Droplet-based microfluidics manipulate discrete volumes of fluids in immiscible phases with low Reynolds number and laminar flow regimes. Interest in droplet-based microfluidics systems has been growing substantially in past decades. Microdroplets offer the feasibility of handling miniature volumes (μl to fl) of fluids conveniently, provide better mixing, encapsulation, sorting, sensing and are suitable for high throughput experiments. Two immiscible phases used for the droplet generation are referred to as the continuous phase (medium in which droplets are generated) and dispersed phase (the droplet phase). The size of the generated droplets is mainly controlled by the flow rates of the continuous phase and dispersed phase, interfacial tension between two phases and the geometry used for the droplet generation. Generally, three types of microfluidic geometries are utilized for the droplet generation: (i) T-Junction, (ii) Flow Focusing, and (iii) Co-Flowing. The benefits of microfluidics can be ...
Synthetic biology aims to engineer biological systems for desired behaviors. The construction of these systems can be complex, often requiring genetic reprogramming, extensive de novo DNA synthesis, and functional screening. Herein, we present a programmable, multipurpose microfluidic platform and associated software and apply the platform to major steps of the synthetic biology research cycle: design, construction, testing, and analysis. We show the platforms capabilities for multiple automated DNA assembly methods, including a new method for Isothermal Hierarchical DNA Construction, and for Escherichia coli and Saccharomyces cerevisiae transformation. The platform enables the automated control of cellular growth, gene expression induction, and proteogenic and metabolic output analysis. Taken together, we demonstrate the microfluidic platforms potential to provide end-to-end solutions for synthetic biology research, from design to functional analysis.
View more ,Bioaffinity mass spectrometry screening is a novel approach using non-denaturing electrospray ionization (ESI) mass spectrometry (MS) in identifying drug leads. This screening technique can detect and preserve noncovalent protein-active drug ligand complexes under different physiological conditions. Although there are many successful screening campaigns employing this technique, the big challenge of the screening is the reduction of sample volume needed. We demonstrate in this paper that analysis of samples can be performed using droplet-based microfluidics. Droplets of samples to be screened are formed and delivered directly into the electrospray emitter of a Fourier Transform mass spectrometer. The results show that a MS instrument with a conventional ESI source can clearly detect the samples and distinguish it with the separating oil phase. The proposed technique opens the possibility of bioaffinity mass spectrometry screening of small samples with a simple microfluidic device ...
Polymers have assumed the leading role as substrate materials for microfluidic devices in recent years. They offer a broad range of material parameters as well as material and surface chemical properties which enable microscopic design features that cannot be realised by any other class of materials. A similar range of fabrication technologies exist to generate microfluidic devices from these materials. This review will introduce the currently relevant microfabrication technologies such as replication methods like hot embossing, injection molding, microthermoforming and casting as well as photodefining methods like lithography and laser ablation for microfluidic systems and discuss academic and industrial considerations for their use. A section on back-end processing completes the overview. ...
Microfluidics based Lab-on-a-chip technology exhibits an unprecedented perspective in studying microbiology and biochemistry. With microfluidic technology, researchers can manipulate and probe individual cells, and can precisely control their microenvironments. Thus microfluidics enables quantitative measurements with high biological/chemical selectivity and sensitivity, as well as high temporal and spatial resolution. This IDI proposal envisages Western becoming a national leader in multidisciplinary research and education in bionanotechnology and related subjects. As a part of the Westerns overall efforts to accomplish this, the research team plans to apply microfluidic technology to answer essential microbiology questions.. The combination of microfluidics and microbiology also opens a brand new field for education, specifically, bionanotechnology. In the aspect of education, the research team aims:. ...
In recent years there has been an increasing interest in using lipid vesicles and related membrane structures as (i) artificial cells that mimic biological processes and (ii) bio-inspired micro-machines that serve functional purposes. To date, vesicles have largely been single-compartment structures with homogenous interiors, which has impeded the fulfilment of these goals. This thesis details the development of technologies to address this. We develop droplet-based methods to controllably generate multi-compartment vesicles (MCVs) for the first time. The potential of these novel structures as artificial cells capable of hosting a range of biological and bio-mimetic processes is explored. Most notably, we introduce spatial segregation of function, thus mimicking eukaryotic organelles, and incorporate an artificial enzymatic signalling cascade to transmit chemical signals between distinct vesicle regions. We also construct microfluidic devices to generate related structures known as multisomes. ...
Plasma is a host of various analytes such as proteins, metabolites, circulating nucleic acids (CNAs), pathogens. The key process of plasma extraction is to eliminate the contamination from blood cells. Conventional methods, such as centrifugation and membrane filtration, are generally lab-intensive, time consuming and even dangerous. In this study, we report an integrated microfluidic device that combines inertial microfluidics and membrane filter. The integrated microfluidic device was evaluated by the diluted (x1/10, x1/20) whole blood, and the quality of the extracted blood plasma was tested. It was found that quality of extracted blood plasma from integrated device was equivalent to that obtained by the centrifugation. This study demonstrates a significant progress towards the practical application of inertial microfluidics with membrane filter for high-throughput and high efficient blood plasma extraction ...
Identification of rare cells or molecules from a mixture population is important in biology such as identification of rare cancer cells or nucleic acid in early stage cancer diagnosis. Recent advances in droplet-based microfluidics and hydrogel barcoded microsphere to capture all the mRNA molecules in each cell in a single step enables scientists to identify cells based on their whole transcriptome information. However, due to the large number of sequencing reads required to cover the whole transcriptome, this limits the number of cells processed in one sequencing run. We address this problem by using a stepwise approach by first encapsulating single cell and lysis buffer together in a water-in-oil picoliter droplet, then amplifying only the target DNA/RNA molecule of interest in each droplet, pico-inject hydrogel barcoded microsphere into each droplet to tag the amplicons prior to next generation sequencing. We demonstrated the use of this technology by applying it to study how single tumor ...
This high-quality international symposium will bring together leading experts in all fields of droplet-based microfluidics from all around the world. We fully believe that all the presentations in this symposium will stimulate the exchange of ideas and experiences amongst all the participants. There will be four sequential sessions during the course of the two days with plenty of opportunities for discussion and interaction. The topics of the whole symposium include: ...
Crystallization from lipidic mesophase matrices is a promising route to diffraction-quality crystals and structures of membrane proteins. The microfluidic approach reported here eliminates two bottlenecks of the standard mesophase-based crystallization protocols: (i) manual preparation of viscous mesophases and (ii) manual harvesting of often small and fragile protein crystals. In the approach reported here, protein-loaded mesophases are formulated in an X-ray transparent microfluidic chip using only 60 nL of the protein solution per crystallization trial. The X-ray transparency of the chip enables diffraction data collection from multiple crystals residing in microfluidic wells, eliminating the normally required manual harvesting and mounting of individual crystals. In addition, we validated our approach by on-chip crystallization of photosynthetic reaction center, a membrane protein from Rhodobacter sphaeroides, followed by solving its structure to a resolution of 2.5 Å using X-ray ...
We review microfluidic platforms that enable the miniaturization, integration and automation of biochemical assays. Nowadays nearly an unmanageable variety of alternative approaches exists that can do this in principle. Here we focus on those kinds of platforms only that allow performance of a set o …
Electrophoresis.. 12.1 Introduction.. 12.2 Experimental Section.. 12.3 Results and Discussion.. 12.4 Applications.. 12.5 Conclusions.. 13 Chemical Separations in 3D Microfluidics.. 13.1 Introduction.. 13.2 Fabrication.. 13.3 Results and Discussion on 3D Valves.. 13.4 Microfluidic Three-Dimensional Separation Columns.. 13.5 Results on Liquid Chromatography.. 13.6 Conclusions.. 14 Enabling Fundamental Research in Proteomics.. 14.1 Introduction.. 14.2 Membrane Protein Extraction.. 14.3 Conclusion.. PART IV BIOMEDICAL APPLICATIONS OF MICROFLUIDICS.. 15 Microengineering Neural Development.. 15.1 Introduction.. 15.2 Microengineering Guidance of Axons to their Targets.. 15.3 Synaptogenesis on a Microfluidic Chip.. 15.4 Conclusions.. 16 Applications of Centrifugal Microfluidics in Biology.. 16.1 Introduction.. 16.2 Why Use Centrifugal Force for Fluid Manipulation?. 16.3 How Centrifugal Microfluidic Platforms Work.. 16.4 CD Applications.. 16.5 Conclusions.. 17 Microfluidic Techniques for Point-of-Care In ...
Impedimetric measurement methods are a novel approach to the characterization of fluid in biological applications. Lab on a chip (LOAC) technologies could be combined with impedimetrics to benefit these applications. LOAC devices are currently being developed to pursue the miniaturization of larger scale processes. Current research shows great flexibility in using LOAC devices to reproduce biological processes such as those used in medical diagnostic applications. With a smaller form factor, testing that generally requires off-site lab usage can be deployed at the point-of-care. LOAC devices also have the potential to lower operating costs by reducing reagent volumes, labor costs, and cycle times.. Digital microfluidic devices (DMF) are one promising LOAC platform. These devices manipulate discrete droplets of fluid using electric fields. As such, DMF devices can create, move, merge, and mix droplets while eliminating mechanical components like channels, pumps, and valves. Manipulation of ...
MICROFLUIDIC PLATFORMS FOR CELL CULTURE AND MICROENVIRONMENT CONTROL By Yandong Gao Dissertation Submitted to the Faculty of the Graduate School of Vanderbilt University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Mechanical Engineering December, 2011 Nashville, Tennessee Approved: Associate Professor Deyu Li Assistant Professor Joh F. Edd Assistant Professor Haoxiang Luo Professor Taylor G. Wang Assistant Professor Donna J. Webb To my beloved parents
This thesis contributes to the development of Lab-on-a-Chip systems that enables reliable, rapid medical diagnostics at the point-of-care. These contributions are focused on microfluidic Lab-on-a-Chip systems for sepsis diagnosis, autonomous sample-to-answer tests, and dried blood spot sampling.. Sepsis is a serious condition with high mortality and high costs for society and healthcare. To facilitate rapid and effective antibiotic treatment, improved sepsis diagnostics is needed. Diagnosis of sepsis requires the processing of relatively large blood volumes, creating a need for novel and effective techniques for the handling of large volume flows and pressures on chip. Components, materials, and manufacturing methods for pneumatically driven Lab-on-a-Chip systems have therefore been developed in this thesis. Microvalves, an essential component in many Lab-on-a-Chip systems have been the focus on several of the advances: a novel elastomeric material (Rubbery Off-Stoichiometric-Thiol-Ene-Epoxy) ...
We have evaluated double-stranded DNA separations in microfluidic devices which were designed to couple a sample preconcentration step based on isotachophoresis (ITP) with a zone electrophoretic (ZE) separation step as a method to increase the concentration limit of detection in microfluidic devices. Developed at ACLARA BioSciences, these LabCard™ devices are plastic 32 channel chips, designed with a long sample injection channel segment to increase the sample loading. These chips were designed to allow stacking of the sample into a narrow band using discontinuous ITP buffers, and subsequent separation in the ZE mode in sieving polymer solutions. Compared to chip ZE, the sensitivity was increased by 40-fold and we showed baseline resolution of all fragments in the ΦX174/HaeIII DNA digest. The total analysis time was 3 min/sample, or less than 100 min per LabCard device. The resolution for multiplexed PCR samples was the same as obtained in chip ZE. The limit of detection was 9 fg/μL of DNA ...
Inertial microfluidics has been broadly investigated, resulting in the development of various applications, mainly for particle or cell separation. Lateral migrations of these particles within a microchannel strictly depend on the channel design and its cross-section. Nonetheless, the fabrication of these microchannels is a continuous challenging issue for the microfluidic community, where the most studied channel cross-sections are limited to only rectangular and more recently trapezoidal microchannels. As a result, a huge amount of potential remains intact for other geometries with cross-sections difficult to fabricate with standard microfabrication techniques. In this study, by leveraging on benefits of additive manufacturing, we have proposed a new method for the fabrication of inertial microfluidic devices. In our proposed workflow, parts are first printed via a high-resolution DLP/SLA 3D printer and then bonded to a transparent PMMA sheet using a double-coated pressure-sensitive adhesive tape.
This study aims to develop droplet-based microfluidics for massively parallel single-cell genomics, to elucidate intra-tissue genetic heterogeneity at the single-cell resolution. Most tumors display extensive intra-tumor heterogeneity, with various subpopulations of cells contains different mutations. For understanding these intra-tissue heterogeneities, ideal single-cell genomics methods should analyze tens of thousands of single cells in an efficient manner. In this study, I will develop droplet-based microfluidic techniques to produce the compartmentalized reaction environments for single-cell sequencing.. ...
Microfluidics is the science and technology that deals with the flow of liquids from microliters (mL) to picoliters (pL) inside a micrometer sized channels1. The ability of microfluidics to miniaturize and mimic various laboratory procedures with limited space, great efficiency and low sample volumes these systems find use in various applications involving continuous flow microfluidics, droplet-based microfluidics, DNA chips (microarrays), molecular biology, etc.. A microfluidic chip is a set of microchannels molded into materials such as glass, silicon or polymers like polydimethyl siloxane (PDMS) 1.. Microfluidic platforms allow physicians to analyze a single drop of blood or urine sample for various markers of diseases without the need of sending comparatively large volumes of these samples to external laboratories for analysis2.. To determine a disease state, microfluidic sensors require specific disease-detecting biomolecules to be inserted into the platform of the system. These ...
Microfluidic mixing plays a key role in various fields, including biomedicine and chemical engineering. To date, although various approaches for imaging microfluidic mixing have been proposed, they provide only quantitative imaging capability and require exogenous labeling agents. Quantitative phase imaging techniques, however, circumvent these problems and offer label-free quantitative information about concentration maps of microfluidic mixing. We present the quantitative phase imaging of microfluidic mixing in various types of polydimethylsiloxane microfluidic channels with different geometries; the feasibility of the present method was validated by comparing it with the results obtained by theoretical calculation based on Fick's law. (C) 2017 Optical Society of ...
Adam R. Abate and David A. Weitz Syringe-vacuum microfluidics: A portable technique to create monodisperse emulsions Entry by [[Fei Pu]], AP 225, Fall 2012 Keywords: [[microfluidics]], [[emulsions]], [[monodisperse]] ==Summary== Monodisperse drop formation is the central operation in droplet-based microfluidics but can be quite challenging due to the need for precise, steady pumping of reagents; forming monodisperse drops with controlled properties is thus a stringent demonstration of the effectiveness of a control system.A simple method for creating monodisperse emulsions with microfluidic devices is presented. Unlike conventional approaches that require bulky pumps, control computers,and expertise with device physics to operate devices, this method requires only the microfluidic device and a hand-operated syringe. The fluids needed for the emulsion are loaded into the device inlets, while the syringe is used to create a vacuum at the device outlet; this sucks the fluids through the ...
Co-advisor: Brad Berron, Chemical Engineering. All living systems have a need to transport critical nutrients throughout their structures. This need is a critical challenge in the next generation of medical devices which use live cells to perform basic functions. It is also one of the primary challenges in engineering thick three-dimensional tissues. In these systems, the flow of nutrients needs to be uniform throughout the material at the micron-scale. In vivo, this is accomplished by an integrated circulatory system, but the detailed multi-scale geometry involved is particularly difficult to recreate ex vivo. In this project, we seek to use lithography-based microfabrication to generate 3D cell/hydrogel structures with embedded microfluidic channels.. Objective: To develop hydrogel-based microfluidic devices that mimic in vivo blood flow. Major project outcomes:. ...
In vitro compartmentalization (IVC) of reactions in bulk water-in-oil emulsions has been identified as a promising method for massively parallel processing (Griffiths & Tawfik 2006). In principle, such an approach allows access to the huge combinatorial parameter spaces required for screening, selecting and developing both natural and artificial biological and macromolecular systems by directed evolution (Kelly et al. 2007). For example, aqueous solutions containing a gene library could be emulsified with a homogenizer in an oil-surfactant mixture within a matter of minutes to produce a water-in-oil emulsion containing in excess of 1010 droplets per millilitre. Such a combinatorial approach would greatly benefit synthetic biology, providing a powerful paradigm in the characterization of biological systems. Each droplet would constitute an independent experiment where the inputs of the synthetic biology system would be stimulated in a specific way. A large collection of droplets could ...
TY - JOUR. T1 - All-in-one microfluidic assembly of insulin-loaded pH-responsive nano-in-microparticles for oral insulin delivery. AU - Costa, Clarinda. AU - Liu, Zehua. AU - Martins, João P.. AU - Correia, Alexandra. AU - Figueiredo, Patrícia. AU - Rahikkala, Antti. AU - Li, Wei. AU - Seitsonen, Jani. AU - Ruokolainen, Janne. AU - Hirvonen, Sami Pekka. AU - Aguiar-Ricardo, Ana. AU - Corvo, M. Luísa. AU - Santos, Hélder A.. N1 - UIDB/50006/2020 PD/BD/142880/2018 UID/DTP/04138/2020 PY - 2020/6/21. Y1 - 2020/6/21. N2 - Here, a continuous two-step glass-capillary microfluidic technique to produce a multistage oral delivery system is reported. Insulin is successfully encapsulated into liposomes, which are coated with chitosan to improve their mucoadhesion. The encapsulation in an enteric polymer offers protection from the harsh gastric conditions. Insulin permeability is enhanced across an intestinal monolayer.. AB - Here, a continuous two-step glass-capillary microfluidic technique to produce a ...
Bacterial chemotaxis, a remarkable behavioral trait which allows bacteria to sense and respond to chemical gradients in the environment, has implications in a broad range of fields including but not limited to disease pathogenesis, in-situ bioremediation and marine biogeochemistry. And therefore, studying bacterial chemotaxis is of significant importance to scientists and engineers alike. Microfluidics has revolutionized the way we study the motile behavior of cells by enabling observations at high spatial and temporal resolution in carefully controlled microenvironments. This thesis aims to explore the potential of microfluidic technology in studying bacterial behavior by investigating different aspects of bacterial chemotaxis on a microfluidic platform. We quantified population-scale transport parameters of bacteria using videomicroscopy and cell tracking in controlled chemoattractant gradients. Previously, transport parameters have been derived theoretically from single-cell swimming behavior ...
TY - JOUR. T1 - PDMS microchannel surface modification with teflon for algal lipid research. AU - Park, Jae Woo. AU - Na, Sangcheol. AU - Kang, Myeongwoo. AU - Sim, Sang Jun. AU - Jeon, Noo Li. PY - 2017/9/1. Y1 - 2017/9/1. N2 - This paper presents a simple method for modifying the polydimethylsiloxane (PDMS) microfluidic channels with Teflon for algal lipid research. When culturing and staining algae inside microfluidic devices, the small molecule dyes absorbed by the microchannel surface render it difficult for imaging and quantification. PDMS surface coated with Teflon-AF resists the absorption of hydrophobic dye molecules (i.e., BODIPY and Nile red) as confirmed using fluorescence microscopy. Here, we introduce a surface modification of PDMS microchannel using Teflon-AF using a procedure of filling and drying to directly treat the PDMS surface with perfluorinated materials. This method can be used to prevent the absorption of fluorescent probe and obtain clear fluorescence micrographs ...
TY - JOUR. T1 - Microfluidic-based multiplex immunoassay system integrated with an array of QD-encoded microbeads. AU - Han, Sang Won. AU - Jang, Eunji. AU - Koh, Won Gun. PY - 2015/3/31. Y1 - 2015/3/31. N2 - Here, we developed a multiplex immunoassay platform within microfluidic devices that combines suspension and the planar microarray format. For the suspension microarray format, QD-embedded polymeric microbeads with an average diameter of 24 μm were prepared using the Shirasu Porous Glass (SPG) membrane emulsification technique. To furnish the microbeads with resolvable spectral codes, QDs with two different colors (450 nm for blue and 520 nm for green) were used and different spectral codes were obtained by changing the ratio of emission intensity of the two different QDs within the microbeads. The surfaces of the QD-encoded microbeads were then functionalized with probe antibodies for immunoassays. The planar microarray format was achieved by an array of microholes fabricated in PDMS. ...
15th Internat.Conf.on Solid-State Sensors, Actuators and Microsystems (Transducers 2009), Denver, Colo., June 21-25, 2009 Technical Digest Piscataway, N.J. : IEEE, ...
This paper presents a new hermetic encapsulation method for negative-pressure-driven polydimethylsiloxane (PDMS) microfluidic devices. The hermetic materials used in this encapsulation are mainly para
Nanofluidic devices are structures having at least one dimension in the submicron range, which is of the same order of magnitude as the sizes of biomolecules and bioparticles such as proteins and viruses. As a result, size-selective separations are important applications for nanofluidics. Well-defined micro or nano device structures fabricated via micromachining have greatly reduced sample consumption and enabled separations in a parallel fashion, promising significant speed and resolution advantages over conventional size separation techniques, such as gel electrophoresis and size exclusion chromatography. In collaboration with others, I have developed a size separation method using nanofluidic devices consisting of an array of parallel planar nanochannels with varying heights. Separation of nanoparticles is accomplished by simply flowing a liquid suspension of the particles through the nanochannels via capillary action. When a mixture of particles arrives at an interface, where the channel steps from
This paper reports a novel method for the statistical analysis of quantum dot (QD) cytotoxicity and cellular uptake based on single cell cycles, which is part of a series of works on the study of QD cytotoxicity using a microfluidic system (Lab Chip, 2012, 12, 34743480; 2013, 13, 19481954). The specially designed microfluidic system consisted of a polydimethylsiloxane (PDMS) microwell array for single-cell arrangement and microchannels for QD solution diffusion, enabling effective control of stable cell density and the interdistance between them, as well as maintaining a constant QD concentration with no disturbance of the fluids which can affect cellular uptake. We showed that the treatment of QDs had no influence on cell cycles. However, the QD cytotoxicity was found to be dependent on cellular uptake in various cell cycle phases, because the accumulation and dilution of QDs happened in single cell cycles. The rank of QD cytotoxicity was G2/M > S > G0/G1. Thus, this technology could serve as a ...
The present invention relates to systems and methods for minimizing or eliminating diffusion effects. Diffused regions of a segmented flow of multiple, miscible fluid species may be vented off to a waste channel, and non-diffused regions of fluid may be preferentially pulled off the channel that contains the segmented flow. Multiple fluid samples that are not contaminated via diffusion may be collected for analysis and measurement in a single channel. The systems and methods for minimizing or eliminating diffusion effects may be used to minimize or eliminate diffusion effects in a microfluidic system for monitoring the amplification of DNA molecules and the dissociation behavior of the DNA molecules.
MicroFluidic Systems Has Received Over $45 Million in Government Contracts in the Last Ten YearsMicroFluidic Systems Biological Detection and Sample Prep Technologies Will Complement PositiveIDs Virus Detection and Diabetes Management Focus, While Providing Expanded Capabilities for Homeland Security Applications
Developing Microfluidic Systems for Proteome Analysis,” K. Jo, B.R. Reschke, X. Mao, R. L. Carroll, B. Edwards, and A. Timperman,Midwestern Universities Analytical Chemistry Conference, EastLansing, Michigan, December 4, 2009.. ...
TY - JOUR. T1 - Neurotrophin-mediated dendrite-to-nucleus signaling revealed by microfluidic compartmentalization of dendrites. AU - Cohen, Michael S.. AU - Orth, Carlos Bas. AU - Kim, Hyung Joon. AU - Jeon, Noo Li. AU - Jaffrey, Samie R.. PY - 2011/7/5. Y1 - 2011/7/5. N2 - Signaling from dendritic synapses to the nucleus regulates important aspects of neuronal function, including synaptic plasticity. The neurotrophin brain-derived neurotrophic factor (BDNF) can induce long-lasting strengthening of synapses in vivo and this effect is dependent on transcription. However, the mechanism of signaling to the nucleus is not well understood. Here we describe a microfluidic culture device to investigate dendrite-to-nucleus signaling. Using these microfluidic devices, we demonstrate that BDNF can act directly on dendrites to elicit an anterograde signal that induces transcription of the immediate early genes, Arc and c-Fos. Induction of Arc is dependent on dendrite- and cell body-derived calcium, whereas ...
0008] Another portable blood component analysis device has a microfluidic unit with a sample chamber; the sample chamber having a surface augmentation features with biospecific surface configured to capture particles from blood. an analyzer component having a signal detector and a receiving slot configured to receive the microfluidic unit and align the sample chamber with the signal detector; Preferably, the surface augmentation features include a packed bead bed with glass beads. The device claim 13, wherein the analyzer contains a pump configured to generate a vacuum of at least 10 kPa; Preferably, the surface augmentation features include a packed bead bed with glass beads with a diameter between 50 and 100 μm and the first longitudinal channel contains a narrow portion with a minimum dimension of less than the diameter of the glass beads. Preferably, the device includes a controller and a solar power source connected to power the pump and controller. Preferably, the microfluidic unit ...
Louis Jun Ye Ong, Lor Huai Chong, Lin Jin, Pawan Kumar Singh, Poh Seng Lee, Hanry Yu, Abhishek Ananthanarayanan, Hwa Liang Leo, Yi-Chin Toh. The practical application of microfluidic liver models for in vitro drug testing is partly hampered by their reliance on human primary hepatocytes, which are limited in number and have batch-to-batch variation. Human stem cell-derived hepatocytes offer an attractive alternative cell source, although their 3D differentiation and maturation in a microfluidic platform have not yet been demonstrated. We develop a pump-free microfluidic 3D perfusion platform to achieve long-term and efficient differentiation of human liver progenitor cells into hepatocyte-like cells (HLCs). The device contains a micropillar array to immobilize cells three-dimensionally in a central cell culture compartment flanked by two side perfusion channels. Constant pump-free medium perfusion is accomplished by controlling the differential heights of horizontally orientated inlet and outlet ...
To demonstrate the power of multilayer soft lithography, we fabricated active valves and pumps. Monolithic elastomeric valves and pumps, like other mechanical microfluidic devices, avoid several practical problems affecting flow systems based on electroosmotic flow (8,9, 20, 27-29) or dielectrophoresis (30, 31), such as electrolytic bubble formation around the electrodes and a strong dependence of flow on the composition of the flow medium (32-34). Electrolytic bubble formation, although not a problem for laboratory devices, seriously restricts the use of electroosmotic flow in integrated microfluidic devices. Also, neither electroosmotic nor dielectrophoretic flow can easily be used to stop flow or balance pressure differences.. We fabricated our valves using a crossed-channel architecture (Fig. 1A). Typical channels are 100 μm wide and 10 μm high, making the active area of the valve 100 μm by 100 μm. The membrane of polymer between the channels is engineered to be relatively thin ...
Dive into the research topics of A rapid diagnosis of SARS-CoV-2 using DNA hydrogel formation on microfluidic pores. Together they form a unique fingerprint. ...
We detail a method to fabricate three-dimensional paper-based microfluidic devices for use in the development of immunoassays. Our...
The present invention relates to methods and systems for delivering microwave radiation, e.g., for heating, to a microfluidic device. The microfluidic device of the present invention contains a microwave integrated circuit (MMIC) for applying microwave radiation to specific areas within the microfluidic device. The circuit preferably includes a transmission line on one surface of the microfluidic device and a ground plane on the opposing surface.