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Find video protocols related to scientific articles indexed in Pubmed.
Multiplexed microfluidic blotting of proteins and nucleic acids by parallel, serpentine microchannels.
Lab Chip
PUBLISHED: 10-25-2014
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This work develops a high-throughput, high-efficiency and straightforward microfluidic blotting method for analyzing proteins and nucleic acids. Sample solutions containing antibodies (for protein detection) or hybridization probes (for nucleic acid detection) are introduced into the parallel, serpentine microchannels to specifically recognize the immobilized targets on the substrate, achieving the identification of multiple targets in multiple samples simultaneously. The loading control, molecular weight markers, and antigen/antibody titration are designed and integrated into the microfluidic chip, thus allowing for the quantification of proteins and nucleic acids. Importantly, we could easily distinguish the adjacent blotting bands inside parallel microchannels, which may be difficult to achieve in conventional blotting. The small dimensions of microfluidic channels also help to reduce the amount of probing molecules and to accelerate the biochemical reaction. Our microfluidic blotting could bypass the steps of blocking and washing, further reducing the operation time and complexity.
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Integrated Microcapillary for Sample-to-Answer Nucleic Acid Pretreatment, Amplification, and Detection.
Anal. Chem.
PUBLISHED: 10-02-2014
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This work develops an integrated microcapillary-based loop-mediated isothermal amplification (icLAMP) containing preloaded reagents and DNA extraction card, allowing for sample-to-answer screening of single nucleotide polymorphisms (SNPs) typing of the CYP2C19 gene from untreated blood samples with minimal user operation. With all reagents and the DNA extraction card preloaded inside the capillary, this icLAMP system can achieve on-site pretreatment, extraction, amplification, and detection of nucleic acids within 150 min, without the requirement for advanced instruments. As icLAMP technology carries many advantages such as disposability, easy operation, low cost, and reduced cross contamination and biohazard risks, we expect this system to have a great impact on point-of-care (POC) nucleic acid detection.
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Study of the damage rate caused by intervertebral foramen type inside and outside and the pass of the intervertebral DRG RF puncture way.
Pak J Pharm Sci
PUBLISHED: 09-29-2014
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This paper was to analyze and contrast the damage rate on the thoracic segment different position of the dorsal root ganglion(dorsal root ganglion, DRG) caused by different puncture path in radiofrequency ablation, thus the best RF target way for the thoracic segment of different types of DRG was confirmed. According to the difference of puncture and ablation damage way, 14 segmental spinal specimens were randomly divided into three groups, and then conducted DRG radiofrequency damage on percutaneous puncture path according to the type of DRG position.The damage effect of different puncture path by the judgment standard of the result of pathology analyzed. The experiment showed that RF damage of group A were 72.58±18.88%, 54.16±24.84% and 32.85±28.11%; that of group B were 771.86±15.15% and 72.02±17.86%, 57.14±18.02% and 52.47±20.64%, 68.75±14.63% and 71.78±16.00%; and that of group C were 82.46±14.10%, 81.53±11.81% and 80.83±13.33%. It was concluded that the singleness of DRG puncture route is one of the important reasons for the poor thoracic segments DRG radiofrequency (RF) ablation effect. While according to the type of DRG different positions with double joint puncture path can significantly improve the rate of DRG RF damage.
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Point-of-care multiplexed assays of nucleic acids using microcapillary-based loop-mediated isothermal amplification.
Anal. Chem.
PUBLISHED: 07-01-2014
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This report demonstrates a straightforward, robust, multiplexed and point-of-care microcapillary-based loop-mediated isothermal amplification (cLAMP) for assaying nucleic acids. This assay integrates capillaries (glass or plastic) to introduce and house sample/reagents, segments of water droplets to prevent contamination, pocket warmers to provide heat, and a hand-held flashlight for a visual readout of the fluorescent signal. The cLAMP system allows the simultaneous detection of two RNA targets of human immunodeficiency virus (HIV) from multiple plasma samples, and achieves a high sensitivity of two copies of standard plasmid. As few nucleic acid detection methods can be wholly independent of external power supply and equipment, our cLAMP holds great promise for point-of-care applications in resource-poor settings.
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Point-of-care biochemical assays using gold nanoparticle-implemented microfluidics.
Chem Soc Rev
PUBLISHED: 06-03-2014
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One of the goals of point-of-care (POC) is a chip-based, miniaturized, portable, self-containing system that allows the assay of proteins, nucleic acids, and cells in complex samples. The integration of nanomaterials and microfluidics can help achieve this goal. This tutorial review outlines the mechanism of assaying biomarkers by gold nanoparticles (AuNPs), and the implementation of AuNPs for microfluidic POC devices. In line with this, we discuss some recent advances in AuNP-coupled microfluidic sensors with enhanced performance. Portable and automated instruments for device operation and signal readout are also included for practical applications of these AuNP-combined microfluidic chips.
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Mesosilica-coated ultrafine fibers for highly efficient laccase encapsulation.
Nanoscale
PUBLISHED: 05-14-2014
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In this paper, we present a simple but efficient biomimetic method to encapsulate laccase on mesoporous silica-modified electrospun (ES) ultrafine fibers. Because of the mild immobilization conditions (room temperature, aqueous condition), the encapsulated laccase retained a high activity of 94%. Because of the protection from the silica layer, the laccase worked efficiently at 60 °C and retained a long-term activity in the presence of proteinase K. After recycling for 10 times the laccase still preserved 96% of its original reactivity. More remarkably, the immobilized laccase on fibers could completely recover its activity after thermal denature, while the free laccase permanently lost the activity. We also demonstrated that the laccase on silica-coated fibers exhibited an enhanced decolorization capability of Brilliant Blue KN-R (BBKN-R) as compared to the free laccase, showing its great potential for industrial applications.
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A microfluidic tubing method and its application for controlled synthesis of polymeric nanoparticles.
Lab Chip
PUBLISHED: 03-27-2014
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This report describes a straightforward but robust tubing method for connecting polydimethylsiloxane (PDMS) microfluidic devices to external equipment. The interconnection is irreversible and can sustain a pressure of up to 4.5 MPa that is characterized experimentally and theoretically. To demonstrate applications of this high-pressure tubing technique, we fabricate a semicircular microfluidic channel to implement a high-throughput, size-controlled synthesis of poly(lactic-co-glycolic acid) (PLGA) nanoparticles ranging from 55 to 135 nm in diameter. This microfluidic device allows for a total flow rate of 410 mL h(-1), resulting in enhanced convective mixing which can be utilized to precipitate small size nanoparticles with a good dispersion. We expect that this tubing technique would be widely used in microfluidic chips for nanoparticle synthesis, cell manipulation, and potentially nanofluidic applications.
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Colorimetric Logic Gates through Molecular Recognition and Plasmonic Nanoparticles.
Small
PUBLISHED: 02-21-2014
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A colorimetric logic system capable of AND, OR, INHIBIT and AND + OR logic operations is constructed. The principle is modulation of the distance between arginine (lysine)-modified gold nanoparticles via metal ions. A lab-on-chip format for the assembly of versatile logic gates is demonstrated as a proof of concept. These logic gates allow a straightforward readout by the naked eye.
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Enzymatic assay for Cu(II) with horseradish peroxidase and its application in colorimetric logic gate.
Anal. Chem.
PUBLISHED: 07-26-2013
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We report an ultrasensitive and colorimetric assay for Cu(II) via enzymatic amplification strategy. The enzymatic activity of horseradish peroxidase (HRP) is strongly inhibited by Cu(I), which can be used indirectly to assay Cu(II). The limit of detection (LOD) is 0.37 nM, and the detection of 20 nM Cu(II) in solution can be achieved with naked eyes. This assay can be used to construct a colorimetric logic gate.
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Culturing primary human osteoblasts on electrospun poly(lactic-co-glycolic acid) and poly(lactic-co-glycolic acid)/nanohydroxyapatite scaffolds for bone tissue engineering.
ACS Appl Mater Interfaces
PUBLISHED: 06-27-2013
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In this work, we fabricated polymeric fibrous scaffolds for bone tissue engineering using primary human osteoblasts (HOB) as the model cell. By employing one simple approach, electrospinning, we produced poly(lactic-co-glycolic acid) (PLGA) scaffolds with different topographies including microspheres, beaded fibers, and uniform fibers, as well as the PLGA/nanohydroxyapatite (nano-HA) composite scaffold. The bone-bonding ability of electrospun scaffolds was investigated by using simulated body fluid (SBF) solution, and the nano-HA in PLGA/nano-HA composite scaffold can significantly enhance the formation of the bonelike apatites. Furthermore, we carried out in vitro experiments to test the performance of electrospun scaffolds by utilizing both mouse preosteoblast cell line (MC 3T3 E1) and HOB. Results including cell viability, alkaline phosphatase (ALP) activity, and osteocalcin concentration demonstrated that the PLGA/nano-HA fibers can promote the proliferation of HOB efficiently, indicating that it is a promising scaffold for human bone repair.
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An ultrasensitive, non-enzymatic glucose assay via gold nanorod-assisted generation of silver nanoparticles.
Nanoscale
PUBLISHED: 06-06-2013
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This report demonstrates a colorimetric, non-enzymatic glucose assay with a low detection limit of 0.07 ?M based on negatively charged gold nanorod-enhanced redox reaction. This glucose assay could generate silver nanoparticles as the readout that can be visualized by the naked eye, and only 4 femtomoles of nanorods are needed for glucose determination in one human plasma sample.
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A microfluidic origami chip for synthesis of functionalized polymeric nanoparticles.
Nanoscale
PUBLISHED: 05-09-2013
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This report demonstrates a microfluidic origami chip to synthesize monodisperse, doxorubicin-loaded poly(lactic-co-glycolic acid) nanoparticles with diameters of ~100 nm, a size optimized for cellular uptake and anticancer efficacy, but difficult to achieve with existing approaches. This three-dimensional design in a microchannel may allow for the fabrication of polymeric nanoparticles in this size regime with ease.
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Stress-induced self-assembly of complex three dimensional structures by elastic membranes.
Small
PUBLISHED: 03-23-2013
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Based on the stress-induced rolling membrane technique, complex three-dimensional structures are designed, such as tubes with wrinkled walls, tubes-in-a-tube, and spiral structures. Narrow PDMS strips are used instead of the whole PDMS top layer, thus obtaining tubes made of the bottom polymer.
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A compact microfluidic gradient generator using passive pumping.
Microfluid Nanofluidics
PUBLISHED: 12-18-2011
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Creating and maintaining a precise molecular gradient which is stable in space and time are essential to studies of chemotaxis. This paper describes a simple, compact, and user-friendly microfluidic device using a passive pumping method to drive the liquid flow to generate a stable concentration gradient. A fluidic circuit is designed to offset the effects of the pressure imbalance between the two inlets. After loading approximately the same amount of culture media containing different concentrations of a certain chemotactic agent into the two inlet reservoirs, a linear concentration gradient will be automatically and quickly established at the downstream. Our device takes advantage of passive pumping and is compact enough to fit into a Petri dish, which is an attractive feature to biologists. Furthermore, this microfluidic gradient generator offers a platform for a facile way of long-term imaging and analysis using high resolution microscopy.
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A highly sensitive gold-nanoparticle-based assay for acetylcholinesterase in cerebrospinal fluid of transgenic mice with Alzheimers disease.
Adv Healthc Mater
PUBLISHED: 09-25-2011
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A highly sensitive, selective, and dual-readout (colorimetric and fluorometric) assay for acetylcholinesterase (AChE) based on Rhodamine B-modified gold nanoparticle is reported. Due to its good sensitivity and selectivity, the assay can be used for monitoring AChE levels in the cerebrospinal fluid of transgenic mice with Alzheimers disease.
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Measurement of the volume growth rate of single budding yeast with the MOSFET-based microfluidic Coulter counter.
Lab Chip
PUBLISHED: 08-18-2010
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We report on measurements of the volume growth rate of ten individual budding yeast cells using a recently developed MOSFET-based microfluidic Coulter counter. The MOSFET-based microfluidic Coulter counter is very sensitive, provides signals that are immune from the baseline drift, and can work with cell culture media of complex composition. These desirable features allow us to directly measure the volume growth rate of single cells of Saccharomyces cerevisiae LYH3865 strain budding yeast in YNB culture media over a whole cell cycle. Results indicate that all budding yeast follow a sigmoid volume growth profile with reduced growth rates at the initial stage before the bud emerges and the final stage after the daughter gets mature. Analysis of the data indicates that even though all piecewise linear, Gomperitz, and Hills function models can fit the global growth profile equally well, the data strongly support local exponential growth phenomenon. Accurate volume growth measurements are important for applications in systems biology where quantitative parameters are required for modeling and simulation.
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Highly robust, recyclable displacement assay for mercuric ions in aqueous solutions and living cells.
ACS Nano
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We designed a recyclable Hg(2+) probe based on Rhodamine B isothiocyanate (RBITC)-poly(ethylene glycol) (PEG)-comodified gold nanoparticles (AuNPs) with excellent robustness, selectivity, and sensitivity. On the basis of a rational design, only Hg(2+) can displace RBITC from the AuNP surfaces, resulting in a remarkable enhancement of RBITC fluorescence initially quenched by AuNPs. To maintain stability and monodispersity of AuNPs in real samples, thiol-terminated PEG was employed to bind with the remaining active sites of AuNPs. Besides, this displacement assay can be regenerated by resupplying free RBITC into the AuNPs solutions that were already used for detecting Hg(2+). Importantly, the detection limit of this assay for Hg(2+) (2.3 nM) was lower than the maximum limits guided by the United States Environmental Protection Agency as well as that permitted by the World Health Organization. The efficiency of this probe was demonstrated in monitoring Hg(2+) in complex samples such as river water and living cells.
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Microfluidics for manipulating cells.
Small
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Microfluidics, a toolbox comprising methods for precise manipulation of fluids at small length scales (micrometers to millimeters), has become useful for manipulating cells. Its uses range from dynamic management of cellular interactions to high-throughput screening of cells, and to precise analysis of chemical contents in single cells. Microfluidics demonstrates a completely new perspective and an excellent practical way to manipulate cells for solving various needs in biology and medicine. This review introduces and comments on recent achievements and challenges of using microfluidics to manipulate and analyze cells. It is believed that microfluidics will assume an even greater role in the mechanistic understanding of cell biology and, eventually, in clinical applications.
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Double spiral microchannel for label-free tumor cell separation and enrichment.
Lab Chip
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This work reports on a passive double spiral microfluidic device allowing rapid and label-free tumor cell separation and enrichment from diluted peripheral whole blood, by exploiting the size-dependent hydrodynamic forces. A numerical model is developed to simulate the Dean flow inside the curved geometry and to track the particle/cell trajectories, which is validated against the experimental observations and serves as a theoretical foundation for optimizing the operating conditions. Results from separating tumor cells (MCF-7 and Hela) spiked into whole blood indicate that 92.28% of blood cells and 96.77% of tumor cells are collected at the inner and the middle outlet, respectively, with 88.5% tumor recovery rate at a throughput of 3.33 × 10(7) cells min(-1). We expect that this label-free microfluidic platform, driven by purely hydrodynamic forces, would have an impact on fundamental and clinical studies of circulating tumor cells.
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A strategy for depositing different types of cells in three dimensions to mimic tubular structures in tissues.
Adv. Mater. Weinheim
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The fabrication of tubular structures, with multiple cell types forming different layers of the tube walls, is described using a stress-induced rolling membrane (SIRM). Cell orientation inside the tubes can also be controlled by topographical contact guidance. These layered tubes precisely mimic blood vessels and many other tubular structures, suggesting that they may be of great use in tissue engineering.
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Simultaneous on-chip DC dielectrophoretic cell separation and quantitative separation performance characterization.
Anal. Chem.
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Through integration of a MOSFET-based microfluidic Coulter counter with a dc-dielectrophoretic cell sorter, we demonstrate simultaneous on-chip cell separation and sizing with three different samples including 1) binary mixtures of polystyrene beads, 2) yeast cells of continuous size distribution, and 3) mixtures of 4T1 tumor cells and murine bone marrow cells. For cells with continuous size distribution, it is found that the receiver operator characteristic analysis is an ideal method to characterize the separation performance. The characterization results indicate that dc-DEP separation performance degrades as the sorting throughput (cell sorting rate) increases, which provides insights into the design and operation of size-based microfluidic cell separation.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.