Microfluidic Analytical Techniques: Methods utilizing the principles of MICROFLUIDICS for sample handling, reagent mixing, and separation and detection of specific components in fluids.Microfluidics: The study of fluid channels and chambers of tiny dimensions of tens to hundreds of micrometers and volumes of nanoliters or picoliters. This is of interest in biological MICROCIRCULATION and used in MICROCHEMISTRY and INVESTIGATIVE TECHNIQUES.Dimethylpolysiloxanes: Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.Canada: The largest country in North America, comprising 10 provinces and three territories. Its capital is Ottawa.Chemistry Techniques, Analytical: Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.Lab-On-A-Chip Devices: Microdevices that combine microfluidics technology with electrical and/or mechanical functions for analyzing very small fluid volumes. They consist of microchannels etched into substrates made of silicon, glass, or polymer using processes similar to photolithography. The test fluids in the channels can then interact with different elements such as electrodes, photodetectors, chemical sensors, pumps, and valves.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Electrophoresis, Capillary: A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)Biosensing Techniques: Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.Equipment Design: Methods of creating machines and devices.Microchip Analytical Procedures: The preparation and analysis of samples on miniaturized devices.Electrophoresis, Microchip: A highly miniaturized version of ELECTROPHORESIS performed in a microfluidic device.Metabolomics: The systematic identification and quantitation of all the metabolic products of a cell, tissue, organ, or organism under varying conditions. The METABOLOME of a cell or organism is a dynamic collection of metabolites which represent its net response to current conditions.Spectrometry, X-Ray Emission: The spectrometric analysis of fluorescent X-RAYS, i.e. X-rays emitted after bombarding matter with high energy particles such as PROTONS; ELECTRONS; or higher energy X-rays. Identification of ELEMENTS by this technique is based on the specific type of X-rays that are emitted which are characteristic of the specific elements in the material being analyzed. The characteristic X-rays are distinguished and/or quantified by either wavelength dispersive or energy dispersive methods.Antibodies, Immobilized: Antibodies that are chemically bound to a substrate material which renders their location fixed.Microtechnology: Manufacturing technology for making microscopic devices in the micrometer range (typically 1-100 micrometers), such as integrated circuits or MEMS. The process usually involves replication and parallel fabrication of hundreds or millions of identical structures using various thin film deposition techniques and carried out in environmentally-controlled clean rooms.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Miniaturization: The design or construction of objects greatly reduced in scale.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Food Analysis: Measurement and evaluation of the components of substances to be taken as FOOD.PrintingEnvironmental Monitoring: The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.Calibration: Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.Chromatography, Gas: Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.Single-Cell Analysis: Assaying the products of or monitoring various biochemical processes and reactions in an individual cell.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Equipment Failure Analysis: The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.Hydrodynamics: The motion of fluids, especially noncompressible liquids, under the influence of internal and external forces.Flow Injection Analysis: The analysis of a chemical substance by inserting a sample into a carrier stream of reagent using a sample injection valve that propels the sample downstream where mixing occurs in a coiled tube, then passes into a flow-through detector and a recorder or other data handling device.Spectrometry, Mass, Electrospray Ionization: A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.Health Surveys: A systematic collection of factual data pertaining to health and disease in a human population within a given geographic area.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Silicones: A broad family of synthetic organosiloxane polymers containing a repeating silicon-oxygen backbone with organic side groups attached via carbon-silicon bonds. Depending on their structure, they are classified as liquids, gels, and elastomers. (From Merck Index, 12th ed)Spectrophotometry, Atomic: Spectrophotometric techniques by which the absorption or emmision spectra of radiation from atoms are produced and analyzed.Electrochemical Techniques: The utilization of an electrical current to measure, analyze, or alter chemicals or chemical reactions in solution, cells, or tissues.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Pharmaceutical Preparations: Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.Polymethyl Methacrylate: Polymerized methyl methacrylate monomers which are used as sheets, moulding, extrusion powders, surface coating resins, emulsion polymers, fibers, inks, and films (From International Labor Organization, 1983). This material is also used in tooth implants, bone cements, and hard corneal contact lenses.Cell Culture Techniques: Methods for maintaining or growing CELLS in vitro.Chromatography, Liquid: Chromatographic techniques in which the mobile phase is a liquid.Nanotechnology: The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.Spectroscopy, Fourier Transform Infrared: A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.Cycloparaffins: Alicyclic hydrocarbons in which three or more of the carbon atoms in each molecule are united in a ring structure and each of the ring carbon atoms is joined to two hydrogen atoms or alkyl groups. The simplest members are cyclopropane (C3H6), cyclobutane (C4H8), cyclohexane (C6H12), and derivatives of these such as methylcyclohexane (C6H11CH3). (From Sax, et al., Hawley's Condensed Chemical Dictionary, 11th ed)Data Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.Longitudinal Studies: Studies in which variables relating to an individual or group of individuals are assessed over a period of time.Electroosmosis: The motion of a liquid through a membrane (or plug or capillary) consequent upon the application of an electric field across the membrane. (Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Models, Statistical: Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Microchemistry: The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Logistic Models: Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Polycarboxylate Cement: Water-soluble low-molecular-weight polymers of acrylic or methacrylic acid that form solid, insoluble products when mixed with specially prepared ZnO powder. The resulting cement adheres to dental enamel and is also used as a luting agent.Glass: Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.Reference Standards: A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.Cluster Analysis: A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization: A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.PaperResearch Design: A plan for collecting and utilizing data so that desired information can be obtained with sufficient precision or so that an hypothesis can be tested properly.Electrowetting: Reducing the SURFACE TENSION at a liquid/solid interface by the application of an electric current across the interface thereby enhancing the WETTABILITY of the surface.Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.Silicon: A trace element that constitutes about 27.6% of the earth's crust in the form of SILICON DIOXIDE. It does not occur free in nature. Silicon has the atomic symbol Si, atomic number 14, and atomic weight [28.084; 28.086].Capillary Action: A phenomenon in which the surface of a liquid where it contacts a solid is elevated or depressed, because of the relative attraction of the molecules of the liquid for each other and for those of the solid. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Point-of-Care Systems: Laboratory and other services provided to patients at the bedside. These include diagnostic and laboratory testing using automated information entry.Health Services Research: The integration of epidemiologic, sociological, economic, and other analytic sciences in the study of health services. Health services research is usually concerned with relationships between need, demand, supply, use, and outcome of health services. The aim of the research is evaluation, particularly in terms of structure, process, output, and outcome. (From Last, Dictionary of Epidemiology, 2d ed)Age Distribution: The frequency of different ages or age groups in a given population. The distribution may refer to either how many or what proportion of the group. The population is usually patients with a specific disease but the concept is not restricted to humans and is not restricted to medicine.Analytic Sample Preparation Methods: Use of various chemical separation and extraction methods, such as SOLID PHASE EXTRACTION; CHROMATOGRAPHY; and SUPERCRITICAL FLUID EXTRACTION; to prepare samples for analytical measurement of components.Cells: The fundamental, structural, and functional units or subunits of living organisms. They are composed of CYTOPLASM containing various ORGANELLES and a CELL MEMBRANE boundary.Immunoassay: A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.Polystyrenes: Polymerized forms of styrene used as a biocompatible material, especially in dentistry. They are thermoplastic and are used as insulators, for injection molding and casting, as sheets, plates, rods, rigid forms and beads.Electrodes: Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.Limit of Detection: Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.

Metabolite fingerprinting: detecting biological features by independent component analysis. (1/1368)

MOTIVATION: Metabolite fingerprinting is a technology for providing information from spectra of total compositions of metabolites. Here, spectra acquisitions by microchip-based nanoflow-direct-infusion QTOF mass spectrometry, a simple and high throughput technique, is tested for its informative power. As a simple test case we are using Arabidopsis thaliana crosses. The question is how metabolite fingerprinting reflects the biological background. In many applications the classical principal component analysis (PCA) is used for detecting relevant information. Here a modern alternative is introduced-the independent component analysis (ICA). Due to its independence condition, ICA is more suitable for our questions than PCA. However, ICA has not been developed for a small number of high-dimensional samples, therefore a strategy is needed to overcome this limitation. RESULTS: To apply ICA successfully it is essential first to reduce the high dimension of the dataset, by using PCA. The number of principal components determines the quality of ICA significantly, therefore we propose a criterion for estimating the optimal dimension automatically. The kurtosis measure is used to order the extracted components to our interest. Applied to our A. thaliana data, ICA detects three relevant factors, two biological and one technical, and clearly outperforms the PCA.  (+info)

Microviscoelasticity of the apical cell surface of human umbilical vein endothelial cells (HUVEC) within confluent monolayers. (2/1368)

We studied the local viscoelasticity of the apical membrane of human umbilical vein endothelial cells within confluent layers by magnetic tweezers microrheometry. Magnetic beads are coupled to various integrins by coating with fibronectin or invasin. By analyzing the deflection of beads evoked by various force scenarios we demonstrate that the cell envelope behaves as a linear viscoelastic body if forces up to 2 nN are applied for short times (<20 s) but can respond in an adaptive way if stress pulses are applied longer (>30 s). The time-dependent shear relaxation modulus G(t) exhibits three time regimes: a fast response (t < 0.05 s) where the relaxation modulus G(t) obeys a power law G(t) approximately t(-0.82+/-0.02); a plateau-like behavior (at 0.05 s < t < 0.15 s); and a slow flow-like response which is, however, partially reversible. Strain field mapping experiments with colloidal probes show that local forces induce a strain field exhibiting a range of zeta = 10 +/- 1 microm, but which could only be observed if nonmagnetic beads were coupled to the cell surface by invasin. By application of the theory of elasticity of planar bodies we estimated a surface shear modulus of 2.5 x10(-4) N/m. By assuming a thickness of the actin cortex of approximately 0.5 microm we estimate a Young modulus micro approximately 400 Pa for the apical membrane. The value agrees with a plateau modulus of an entangled or weakly cross-linked actin network of an actin concentration of 100 microM (mesh size 0.2 microm). This result together with our observation of a strong reduction of the shear modulus by the actin destabilizing agent latrunculin A suggests that the shear modulus measured by our technique is determined by the actin cortex. The effect of two ligands inducing actin stress fiber formation and centripetal contraction of cells (associated with the formation of gaps in the confluent cell monolayer) on the viscoelastic responses were studied: histamine and lysophosphatidic acid (LPA). Histamine evoked a dramatic increase of the cell stiffness by >1 order of magnitude within <30 s, which is attributed to a transient rise of the intracellular Ca(2+) level, since DMSO exerted a similar effect. The stiffening is accompanied by a concomitant rounding of the cells as observed by microinterferometry and relaxes partially in the timescale of 5 min, whereas gaps between cells close after approximately 30 min. LPA did not exert a remarkable and reproducible effect other than an occasional very weak transient increase of the shear stiffness, which shows that the gap formation activated by LPA is mediated by a different mechanism than that induced by histamine.  (+info)

Formation of droplets of alternating composition in microfluidic channels and applications to indexing of concentrations in droplet-based assays. (3/1368)

For screening the conditions for a reaction by using droplets (or plugs) as microreactors, the composition of the droplets must be indexed. Indexing here refers to measuring the concentration of a solute by addition of a marker, either internal or external. Indexing may be performed by forming droplet pairs, where in each pair the first droplet is used to conduct the reaction, and the second droplet is used to index the composition of the first droplet. This paper characterizes a method for creating droplet pairs by generating alternating droplets, of two sets of aqueous solutions in a flow of immiscible carrier fluid within PDMS and glass microfluidic channels. The paper also demonstrates that the technique can be used to index the composition of the droplets, and this application is illustrated by screening conditions of protein crystallization. The fluid properties required to form the steady flow of the alternating droplets in a microchannel were characterized as a function of the capillary number Ca and water fraction. Four regimes were observed. At the lowest values of Ca, the droplets of the two streams coalesced; at intermediate values of Ca the alternating droplets formed reliably. At even higher values of Ca, shear forces dominated and caused formation of droplets that were smaller than the cross-sectional dimension of the channel; at the highest values of Ca, coflowing laminar streams of the two immiscible fluids formed. In addition to screening of protein crystallization conditions, understanding of the fluid flow in this system may extend this indexing approach to other chemical and biological assays performed on a microfluidic chip.  (+info)

Computerized microfluidic cell culture using elastomeric channels and Braille displays. (4/1368)

Computer-controlled microfluidics would advance many types of cellular assays and microscale tissue engineering studies wherever spatiotemporal changes in fluidics need to be defined. However, this goal has been elusive because of the limited availability of integrated, programmable pumps and valves. This paper demonstrates how a refreshable Braille display, with its grid of 320 vertically moving pins, can power integrated pumps and valves through localized deformations of channel networks within elastic silicone rubber. The resulting computerized fluidic control is able to switch among: (i) rapid and efficient mixing between streams, (ii) multiple laminar flows with minimal mixing between streams, and (iii) segmented plug-flow of immiscible fluids within the same channel architecture. The same control method is used to precisely seed cells, compartmentalize them into distinct subpopulations through channel reconfiguration, and culture each cell subpopulation for up to 3 weeks under perfusion. These reliable microscale cell cultures showed gradients of cellular behavior from C2C12 myoblasts along channel lengths, as well as differences in cell density of undifferentiated myoblasts and differentiation patterns, both programmable through different flow rates of serum-containing media. This technology will allow future microscale tissue or cell studies to be more accessible, especially for high-throughput, complex, and long-term experiments. The microfluidic actuation method described is versatile and computer programmable, yet simple, well packaged, and portable enough for personal use.  (+info)

Syntheses of 11C- and 18F-labeled carboxylic esters within a hydrodynamically-driven micro-reactor. (5/1368)

Carboxylic esters were successfully labeled with one of two short-lived positron-emitters, carbon-11 or fluorine-18, within a hydrodynamically-driven micro-reactor. The non-radioactive methyl ester was obtained at room temperature; its yield increased with higher substrate concentration and with reduced infusion rate. Radioactive methyl ester was obtained from the reaction of (10 mM) with in 56% decay-corrected radiochemical yield (RCY) at an infusion rate of 10 microL min(-1), and when the infusion rate was reduced to 1 microL min(-1), the RCY increased to 88%. The synthesis of the non-radioactive fluoroethyl ester from and required heating of the micro-reactor on a heating block at 80 degrees C (14-17% RCY), whilst the corresponding radioactive from and was obtained in 10% RCY. The radioactive 'peripheral' benzodiazepine receptor ligand was obtained from the reaction of acid with labeling agent in 45% RCY at an infusion rate of 10 microL min(-1). When the infusion rate was reduced to 1 microL min(-1), the RCY increased to 65%. The results exemplify a new methodology for producing radiotracers for imaging with positron emission tomography that has many potential advantages, including a requirement for small quantities of substrates, enhanced reaction, rapid reaction optimisation and easy product purification.  (+info)

Wetting morphologies at microstructured surfaces. (6/1368)

The wetting of microstructured surfaces is studied both experimentally and theoretically. Even relatively simple surface topographies such as grooves with rectangular cross section exhibit a large variety of different wetting morphologies as observed by atomic force microscopy. This polymorphism arises from liquid wedge formation along the groove corners and from contact line pinning along the groove edges. A global morphology diagram is derived that depends only on two system parameters: (i) the aspect ratio of the groove geometry and (ii) The contact angle of the underlying substrate material. For microfluidics, the most interesting shape regimes involve extended liquid filaments, which can grow and shrink in length while their cross section stays essentially constant. Thus, any method by which one can vary the contact angle can be used to switch the length of the filament, as is demonstrated in the context of electrowetting.  (+info)

Controlling nonspecific protein adsorption in a plug-based microfluidic system by controlling interfacial chemistry using fluorous-phase surfactants. (7/1368)

Control of surface chemistry and protein adsorption is important for using microfluidic devices for biochemical analysis and high-throughput screening assays. This paper describes the control of protein adsorption at the liquid-liquid interface in a plug-based microfluidic system. The microfluidic system uses multiphase flows of immiscible fluorous and aqueous fluids to form plugs, which are aqueous droplets that are completely surrounded by fluorocarbon oil and do not come into direct contact with the hydrophobic surface of the microchannel. Protein adsorption at the aqueous-fluorous interface was controlled by using surfactants that were soluble in fluorocarbon oil but insoluble in aqueous solutions. Three perfluorinated alkane surfactants capped with different functional groups were used: a carboxylic acid, an alcohol, and a triethylene glycol group that was synthesized from commercially available materials. Using complementary methods of analysis, adsorption was characterized for several proteins (bovine serum albumin (BSA) and fibrinogen), including enzymes (ribonuclease A (RNase A) and alkaline phosphatase). These complementary methods involved characterizing adsorption in microliter-sized droplets by drop tensiometry and in nanoliter plugs by fluorescence microscopy and kinetic measurements of enzyme catalysis. The oligoethylene glycol-capped surfactant prevented protein adsorption in all cases. Adsorption of proteins to the carboxylic acid-capped surfactant in nanoliter plugs could be described by using the Langmuir model and tensiometry results for microliter drops. The microfluidic system was fabricated using rapid prototyping in poly(dimethylsiloxane) (PDMS). Black PDMS microfluidic devices, fabricated by curing a suspension of charcoal in PDMS, were used to measure the changes in fluorescence intensity more sensitively. This system will be useful for microfluidic bioassays, enzymatic kinetics, and protein crystallization, because it does not require surface modification during fabrication to control surface chemistry and protein adsorption.  (+info)

High-throughput mouse genotyping using robotics automation. (8/1368)

The use of mouse models is rapidly expanding in biomedical research. This has dictated the need for the rapid genotyping of mutant mouse colonies for more efficient utilization of animal holding space. We have established a high-throughput protocol for mouse genotyping using two robotics workstations: a liquid-handling robot to assemble PCR and a microfluidics electrophoresis robot for PCR product analysis. This dual-robotics setup incurs lower start-up costs than a fully automated system while still minimizing human intervention. Essential to this automation scheme is the construction of a database containing customized scripts for programming the robotics workstations. Using these scripts and the robotics systems, multiple combinations of genotyping reactions can be assembled simultaneously, allowing even complex genotyping data to be generated rapidly with consistency and accuracy. A detailed protocol, database, scripts, and additional background information are available at http://dir.nhlbi.nih.gov/labs/ldb-chd/autogene/.  (+info)

  • A number of the group's members use a variety of imaging techniques in order to provide an insight into physical processes occurring within the microfluidic devices. (cam.ac.uk)
  • Using the department's SRIF funded confocal microscope facility we have quantitatively analysed diffusive mixing within microfluidic devices for both chemical and biochemical systems. (cam.ac.uk)
  • his technique allows high resolution xyz imaging of the devices as well as the imaging of time evolutionary processses. (cam.ac.uk)
  • We have worked in collaboration with the Laser Analytics Group in the department to develop the use of FLIM for quantitatively studying mass transport and reaction kinetics within microfluidic devices. (cam.ac.uk)
  • In collaboration with the Magnetic Resonance Research Centre (MRRC) in the department, we have imaged microfluidic devices using MRI. (cam.ac.uk)
  • By using microfluidic devices it is possible to improve the signal to noise ratio by decreasing the dielectric losses of the system. (cam.ac.uk)
  • Traditionally, the application of ESR techniques to identify radical species produced by electrochemical methods have been succesful, but ultimately limited by the sensitivity of the spectroscopic method. (cam.ac.uk)
  • In the case of in vitro transfection, it is known that conventional procedure in wells lead to a diffusive micro/nanoparticles transport to cells, however in droplet microfluidic platforms there is also the convective contribution that facilitates and enhances the control of transfection. (rroij.com)
  • Moreover, microfluidic droplets platform can provide a high encapsulation efficiency, since it allows self-assembly processes in which nanoparticles are formed and actives inserted in only one-step, using low quantity of reagents [ 6 ]. (rroij.com)
  • One of the key benefits of the MRI technique is the ability to image confluent immisicible liquids flowing through a channel. (cam.ac.uk)
  • Biosensors are a kind of analytical tool that combine recognition biomolecules with a transducer, which transforms (bio)chemical information into a chemical or physical signal. (sigma-not.pl)
  • The silver enhancement reagents may be integrated into the microfluidic assay platform to be released upon sample addition. (hindawi.com)
  • To develop a rapid and sensitive assay based on microfluidic isoelectric focusing, we previously prepared reagent-release capillaries retaining ampholytes by physical adsorption on the inner surface of a short capillary, which were then applied to isoelectric focusing. (go.jp)
  • In particular, digital microfluidic systems provide an analytical tool for precise control of discrete volume droplets, improving assay fluidics. (ku.edu)
  • Neutral and acidic oligosaccharides in Holstein-Friesian colostrum during the first 3 days of lactation measured by high performance liquid chromatography on a microfluidic chip and time-of-flight mass spectrometry. (nih.gov)
  • Ambient ionization techniques, direct analysis in real time (DART) and desorption atmospheric pressure photoionization (DAPPI), were combined with travelling wave ion mobility-mass spectrometry. (helsinki.fi)
  • He is particularly interested in the development of integrated chemo-enzymatic microfluidic reactors for the synthesis of commercially useful compounds. (ucl.ac.uk)
  • The rapid test is based on a new plastic microfluidic chip where the bacteria are trapped and methods for analysing bacterial growth at single-cell level," says PhD student Özden Baltekin, who performed most of the experimental work. (eurekalert.org)
  • Collaboration between researchers and the manufacturers of analytical equipment allow an ongoing cycle of research and development to provide the analytical methodologies and instrumentation capabilities needed to implement the latest research projects. (news-medical.net)
  • The micro-magnetofluidic method is the control of magnetic fluids by an applied magnetic field on a microfluidic platform, offering wireless and programmable control of the magnetic droplets. (wikipedia.org)
  • Here, we show that an early diverging land plant, Physcomitrella patens, can be continuously cultured within PDMS microfluidic chambers. (mblwhoilibrary.org)
  • By coupling the powerful genetic tools available to P. patens with long-term growth and imaging provided by PDMS microfluidic chambers, we demonstrate the capability to study cellular and subcellular developmental events in plants directly and in real time. (mblwhoilibrary.org)
  • The short path lengths of microfluidic flow cells therefore allow the researchers to increase the temporal resolution to where they can measure events occurring on the faster timescales. (photonics.com)
  • This imaging technique provides a wide field of view (≈30mm²) resulting in a counting statistic (a few thousand of cells) in one single acquisition consistent with required hematological performance," explains Sophie Morales, laboratory head at CEA-Leti. (horiba.com)
  • Many commonly used measurement techniques for oxygen monitoring are not applicable in such small volumes, consume oxygen during the measurement process, or directly affect the cells. (genengnews.com)
  • Cells were grown to confluence, and cell viability was documented for the different substrates by an established live/dead staining technique ( Figure 2 ). (genengnews.com)
  • Microfluidic endothelium for studying the intravascular adhesion of metastatic breast cancer cells. (nih.gov)
  • In addition, the technique allows living cells to be analysed in a non-destructive way, which has numerous potential benefits in research. (europeanpharmaceuticalreview.com)
  • With current technologies, cost of production soars due to the need for specialized radiation safety infrastructure (e.g., hot cells), automated synthesis equipment, analytical testing equipment, and personnel trained in radiochemistry. (ucla.edu)
  • Some of the possible clinical applications for this technique include phasing of multiple mutations when parental samples are unavailable, preimplantation genetic diagnosis, prenatal diagnosis and in the characterization of cancer cells. (wikipedia.org)
  • This paper introduces microfluidic manipulation of microorganism by opto-electrokinetic technique, named rapid electrokinetic patterning (REP). REP is a hybrid method that utilizes the simultaneous application of a uniform electric field and a focused laser to manipulate various kinds and types of colloidal particles. (koreascience.or.kr)
  • In many cases the various reactants are held within the same vessel which severely limits the application of these techniques to quantitative mechanistic and kinetic investigation of rapid chemical reactions. (cam.ac.uk)
  • During the past decades, plasmonic sensors have been explored extensively due to their ultra-sensitivity and emerged as a new generation of analytical tools. (washington.edu)
  • Scientists today are challenged in gathering a complete understanding using available techniques. (genengnews.com)
  • Spectradyne s CEO Jean-Luc Fraikin described the importance of the deal: This partnership will expand access to the powerful insights that our technology delivers by providing a low barrier to entry for scientists who are new to Microfluidic Resistive Pulse Sensing (MRPS). (nanotech-now.com)
  • We developed microfluidic microbioreactors that have been used for biological studies involving cell cultures. (unipd.it)
  • Particle Technology Labs is already a trusted provider of high-quality analytical services in many of our target markets, and Spectradyne will provide PTL with increased access to biological markets, including extracellular vesicle research in particular. (nanotech-now.com)
  • One technique uses immunofluorescent staining to determine the levels of biomarkers to indicate a cell is undergoing HPV-related cancerous growth. (phys.org)
  • The high sensitivity and resolution of the analytical technique made it possible to monitor all OS species, thus providing a comprehensive and quantitative analysis of OS variations during colostrum production. (nih.gov)
  • Researchers at Oregon State University have developed an improved technique for using magnetic nanoclusters to kill hard-to-reach tumors. (phys.org)
  • To demonstrate this microfluidic flow-flash technique, the researchers used it to probe the kinetics of CO recombination or oxygen binding to myoglobin after laser-induced dissociation of CO from horse heart myoglobin. (photonics.com)
  • 3D Cell Culture 2017 will bring together leading professionals and researchers in the industry to discuss the latest developments and future potential of this technique. (smi-online.co.uk)
  • These sensors are small, and the signals are recorded in the form of visible light, so that data acquisition from the outside through the transparent walls of microfluidic chips is easily accessible. (genengnews.com)
  • Benham, G. S., Practical aspects of objective lens selection for confocal and multiphoton digital imaging techniques . (fsu.edu)
  • By using patient specific details at the genome, proteome and metabolome level, Prof. Nicholson will explore how the analytical technologies described throughout this article can deliver improved healthcare solutions. (news-medical.net)
  • Meanwhile, opto-microfluidic sensors are gaining increasing acceptance in clinical medicine for bioanalysis and disease diagnosis with continuous emergence of new applications. (mdpi.com)
  • Microfluidic technology can potentially provide a platform for evaluation of clinical and patient-specific features for cancer therapy, while as an alternative to animal models to reduce the amount of animal tests. (southampton.ac.uk)
  • This highly adaptable technology is likely to ripple out into many areas of analytical and biochemistry, as well as cell biology, and clinical medicine. (europeanpharmaceuticalreview.com)
  • Previous studies have demonstrated that flow-induced shear stress induces a motile and aggressive tumor phenotype in a microfluidic model of 3D ovarian cancer. (spie.org)