JoVE General
Fluorescence-based Measurement of Store-operated Calcium Entry in Live Cells: from Cultured Cancer Cell to Skeletal Muscle Fiber
1Department of Physiology and Biophysics, Confocal Microscopy and Cell Imaging Core, Robert Wood Johnson Medical School, 2Department of Physiology and Biophysics, Robert Wood Johnson Medical School, 3Muscle Biology Research Group-MUBIG Schools of Nursing & Medicine, University of Missouri-Kansas City
The extent of store-operated Ca2+ entry (SOCE) can be monitored using fluorescent Ca2+ indicators. Mn2+ quenching of such indicators assays SOCE in cultured cells and skeletal muscle fibers. A technique allowing spatial and temporal resolution of SOCE by confocal imaging of mechanically skinned muscle fibers is also described.
JoVE General
Double Whole Mount in situ Hybridization of Early Chick Embryos
1Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology - Texas A&M Health Science Center, 2Center for Environmental and Genetic Medicine, Texas A&M University (TAMU)
This video demonstrates 2-color whole mount in situ hybridization, a method by which the spatial and temporal expression pattern of 2 different genes can be visualized in young chick embryos. This method was originally introduced by David Wilkinson, Domingos Henrique, Phil Ingham and David Ish -Horowicz.
JoVE General
Method for Whole Mount Antibody Staining in Chick
This video demonstrates whole mount immunohistochemistry, a method by which the spatial and temporal expression pattern of an antigen can be visualized in young chick embryos. This method was originally introduced by Jane Dodd and Tom Jessell.
JoVE Clinical and Translational Medicine
Myo-mechanical Analysis of Isolated Skeletal Muscle
1Cardiovascular Research Institute, University of California San Francisco, 2Department of Pediatrics, University of California San Francisco, 3Department of Biology, San Francisco State University, 4Department of Medicine, University of California San Francisco, 5Eli and Edythe Broad Center of Regeneration Medicine & Stem Cell Research, University of California San Francisco
To assess the in vivo effects of therapeutic interventions for muscle disease, methods are needed to quantitate force generation and fatigability in treated muscle. We detail an approach to evaluating myo-mechanical properties in explanted mouse hindlimb muscle. This analysis provides a robust approach to quantitating the effects of genetic modification on muscle function, as well as comparison of therapies in mouse models of muscle disease.
JoVE Neuroscience
Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI
1Department of Radiology, Stanford University, 2Center for In Vivo Microscopy, Duke University Medical Center, 3Department of Biomedical Engineering, Duke University
A technique is described for broadly opening the blood-brain barrier in the mouse using microbubbles and ultrasound. Using this technique, manganese can be administered to the mouse brain. Because manganese is an MRI contrast agent that accumulates in depolarized neurons, this approach enables imaging of neuronal activity.
JoVE General
Assay for Neural Induction in the Chick Embryo
Neural induction is the first step in the formation of the brain. It is a mechanism by which Hensen's node (organizer), instructs adjacent tissue to adopt a neural fate, i.e. to give rise to the nervous system. This video demonstrates an assay for neural induction in chick embryo.
JoVE Clinical and Translational Medicine
Direct Pressure Monitoring Accurately Predicts Pulmonary Vein Occlusion During Cryoballoon Ablation
1Department of Cardiac Electrophysiology, Piedmont Heart Institute, 2Cardiac Rhythm, Medtronic Inc.
Effective pulmonary vein isolation utilizing a cryoballoon depends on complete pulmonary vein occlusion. The point of occlusion can be effectively predicted by direct analysis of pulmonary vein pressure waveform analysis during balloon inflation using a simple and reproducible technique.
JoVE Neuroscience
The Culture of Primary Motor and Sensory Neurons in Defined Media on Electrospun Poly-L-lactide Nanofiber Scaffolds
1Department of Biomedical Engineering, University of Michigan, 2State Key Laboratory of Bioelectronics, Southeast University, 3Department of Neurology, University of Michigan, 4Geriatric Research, Education and Clinical Center, Veterans Affairs Ann Arbor Health System
Aligned electrospun fibers direct the growth of neurons in vitro and are a potential component of nerve regeneration scaffolds. We describe a procedure for preparing electrospun fiber substrates and the serum-free culture of primary rat E15 sensory (DRG) and motor neurons. Visualization of neurons by immunocytochemistry is also included.
JoVE Immunology and Infection
Live-cell Video Microscopy of Fungal Pathogen Phagocytosis
1Division of Applied Medicine, University of Aberdeen, 2Aberdeen Fungal Group, University of Aberdeen
We describe methods for live-cell video microscopy of Candida albicans phagocytosis by macrophages. These methods enable stage-specific analysis of macrophage migration, recognition, engulfment and phagosome maturation and reveal novel aspects of phagocytosis.
JoVE Neuroscience
An Optimized Procedure for Fluorescence-activated Cell Sorting (FACS) Isolation of Autonomic Neural Progenitors from Visceral Organs of Fetal Mice
Division of Genetic Medicine, Department of Medicine, Vanderbilt University School of Medicine
An optimized procedure to purify neural crest-derived neuronal progenitors from fetal mouse tissues is described. This method takes advantage of expression from fluorescent reporter alleles to isolate discrete populations by fluorescence-activated cell sorting (FACS). The technique can be applied to isolate neuronal subpopulations throughout development or from adult tissues.
JoVE General
Gramicidin-based Fluorescence Assay; for Determining Small Molecules Potential for Modifying Lipid Bilayer Properties
Department of Physiology and Biophysics, Weill Cornell Medical College
We introduce a fast fluorescence-based assay that monitors the rate of fluorescence quenching as a measure of gramicidin channel activity. The gramicidin channels are used as molecular force transducers to monitor changes in lipid bilayer properties as sensed by bilayer spanning proteins.
JoVE General
A Chromatin Assay for Human Brain Tissue
Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School
Until recently, expression studies on human brain were limited to quantification of RNA or protein. With the chromatin immunoprecipitation techniques described in this paper, it will be possible to map histone methylation and other epigenetic regulators of gene expression in postmortem brain.
JoVE Neuroscience
Lectin-based Isolation and Culture of Mouse Embryonic Motoneurons
1Institute for Cellmorphology and molecular Neurobiology, Group for Cellbiology, Ruhr-University Bochum, 2Institute for Clinical Neurobiology, University of Wuerzburg
An alternative way of isolating mouse embryonic motoneurons from the spinal cord is described. The method takes into account the fact that lectin can bind to the low affinity nerve growth factor receptor p75NTR. This lectin-based preplating allows a purification similar to that with a specific antibody against the p75NTR.
JoVE Clinical and Translational Medicine
Implantation of Radiotelemetry Transmitters Yielding Data on ECG, Heart Rate, Core Body Temperature and Activity in Free-moving Laboratory Mice
1Division of Surgical Research, University Hospital Zurich, 2Institute of Laboratory Animal Science, University of Zurich
A surgical technique for implantation of commercially available telemetry transmitters used for continuous measurement of biopotential (one-lead ECG), heart rate, core body temperature and locomotor activity in freely moving mice is shown. Recommendations and protocols for post-operative care and pain relief, improving recovery, well being and survival rate are also presented.
JoVE Clinical and Translational Medicine
In vitro Measurements of Tracheal Constriction Using Mice
Department of Physiology, UT Health Science Center, San Antonio
Transgenic mice have been extremely useful in ascribing physiological function to genes. As such, research in general, and functional studies of airway, in particular, have undergone a remarkable shift toward murine models. Here we provide protocols for in vitro trachea constriction studies to evaluate smooth muscle function in murine airway.
JoVE General
Synthesis and Calibration of Phosphorescent Nanoprobes for Oxygen Imaging in Biological Systems
Department of Biochemistry and Biophysics, University of Pennsylvania
We present principles of oxygen measurements by phosphorescence quenching and review design of porphyrin-based dendritic nanosensors for oxygen imaging in biological systems.
JoVE General
Freezing Human ES Cells
Department of Molecular and Cell Biology, Harvard
Here we demonstrate how our lab freezes HuES human embryonic stem cell lines.
JoVE General
Photo-Induced Cross-Linking of Unmodified Proteins (PICUP) Applied to Amyloidogenic Peptides
1Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, 2Brain Research Institute, Molecular Biology Institute, University of California, Los Angeles, 3Department of Neurology, University of California, Los Angeles
Photo-induced cross-linking of unmodified proteins (PICUP) allows characterization of oligomer size distribution in metastable protein mixtures. We demonstrate application of PICUP to three representative amyloidogenic peptides the 40- and 42-residue forms of amyloid β-protein, and calcitonin, and a control peptide growth-hormone releasing factor.
JoVE Immunology and Infection
Real-time Imaging of Leukotriene B4 Mediated Cell Migration and BLT1 Interactions with β-arrestin
Microbiology and Immunology, James Graham Brown Cancer Center, University of Louisville
This paper describes the methodology to determine the chemotactic response of leukocytes to specific ligands and identify interactions between the cell surface receptors and cytosolic proteins using live cell imaging techniques.
JoVE Clinical and Translational Medicine
Mesenteric Artery Contraction and Relaxation Studies Using Automated Wire Myography
1Julius L. Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, Durham, 2Department of Biology, North Carolina Central University, Durham, 3Department of Physiology & Pharmacology and Hypertension & Vascular Research Center, Wake Forest University School of Medicine
An automated myography method for force measurements in isolated mesenteric arteries is described. It employs a Mulvany-Halpern Auto Dual Wire Myograph 510A to determine responses to phenylephrine and extracellular calcium. The method allows consistent determination of isometric responses to agonists in small vessels of diameters of 60 - 300 μm, independently.
JoVE General
Measuring Plasma Membrane Protein Endocytic Rates by Reversible Biotinylation
University of Massachusetts Medical School
Regulated endocytosis governs the cell surface expression levels of the majority of membrane proteins. Here we utilize reducible, membrane impermeant biotinylation reagents to measure the endocytic rate of the dopamine transporter (DAT), a polytopic membrane protein. The method facilitates a straightforward approach to measuring the endocytic rate of most plasma membrane proteins.
JoVE General
Direct Tracheal Instillation of Solutes into Mouse Lung
1Department of Physiology, Emory University, 2Center for Respiratory Health, Emory University, 3Department of Medicine, Emory University
Intratracheal instillations deliver solutes directly into the lungs. This procedure targets the delivery of the instillate into the distal regions of the lung, and is therefore often incorporated in studies aimed at studying alveoli. We provide a detailed survival protocol for performing intratracheal instillations in mice.
JoVE Clinical and Translational Medicine
Endothelin-1 Induced Middle Cerebral Artery Occlusion Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Rat
1Department of Neurosurgery, University of Florida, 2Department of Anatomical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran, 3Department of Physiology and Functional Genomics, University of Florida, 4Department of Neurology, University of Florida
Several animal models of cerebral ischemia have been developed to simulate the human condition of stroke. This protocol describes the endothelin-1 (ET-1) induced middle cerebral artery occlusion (MCAO) model for ischemic stroke in rats. In addition, important considerations, advantages, and shortcomings of this model are discussed.
JoVE Chemistry
Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
ISOF - Bio Free Radicals, Consiglio Nazionale delle Ricerche
Radical-based biomimetic chemistry has been applied to building-up libraries necessary for biomarker development.
JoVE Neuroscience
Behavioral Determination of Stimulus Pair Discrimination of Auditory Acoustic and Electrical Stimuli Using a Classical Conditioning and Heart-rate Approach
School of Psychological Science, La Trobe University
The application of a classical fear conditioning behavioral paradigm for auditory prosthetic research in rats is described. This paradigm provides a mechanism for identifying both detection of, and discrimination between, distinct acoustic and electrical stimuli using heart-rate as an outcome measure.
JoVE Clinical and Translational Medicine
Characterization of Molecular Mechanisms of In vivo UVR Induced Cataract
1St. Erik's Eye Hospital, Karolinska Institutet, 2Gullstrand lab, Section for Ophthalmology, Department of Neuroscience, Uppsala University
Cataract is the leading cause of blindness in the world. Solar ultraviolet radiation (UVR) is the main risk factor for cataract development. An animal model of far UVR-B induced cataract was developed. In this article we describe methods for investigation of cataract formation: exposure to UVR, quantitative RT-PCR and immunohistochemistry.
JoVE Neuroscience
Cerebral Blood Oxygenation Measurement Based on Oxygen-dependent Quenching of Phosphorescence
1Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 2Department of Biochemistry and Biophysics, University of Pennsylvania, 3Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 4Departments of Neurosciences and Radiology, University of California
We present an experimental procedure for measuring the partial pressure of oxygen (pO2) in cerebral vasculature based on oxygen-dependent quenching of phosphorescence. Animal preparation and imaging procedures were outlined for both large field of view CCD-based imaging of pO2 in rats and 2-photon excitation based imaging of pO2 in mice.
JoVE General
Preparation of Drosophila Polytene Chromosome Squashes for Antibody Labeling
Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University
This video protocol illustrates the squash technique used in the Johansen laboratory to prepare Drosophila polytene chromosomes for antibody labeling.
JoVE General
Application of Stopped-flow Kinetics Methods to Investigate the Mechanism of Action of a DNA Repair Protein
Molecular Biology and Biochemistry Department, Wesleyan University
Msh2-Msh6 is responsible for initiating repair of replication errors in DNA. Here we present a transient kinetics approach towards understanding how this critical protein works. The report illustrates stopped-flow experiments for measuring the coupled DNA binding and ATPase kinetics underlying Msh2-Msh6 mechanism of action in DNA repair.
JoVE Clinical and Translational Medicine
Modeling and Imaging 3-Dimensional Collective Cell Invasion
1Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, 2The Beatson Institute for Cancer Research
Models of tumor cell invasion into three-dimensional extracellular matrix better reflect the in vivo situation than two-dimensional motility assays. Using matrix invasion assays combined with confocal imaging of fluorescently-labeled cells, detailed information on invasion modes and the distinct contributions of leading versus following cells can be obtained.
JoVE Chemistry
Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction
Department of Chemistry, Lehigh University
A straightforward procedure for the preparation of samarium diiodide (SmI2) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)2 in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.
JoVE General
Amide Hydrogen/Deuterium Exchange & MALDI-TOF Mass Spectrometry Analysis of Pak2 Activation
1Department of Chemistry, Tunghai University, 2Department of Biochemistry, University of California, Riverside
MALDI-TOF mass spectrometry was successfully utilized to monitor the amide hydrogen/deuterium exchange in protein kinase Pak2 activation.
JoVE Bioengineering
Integrated Photoacoustic Ophthalmoscopy and Spectral-domain Optical Coherence Tomography
1Department of Biomedical Engineering, Northwestern University, 2Department of Physics, Harbin Institute of Technology, 3Department of Ophthalmology, University of Southern California, 4Department of Ophthalmology, Northwestern University
Photoacoustic ophthalmology (PAOM), an optical-absorption-based imaging modality, provides the complementary evaluation of the retina to the currently available ophthalmic imaging technologies. We report the using of PAOM integrated with spectral-domain optical coherence tomography (SD-OCT) for simultaneous multimodal retinal imaging in rats.
JoVE General
Lineage Labeling of Zebrafish Cells with Laser Uncagable Fluorescein Dextran
1Department of Biological Sciences, Vanderbilt University, 2Department of Chemical and Systems Biology, Stanford University
This protocol delineates a way to label and trace the fate of small groups of cells zebrafish embryos using UV-uncaging of caged fluorescein, followed by whole mount immunolabeling to amplify the signal from the uncaged fluorescein.
JoVE Neuroscience
Focussed Ion Beam Milling and Scanning Electron Microscopy of Brain Tissue
Centre of interdisciplinary electron microscopy, École Polytechnique Fédérale de Lausanne
This protocol describes how resin embedded brain tissue can be prepared and imaged in the three dimensions in the focussed ion beam, scanning electron microscope.
JoVE General
Intravenous Microinjections of Zebrafish Larvae to Study Acute Kidney Injury
1Department of Developmental Biology, University of Pittsburgh, 2Department of Biological Sciences, University of Pittsburgh, 3Department of Medicine and Genetics, Harvard Medical School
We describe a technique of microinjecting the aminoglycoside, gentamicin, into 2 days post-fetilization (dpf) zebrafish larvae to induce acute kidney injury (AKI). We also describe a method for whole mount immunohistochemistry, plastic embedding and sectioning of zebrafish larvae to visualize the AKI mediated damage.
JoVE Immunology and Infection
Customization of Aspergillus niger Morphology Through Addition of Talc Micro Particles
Institute of Biochemical Engineering, Technische Universität Braunschweig
A method to precisely generate and to comprehensively characterize morphology of filamentous fungus Aspergillus niger is described, which allows the mathematical correlation of morphological appearance and productivity.
JoVE General
Quantitative Real-Time PCR using the Thermo Scientific Solaris qPCR Assay
Thermo Scientific Solaris qPCR Products
The Solaris qPCR Gene Expression Assays are novel pre-designed qPCR primer/probe combinations designed to simplify the qPCR process without sacrificing the specificity and robustness of the assay.
JoVE General
Isolation of Labile Multi-protein Complexes by in vivo Controlled Cellular Cross-Linking and Immuno-magnetic Affinity Chromatography
1Department of Cell Biology, Emory University, 2Department of Medicine, Division of Cardiology, Emory University
The cell permeable crosslinker DSP [dithiobis-(succinimidyl propionate)] stabilizes transient and labile interactions in vivo, which allows their isolation using stringent protein complex purification techniques. Here we present a technique for crosslinking cells grown in culture followed by isolation of protein complexes by immunoprecipitation.
JoVE General
Closed System Cell Culture Protocol Using HYPERStack Vessels with Gas Permeable Material Technology
1Business Development, Corning Life Science, 2Applications, Corning Life Science, 3Product Development, Corning Life Science
An Introduction into the technology, protocol and handling of the Corning HYPERStack Vessels and accessories used for high yield adherent cell culture. The protocol will show how to use the closed system vessels for increasing cell harvesting over current stacked plate products.
JoVE Applied Physics
Harvesting Solar Energy by Means of Charge-Separating Nanocrystals and Their Solids
1Department of Physics, Bowling Green State University, 2The Center for Photochemical Sciences, Bowling Green State University, 3Department of Chemistry, Bowling Green State University
A general strategy for the development of charge-separating semiconductor nanocrystal composites deployable for solar energy production is presented. We show that assembly of donor-acceptor nanocrystal domains in a single nanoparticle geometry gives rise to a photocatalytic function, while bulk-heterojunctions of donor-acceptor nanocrystal films can be used for photovoltaic energy conversion.
JoVE General
Isolation of Genomic DNA from Mouse Tails
Department of Physiology and Biophysics, University of California, Irvine (UCI)
JoVE General
High-throughput Screening and Biosensing with Fluorescent C. elegans Strains
1Department of Biology, University of Florida, 2Mount Desert Island Biological Laboratory
A procedure for liquid-based culturing and dispensing of C. elegans strains expressing fluorescent reporter proteins is described that does not require expensive sorting equipment. This approach can be applied to numerous inducible C. elegans genes for drug discovery or biosensing of contaminants.
JoVE Immunology and Infection
Using Eggs from Schistosoma mansoni as an In vivo Model of Helminth-induced Lung Inflammation
1Institute of Immunology, Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, 2Pathobiology, School of Veterinary Medicine, University of Pennsylvania
Schistosoma mansoni eggs are potent stimulators of the T helper type 2 (Th2) immune response, characteristic of parasite infection, asthma and allergic inflammation. This protocol utilizes S. mansoni egg injection to generate a CD4 Th2 cytokine-induced inflammatory response in the lung, characterized by lung granuloma formation around the egg, eosinophilia and macrophage alternative activation.
JoVE General
Small-scale Nuclear Extracts for Functional Assays of Gene-expression Machineries
Department of Cell Biology, Harvard Medical School
A protocol for preparation of robust, small-scale HeLa nuclear extracts is described. This protocol is valuable for assays that require use of small populations of cells, such as cells treated with drugs or RNAi. The method should be applicable to a wide variety of gene expression assays and other cell types, including patient cells.
JoVE Immunology and Infection
Isolating And Immunostaining Lymphocytes and Dendritic Cells from Murine Peyer's Patches
Division of Infectious Diseases, New York State Department of Health
There is an increasing interest in understanding the immunological functions of specific subpopulations of cells in Peyer's patches (PPs), the primary inductive sites of gut-associated lymphoid tissues. Here we outline parallel protocols for preparing PP single cell preparations for flow cytometric analysis and PP cryosections for immunostaining.
JoVE Immunology and Infection
Recognition of Epidermal Transglutaminase by IgA and Tissue Transglutaminase 2 Antibodies in a Rare Case of Rhesus Dermatitis
1Division of Microbiology, Tulane National Primate Research Center, 2Division of Comparative Pathology, Tulane National Primate Research Center, 3Division of Veterinary Medicine, Tulane National Primate Research Center
Dermatitis herpetiformis (DH) is a chronic inflammatory condition characterized by an autoimmune reaction between IgA and epidermal transglutaminase (eTG). DH develops in a very small portion of gluten-sensitive and/or celiac patients. The results of this study indicate that DH can also develop in a rhesus monkey host with symptoms of idiopatic dermatitis.
JoVE General
Digital Microfluidics for Automated Proteomic Processing
1Department of Chemistry, University of Toronto, 2Donnelly Centre for Cellular and Biomolecular Research, 3Institute for Biomaterials and Biomedical Engineering, University of Toronto
Digital Microfluidics is a technique characterized by the manipulation of discrete droplets (~nL - mL) on an array of electrodes by the application of electrical fields. It is well-suited for carrying out rapid, sequential, miniaturized automated biochemical assays. Here, we report a platform capable of automating several proteomic processing steps.
JoVE Bioengineering
Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
1Department of Chemistry and Biochemistry, University Of California Santa Barbara, 2Department of Chemistry and Biochemistry, Program in BioMolecular Science and Engineering, University Of California Santa Barbara
"E-DNA" sensors, reagentless, electrochemical biosensors that perform well even when challenged directly in blood and other complex matrices, have been adapted to the detection of a wide range of nucleic acid, protein and small molecule analytes. Here we present a general procedure for the fabrication and use of such sensors.
JoVE Bioengineering
Directed Cellular Self-Assembly to Fabricate Cell-Derived Tissue Rings for Biomechanical Analysis and Tissue Engineering
Biomedical Engineering Department, Worcester Polytechnic Institute
This article outlines a versatile method to create cell-derived tissue rings by cellular self-assembly. Smooth muscle cells seeded into ring-shaped agarose wells aggregate and contract to form robust three-dimensional (3D) tissues within 7 days. Millimeter-scale tissue rings are conducive to mechanical testing and serve as building blocks for tissue assembly.
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