Focal Adhesions:
An anchoring junction of the cell to a non-cellular substrate. It is composed of a specialized area of the plasma membrane where bundles of the Actin cytoskeleton terminate and attach to the transmembrane linkers, Integrins, which in turn attach through their extracellular domains to Extracellular matrix proteins.
JoVE Bioengineering
Induction of Adhesion-dependent Signals Using Low-intensity Ultrasound
1School of Biochemistry, University of Bristol, 2Smith and Nephew
This protocol describes the stimulation of cultured fibroblasts with low-intensity pulsed ultrasound, which drives focal adhesion formation and Rac1 activation by mimicking engagement of the transmembrane matrix receptor, syndecan-4. This approach allows investigation of a successful clinical technique at the cellular level, thereby providing opportunities for refinement of the therapy.
JoVE General
Live Cell Response to Mechanical Stimulation Studied by Integrated Optical and Atomic Force Microscopy
1Department of Systems Biology and Translational Medicine, College of Medicine, Cardiovascular Research Institute, Texas A&M Health Science Center, 2Department of Biomedical Engineering, Texas A&M University
This paper aims to instruct the reader in the operation of an integrated atomic force-optical imaging microscope for mechanical stimulation of live cells in culture. A step-by-step protocol is presented. A representative data set that shows live cell response to mechanical stimulation is presented.
JoVE Bioengineering
Preparation of Complaint Matrices for Quantifying Cellular Contraction
1Institute for Biophysical Dynamics, University of Chicago, 2Physics Department - James Franck Institute, University of Chicago, 3Interdisciplinary Scientist Training Program, University of Chicago
In this video, we demonstrate the experimental techniques used to fabricate compliant, extracellular matrix (ECM) coated substrates suitable for cell culture, and which are amenable to traction force microscopy and observing effects of ECM stiffness on cell behavior.
JoVE Bioengineering
Creating Adhesive and Soluble Gradients for Imaging Cell Migration with Fluorescence Microscopy
1Centre for Vascular Research and Australian Centre for Nanomedicine, The University of New South Wales, 2School of Chemistry and Australian Centre for Nanomedicine, The University of New South Wales
A method for the assembly of adhesive and soluble gradients in a microscopy chamber for live cell migration studies is described. The engineered environment combines antifouling surfaces and adhesive tracks with solution gradients and therefore allows one to determine the relative importance of guidance cues.
JoVE General
Isolation of Valvular Endothelial Cells
Department of Biomedical Engineering, Cornell University
We provide a method for isolating and culturing pure populations of heart valve endothelial cells (VEC). VEC can be isolated from either side of the cusp or leaflet and immediately following, underlying interstitial cell (VIC) isolation is straightforward.
JoVE General
Adenovirus-mediated Genetic Removal of Signaling Molecules in Cultured Primary Mouse Embryonic Fibroblasts
Department of Molecular and Cellular Biology, University of Guelph
In this video we use an adenovirus carrying the Cre recombinase gene to infect primary mouse embryonic fibroblasts carrying a floxed Rac1 allele.
JoVE General
Studying the Effects of Matrix Stiffness on Cellular Function using Acrylamide-based Hydrogels
Department of Pharmacology, University of Pennsylvania
The effect of substrata stiffness on cellular function can be modeled in vitro using polyacrylamide hydrogels of varying compliances.
JoVE General
Genetic Modification and Recombination of Salivary Gland Organ Cultures
Department of Biological Sciences, University at Albany, SUNY
A technique to genetically manipulate epithelial cells within whole ex vivo cultured embryonic mouse submandibular glands (SMGs) using viral gene transfer is described. This method takes advantage of the innate ability of SMG epithelium and mesenchyme to spontaneously recombine after separation and infection of epithelial rudiments with adenoviral vectors.
JoVE Clinical and Translational Medicine
In vivo Dual Substrate Bioluminescent Imaging
Case Comprehensive Cancer Center, Case Western Reserve University
Herein we describe the methods to construct, visualize, and quantify the bioluminescent reactions of both firefly and renilla luciferase enzymes expressed in metastatic breast cancer cells during their growth and metastasis in vivo.
JoVE Bioengineering
Nanotopology of Cell Adhesion upon Variable-Angle Total Internal Reflection Fluorescence Microscopy (VA-TIRFM)
Hochschule Aalen, Institut für Angewandte Forschung
Topology of cell adhesion on a substrate is measured with nanometre precision by variable-angle total internal reflection fluorescence microscopy (VA-TIRFM).
JoVE General
Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy
1Department of Biochemistry and Molecular Medicine, University of California, Davis, 2NSF Center for Biophotonics Science & Technology, University of California, Davis, 3University of Tromsø, 4Department of Surgery (Division of Surgical Oncology), University of California, Davis, 5UC Davis Comprehensive Cancer Center, University of California, Davis, 6Department of Biological Chemistry, University of California, Davis
Autophagy is a ubiquitous process that enables cells to degrade and recycle proteins and organelles. We apply advanced fluorescence microscopy to visualize and quantify the small, but essential, physical changes associated with the induction of autophagy, including the formation and distribution of autophagosomes and lysosomes, and their fusion into autolysosomes.
JoVE General
Quantitative Analysis of Random Migration of Cells Using Time-lapse Video Microscopy
1Department of Biochemistry and Molecular Biology, LSU School of Medicine, 2Department of Oral Biology, LSU School of Dentistry, 3Stanley S. Scott Cancer Center, LSU School of Medicine
This method allows monitoring of cells in real time and quantitative measurements of different cell migration parameters such as speed, displacement, and velocity. Unlike the traditional methods, this real time approach is not based on endpoint quantitative migration measurements; instead it allows monitoring and calculating different parameters continuously.
JoVE Bioengineering
On-Chip Endothelial Inflammatory Phenotyping
Department of Biomedical Engineering, University of California, Davis
Microfluidic flow chambers etched by photolithography and fabricated from PDMS are applied to probe functional outcomes associated with EC dysfunction and inflammation. In a representative experiment, the ability of differential shear stress to modulate monocytic cell adhesion to cytokine activated EC monolayers is demonstrated.
JoVE General
Mapping Molecular Diffusion in the Plasma Membrane by Multiple-Target Tracing (MTT)
1Institut National de la Santé et de la Recherche Médicale, UMR 631, Parc scientifique de Luminy, 2Centre National de la Recherche Scientifique, UMR 6102, Parc scientifique de Luminy, 3Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University, 4École Centrale Marseille, Technopôle de Château-Gombert, 5Institut Fresnel, Aix-Marseille University, 6Centre National de la Recherche Scientifique, UMR 6133, Aix-Marseille University
Multiple-Target Tracing is a homemade algorithm developed for tracking individually labeled molecules within the plasma membrane of living cells. Efficiently detecting, estimating and tracing molecules over time at high-density provide a user-friendly, comprehensive tool to investigate nanoscale membrane dynamics.
JoVE General
Determination of Lipid Raft Partitioning of Fluorescently-tagged Probes in Living Cells by Fluorescence Correlation Spectroscopy (FCS)
1Centre de Recherche de l’Institut du Cerveau et de la Moelle Épinière, Hôpital de la Pitié-Salpêtrière, 2Institut des Sciences Moléculaires d'Orsay, Université Paris-Sud, 3Centre de Photonique Biomédicale du Centre Laser, Université Paris-Sud
A technique to probe the lipid raft partitioning of fluorescent proteins at the plasma membrane of living cells is described. It takes advantage of the disparity in diffusion times of proteins located inside or outside of lipid rafts. Acquisition can be performed dynamically in control conditions or after drug addition.
JoVE Immunology and Infection
A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins
The compartmentalization of proteins either within the plasma membrane or into intracellular locations is one regulatory mechanism that can greatly influence signaling outcomes; hence, to understand signaling it is important to study the spatial and temporal behavior of the proteins involved. We describe here a TIRF microscopy based system to study signal transduction in T cells, but is broadly applicable.
JoVE Bioengineering
Fabrication of Micropatterned Hydrogels for Neural Culture Systems using Dynamic Mask Projection Photolithography
Biomedical Engineering, Tulane University
Simple techniques are described for the rapid production of microfabricated neural culture systems using a digital micromirror device for dynamic mask projection lithography on regular cell culture substrates. These culture systems may be more representative of natural biological architecture, and the techniques described could be adapted for numerous applications.
JoVE General
Live Imaging of GFP-labeled Proteins in Drosophila Oocytes
Department of Biology, Vassar College
A protocol for live imaging of GFP-tagged proteins or autofluorescent structures in individual Drosophila oocytes is described.
JoVE Clinical and Translational Medicine
A Murine Model of Stent Implantation in the Carotid Artery for the Study of Restenosis
1Institute for Molecular Cardiovascular Research, RWTH Aachen University, 2Institute for Textile Technology and Mechanical Engineering, RWTH Aachen University, 3Institute for Applied Medical Engineering, Helmholtz-Institute of RWTH Aachen University, 4Department of Experimental Molecular Imaging, RWTH Aachen University, 5Department of Oral and Maxillofacila Surgery, RWTH Aachen University
A model of stent implantation in mouse carotid artery is described. Compared to other similar methods, this procedure is very rapid, simple and accessible, offering the possibility to study in a convenient way the vascular wall reaction to different drug-eluting stents and the molecular mechanisms of restenosis.
JoVE General
Using Laser Tweezers For Manipulating Isolated Neurons In Vitro
This video describes the manipulation of cultured neurons using laser tweezers in vitro.
JoVE Clinical and Translational Medicine
Retrograde Perfusion and Filling of Mouse Coronary Vasculature as Preparation for Micro Computed Tomography Imaging
1Department of Pathology, Center for Cardiovascular Biology, and Institute for Stem Cell and Regenerative Medicine, University of Washington, 2Departments of Bioengineering and Medicine/Cardiology, University of Washington
Visualization of the coronary vessels is critical to advancing our understanding of cardiovascular diseases. Here we describe a method for perfusing murine coronary vasculature with a radiopaque silicone rubber (Microfil), in preparation for micro-Computed Tomography (μCT) imaging.
JoVE General
Live-cell Imaging and Quantitative Analysis of Embryonic Epithelial Cells in Xenopus laevis
1Bioengineering, University of Pittsburgh, 2Developmental Biology, University of Pittsburgh
Xenopus embryonic epithelia are an ideal model system to study cell behaviors such as polarity development and shape change during epithelial morphogenesis. Traditional histology of fixed samples is increasingly being complemented by live-cell confocal imaging. Here we demonstrate methods to isolate frog tissues and visualize live epithelial cells and their cytoskeleton using live-cell confocal microscopy.
JoVE Neuroscience
Selective Viral Transduction of Adult-born Olfactory Neurons for Chronic in vivo Optogenetic Stimulation
Adult-born neurons of the olfactory bulb can be optogenetically controlled using Channelrhodopsin2-expressing lentiviral injection in the rostral migratory stream and chronic photostimulation with an implanted miniature LED.
JoVE Applied Physics
Fabrication of Silica Ultra High Quality Factor Microresonators
1Department of Chemical Engineering and Materials Science, University of Southern California, 2Department of Electrical Engineering-Electrophysics, University of Southern California
We describe the use of a carbon dioxide laser reflow technique to fabricate silica resonant cavities, including free-standing microspheres and on-chip microtoroids. The reflow method removes surface imperfections, allowing long photon lifetimes within both devices. The resulting devices have ultra high quality factors, enabling applications ranging from telecommunications to biodetection.
JoVE General
Laser Ablation of the Zebrafish Pronephros to Study Renal Epithelial Regeneration
Department of Biological Sciences, University of Notre Dame
Acute kidney injury (AKI) in humans is a common clinical problem caused by damage to the epithelial cells that comprise kidney nephrons, and AKI is associated with high mortality rates of 50-70%1. Following epithelial cell destruction, nephrons have a limited ability to regenerate, though the mechanisms and limitations that guide this phenomenon remain poorly understood. In this video article, we describe our technique for targeted laser ablation of kidney nephron cells in the zebrafish embryo kidney, or pronephros. Our new method can be used to complement nephrotoxicity-induced models of AKI and gain a high-resolution understanding of the cell and molecular alterations that are associated with epithelial regeneration in the kidney nephron.
JoVE Bioengineering
Shape Memory Polymers for Active Cell Culture
Department of Biomedical and Chemical Engineering, Syracuse Biomaterials Institute
A method for developing cell culture substrates with the ability to change topography during culture is described. The method makes use of smart materials known as shape memory polymers that have the ability to memorize a permanent shape. This concept is adaptable to a wide range of materials and applications.
JoVE Clinical and Translational Medicine
In vitro Mesothelial Clearance Assay that Models the Early Steps of Ovarian Cancer Metastasis
Department of Cell Biology, Harvard Medical School
The mesothelial clearance assay described here takes advantage of fluorescently labeled cells and time-lapse video microscopy to visualize and quantitatively measure the interactions of ovarian cancer multicellular spheroids and mesothelial cell monolayers. This assay models the early steps of ovarian cancer metastasis.
JoVE General
Quantitative Measurement of Invadopodia-mediated Extracellular Matrix Proteolysis in Single and Multicellular Contexts
We describe the prototypical method for producing microscope coverslips coated with fluorescent gelatin for visualizing invadopodia-mediated matrix degradation. Computational techniques using available software are presented for quantifying the resultant levels of matrix proteolysis by single cells within a mixed population and for multicellular groups encompassing entire microscopic fields.
JoVE Clinical and Translational Medicine
The Application Of Permanent Middle Cerebral Artery Ligation in the Mouse
1Department of Pharmacology and Physiology, University of Rochester, 2Department of Neurology, University of Alabama at Birmingham, 3Departments of Anesthesiology, Pharmacology and Physiology, University of Rochester
Middle cerebral artery (MCA) ligation is a technique to study focal cerebral ischemia in animal models. In this method, the middle cerebral artery is exposed by craniotomy and ligated by cauterization. This method gives highly reproducible infarct volumes and increased post-operative survival rates compared to other methods available.
JoVE General
Peptides from Phage Display Library Modulate Gene Expression in Mesenchymal Cells and Potentiate Osteogenesis in Unicortical Bone Defects
1Orthopaedics Research, University of Virginia, 2Biological Sciences, University of Delaware, 3Orthopaedic Surgery, University of Virginia
A phage display library was used to identify peptide sequences that target bone. The objective was to investigate the effect of these peptides on mesenchymal cell differentiation and to determine their effect on bone regeneration.
JoVE General
Dissection of Organizer and Animal Pole Explants from Xenopus laevis Embryos and Assembly of a Cell Adhesion Assay
Department of Developmental and Cell Biology, University of California, Irvine (UCI)
This video demonstrates the technique used for preparation of organizer and animal pole explants from Xenopus laevis embryos, including the use of the eyebrow knife - a specialized dissection tool made of one's eyebrow. The protocol for assembling an adhesion assay is also given, which probes for the presence of key adhesion molecules present on the surface organizer or animal pole cells that are critical for proper development.
JoVE Bioengineering
Adhesion Frequency Assay for In Situ Kinetics Analysis of Cross-Junctional Molecular Interactions at the Cell-Cell Interface
Biomedical Engineering Department, Georgia Institute of Technology
An adhesion frequency assay for measuring receptor-ligand interaction kinetics when both molecules are anchored on the surfaces of the interacting cells is described. This mechanically-based assay is exemplified using a micropipette-pressurized human red blood cell as adhesion sensor and integrin αLβ2 and intercellular adhesion molecule-1 as interacting receptors and ligands.
JoVE Applied Physics
Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting
1Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), 2Department of Electrical Engineering and Computer Sciences, University of California, Berkeley
We describe a nanomoulding technique which allows low-cost nanoscale patterning of functional materials, materials stacks and full devices. Nanomoulding can be performed on any nanoimprinting setup and can be applied to a wide range of materials and deposition processes.
JoVE Clinical and Translational Medicine
X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging
We are developing a dynamic adaptive exposure technique using our scanning beam digital X-ray system. Rather than exposing an object uniformly, the exposure is adapted depending on the opacity of the object. Here we show an experiment on an anthropomorphic phantom that resulted in a dose saving of 30%.
JoVE General
LeafJ: An ImageJ Plugin for Semi-automated Leaf Shape Measurement
Department of Plant Biology, University of California Davis
Demonstration of key methods for high throughput leaf measurements. These methods can be used to accelerate leaf phenotyping when studying many plant mutants or otherwise screening plants by leaf phenotype.
JoVE Neuroscience
Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat
Surgical induction of ischemic brain damage in the rat is a widely used model for stroke research. Here we demonstrate the induction of focal cerebral ischemia by occlusion of the middle cerebral artery. Visualization of the resulting infarct by histological staining and magnetic resonance imaging is also shown.
JoVE Applied Physics
Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses
Mechanical Engineering, Purdue University
An experimental method to examine the early plasma evolution induced by ultrashort laser pulses is described. Using this method, high quality images of early plasma are obtained with high temporal and spatial resolutions. A novel integrated atomistic model is used to simulate and explain the mechanisms of early plasma.
JoVE General
Imaging C. elegans Embryos using an Epifluorescent Microscope and Open Source Software
Human Genetics, University of Michigan
The C. elegans embryo is a powerful system for studying cell biology and development. We present a protocol for live imaging of C. elegans embryos utilizing DIC optics or fluorescence using readily available epifluorescent microscopes and open-source software.
JoVE Immunology and Infection
Imaging Leukocyte Adhesion to the Vascular Endothelium at High Intraluminal Pressure
Vascular Pharmacology Laboratory, Baker IDI Heart and Diabetes Institute, Monash University
This is a method to visualise leukocyte adhesion to the endothelium in harvested pressurised vessels. The technique enables studying vascular adhesion under shear flow with differing intraluminal pressures up to 200 mmHg thus mimic-ing the pathophysiological conditions of high blood pressure.
JoVE Bioengineering
Video-rate Scanning Confocal Microscopy and Microendoscopy
1Program in Biophysics, Harvard University, 2Division of Health Sciences and Technology, Harvard-MIT, 3Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School
The complete construction of a custom, real-time confocal scanning imaging system is described. This system, which can be readily used for video-rate microscopy and microendoscopy, allows for an array of imaging geometries and applications not accessible using standard commercial confocal systems, at a fraction of the cost.
JoVE Applied Physics
Construction of a High Resolution Microscope with Conventional and Holographic Optical Trapping Capabilities
Department of Physics and Astronomy, University of Utah
The system described herein employs a traditional optical trap as well as an independent holographic optical trapping line, capable of creating and manipulating multiple traps. This allows for the creation of complex geometric arrangements of refractive particles while also permitting simultaneous high-speed, high-resolution measurements of the activity of biological enzymes.
JoVE Neuroscience
Mouse Models of Periventricular Leukomalacia
We established mouse models of periventricular leukomalacia (PVL), the predominant brain injury in premature infants characterized by periventricular white matter lesions. Hypoxia/ischemia with/without systemic infection are the primary causes of PVL. Unilateral carotid ligation and hypoxia exposure with/without lipopolysaccharide injection creates PVL-like lesions in P6 mice.
JoVE Applied Physics
Determining 3D Flow Fields via Multi-camera Light Field Imaging
1Department of Mechanical Engineering, Brigham Young University, 2Naval Undersea Warfare Center, Newport, RI
A technique for performing quantitative three-dimensional (3D) imaging for a range of fluid flows is presented. Using concepts from the area of Light Field Imaging, we reconstruct 3D volumes from arrays of images. Our 3D results span a broad range including velocity fields and multi-phase bubble size distributions.
JoVE Immunology and Infection
In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells
This protocol is a simple bacterial adhesion assay consisting in counting the numbers of bacterial colony forming units that are adhered onto cultured cells. The assay is robust, independent of the adhesin studied, and numerous variations are used in most laboratories working on bacterial pathogenesis.
JoVE Clinical and Translational Medicine
Mouse Model of Intraluminal MCAO: Cerebral Infarct Evaluation by Cresyl Violet Staining
1Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, 2CHUQ Research Centre, Laval University
The intraluminal middle cerebral occlusion model in mice is herein presented. The extent of cerebral infarct is evaluated by a neurologic score and cresyl violet staining, an alternative staining to TTC, offering the great advantage to test in parallel many interest markers.
JoVE General
Monitoring Heart Function in Larval Drosophila melanogaster for Physiological Studies
Department of Biology, University of Kentucky, Lexington
We present various ways to monitor heart function in the larva of Drosophila for assessing questions dealing with the function of gap junctions, ion channel mutations, modulation of pacemaker activity and pharmacological studies.
JoVE Clinical and Translational Medicine
Modeling Stroke in Mice - Middle Cerebral Artery Occlusion with the Filament Model
Filamentous occlusion of the Middle cerebral artery is a common model for studying ischemic stroke in mice.
JoVE Clinical and Translational Medicine
Optimized System for Cerebral Perfusion Monitoring in the Rat Stroke Model of Intraluminal Middle Cerebral Artery Occlusion
Department of Neuroscience and Biomedical Technologies, University of Milano Bicocca
Cerebral perfusion monitoring has been demonstrated to improve accuracy in ischemic stroke models. Technical difficulties often limit the use of this essential tool for cerebrovascular research. In this video, an optimized system is shown to obtain a single or multi-site hemodynamic monitoring during intraluminal middle cerebral artery occlusion in rats.
JoVE Immunology and Infection
Introducing Shear Stress in the Study of Bacterial Adhesion
Blood vessels as a target for infection, Paris center for cardiovascular research, INSERM U970
During the infection process, a key step is the adhesion of pathogens with host cells. In most instances this adhesion step occurs in the presence of mechanical stress generated by flowing liquid. We describe a technique that introduces shear stress as an important parameter in the study of bacterial adhesion.
JoVE Clinical and Translational Medicine
Spheroid Assay to Measure TGF-β-induced Invasion
An assay to quantitatively measure Transforming Growth Factor (TGF)-β-induced invasion in 3-dimensional collagen gels is described. This assay takes advantage of the MCF10A series of cell lines, which represent different stages of breast cancer development. This method can be adopted to be used with other cell lines and might be used to investigate other potential activators or inhibitors of invasion.
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