Cytoskeleton:
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
JoVE General
Biophysical Assays to Probe the Mechanical Properties of the Interphase Cell Nucleus: Substrate Strain Application and Microneedle Manipulation
1Brigham and Women's Hospital / Harvard Medical School, Department of Medicine, Cardiovascular Division, 2Weill Institute for Cell and Molecular Biology & Department of Biomedical Engineering, Cornell University
We present two independent, microscope-based tools to measure the induced nuclear and cytoskeletal deformations in single, living adherent cells in response to global or localized strain application. These techniques are used to determine nuclear stiffness (i.e., deformability) and to probe intracellular force transmission between the nucleus and the cytoskeleton.
JoVE General
Actin Co-Sedimentation Assay; for the Analysis of Protein Binding to F-Actin
Department of Cell and Tissue Biology, University of California, San Francisco - UCSF
Proteins bind to filamentous actin (F-actin) through distinct actin binding modules. In this video we demonstrate the procedure of actin co-sedimentation, which is an in vitro assay routinely used to analyze proteins or specific domains that bind F-actin.
JoVE Bioengineering
Micropipette Aspiration of Substrate-attached Cells to Estimate Cell Stiffness
1Section of Respiratory, Critical Care and Sleep Medicine, Department of Medicine, University of Illinois, 2Institute for Medicine and Engineering, University of Pennsylvania
Here we describe a quick and simple method to measure cell stiffness. The general principle of this approach is to measure membrane deformation in response to well-defined negative pressure applied through a micropipette to the cell surface. This method provides a powerful tool to study biomechanical properties of substrate-attached cells.
JoVE General
Study of the Actin Cytoskeleton in Live Endothelial Cells Expressing GFP-Actin
Department of Physiology, Louisiana State University Health Sciences Center
Microscopic imaging of live endothelial cells expressing GFP-actin allows characterization of dynamic changes in cytoskeletal structures. Unlike techniques that use fixed specimens, this method provides a detailed assessment of temporal changes in the actin cytoskeleton in the same cells before, during, and after various physical, pharmacological, or inflammatory stimuli.
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 Editorial
November 2011: This Month in JoVE
Here are some highlights from the November 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE Clinical and Translational Medicine
A Real-time Electrical Impedance Based Technique to Measure Invasion of Endothelial Cell Monolayer by Cancer Cells
Lombardi Comprehensive Cancer Center, Georgetown University
This article describes an in vitro technique for monitoring cancer cells invading through a monolayer of endothelial cells. The data is acquired in real-time as a function of changes in impedance on the surface of electrodes at the well bottom.
JoVE Bioengineering
Improved Visualization and Quantitative Analysis of Drug Effects Using Micropatterned Cells
1CYTOO Cell Architects, Grenoble, France, 2Centre Commun de Quantimétrie, Faculté de Médecine Rockefeller, Lyon, France
Adhesive micropatterns that normalize cellular architecture can be used to increase sensitivity in the detection of drug effects, improve reproducibility and simplify automated image acquisition and analysis. Such technology will benefit drug/siRNA screening assays, performed on conventional cell culture supports and consequently suffering from excessive cell-to-cell variability.
JoVE General
Immunocytochemistry: Human Neural Stem Cells
Department of Pathology, University of California, Irvine (UCI)
Immunocytochemistry is a powerful method to determine the presence, subcellular localization, and relative abundance of an antigen of interest in cultured cells. This protocol presents an easy-to-follow series of steps that will enable one to conserve antibodies and get the most out of one's staining.
JoVE General
In situ Subcellular Fractionation of Adherent and Non-adherent Mammalian Cells
1Department of Biochemistry, School of Medical Sciences, University of Bristol, 2Division of Immunity and Infection, School of Medicine, University of Birmingham
In situ subcellular fractionation of mammalian cells on microscope coverslips allows the visualisation of protein localisation.
JoVE General
Live Imaging Of Drosophila melanogaster Embryonic Hemocyte Migrations
1Department of Biology and Biochemistry, University of Bath, 2Randall Division of Cell and Molecular Biophysics, King's College London
Drosophila hemocytes disperse over the entirety of the developing embryo. This protocol demonstrates how to mount and image these migrations using embryos with fluorescently labelled hemocytes.
JoVE General
Live Cell Imaging of F-actin Dynamics via Fluorescent Speckle Microscopy (FSM)
Department of Cell Biology, Scripps Institute
Selection, microinjection, and imaging of fluorescently-labeled F-actin via fluorescent speckle microscopy (FSM).
JoVE Neuroscience
Labeling and Imaging Cells in the Zebrafish Hindbrain
1Department of Biological Sciences, University of Maryland, Baltimore County, 2Center for Neuroscience, Children's National Medical Center
Key to understanding the morphogenetic processes that shape the early embryo is the ability to image cells at high resolution. We describe here a technique for labeling single cells or small clusters of cells in whole zebrafish embryos with membrane-targeted Green Fluorescent Protein.
JoVE General
Respirometric Oxidative Phosphorylation Assessment in Saponin-permeabilized Cardiac Fibers
1Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, 2Faculty of Kinesiology, University of Calgary
Saponin-permeabilized fiber preparation in conjunction with respirometric oxidative phosphorylation analysis provides integrative assessment of mitochondrial function. Mitochondrial respiration in physiological and pathological states can reflect various regulatory influences including mitochondrial interactions, morphology and biochemistry.
JoVE Bioengineering
Flexural Rigidity Measurements of Biopolymers Using Gliding Assays
Department of Physics, Lawrence University
A method to measure the persistence length or flexural rigidity of biopolymers is described. The method uses a kinesin-driven microtubule gliding assay to experimentally determine the persistence length of individual microtubules and is adaptable to actin-based gliding assays.
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 Immunology and Infection
Imaging of HIV-1 Envelope-induced Virological Synapse and Signaling on Synthetic Lipid Bilayers
1Department of Pathology, New York University Langone School of Medicine, 2Program in Molecular Pathogenesis, Marty and Helen Kimmel Center for Biology and Medicine and Skirball Institute for Biomolecular Medicine, 3Laboratory of Molecular Immunogenetics, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, 4Veteran Affairs New York Harbor Healthcare System
This article describes a method to visualize formation of an HIV-1 envelope-induced virological synapse on glass supported planar bilayers by total internal reflection fluorescence (TIRF) microscopy. The method can also be combined with immunofluorescence staining to detect activation and redistribution of signaling molecules that occur during HIV-1 envelope-induced virological synapse formation.
JoVE Neuroscience
Labeling F-actin Barbed Ends with Rhodamine-actin in Permeabilized Neuronal Growth Cones
Department of Neuroscience, University of Minnesota
A method to visualize and quantify F-actin barbed ends in neuronal growth cones is described. After culturing neurons on glass coverslips, cells are permeabilized with a saponin-containing solution. Then, a short incubation with the saponin buffer containing rhodamine-actin incorporates fluorescent actin onto free actin barbed ends.
JoVE Neuroscience
Nucleofection and Primary Culture of Embryonic Mouse Hippocampal and Cortical Neurons
Department of Anatomy, University of Wisconsin-Madison
This protocol outlines the steps required to dissect, transfect via electroporation and culture mouse hippocampal and cortical neurons. Short-term cultures may be used for studies of axon outgrowth and guidance, while long-term cultures can be used for studies of synaptogenesis and dendritic spine analysis.
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 General
Multicolor Time-lapse Imaging of Transgenic Zebrafish: Visualizing Retinal Stem Cells Activated by Targeted Neuronal Cell Ablation
Department of Cellular Biology and Anatomy, Medical College of Georgia
In this video, techniques for multicolor confocal time-lapse imaging and targeted cell ablation are provided. Time-lapse imaging is used to monitor the behavior of multiple cell types of interest in vivo. Targeted cell ablation facilitates the study neural circuit function and cell-specific neuronal regeneration paradigms.
JoVE General
Live Imaging of Cell Extrusion from the Epidermis of Developing Zebrafish
Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah
Dying cells are extruded from epithelial tissues by concerted contraction of neighboring cells without disrupting barrier function. The optical clarity of developing zebrafish provides an excellent system to visualize extrusion in living epithelia. Here we describe methods to induce and image extrusion in the larval zebrafish epidermis at cellular resolution.
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 General
Live Imaging of Cell Motility and Actin Cytoskeleton of Individual Neurons and Neural Crest Cells in Zebrafish Embryos
1Genetics Training Program, University of Wisconsin-Madison, 2Department of Anatomy, University of Wisconsin-Madison, 3Department of Zoology, University of Wisconsin-Madison, 4Cell and Molecular Biology Training Program, University of Wisconsin-Madison
This protocol describes imaging of individual neurons or neural crest cells in living zebrafish embryos. This method is used to examine cellular behaviors and actin localization using fluorescence confocal time-lapse microscopy.
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 General
Correlative Light and Electron Microscopy (CLEM) as a Tool to Visualize Microinjected Molecules and their Eukaryotic Sub-cellular Targets
Department of Molecular Microbiology, University of Texas Southwestern Medical Center
The CLEM technique has been adapted to analyze ultrastructural morphology of membranes, organelles, and subcellular structures affected by microinjected molecules. This method combines the powerful techniques of micromanipulation/microinjection, confocal fluorescent microscopy, and electron microscopy to allow millimeter to multi-nanometer resolution. This technique is amenable to a wide variety of applications.
JoVE Neuroscience
Isolation and Culture of Rat Embryonic Neural Cells: A Quick Protocol
1LSU Health Sciences Center - New Orleans, 2Medical School and Stanley S. Scott Cancer Center
We describe a rapid methodology to isolate and culture hippocampal and cortical neurons from rodent embryos. This protocol allows us to perform experiments in which nearly pure neuronal cultures are required.
JoVE General
Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations
Department of Hematology, Oncology and Stem Cell Transplantation, University Medical Center Freiburg
Metaphase to anaphase transition is triggered through anaphase-promoting complex (APC/C)-dependent ubiquitination and subsequent destruction of cyclin B. Here, we established a system which, following pulse-chase labeling, allows monitoring cyclin B proteolysis in entire cell populations and facilitates the detection of interference by the mitotic checkpoint.
JoVE General
A Protocol for the Production of KLRG1 Tetramer
Department of Molecular Microbiology and Immunology, Brown University
This protocol describes the production of KLRG1 tetramer, which is a powerful tool for the analysis of KLRG1 ligands.
JoVE Neuroscience
Preparation of Mouse Brain Tissue for Immunoelectron Microscopy
1Department of Neurobiology and Anatomy, University of Rochester, 2Douglas Mental Health University Institute
We describe a protocol for transcardiac perfusion of mice, removal and sectioning of the brain, as well as immunoperoxidase staining, resin embedding, and ultrathin sectioning of the brain sections. Upon completion of these procedures, the immunostained material is ready for examination with transmission electron microscopy.
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
An In Vitro System to Study Tumor Dormancy and the Switch to Metastatic Growth
1Department of Biology, University of Haifa, 2Transgenic Oncogenesis and Genomics Section, Laboratory of Cancer Biology and Genetics, National Cancer Institute
A modified 3-D in vitro system is presented in which growth characteristics of several tumor cell lines in reconstituted basement membrane correlate with the dormant or proliferative behavior of the tumor cells at a metastatic secondary site in vivo.
JoVE Bioengineering
Axon Stretch Growth: The Mechanotransduction of Neuronal Growth
1Departments of Biomedical Engineering, New Jersey Institute of Technology, 2Graduate School of Biomedical Sciences, University of Medicine and Dentistry of New Jersey
A unique tissue engineering method was developed to elongate numerous nerve fibers in culture by recapitulating axon stretch growth; a form of nervous system growth whereby nerves elongate in conjunction with growth of the enlarging body.
JoVE General
Antifouling Self-assembled Monolayers on Microelectrodes for Patterning Biomolecules
1Department of Physics, Texas A&M University (TAMU), 2Department of Biomedical Engineering, Texas A&M University (TAMU)
We present a procedure for forming a poly(ethylene glycol) self-assembled monolayer (PEG-SAM) on a silicon substrate with gold microelectrodes. The PEG-SAM is formed in a single step and prevents biofouling on silicon and gold surfaces. Electrophoresis is then used for patterning biomolecules down to the nanoscale.
JoVE General
Live Imaging of Glial Cell Migration in the Drosophila Eye Imaginal Disc
Department of Zoology, University of British Columbia - UBC
Here we describe a protocol to examine the migration of glial cells into the developing Drosophila eye using live microscopic analysis paired with GFP tagged glial cells.
JoVE General
Preparation of Adult Drosophila Eyes for Thin Sectioning and Microscopic Analysis
Department of Developmental and Molecular Biology, Albert Einstein College of Medicine
A standard approach to prepare adult Drosophila eyes for semi-thin sectioning and light microscopic analysis is presented here. The protocol can be used for gross morphological analysis of eye defects, or with the indicated adjustments can be used to determine genetic requirements of genes in specific cell types of the eye (e.g. clonal analysis of photoreceptors) or for electron microscopic analysis.
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 Immunology and Infection
Facilitating Drug Discovery: An Automated High-content Inflammation Assay in Zebrafish
1Institute for Toxicology and Genetics, Karlsruhe Institute of Technology, Karlsruhe, Germany, 2Institute for Applied Informatics, Karlsruhe Institute of Technology, Karlsruhe, Germany
Here we describe a novel high-content chemically induced inflammation assay aiming at the identification of immune-modulatory bioactives. We have successfully combined automated microscopy with custom developed software scripts enabling automated quantification of the inflammatory response as well as further data processing, analysis, mining, and storage.
JoVE General
Monitoring Actin Disassembly with Time-lapse Microscopy
Dept. of Systems Biology, Harvard Medical School
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
Preparing Individual Drosophila Egg Chambers for Live Imaging
Department of Biochemistry, University of Oxford
The Drosophila egg chamber is an excellent model for studying the mechanisms of mRNA localization. In order to capture the dynamic events that underpin the processes of localization, rapid high resolution imaging of live tissue is required. Here, we present a protocol for dissection and imaging of live samples with minimal disruption.
JoVE Neuroscience
Mechanical Manipulation of Neurons to Control Axonal Development
Department of Zoology, Michigan State University, East Lansing
Application and direct measurements of forces on neurons in the 2-1000 microdyne range are achieved with high precision using calibrated glass needles. This methodology can be used to control and measure several aspects of axonal development, including axonal initiation, axonal tension, velocity of axonal elongation, and force vectors.
JoVE Neuroscience
Immunohistological Labeling of Microtubules in Sensory Neuron Dendrites, Tracheae, and Muscles in the Drosophila Larva Body Wall
1Disease Mechanism Research Core, RIKEN Brain Science Institute, 2Graduate School of Science and Engineering, Saitama University
To understand how complex cell shapes, such as neuronal dendrites, are achieved during development, it is important to be able to accurately assay microtubule organization. Here we describe a robust immunohistological labeling method to examine microtubule organization of dendritic arborization neuron sensory dendrites, trachea, muscle, and other Drosophila larva body wall tissues.
JoVE Clinical and Translational Medicine
Three-dimensional Imaging of Nociceptive Intraepidermal Nerve Fibers in Human Skin Biopsies
1Department of Neurology, University of Michigan, 2Department of Internal Medicine, University of Michigan
In order to study the changes of nociceptive intraepidermal nerve fibers (IENFs) in painful neuropathies (PN), we developed protocols that could directly examine three-dimensional morphological changes observed in nociceptive IENFs. Three-dimensional analysis of IENFs has the potential to evaluate the morphological changes of IENF in PN.
JoVE Neuroscience
Generation of an Immortalized Murine Brain Microvascular Endothelial Cell Line as an In Vitro Blood Brain Barrier Model
Klinik und Poliklinik für Anästhesiologie, University of Wurzburg
This method describes how to isolate and immortalize microvascular endothelial cells from mouse brain. We describe a step-by-step protocol starting from the homogenization of brain tissue, digestion steps, seeding and immortalization of the cells. Usually, it takes about five weeks to obtain a homogenous, immortalized microvascular endothelial cell line.
JoVE General
In vivo and in vitro Studies of Adaptor-clathrin Interaction
Department of Biochemistry and Molecular Biology, Colorado State University
Clathrin-mediated endocytosis depends on adaptor proteins that coordinate cargo selection and clathrin coat assembly. Here we describe procedures to study adaptor-clathrin physical interaction and live cell imaging approaches using as a model the yeast endocytic adaptor protein Sla1p.
JoVE Clinical and Translational Medicine
Evaluation of Cancer Stem Cell Migration Using Compartmentalizing Microfluidic Devices and Live Cell Imaging
1Department of Biomedical Engineering, University of Wisconsin-Madison, 2Materials Science Program, University of Wisconsin-Madison, 3Department of Neurological Surgery, University of Wisconsin-Madison, 4Carbone Comprehensive Cancer Center and Center for Stem Cell and Regenerative Medicine, University of Wisconsin-Madison
A compartmentalizing microfluidic device for investigating cancer stem cell migration is described. This novel platform creates a viable cellular microenvironment and enables microscopic visualization of live cell locomotion. Highly motile cancer cells are isolated to study molecular mechanisms of aggressive infiltration, potentially leading to more effective future therapies.
JoVE General
Protein Membrane Overlay Assay: A Protocol to Test Interaction Between Soluble and Insoluble Proteins in vitro
Department of Biochemistry and Cell Biology, State University of New York
Testing protein-protein interaction is indispensable for dissection of protein functionality. Here, we introduce an in vitro protein-protein binding assay to probe a membrane-immobilized protein with a soluble protein. This assay provides a reliable method to test interaction between an insoluble protein and a protein in solution.
JoVE General
Cargo Loading onto Kinesin Powered Molecular Shuttles
1Department of Materials Science and Engineering, University of Florida, 2Department of Biomedical Engineering, Columbia University
Molecular shuttles consisting of functionalized microtubules gliding on surface-adhered kinesin motor proteins can serve as a nanoscale transport system. Here, the assembly of a typical shuttle system is described.
JoVE General
Live Imaging of Dense-core Vesicles in Primary Cultured Hippocampal Neurons
Department of Biological Sciences, Simon Fraser University
Live cell imaging is of particular utility when studying the dynamics of organelle trafficking. Here we describe a protocol for live imaging of dense-core vesicles in cultured neurons using wide-field fluorescence microscopy. This protocol is flexible and can be adapted to image other organelles such as mitochondria, endosomes, and peroxisomes.
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