JoVE Bioengineering
An Experimental System to Study Mechanotransduction in Fetal Lung Cells
Women & Infants Hospital of Rhode Island, Alpert Medical School of Brown University
Mechanical forces play a key role in lung development and lung injury. Here, we describe a method to isolate rodent fetal lung type II epithelial cells and fibroblasts and to expose them to mechanical stimulation using an in vitro system.
JoVE General
Mechanical Stimulation of Stem Cells Using Cyclic Uniaxial Strain
Department of Bioengineering, University of California, Berkeley
It is widely understood that mechanical forces in the body can influence cell differentiation and proliferation. Here we present a video protocol demonstrating the use of a custom-built bioreactor for delivering uniaxial cyclic tensile strain to stem cells cultured on flexible micropatterned substrates.
JoVE Bioengineering
Mechanical Testing of Mouse Carotid Arteries: from Newborn to Adult
Department of Biomedical Engineering, Saint Louis University
Passive mechanical testing of mouse carotid arteries is described, with special consideration for adapting to different specimen ages. The procedures include determining the in vivo length of the artery, mounting it in a pressure myograph, recording data, measuring the unloaded dimensions and analyzing the resulting data.
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 Bioengineering
Stretching Short Sequences of DNA with Constant Force Axial Optical Tweezers
1LSA Biophysics, University of Michigan, 2LSA Biophysics, Department of Physics, University of Michigan
We illustrate the use of a constant force axial optical tweezers to explore the mechanical properties of short DNA molecules. By stretching DNA axially, we minimize steric hindrances and artifacts arising in conventional lateral manipulation, allowing us to study DNA molecules as short as ~100 nm.
JoVE Neuroscience
Muscle Receptor Organs in the Crayfish Abdomen: A Student Laboratory Exercise in Proprioception
Department of Biology, University of Kentucky
The primary purpose of this experiment is to understand how primary sensory neurons convey information of joint movements and positions as proprioceptive information for an animal. An additional objective of this report is present the anatomy of the preparation by dissection and viewing of neurons under a dissecting microscope.
JoVE General
Evaluation of Muscle Function of the Extensor Digitorum Longus Muscle Ex vivo and Tibialis Anterior Muscle In situ in Mice
Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri
Changes in limb muscle contractile and passive mechanical properties are important biomarkers for muscle diseases. This manuscript describes physiological assays to measure these properties in the murine extensor digitorum longus and tibialis anterior muscles.
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 General
Preparation of Rat Tail Tendons for Biomechanical and Mechanobiological Studies
Groupe PERSEUS, Faculté de Génie Département de génie mécanique, Université de Sherbrooke
This article describes the experimental procedures used to prepare rat tail tendons for biomechanical and mechanobiological studies. Several features of the main steps in preparation are demonstrated, beginning with extraction, cross-sectional area measurement, rinsing and loading into the bioreactor chamber.
JoVE Bioengineering
Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves
Department of Agricultural and Biological Engineering, Mississippi State University
A cyclic pressure bioreactor capable of subjecting heart valve tissue to physiological and pathological pressure conditions has been designed. A LabVIEW program allows users to control pressure magnitude, amplitude and frequency. This device can be used to study the mechanobiology of heart valve tissue or isolated cells.
JoVE Bioengineering
Impulsive Pressurization of Neuronal Cells for Traumatic Brain Injury Study
Department of Engineering Mechanics, University of Nebraska-Lincoln
A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate the molecular/cellular mechanisms of blast-induced traumatic brain injury.
JoVE Bioengineering
Elastomeric PGS Scaffolds in Arterial Tissue Engineering
1Department of Bioengineering, University of Pittsburgh, 2McGowan Institute for Regenerative Medicine, University of Pittsburgh
Elastomeric PGS scaffolds with vascular smooth muscle cells cultured in a pulsatile flow bioreactor may lead to promising small-diameter arterial constructs with native ECM production in a relatively short culture period.
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
Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
1Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School, 2Muscle Biology Research Group, University of Missouri-Kansas City, 3Pharmacology division, College of Pharmacy, DHLRI, Ohio State University
We describe a method to directly measure muscle force, muscle power, contractile kinetics and fatigability of isolated skeletal muscles in an in vitro system using field stimulation. Valuable information on Ca2+ handling properties and contractile machinery of the muscle can be obtained using different stimulating protocols.
JoVE Bioengineering
Quantitative Locomotion Study of Freely Swimming Micro-organisms Using Laser Diffraction
1Physics & Astronomy Department, Vassar College, 2Biology Department, Vassar College
Microscopic organisms like the free-swimming nematode C. elegans, live and behave in a complex three-dimensional environment. We report on a novel approach that provides analysis of C. elegans using diffraction patterns. This approach consists of tracking the temporal periodicity of diffraction patterns generated by directing laser light through a cuvette.
JoVE General
Mouse Islet of Langerhans Isolation using a Combination of Purified Collagenase and Neutral Protease
1Department of Pediatrics and the Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, 2VITACYTE, LLC, 3Department of Medicine, Indiana University School of Medicine, 4Department of Cellular and Integrative Physiology, Indiana University School of Medicine
A detailed description of mouse islet isolation is described using the technique of in situ pancreatic ductal cannulation and perfusion of a combination of purified collagenase and neutral protease.
JoVE Clinical and Translational Medicine
Functional Assessment of Intestinal Motility and Gut Wall Inflammation in Rodents: Analyses in a Standardized Model of Intestinal Manipulation
Department of Surgery, University of Bonn
Postoperative ileus (POI) is a complication of abdominal surgery leading to increased morbidity and a prolonged hospital stay. Because prophylactic or therapeutic strategies are lacking intensified research is necessary. Therefore we established a standardized and feasible mouse model to investigate the pathophysiology of POI and to study potential therapeutic options.
JoVE Neuroscience
Preterm EEG: A Multimodal Neurophysiological Protocol
1Department of Children's Clinical Neurophysiology, Helsinki University Hospital, University of Helsinki, 2Department of Biosciences, University of Helsinki, 3Department of Pediatrics, Helsinki University Hospital, University of Helsinki, 4Neuroscience Center, University of Helsinki
This video explains the background theory of the neonatal EEG activity and the sensory responses, followed by a live demonstration of their recording in neonatal intensive care unit.
JoVE Clinical and Translational Medicine
Fixed Volume or Fixed Pressure: A Murine Model of Hemorrhagic Shock
Department of Surgery, University of Pittsburgh
The Hemorrhagic Shock model has been a reliable and reproducible resource facilitating the identification and understanding of signaling cascades associated with inflammation and end-organ damage after trauma. This article provides a step-by-step description of surgical and mechanical aspects associated with the Hemorrhagic Shock experimental procedure in mice.
JoVE Neuroscience
Visualization of Proprioceptors in Drosophila Larvae and Pupae
A method to immunostain and visualize chordotonal organs in larvae and pupae of Drosophila melanogaster is described.
JoVE Bioengineering
Multiplexed Single-molecule Force Proteolysis Measurements Using Magnetic Tweezers
Department of Chemical Engineering, Stanford University
In this article we describe the use of magnetic tweezers to study the effect of force on enzymatic proteolysis at the single molecule level in a highly parallelizable manner.
JoVE Bioengineering
Synthetic Spider Silk Production on a Laboratory Scale
Department of Biological Sciences, University of the Pacific
Despite the outstanding mechanical and biochemical properties of spider silks, this material cannot be harvested in large quantities by conventional means. Here we describe an efficient strategy to spin artificial spider silk fibers, which is an important process for investigators studying spider silk production and their use as next-generation biomaterials.
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 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 General
Direct Observation of Enzymes Replicating DNA Using a Single-molecule DNA Stretching Assay
We describe a method for observing real time replication of individual DNA molecules mediated by proteins of the bacteriophage replication system.
JoVE Immunology and Infection
Use of an Optical Trap for Study of Host-Pathogen Interactions for Dynamic Live Cell Imaging
1Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, 2Department of Mechanical and Aerospace Engineering, The Ohio State University, 3Center for Computational and Integrative Biology, Massachusetts General Hospital, Harvard Medical School, 4Dept. of Chemical and Biomolecular Engineering, Vanderbilt University
A method is described to individually select, manipulate, and image live pathogens using an optical trap coupled to a spinning disk microscope. The optical trap provides spatial and temporal control of organisms and places them adjacent to host cells. Fluorescence microscopy captures dynamic intercellular interactions with minimal perturbation to cells.
JoVE Applied Physics
Concurrent Quantitative Conductivity and Mechanical Properties Measurements of Organic Photovoltaic Materials using AFM
1Center for Nanoscale Materials, Argonne National Laboratory, 2Institute for Molecular Engineering, University of Chicago
Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution.
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 General
A Practical and Novel Method to Extract Genomic DNA from Blood Collection Kits for Plasma Protein Preservation
1Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Emory University School of Medicine and Children's Health Care of Atlanta, 2Division of Rheumatology, Department of Pediatrics, Emory University School of Medicine and Children's Health Care of Atlanta
We are describing a new method of isolating genomic DNA from whole blood collected for plasma/serology. After plasma collection, the compacted blood is usually discarded. Our novel method represents a significant improvement over existing methods and makes DNA and plasma available from a single collection, without requesting additional blood.
JoVE Applied Physics
Fabricating Metamaterials Using the Fiber Drawing Method
Institute of Photonics and Optical Sciences (IPOS), School of Physics, University of Sydney
Metamaterials at terahertz frequencies offer unique opportunities, but are challenging to fabricate in bulk. We adapt the fabrication procedure for microstructured polymer optical fibers to inexpensively fabricate metamaterials potentially on an industrial scale. We produce polymethylmethacrylate fibers containing ~10 μm diameter indium wires separated by ~100 μm, which exhibit a terahertz plasmonic response.
JoVE Bioengineering
Design of a Biaxial Mechanical Loading Bioreactor for Tissue Engineering
1Department of Orthopaedics, The Warren Alpert Brown Medical School of Brown University and the Rhode Island Hospital, 2Center for Restorative and Regenerative Medicine, VA Medical Center, Providence, RI, 3University of Texas Southwestern Medical Center
We designed a novel mechanical loading bioreactor that can apply uniaxial or biaxial mechanical strain to a cartilage biocomposite prior to transplantation into an articular cartilage defect.
JoVE General
Mechanical Stimulation of Chondrocyte-agarose Hydrogels
1Department of Mechanical and Materials Engineering, Queen's University, 2Department of Chemical Engineering, Queen's University
The biosynthesis of cartilaginous extracellular matrix by chondrocytes can be affected by application of mechanical stimuli. This method describes the technique of applying dynamic compressive strains to chondrocytes encapsulated in 3D constructs and the evaluation of induced changes in chondrocyte metabolism.
JoVE General
Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation
1Institute for Biological Interfaces, Karlsruhe Research Centre, 2Institute for BioMedical Technology, University of Twente, 3Department of Materials Research, Institute for Heavy Ion Research, 4Institute of Microstructure Technology, Karlsruhe Research Centre, 5Institute for Micro Process Engineering, Karlsruhe Research Centre
We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.
JoVE Clinical and Translational Medicine
The C-seal: A Biofragmentable Drain Protecting the Stapled Colorectal Anastomosis from Leakage
Department of Surgery, Division of Abdominal Surgery, University Medical Center Groningen
The C-seal is a biofragmentable drain protecting the stapled colorectal anastomosis. In this video, details of the manufacturing, deployment and use are shown.
JoVE Bioengineering
Magnetic Resonance Elastography Methodology for the Evaluation of Tissue Engineered Construct Growth
1Department of Biological Systems Engineering, University of Nebraska-Lincoln, 2Department of Engineering Mechanics, University of Nebraska-Lincoln
The procedure demonstrates the methodology of magnetic resonance elastography for monitoring the engineered outcome of adipose and osteogenic tissue engineered constructs through noninvasive local assessment of the mechanical properties using microscopic magnetic resonance elastography (μMRE).
JoVE Clinical and Translational Medicine
Chronic Constriction of the Sciatic Nerve and Pain Hypersensitivity Testing in Rats
School of Medical Sciences, University of New South Wales
Due to the simplicity of surgery and the robust behavioural outcome, chronic constriction of the sciatic nerve is one of the pre-eminent animal models of neuropathic pain. Within 24 hrs following surgery, pain hypersensitivity is established and can be quantitatively measured using a von Frey aesthesiometer (mechanical test) and plantar analgesia meter (thermal test).
JoVE Clinical and Translational Medicine
Generation of Alginate Microspheres for Biomedical Applications
1Department of Chemical and Biological Engineering, Illinois Institute of Technology, 2Department of Biomedical Engineering, Illinois Institute of Technology, 3Department of Biomedical Engineering, University of California at Irvine, 4Wake Forest Institute for Regenerative Medicine and Department of Biomedical Engineering, Wake Forest University Health Sciences, 5Research Service, Hines Veterans Administration Hospital
In the following sections, we outline procedures for the preparation of alginate microspheres for use in biomedical applications. We specifically illustrate a technique for creating multilayered alginate microspheres for the dual purpose of cell and protein encapsulation as a potential treatment for type 1 diabetes.
JoVE General
Determining heat and mechanical pain threshold in inflamed skin of human subjects
Department of Anesthesia, Stanford University School of Medicine
Algorithms assessing heat and mechanical pain thresholds in experimentally inflamed skin of human study subjects are shown. The two pain testing paradigms independently examine nociceptive processing by the two major peripheral nerve fiber populations transmitting pain, i.e., non-myelinated C fibers and small myelinated A-delta fibers.
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.
JoVE General
Changes in Mammary Gland Morphology and Breast Cancer Risk in Rats
1Department of Oncology, Georgetown University, 2Institute of Biomedicine, University of Turku Medical Faculty
Our protocol describes how to dissect the rat abdominal mammary gland and how to prepare mammary gland whole mounts. It also describes how to analyze mammary gland morphology using three end-points (number of terminal end buds, epithelial elongation and differentiation) and to use these results to predict mammary cancer risk in rats which were exposed to dietary modifications in utero or during prepuberty.
JoVE Clinical and Translational Medicine
High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Center for Arrhythmia Research. Internal Medicine, University of Michigan
This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation.
JoVE General
Drosophila Larval NMJ Dissection
This protocol demonstrates how to dissect Drosophila larvae in preparation for immunohistochemistry and/or imaging of the neuromuscular junction.
JoVE Immunology and Infection
Measurement of Tactile Allodynia in a Murine Model of Bacterial Prostatitis
Department of Urology, Northwestern University Feinberg School of Medicine
Infection of the prostate may be a contributing factor in mediating pelvic pain in chronic prostatitis. We describe the procedure for preparation of standardized bacterial inoculum, instillation of bacteria into the urethra of male mice and methodology for measuring tactile allodynia in mice over time.
JoVE Bioengineering
Introduction to the Ultrasound Targeted Microbubble Destruction Technique
Department of Medicine, JABSOM, University of Hawaii
Ultrasound Targeted Microbubble Destruction (UTMD) can be used to direct site-specific delivery of bioactive molecules, including therapeutic genes, to target organs accessible to ultrasound, such as the heart and liver1-6.
JoVE General
High-throughput Physical Mapping of Chromosomes using Automated in situ Hybridization
Department of Entomology, Virginia Tech
Genome assemblies based on massively parallel DNA sequencing technologies are usually highly fragmented. The development of physical chromosome maps can potentially improve genome assemblies. Here, we demonstrate innovative approaches to chromosome preparation, fluorescent in situ hybridization, and imaging that significantly increase throughput of the physical map development.
JoVE General
Differential Imaging of Biological Structures with Doubly-resonant Coherent Anti-stokes Raman Scattering (CARS)
1Center for Biophotonics, University of California, Davis, 2Department of Internal Medicine, University of California, Davis
A combination of three single wavelength short-pulsed lasers is used to generate coherent anti-Stokes Raman scattering (CARS) and doubly-resonant CARS (DR-CARS). The difference between these signals provides enhanced sensitivity for otherwise difficult to detect coherent Raman signals, enabling imaging of weak Raman scatterers.
JoVE Clinical and Translational Medicine
Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI
1Sensory Motor Performance Program, Rehabilitation Institute of Chicago, 2Department of Kinesiology and Nutrition, University of Illinois at Chicago, 3Department of Physical Therapy, University of Illinois at Chicago
This video demonstrates modulation of reflex activity, volitional strength and ambulation through clinical and quantitative assessments in individuals with motor incomplete SCI as a result of acute oral administration of a serotonin reuptake inhibitor (SSRI).
JoVE Editorial
July 2012: This Month in JoVE
1JoVE Content Production, 2Department of Ophthalmology, Massachusetts Eye and Ear
Historically, JoVE, The Journal of Visualized Experiments, has focused primarily on biomedical research and has developed subsections for Bioengineering, Clinical and Translational Medicine, Immunology and Infection, and Neuroscience. This July, JoVE launches its Applied Physics section, which includes a range of content from Plasma Physics to Materials Science. We begin the new section with a notable article from Purdue University, where researchers in the Center for Laser-Based Manufacturing are studying.
JoVE Clinical and Translational Medicine
Patient Derived Cell Culture and Isolation of CD133+ Putative Cancer Stem Cells from Melanoma
1Institute of Pathology, Laboratory of Molecular Tumor Pathology, Charité - Universitätsmedizin Berlin, 2Institute for Chemistry and Biochemistry, Free University Berlin, 3Laboratory for Functional Genomics Charité (LFGC), Charité - Universitätsmedizin Berlin, 4Comprehensive Cancer Center Charité, Charité - Universitätsmedizin Berlin
This article describes the preparation of freshly obtained melanoma tissue into primary cell cultures, and how to remove contaminations of erythrocytes and fibroblasts from the tumor cells. Finally, we describe how CD133+ putative melanoma stem cells are sorted from the CD133- bulk using Magnetic Activated Cell Sorting (MACS).
JoVE Application Notes
CryoStor Cryopreservation Protocol - ADVERTISEMENT
BioLife Solutions, Inc.
CryoStor cryopreservation solutions are used to prepare and preserve cells in ultra low temperature environments, without the need for serum, proteins, or high levels of cytotoxic agents.
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