JoVE General
Use of Arabidopsis eceriferum Mutants to Explore Plant Cuticle Biosynthesis
1Department of Botany, University of British Columbia - UBC, 2Department of Chemistry, University of British Columbia - UBC
The plant cuticle is a waxy outer covering on plants that has a primary role in water conservation but is also an important barrier against the entry of pathogenic microorganisms. In this video, we demonstrate the analysis of plant cuticle mutants identified by forward and reverse genetics approaches.
JoVE Applied Physics
Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments
1Materials Science Division, Argonne National Laboratory, 2Energy Systems Division, Argonne National Laboratory, 3MassThink LLC
White light microscope interferometry is an optical, noncontact and quick method for measuring the topography of surfaces. It is shown how the method can be applied toward mechanical wear analysis, where wear scars on tribological test samples are analyzed; and in materials science to determine ion beam sputtering or laser ablation volumes and depths.
JoVE Neuroscience
VisioTracker, an Innovative Automated Approach to Oculomotor Analysis
1Institute of Molecular Life Sciences, University of Zurich, 2TSE Systems GmbH
The VisioTracker is an automated system for the quantitative analysis of visual performance of larval and small adult fish based on the recording of eye movements. It features full control over visual stimulus properties and real-time analysis, enabling high-throughput research in fields such as visual system development and function, pharmacology, neural circuit studies and sensorimotor integration.
JoVE Clinical and Translational Medicine
A Human Fallopian Tube Model for Investigation of C. trachomatis Infections
1Institute of Medical Microbiology and Hygiene, University of Lübeck, 2Institute of Anatomie, University of Lübeck, 3Department of Obstetrics and Gynecology, University Hospital of Schleswig-Holstein, University of Lübeck, 4Medical Clinic III, University Hospital of Schleswig-Holstein, University of Lübeck
We describe an ex vivo infection model for visualisation of direct interactions from bacterial pathogens with human fallopian tube cells. The whole organ tissue model was established to investigate C. trachomatis induced pathology to the female fallopian tube under "life-like" conditions.
JoVE Bioengineering
Planar and Three-Dimensional Printing of Conductive Inks
1Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 2Center for Micro- and Nanotechnology, Lawrence Livermore National Laboratory, 3Presently at the Interdisciplinary Center for Wide Band-gap Semiconductors, University Of California Santa Barbara
Planar and three-dimensional printing of conductive metallic inks is described. Our approach provides new avenues for fabricating printed electronic, optoelectronic, and biomedical devices in unusual layouts at the microscale.
JoVE General
Purification of Mitochondria from Yeast Cells
Department of Biology, Concordia University
We describe a rapid and effective method for purification of mitochondria from the yeast Saccharomyces cerevisiae. This method enables the high-yield isolation of pure mitochondria that are essentially free of contamination by other organelles and retain their structural and functional integrity after their purification.
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 Clinical and Translational Medicine
Intraoperative Detection of Subtle Endometriosis: A Novel Paradigm for Detection and Treatment of Pelvic Pain Associated with the Loss of Peritoneal Integrity
1Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Greenville Hospital System, 2Department of Pathology, Duke University Health System, 3Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Duke University
Loss of peritoneal integrity provides a new paradigm to understand and treat chronic pelvic pain in women with mild forms of endometriosis and can be easily detected using intraoperative instillation of dye at the time of laparoscopy.
JoVE Immunology and Infection
Neutrophil Extracellular Traps: How to Generate and Visualize Them
1Core Facility Microscopy, Max Planck Institute for Infection Biology, 2Cellular Microbiology, Max Planck Institute for Infection Biology
Neutrophil Extracellular Traps (NETs) are an important innate immune mechanism to fight pathogenic bacteria, fungi and parasites. Here we describe methods to isolate neutrophil granulocytes from human blood and to activate them to form NETs. We present preparation techniques to visualize NETs in light and electron microscopy.
JoVE Applied Physics
Atom Probe Tomography Studies on the Cu(In,Ga)Se2 Grain Boundaries
1Department of Microstructure Physics and Alloy Design, Max-Planck-Institut für Eisenforschung GmbH, 2Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg ( ZSW )
In this work, we describe the use of the atom-probe tomography technique for studying the grain boundaries of the absorber layer in a CIGS solar cell. A novel approach to prepare the atom probe tips containing the desired grain boundary with a known structure is also presented here.
JoVE Bioengineering
Air Filter Devices Including Nonwoven Meshes of Electrospun Recombinant Spider Silk Proteins
Biomaterials Research Group, University of Bayreuth
Spider silk fibers display extraordinary mechanical properties. Engineered Araneus diadematus Fibroin 4 (eADF4) can be processed into nonwoven meshes using electrospinning. Here, the eADF4 nonwoven meshes are used to improve the performance of air filtering devices.
JoVE Bioengineering
Soft Lithographic Functionalization and Patterning Oxide-free Silicon and Germanium
1Department of Chemistry, Duke University, 2Hajim School of Engineering and Applied Sciences, University of Rochester, 3Department of Chemical Engineering, University of Rochester
Here we describe a simple method for patterning oxide-free silicon and germanium with reactive organic monolayers and demonstrate functionalization of the patterned substrates with small molecules and proteins. The approach completely protects surfaces from chemical oxidation, provides precise control over feature morphology, and provides ready access to chemically discriminated patterns.
JoVE Bioengineering
Ex vivo Mimicry of Normal and Abnormal Human Hematopoiesis
1Department of Chemical Engineering and Chemical Technology, South Kensington campus, Imperial College London, 2Department of Hematology, Northwick Park & St. Mark's campus, Imperial College London
A 3D culture system for hematopoiesis is described using human cord blood and leukemic bone marrow cells. The method is based on the use of a porous synthetic polyurethane scaffold coated with extracellular matrix proteins. This scaffold is adaptable to accommodate a wide range of cells.
JoVE Neuroscience
Methods for Intravenous Self Administration in a Mouse Model
Addictions Unit, McGill University Health Centre
The intravenous self-administration (IVSA) paradigm is considered to be the gold standard in examining the reinforcing properties of drugs of abuse in rodents. This manuscript outlines the experimental procedures and surgical techniques necessary to obtain reliable IVSA data. In particular, meticulous catheter implantation and maintenance are highlighted.
JoVE General
Metabolic Profile Analysis of Zebrafish Embryos
Zebrafish represent a powerful vertebrate model that has been under-utilised for metabolic studies. Here we describe a rapid way to measure the in vivo metabolic profile of developing zebrafish that allows the comparison of different mitochondrial function parameters between genetically or pharmacologically manipulated embryos, thereby increasing the applicability of this organism.
JoVE Applied Physics
A Method to Fabricate Disconnected Silver Nanostructures in 3D
1School of Engineering and Applied Sciences, Harvard University, 2Department of Physics, Harvard University
Femtosecond-laser direct-writing is frequently used to create three-dimensional (3D) patterns in polymers and glasses. However, patterning metals in 3D remains a challenge. We describe a method for fabricating silver nanostructures embedded inside a polymer matrix using a femtosecond laser centered at 800 nm.
JoVE Immunology and Infection
Quantitative Assessment of Immune Cells in the Injured Spinal Cord Tissue by Flow Cytometry: a Novel Use for a Cell Purification Method
1Institute for Memory Impairments and Neurological Disorders, University of California, 2Physical Medicine & Rehabilitation, University of California, 3Anatomy & Neurobiology, University of California, 4Sue and Bill Gross Stem Cell Research Center, University of California, 5Section of Molecular Biology, University of California, 6Reeve-Irvine Research Center, University of California
Quantification of cellular inflammation in the injured/pathological CNS by flow cytometry is complicated by lipid/myelin debris that can have similar size and granulation to cells, decreasing sensitivity/accuracy. We have advanced a cell preparation method to remove myelin debris and improve cell detection by flow cytometry in the injured spinal cord.
JoVE Bioengineering
Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation
1Electrical Engineering Department, University of Washington, 2Division of Human Biology, Fred Hutchinson Cancer Research Center, 3Molecular and Cellular Biology Program, University of Washington, 4Clinical Research, Fred Hutchinson Cancer Research Center, 5Public Health Sciences, Fred Hutchinson Cancer Research Center
Plasmonic tweezers and photonic crystal nanostructures are shown to produce useful enhancements in the efficiency and orientation control of optically trapping micro- and nano-particles.
JoVE Bioengineering
Simultaneous Synthesis of Single-walled Carbon Nanotubes and Graphene in a Magnetically-enhanced Arc Plasma
Department of Mechanical and Aerospace Engineering, The George Washington University
Anodic arc discharge is one of the most practical and efficient methods to synthesize various carbon nanostructures. To increase the arc controllability and flexibility, a non-uniform magnetic field was introduced to process the one-step synthesis of large-scale graphene flakes and high-purity single-walled carbon nanotubes.
JoVE Clinical and Translational Medicine
Roux-en-Y Gastric Bypass Operation in Rats
1Department of Surgery, University Hospital Zürich, 2Zürich Centre for Integrative Human Physiology, University of Zürich, 3Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 4Imperial Weight Centre, Department of Investigative Medicine, Imperial College London
Numerous studies using gastric bypass rat models have been recently conducted to uncover the underlying physiological mechanisms of Roux-en-Y gastric bypass operations. This article aims to demonstrate and discuss the technical and experimental details of our published gastric bypass rat model to understand advantages and limitations of this experimental tool.
JoVE General
Nano-fEM: Protein Localization Using Photo-activated Localization Microscopy and Electron Microscopy
Department of Biology, Howard Hughes Medical Institute, University of Utah
We describe a method to localize fluorescently tagged proteins in electron micrographs. Fluorescence is first localized using photo-activated localization microscopy on ultrathin sections. These images are then aligned to electron micrographs of the same section.
JoVE Clinical and Translational Medicine
Longitudinal Evaluation of Mouse Hind Limb Bone Loss After Spinal Cord Injury using Novel, in vivo, Methodology
A longitudinal examination of bone loss in the femurs and tibiae of adult mice was performed following spinal cord injury using sequential low-dose X-ray scans. Tibia bone loss was detected throughout the study, while bone loss in the femur was not detected until 40 days post injury.
JoVE General
Investigating Intestinal Inflammation in DSS-induced Model of IBD
Experimental models of inflammatory bowel disease have allowed us to examine the complex innate and adaptive immune responses associated with pathogenesis. Using histological scoring, quantification of pro-inflammatory cytokines and myeloperoxidase activity, one can begin to assess these responses seen in inflammatory bowel disease.
JoVE Neuroscience
Rapid Determination of the Thermal Nociceptive Threshold in Diabetic Rats
1Department of Pharmacology and Toxicology, Wright State University, 2Human Movement Laboratory, Universidade São Judas Tadeu
Here, we describe a rapid reliable and simple procedure to determine the lowest temperature at which rats or mice show nocifensive behavior, i.e. the thermal nociceptive threshold (TNT). This method applies a slowly increasing thermal stimulus allowing precise and reproducible estimation of TNTs with minimum, if any, stress to the animals.
JoVE Applied Physics
Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates
Mechanical and Aerospace Engineering, University of Texas at Arlington
A micropunching lithography approach is developed to generate micro- and submicron-patterns on top, sidewall and bottom surfaces of polymer substrates. It overcomes the obstacles of patterning conducting polymers and generating sidewall patterns. This method allows rapid fabrication of multiple features and is free of aggressive chemistry.
JoVE Applied Physics
Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition
1Department of Energy and NEMAS - Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, 2Center for Nano Science and Technology, Instituto Italiano di Tecnologia
We describe the experimental method to deposit nanostructured oxide thin films by nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas. By using this method Al-doped ZnO (AZO) films, from compact to hierarchically structured as nano-tree forests, can be deposited.
JoVE Bioengineering
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
1Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, 2Clinical Research Laboratory, 81st Medical Group, Keesler Air Force Base
Lytic phage biosensors and antibody beads are able to discriminate between methicillin resistant (MRSA) and sensitive staphylococcus bacteria. The phages were immobilized by a Langmuir-Blodgett method onto a surface of a quartz crystal microbalance sensor and worked as broad range staphylococcus probes. Antibody beads recognize MRSA.
JoVE Neuroscience
Preparation of Synaptoneurosomes from Mouse Cortex using a Discontinuous Percoll-Sucrose Density Gradient
1Department of Pathology and Laboratory Medicine, Waisman Center for Developmental Disabilities, University of Wisconsin, 2Department of Biochemistry, Waisman Center for Developmental Disabilities, University of Wisconsin
A method to prepare translationally active, intact synaptoneurosomes (SNs) from mouse brain cortex is described. The method uses a discontinuous Percoll-sucrose density gradient allowing for the quick preparation of active SNs.
JoVE General
Electrospinning Fibrous Polymer Scaffolds for Tissue Engineering and Cell Culture
Department of Bioengineering, University of Pennsylvania
The process of electrospinning polymers for tissue engineering and cell culture is addressed in this article. Specifically, the electrospinning of photoreactive macromers with additional processing capabilities of photopatterning and multi-polymer electrospinning is described.
JoVE General
Procedure for Fabricating Biofunctional Nanofibers
1Department of Chemistry, Clark Atlanta University, 2Department of Physics, Clark Atlanta University, 3Department of Chemistry and Chemical Biology, Cornell University
An efficient approach for preparing nanofibers decorated with functional groups capable of specifically interacting with proteins is described. The approach first requires the preparation of a polymer functionalized with the appropriate functional group. The functional polymer is fabricated into nanofibers by electrospinning. The effectiveness of the binding of the nanofibers with a protein is studied by confocal microscopy.
JoVE Clinical and Translational Medicine
Repair of a Critical-sized Calvarial Defect Model Using Adipose-derived Stromal Cells Harvested from Lipoaspirate
1Department of Surgery, Stanford University, 2Department of Surgery, Duke University, 3Department of Surgery, Saint Joseph Mercy Hospital, 4School of Medicine, University of California, San Francisco, 5School of Dentistry, University of California, Los Angeles
This protocol describes the isolation of adipose-derived stromal cells from lipoaspirate and the creation of a 4 mm critical-sized calvarial defect to evaluate skeletal regeneration.
JoVE Clinical and Translational Medicine
Cardiac Stress Test Induced by Dobutamine and Monitored by Cardiac Catheterization in Mice
Instituto de Ciencias, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo
We describe the protocol to perform a cardiac stress test induced by dobutamine and monitored by cardiac catheterization in normal mice. Also we show its application to unmask subclinical cardiac disease in high fat diet-induced obese mice.
JoVE General
Isolation of Native Soil Microorganisms with Potential for Breaking Down Biodegradable Plastic Mulch Films Used in Agriculture
1Biology Department, Western Washington University, 2Washington State University Northwestern Research and Extension Center, 3Department of Plant and Soil Science, Texas Tech University
Plastic films labeled "biodegradable" are commercially available for agricultural use as mulches. Tillage represents an attractive disposal method, but degradation under field conditions is poorly understood. The purpose of this study was to develop methods for isolating native soil fungi and bacteria that colonize plastic mulch films after field burial.
JoVE General
Agar-Block Microcosms for Controlled Plant Tissue Decomposition by Aerobic Fungi
Department of Bioproducts and Biosystems Engineering, University of Minnesota
This video demonstrates a controlled environment approach to study degradation of lignocellulosic plant tissues by aerobic fungi. The ability to control nutrient sources and moisture is a key advantage of agar-block microcosms, but the approach often yields mixed success. We address critical pitfalls to yield reproducible, low-variability results.
JoVE Neuroscience
Assessment of Social Interaction Behaviors
1Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 2Toronto Centre for Phenogenomics, Mount Sinai Hospital, 3Department of Medical Biophysics, University of Toronto, 4Department of Psychology, University of Toronto, 5Department of Psychiatry, University of Toronto
Here we describe a detailed protocol for examination of sociability in mice by using Crawley's sociability and preference for social novelty test. We describe the advantages and possible applications for this procedure, including critical details important for correct interpretation of the results.
JoVE Neuroscience
Assaying β-amyloid Toxicity using a Transgenic C. elegans Model
1Institute for Behavioral Genetics, University of Colorado, 2Integrative Physiology, University of Colorado
The intensely studied nematode worm Caenorhabditis elegans can be transgenically engineered to express the human β-amyloid peptide (Aβ). Induced expression of Aβ in C. elegans muscle leads to a rapid, reproducible paralysis phenotype that can be used to monitor treatments that modulate Aβ toxicity.
JoVE Bioengineering
Therapeutic Gene Delivery and Transfection in Human Pancreatic Cancer Cells using Epidermal Growth Factor Receptor-targeted Gelatin Nanoparticles
Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University
Type B gelatin-based engineered nanovectors system (GENS) was developed for systemic gene delivery and transfection in the treatment of pancreatic cancer. By modification with epidermal growth factor receptor (EGFR) specific peptide on the surface of nanparticles, they could target on EGFR receptor and release plasmid under reducing environment, such as high intracellular glutathione concentrations.
JoVE Neuroscience
Ex Vivo Organotypic Corneal Model of Acute Epithelial Herpes Simplex Virus Type I Infection
Department of Biochemistry and Molecular Biology, Drexel University College of Medicine
In this video article we describe the use of a new ex vivo model of acute herpes simplex virus type I corneal epithelial infection.
JoVE Neuroscience
Progressive-ratio Responding for Palatable High-fat and High-sugar Food in Mice
CRCHUM and the Montreal Diabetes Research Center, University of Montreal
The present report details the protocol employed to measure the rewarding effects of high-fat food in mice using a progressive ratio operant conditioning task.
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 Immunology and Infection
Recurrent Herpetic Stromal Keratitis in Mice, a Model for Studying Human HSK
Department of Ophthalmology, Saint Louis University
Most studies of herpetic corneal disease use a primary infection model. However, primary infection with HSV-1 does not typically lead to human disease. Here we describe a recurrent model of herpetic corneal disease, which more closely mimics human disease.
JoVE Clinical and Translational Medicine
Modeling Intracerebral Hemorrhage in Mice: Injection of Autologous Blood or Bacterial Collagenase
1Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 2College of Natural and Agricultural Sciences, University of California, Riverside, 3Department of Anesthesiology, Loma Linda University School of Medicine, 4Department of Neurosurgery, Loma Linda University School of Medicine
Clinically relevant animal models of intracerebral hemorrhage (ICH) are needed to extend our knowledge of hemorrhagic stroke and to examine novel therapeutic strategies. In this study, we describe and evaluate two ICH models that implement unilateral injections of either autologous whole blood or bacterial collagenase into the basal ganglia (corpus striatum) of mice.
JoVE Applied Physics
Optical Trapping of Nanoparticles
Electrical and Computer Engineering, University of Victoria
The following setup approach details low power optical trapping of dielectric nanoparticles using a double-nanohole in metal film.
JoVE General
Whole-Body Nanoparticle Aerosol Inhalation Exposures
1Department of Physiology and Pharmacology, School of Medicine, West Virginia University, 2Center for Cardiovascular and Respiratory Sciences, West Virginia University, 3National Institute for Occupational Safety and Health
A whole-body nanoparticle aerosol inhalation exposure facility was constructed for nano-sized titanium dioxide (TiO2) inhalation toxicology studies. This system provides nano-TiO2 aerosol test atmospheres that have: 1) a steady mass concentration; 2) a homogenous composition free of contaminants; and 3) a stable particle size distribution during aerosol generation.
JoVE Bioengineering
Tissue Engineering of the Intestine in a Murine Model
This article and the accompanying video present our protocol for generating tissue-engineered intestine in the mouse, using an organoid units-on-scaffold approach.
JoVE Bioengineering
Contrast Ultrasound Targeted Treatment of Gliomas in Mice via Drug-Bearing Nanoparticle Delivery and Microvascular Ablation
1Department of Biomedical Engineering, University of Virginia, 2Neurological Surgery , University of Virginia
Insonation of microbubbles is a promising strategy for tumor ablation at reduced time-averaged acoustic powers, as well as for the targeted delivery of therapeutics. The purpose of the present study is to develop low duty cycle ultrasound pulsing strategies and nanocarriers to maximize non-thermal microvascular ablation and payload delivery to subcutaneous C6 gliomas.
JoVE Bioengineering
Measurement of Aggregate Cohesion by Tissue Surface Tensiometry
Department of Surgery, UMDNJ-Robert Wood Johnson Medical School
We describe a method of measuring binding energy, expressible as tissue surface tension, between cells within 3D tissue-like aggregates. Differences in tissue surface tension have been demonstrated to correlate with invasiveness of lung, muscle, and brain tumors, and are fundamental determinants of establishing spatial relationships between different cell types.
JoVE Bioengineering
Solid-phase Submonomer Synthesis of Peptoid Polymers and their Self-Assembly into Highly-Ordered Nanosheets
Molecular Foundry, Lawrence Berkeley National Laboratory
A simple and general manual peptoid synthesis method involving basic equipment and commercially available reagents is outlined, enabling peptoids to be easily synthesized in most laboratories. The synthesis, purification and characterization of an amphiphilic peptoid 36mer is described, as well as its self-assembly into highly-ordered nanosheets.
JoVE Clinical and Translational Medicine
Real-time Digital Imaging of Leukocyte-endothelial Interaction in Ischemia-reperfusion Injury (IRI) of the Rat Cremaster Muscle
Department of Plastic and Hand Surgery, University of Freiburg Medical Centre
Digital intravital epifluorescence microscopy of postcapillary venules in the cremasteric microcirculation is a convenient method to gain insights into leukocyte-endothelial interaction in vivo in ischemia-reperfusion injury (IRI) of striated muscle tissue. We here provide a detailed protocol to safely perform the technique and discuss its applications and limitations.
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.
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