Genetic Studies of Human DNA Repair Proteins Using Yeast as a Model System
Laboratory of Molecular Gerontology, National Institute on Aging, NIH
Genetic studies in yeast can be employed to investigate the molecular and cellular functions of human genes in cellular DNA metabolism. Methods are described for the genetic characterization of the human WRN gene product defective in the premature aging disorder Werner syndrome in functionally conserved pathways using yeast as a tractable model system.
Visualization of DNA Replication in the Vertebrate Model System DT40 using the DNA Fiber Technique
1Department of Molecular Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, 2Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw
DT40, a model vertebrate genetic system, provides a powerful tool to analyze protein function. Here we describe a simple method that allows qualitative analysis of parameters that influence DNA synthesis during the S-phase in DT40 cells at the single molecule level.
September 2011: This Month in JoVE
Here are some highlights from the September 2011 Issue of Journal of Visualized Experiments (JoVE).
Bioluminescence Imaging of NADPH Oxidase Activity in Different Animal Models
1Department of Medicine, Vanderbilt University School of Medicine, 2Departments of Medicine and Immunology, Roswell Park Cancer Institute, 3Department of Medicine, University at Buffalo School of Medicine
NADPH oxidase is the major source of reactive oxygen species (ROS) in phagocytes. Because of the ephemeral nature of ROS, it is difficult to measure and monitor ROS levels in living animals. A minimally invasive method for serial quantification of ROS in living mice is described.
The 2009 Lindau Nobel Laureate Meeting: Werner Arber, Physiology or Medicine 1978
Swiss microbial geneticist, Werner Arber shared the 1978 Nobel Prize in Physiology or Medicine with Hamilton Smith and Daniel Nathans for their discovery of restriction endonucleases. Arber found that viral DNA introduced into a non-specific bacterial host was changed, while host DNA was protected by methylation. He theorized that a microbial enzyme cut the DNA into smaller pieces, while at the same time, the methylated host DNA was protected from its own enzymes. Later work done by Nathans and Smith validated his theory, which laid the foundation for recombinant DNA technology.
Trans-vivo Delayed Type Hypersensitivity Assay for Antigen Specific Regulation
Department of Surgery, University of Wisconsin-Madison, School of Medicine and Public Health
We describe a valuable diagnostic assay that could potentially be used to decide the withdrawal of immunosuppression after transplant without elevated risk of graft rejection. The assay uses the principles of Delayed Type Hypersensitivity and provides accurate assessment of both donor specific effector and regulatory immune responses mounted by recipients.
The Measurement and Treatment of Suppression in Amblyopia
1Department of Optometry and Vision Science, University of Auckland, 2Department of Ophthalmology, McGill University, 3Centre for Intelligent Machines, McGill University
Amblyopia is a developmental disorder of the visual cortex that is often accompanied by strong suppression of one eye. We present a new technique for measuring and treating interocular suppression in patients with amblyopia that can be deployed using virtual reality goggles or a portable iPod Touch device.
Murine Model of Wound Healing
1The Heart Research Institute, 2Sydney Medical School, University of Sydney, 3Cardiology Department, Royal Prince Alfred Hospital
A murine model of cutaneous wound healing that can be used to assess therapeutic compounds in physiological and pathophysiological settings.
Electrode Positioning and Montage in Transcranial Direct Current Stimulation
1Headache & Orofacial Pain Effort (H.O.P.E.), Biologic & Material Sciences, School of Dentistry, University of Michigan, 2Laboratory of Neuromodulation, Department of Physical Medicine & Rehabilitation, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, 3Charité, University Medicine Berlin, 4Department of Biomedical Engineering, The City College of New York
Transcranial direct current stimulation (tDCS) is an established technique to modulate cortical excitability1,2. It has been used as an investigative tool in neuroscience due to its effects on cortical plasticity, easy operation, and safe profile. One area that tDCS has been showing encouraging results is pain alleviation 3-5.
The Green Monster Process for the Generation of Yeast Strains Carrying Multiple Gene Deletions
1Department of Synthetic Biology and Bioenergy, J. Craig Venter Institute, 2Department of Microbial and Environmental Genomics, J. Craig Venter Institute, 3Donnelly Centre & Department of Molecular Genetics, University of Toronto, 4Lunenfeld Research Institute, Mt Sinai Hospital
The Green Monster method enables the rapid assembly of multiple deletions marked with a reporter gene encoding green fluorescent protein. This method is based on driving yeast strains through repeated cycles of sexual assortment of deletions and fluorescence-based enrichment of cells carrying more deletions.
TMS: Using the Theta-Burst Protocol to Explore Mechasnism of Plasticity in Individuals with Fragile X Syndrome and Autism
Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center
In this article, we examine the effects of Theta-Burst TMS stimulation on cortical plasticity in individuals suffering from Fragile X syndrome and individuals on the autistic spectrum.
Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye
1Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, 2Division of Fetal Therapy, Department of Obstetrics, Leiden University Medical Center, 3Department of Obstetrics, Leiden University Medical Center
Twin-to-twin transfusion syndrome and twin anemia polycythemia sequence are two potentially devastating problems in perinatal medicine. Both disorders occur only in monochorionic twins and result from unbalanced blood flow through placental vascular anastomoses. We provide a simple protocol to accurately evaluate the presence of vascular anastomoses using colored dye injection of placental vessels after birth.
Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas
1Division of Pediatric and Fetal Surgery, Department of Surgery, University of California, San Francisco, 2Department of Pathology, University of Alberta, 3Department of Obstretics and Gynecology, University of California, San Francisco, 4Department of Radiology, University of California, San Francisco
Vascular mapping of monochorionic (MC) twin placentas after birth provides a means for detailed demonstration of vascular connections between the twins’ circulations. Imbalance of these connections is thought to play a pivotal role in the development of complications of MC twinning including twin-to-twin transfusion syndrome.
Fluorescent Labeling of Drosophila Heart Structures
1Biology Department, San Diego State University, 2Development and Aging Program, NASCR Center, The Sanford Burnham Institute for Medical Research
Here we describe a basic protocol for fluorescent labeling of different elements of heart tubes from larva and adult Drosophila melanogaster. These specimens are well-suited for imaging via fluorescent or confocal microscopy. This technique permits detailed structural analysis of the features of the hearts from a powerful model organism.
One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure
The urease method of sample preparation for GC/MS analysis of intermediary metabolites is presented by its inventor. The method allows one-step follow-up of newborn screening for inborn errors by tandem mass spectrometry by quantifying carbohydrates, organic and amino acids all in a single process.
Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance
Department of Biomedical Physiology and Kinesiology, Simon Fraser University
We describe a "gold standard" for evaluating orthostatic tolerance (OT) using tilt testing with combined lower body negative pressure (LBNP). This can be combined with non-invasive evaluations of cardiovascular reflex control. Normal and abnormal responses are defined.
Naïve Adult Stem Cells Isolation from Primary Human Fibroblast Cultures
1Department of Dermatology and Institute for Medical Engineering, Technische Universität München, 2Department of Dermatology and Allergology, Technische Universität München
We report a method to isolate naïve multipotent skin-derived precursor (SKP) cells from primary human fibroblast cultures. We show that these SKPs derived from fibroblast cultures share similar stem cell properties to the ones derived directly from human skin biopsies. These cells express the neural crest marker, nestin, in addition to the multipotent markers such as OCT4 and Nanog.
A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis
1Orvis School of Nursing, University of Nevada, Reno, 2The State University of New York at Buffalo, St. Joseph's Medical Center, 3Strong Memorial Hospital, University of Rochester Medical Center
Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia.
Isolation and Culture of Mouse Cortical Astrocytes
1Institute of Anatomy and Cell Biology, University of Freiburg, 2Centre of Chronic Immunodeficiency (CCI), University Medical Centre Freiburg, University of Freiburg
Astrocytes have been recognized to be versatile cells participating in fundamental biological processes that are essential for normal brain development and function, and central nervous system repair. Here we present a rapid procedure to obtain pure mouse astrocyte cultures to study the biology of this major class of central nervous system cells.
Generation of Aligned Functional Myocardial Tissue Through Microcontact Printing
1Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, 2Harvard Stem Cell Institute
The generation of aligned myocardial tissue is a key requirement for adapting the recent advances in stem cell biology to clinically useful purposes. Herein we describe a microcontact printing approach for the precise control of cell shape and function. Using highly purified populations of embryonic stem cell derived cardiac progenitors, we then generate anisotropic functional myocardial tissue.
Manual Muscle Testing: A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients
1Outcomes After Critical Illness and Surgery (OACIS) Group, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, 2Critical Care Physical Medicine and Rehabilitation Program, Johns Hopkins Hospital, 3Department of Physical Medicine and Rehabilitation, Johns Hopkins University, 4Department of Rehabilitation Services, University of Maryland Medical System
Survivors of acute respiratory distress syndrome (ARDS) and critical illness frequently develop long-lasting muscle weakness. Manual muscle testing (MMT) is a standardized clinical examination commonly used to measure strength of peripheral skeletal muscle groups. This video demonstrates MMT using the 6-point Medical Research Council scale.
Antibody Profiling by Luciferase Immunoprecipitation Systems (LIPS)
The technical aspects of performing LIPS (Luciferase Immunoprecipitation Systems) are described. The overall approach involves expressing chimeric genes encoding antigens fused to Renilla luciferase (Ruc) in mammalian cells. Crude Ruc-antigen extracts are then prepared and, without purification, employed in immunoprecipitation assays to quantify antibodies.
Intravital Microscopy of the Mouse Brain Microcirculation using a Closed Cranial Window
1Bioengineering, University of California, San Diego, 2La Jolla Bioengineering Institute
Intravital microscopy to follow temporal and spatial hemodynamic and inflammatory events in the pial microcirculation.
Double Fluorescence in situ Hybridization in Fresh Brain Sections
1Department of Brain and Cognitive Sciences, University of Rochester, 2Center for Visual Science, University of Rochester
This protocol involves a non-radioactive in-situ hybridization procedure that enables the simultaneous identification of two transcript species, at a single cell resolution, in thin sections of the vertebrate brain.
Reverse Total Shoulder Arthroplasty
Reverse total shoulder arthroplasty is indicated for the treatment of conditions that cannot be treated with conventional arthroplasty or other procedures. These primarily include degenerative and incapacitating conditions with irreparable rotator cuff and loss of the normal biomechanical coupling of the shoulder.
High-throughput Purification of Affinity-tagged Recombinant Proteins
Department of Life Sciences, Imperial College London
We describe a method for the affinity-tagged purification of recombinant proteins using liquid-handling robotics. This method is generally applicable to the small-scale purification of soluble His-tagged proteins in a high-throughput format.
Introduction to Solid Supported Membrane Based Electrophysiology
1Department of Biophysical Chemistry, Max Planck Institute of Biophysics, 2Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt
Here we present an electrophysiological method based on solid supported membranes with focus on its applications for the characterization of electrogenic membrane transporters.
Antibody Transfection into Neurons as a Tool to Study Disease Pathogenesis
1Research Service, Veterans Administration Medical Center, Memphis, TN, 2Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, 3Department of Anatomy/Neurobiology, University of Tennessee Health Science Center, Memphis, TN
A rapid approach to investigate interactions and effects on molecular mechanisms related to the presence of antibodies in an intracellular environment is described. The method involves transfection of antibodies into live cells using a non-covalent complex formation based on a lipid formulation. The technique is adaptable to immortalized cell lines and primary cells.
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.
Guidelines for Elective Pediatric Fiberoptic Intubation
1Department of Anesthesia, St. Jude Children's Research Hospital, 2Department of Anesthesia, Children's Hospital of Michigan, 3Department of Anesthesiology, Children's Hospital of Michigan
We describe guidelines to perform a safe and efficient elective fiberoptic intubation in pediatric patients while maintaining spontaneous ventilation.
Evisceration of Mouse Vitreous and Retina for Proteomic Analyses
1Omics Laboratory, University of Iowa, 2Ophthalmology and Visual Sciences, University of Iowa, 3Harkness Eye Institute, Columbia University College of Physicians and Surgeons
The dissection technique illustrates evisceration of the vitreous, retina, and lens from the mouse eye, separation by centrifugation, and characterization with protein assays.
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.
Whole-cell Recordings of Light Evoked Excitatory Synaptic Currents in the Retinal Slice
1Program in Neuroscience, Boston University, 2Department of Biology, Boston University, 3Department of Biomedical Engineering, Boston University
This video shows the process of whole-cell voltage clamp recordings in the retinal slice of the aquatic tiger salamander. We demonstrate the preparation of the slice as well as how to perform patch clamp recordings during visual stimulation of the retina.
Drosophila Larval NMJ Immunohistochemistry
This protocol demonstrates how to perform immunohistochemistry on dissected Drosophila larva.
Drosophila Larval NMJ Dissection
This protocol demonstrates how to dissect Drosophila larvae in preparation for immunohistochemistry and/or imaging of the neuromuscular junction.
Formulation of Diblock Polymeric Nanoparticles through Nanoprecipitation Technique
1Laboratory of Nano- and Translational Medicine, Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, 2Carolina Center for Nanotechnology Excellence, University of North Carolina
This article describes a nanoprecipitation method to synthesize polymer-based nanoparticles using diblock co-polymers. We will discuss the synthesis of diblock co-polymers, the nanoprecipitation technique, and potential applications.
Genomic Transformation of the Picoeukaryote Ostreococcus tauri
1SynthSys, University of Edinburgh, 2Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Paris 06, 3UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, Banyuls-sur-Mer, Université Pierre et Marie Curie, Paris 06
This article describes genetic transformation of the unicellular marine alga Ostreococcus tauri by electroporation. This eukaryotic organism is an effective model platform for higher plants, possesing greatly reduced genomic and cellular complexity and being readily amenable to both cell culture and chemical biology.
Generation of Neural Stem Cells from Discarded Human Fetal Cortical Tissue
1Department of Neurology, Beth Israel Deaconess Medical Center, 2Department of Obstetrics and Gynecology, Brigham and Women's Hospital, 3Department of Pathology, Beth Israel Deaconess Medical Center, 4Department of Pathology, Division of Neuropathology, Brigham and Women's Hospital
A simple and reliable method on isolation and culture of neural stem cells from discarded human fetal cortical tissue is described. Cultures derived from known human neurological disorders can be used for characterization of pathological cellular and molecular processes, as well as provide a platform to assess pharmacological efficacy.
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.
Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes
1Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, 2Department of Biomedical Engineering, Washington University in St. Louis, 3Department of Biomedical Engineering and Cardiac Bioelectricity and Arrhythmia Center, Washington University in St. Louis
Ionic current of BK channels is recorded using patch clamp techniques. BK channels are expressed in Xenopus oocytes by injecting messenger RNA. The intracellular solution during patch clamp recordings is controlled by a perfusion system.
Primary Microglia Isolation from Mixed Glial Cell Cultures of Neonatal Rat Brain Tissue
1Neuroscience Program, Uniformed Services University, 2Department of Anatomy, Physiology, and Genetics, Uniformed Services University, 3Molecular and Cell Biology, Uniformed Services University
Isolating primary microglia from the cellular heterogeneity of the brain is essential to investigate their role in both physiological and pathological conditions. This protocol describes a mechanical isolation and mixed cell culture technique that provides high yield and high purity, viable primary microglial cells for in vitro study and downstream applications.
Experimental Endocarditis Model of Methicillin Resistant Staphylococcus aureus (MRSA) in Rat
1Department of Medicine, Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, 2Geffen School of Medicine at UCLA
Experimental rat endocarditis model due to methicillin-resistant S. aureus.
Continuously-stirred Anaerobic Digester to Convert Organic Wastes into Biogas: System Setup and Basic Operation
Department of Biological and Environmental Engineering, Cornell University
Laboratory-scale anaerobic digesters allow scientists to research new ways of optimizing existing applications of anaerobic biotechnology and to evaluate the methane producing potential of various organic wastes. This article introduces a generalized model for the construction, inoculation, operation, and monitoring of a laboratory-scale continuously stirred anaerobic digester.
Recapitulation of an Ion Channel IV Curve Using Frequency Components
Bioengineering, University of Utah
There are technical obstacles to measuring current flux through multiple ion channels simultaneously, and later discerning what portion of the transmembrane current is due to each channel type. To address this need, this method presents a way to generate the IV curve of individual channel types using specific frequency components.
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.
A Strategy to Identify de Novo Mutations in Common Disorders such as Autism and Schizophrenia
1Centre of Excellence in Neuromics, CHUM Research Center and the Department of Medicine, Universite de Montreal, 2Center of Excellence in Neuromics, CHU Sainte Justine and CHUM Notre-Dame Research Centers, Universite de Montreal, 3Department of Medicine, Universite de Montreal
Molecular genetic strategy for finding de novo mutations causing common disorders such as autism and schizophrenia.
Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT)
1Division of Cardiovascular Medicine, University of Pennsylvania, Perelman School of Medicine, 2Department of Radiology, University of Pennsylvania, Perelman School of Medicine, 3Department of Dermatology, University of Pennsylvania, Perelman School of Medicine
There is great need to identify atherosclerosis non-invasively, and here we demonstrate how FDG-PET/CT can be used to detect and quantify atherosclerotic plaque activity and vascular inflammation.
Using a Pan-Viral Microarray Assay (Virochip) to Screen Clinical Samples for Viral Pathogens
1Department of Laboratory Medicine, University of California, San Francisco, 2Division of Infectious Diseases, University of California, San Francisco
The Virochip is a pan-viral microarray designed to simultaneously detect all known viruses as well as novel viruses on the basis of conserved sequence homology. Here we demonstrate how to run a Virochip assay to analyze clinical samples for the presence of both known and unknown viruses.
Electrolytic Inferior Vena Cava Model (EIM) of Venous Thrombosis
1Conrad Jobst Vascular Research Laboratories, Section of Vascular Surgery, University of Michigan, 2Department of Pharmacology, University of Michigan
The electrolytic induction of endothelial activation to the internal surface of the Inferior Vena Cava results in venous type thrombus formation due to endothelial activation and partial blood stasis, two components of Virchow's triad.
Programmed Electrical Stimulation in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Programmed electrical stimulation provides the ability to determine conduction properties of the heart, and the possibility to induce and terminate cardiac arrhythmias using various pacing protocols. Using a transvenous catheter, intracardiac electrogram recordings can be obtained in mice following programmed electrical stimulation protocols to identify arrhythmogenic substrates.
