JoVE General
An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations
Wellcome Trust Centre for Human Genetics, University of Oxford
Genetic associations often remain unexplained at a functional level. This method aims to assess the effect of phenotype-associated genetic markers on gene expression by analyzing cells heterozygous for transcribed SNPs. The technology allows accurate measurement by MALDI-TOF mass spectrometry to quantify allele-specific primer extension products.
JoVE General
Quantitative Comparison of cis-Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster
1Department of Biology, University of Dayton, 2Department of Biology, Center for Tissue Regeneration and Engineering at Dayton, University of Dayton
Phenotypic variation for traits can result from mutations in cis-regulatory element (CRE) sequences that control gene expression patterns. Methods derived for use in Drosophila melanogaster can quantitatively compare the levels of spatial and temporal patterns of gene expression mediated by modified or naturally occurring CRE variants.
JoVE General
Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos
Institute for Cell and Molecular Biosciences, University of Newcastle, United Kingdom
The kinetochore is where the SAC initiates its signal monitoring the mitotic segregation of the sister chromatids. A method is described to visualize the recruitment and turnover of one of the kinetochore proteins and its coordination with the chromosome motion in Drosophila embryos using a Leica laser scanning confocal system.
JoVE Clinical and Translational Medicine
Quantitative Analysis of Chromatin Proteomes in Disease
1Department of Anesthesiology, David Geffen School of Medicine at UCLA, 2Department of Medicine, David Geffen School of Medicine at UCLA, 3Department of Physiology, David Geffen School of Medicine at UCLA, 4Department of Internal Medicine, Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah
Advances in mass spectrometry have allowed the high throughput analysis of protein expression and modification in a host of tissues. Combined with subcellular fractionation and disease models, quantitative mass spectrometry and bioinformatics can reveal new properties in biological systems. The method described herein analyzes chromatin-associated proteins in the setting of heart disease and is readily applicable to other in vivo models of human disease.
JoVE Immunology and Infection
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.
JoVE General
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.
JoVE Clinical and Translational Medicine
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.
JoVE Immunology and Infection
Isolation of Fidelity Variants of RNA Viruses and Characterization of Virus Mutation Frequency
Viral Populations and Pathogenesis lab and CNRS 3015, Institut Pasteur
The present article describes the steps required to isolate and characterize RNA polymerase fidelity variants of RNA viruses and how to use mutation frequency data to confirm fidelity changes in tissue culture.
JoVE General
Detection of Rare Genomic Variants from Pooled Sequencing Using SPLINTER
1Center for Genome Sciences and Systems Biology, Department of Genetics, Washington University School of Medicine, 2Department of Internal Medicine, Washington University School of Medicine, 3Department of Pediatrics, Washington University School of Medicine
Pooled DNA sequencing is a fast and cost-effective strategy to detect rare variants associated with complex phenotypes in large cohorts. Here we describe the computational analysis of pooled, next-generation sequencing of 32 cancer-related genes using the SPLINTER software package. This method is scalable, and applicable to any phenotype of interest.
JoVE Immunology and Infection
Recognition of Epidermal Transglutaminase by IgA and Tissue Transglutaminase 2 Antibodies in a Rare Case of Rhesus Dermatitis
1Division of Microbiology, Tulane National Primate Research Center, 2Division of Comparative Pathology, Tulane National Primate Research Center, 3Division of Veterinary Medicine, Tulane National Primate Research Center
Dermatitis herpetiformis (DH) is a chronic inflammatory condition characterized by an autoimmune reaction between IgA and epidermal transglutaminase (eTG). DH develops in a very small portion of gluten-sensitive and/or celiac patients. The results of this study indicate that DH can also develop in a rhesus monkey host with symptoms of idiopatic dermatitis.
JoVE Immunology and Infection
Generation of Induced Regulatory T Cells from Primary Human Naïve and Memory T Cells
Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky
We describe a method for generating regulatory, memory and naïve T cells from a single human blood donor. Polarized Tregs can be then compared to other subsets in a variety of genetic and functional applications with genetic homogeneity, including a suppression assay also detailed here.
JoVE General
The Importance of Correct Protein Concentration for Kinetics and Affinity Determination in Structure-function Analysis
We apply label-free protein interaction analysis using Biacore X100 for structure-function analysis of the binding of several cystatin B mutants to papain through kinetic characterization. Calibration-free concentration analysis (CFCA) measures the concentration of protein with retained binding activity without the need for a standard curve. We show that confirmation of concentrations using CFCA increases the reliability of the kinetic analysis and that kinetic constants can reliably be determined even if the activity of a recombinant protein is reduced.
JoVE General
Identifying the Effects of BRCA1 Mutations on Homologous Recombination using Cells that Express Endogenous Wild-type BRCA1
1Department of Biomedical Informatics, The Ohio State University, 2Departments of Molecular Immunology and Clinical Oncology, Tohoku University
We provide a method for testing BRCA1 variants in a tissue culture based assay for homologous recombination repair of DNA damage by depleting endogenous BRCA1 protein from a cell using RNAi and replacing it with a BRCA1 point mutant that contains a coding change.
JoVE Neuroscience
Quantifying the Activity of cis-Regulatory Elements in the Mouse Retina by Explant Electroporation
Department of Pathology and Immunology, Washington University School of Medicine
This protocol describes a simple and inexpensive way to quantify the activity of cis-regulatory elements (i.e., enhancer/promoters) in living mouse retinas via explant electroporation. DNA preparation, retinal dissection, electroporation, retinal explant culture, and post-fixation analysis and quantification are described.
JoVE General
Fluorescence-microscopy Screening and Next-generation Sequencing: Useful Tools for the Identification of Genes Involved in Organelle Integrity
DOE Plant Research Laboratory, Michigan State University
A fundamental quest in cell biology is to define the mechanisms that underlie the identity of the organelles that make eukaryotic cells. Here we propose a method to identify the genes responsible for the morphological and functional integrity of plant organelles using fluorescence microscopy and next-generation sequencing tools.
JoVE General
Using SCOPE to Identify Potential Regulatory Motifs in Coregulated Genes
Department of Biology, Dartmouth College
A straight-forward and robust method to identify potential regulatory motifs in co-regulated genes is presented. SCOPE does not require any user parameters and returns motifs that represent excellent candidates for regulatory signals. The identification of such regulatory signals helps to understand the underlying biology.
JoVE General
Assaying the Kinase Activity of LRRK2 in vitro
Department of Molecular Neuroscience, UCL Institute of Neurology
Leucine Rich Repeat Kinase 2 is a large multidomain kinase, mutations in which are the most common genetic cause of Parkinson's disease. Analysis of the kinase activity of this protein has proven to be a crucial tool in understanding the biology and dysfunction of this protein. In this paper, in vitro assaying of the kinase activity of LRRK2 and a selection of its mutants is described, providing an experimental system to examine phosphorylation of putative substrates and potential dysfunction of LRRK2 in disease.
JoVE General
Chromatin Immunoprecipitation from Human Embryonic Stem Cells
Department of Biochemistry, University of California - Riverside
The differentiation of ESC coincides with cell-type specific changes in the structure and composition of chromatin. The detection of those changes provides valuable insights into the mechanisms that define stemcellness and cell differentiation. Chromatin immunoprecipitation (ChIP) represents a valuable method to dissect the molecular mechanisms underlying stem cell differentiation.
JoVE General
Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay
Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine
We have developed a cell fusion assay that quantifies SNARE-mediated membrane fusion events by activated expression of β-galactosidase.
JoVE Neuroscience
Assessing Neurodegenerative Phenotypes in Drosophila Dopaminergic Neurons by Climbing Assays and Whole Brain Immunostaining
Department of Biomolecular Genetics, University of Rochester Medical Center
Here we describe two assays that have been established to study age-dependent neurodegeneration of dopaminergic (DA) neurons in Drosophila: the climbing/startle-induced negative geotaxis assay which allows to study the functional effects of DA neurons degeneration and the tyrosine hydroxylase immunostaining which is used to identify and count DA neurons in whole brain mounts.
JoVE Immunology and Infection
Human In Vitro Suppression as Screening Tool for the Recognition of an Early State of Immune Imbalance
1Department of Pediatrics/Allergy, Medical College of Wisconsin, 2Flow Cytometry Core Facility, Medical College of Wisconsin, 3Max McGee National Research Center for Juvenile Diabetes and Human Molecular Genetics Center, Medical College of Wisconsin
Tregs are potent suppressors of the immune system. There is a lack of unique surface markers to define them, hence, definitions of Tregs are primarily functional. Here we describe an optimized in vitro assay capable of identifying immune imbalance in subjects at risk to develop T1D.
JoVE General
Monitoring Acupuncture Effects on Human Brain by fMRI
1Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 2William Beaumont Hospital
FMRI and physiological monitoring is used to study the effects of Acupuncture on the central and peripheral nervous systems. Acupuncture mobilizes a limbic-paralimbic-neocortical network, with great overlap with the default mode network, to modulate neurological activity, possibly related to its autonomic effect in the peripheral nervous system.
JoVE General
The Production of C. elegans Transgenes via Recombineering with the galK Selectable Marker
1Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, 2Department of Medicine, Division of Geriatric Medicine and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh
The ability to produce transgenes for Caenorhabditis elegans using genomic DNA carried by fosmids is particularly attractive as all of the native regulatory elements are retained. Described is a simple and robust procedure for the production of transgenes via recombineering with the galK selectable marker.
JoVE General
Mosaic Zebrafish Transgenesis for Evaluating Enhancer Sequences
Department of Cell and Developmental Biology, University of Pennsylvania
We demonstrate our approach to finding potential enhancer elements from developmentally regulated genes and evaluating their function through mosaic zebrafish transgenesis.
JoVE General
Quantification of γH2AX Foci in Response to Ionising Radiation
1Epigenomic Medicine, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, 2Department of Pathology, The University of Melbourne, 3Epigenetics in Human Health and Disease, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct
Quantification of DNA double-strand streaks using γH2AX formation as a molecular marker has become an invaluable tool in radiation biology. Here we demonstrate the use of an immunofluorescence assay for quantification of γH2AX foci after exposure of cells to radiation.
JoVE General
Primary Culture of Adult Rat Heart Myocytes
1Department of Physiology and Cellular Biophysics, Columbia University, 2Department of Pharmacology, Columbia University
In this paper, we described a typical way to isolate and culture adult rat heart myocytes. Collagenase and protease are used to digest and isolate single myocytes. Myocytes cultured follow this protocol meet most experiment requirements.
JoVE Immunology and Infection
Intravital Imaging of the Mouse Thymus using 2-Photon Microscopy
Laboratory of Immune Regulation, Instituto Gulbenkian de Ciência
We have developed novel laboratory tools and protocols for intravital imaging acquisition of the thymus. Our technique should help in the identification of “niches” within the thymus where T cell development occurs.
JoVE General
Measuring Caenorhabditis elegans Life Span in 96 Well Microtiter Plates
1Department of Chemical Physiology, The Scripps Research Institute, 2Department of Molecular and Experimental Medicine, The Scripps Research Institute
In this protocol we present a method to measure Caenorhabditis elegans lifespan in 96 well microtiter plates.
JoVE General
Generation of High Quality Chromatin Immunoprecipitation DNA Template for High-throughput Sequencing (ChIP-seq)
1Division of Human Genetics, Children's Hospital of Philadelphia Research Institute, 2Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania
The combination of chromatin immunoprecipitation and ultra-high-throughput sequencing (ChIP-seq) can identify and map protein-DNA interactions in a given tissue or cell line. Outlined is how to generate a high quality ChIP template for subsequent sequencing, using experience with the transcription factor TCF7L2 as an example.
JoVE General
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.
JoVE General
Laser Microdissection Applied to Gene Expression Profiling of Subset of Cells from the Drosophila Wing Disc
Dipartimento di Biologia Strutturale e Funzionale, University of Naples
Laser microdissection was applied to analyse gene expression profiling in specific compartments of Drosophila wing disc subjected to localised RNAi in vivo. RNA extracted from equivalent areas of silenced and unsilenced compartments was analysed by quantitative RT-PCR to determine comparative gene expression profiling within the context of native tissue microecology.
JoVE Immunology and Infection
Overcoming Unresponsiveness in Experimental Autoimmune Encephalomyelitis (EAE) Resistant Mouse Strains by Adoptive Transfer and Antigenic Challenge
1Department of Medicine, Section of Cardiology, St. John-Providence Health System, 2Department of Immunology and Microbiology, Wayne State University School of Medicine
Certain mouse strains are able to resist induction of experimental autoimmune encephalomyelitis (EAE) with myelin basic protein. Described here is a simple immunization protocol that reverses the unresponsiveness and induces paralytic disease in several typical EAE resistant mouse stains.
JoVE Editorial
JoVE 7th Issue
JoVE Editorial
March 2013: This Month in JoVE
1Department of Ophthalmology, Massachusetts Eye and Ear, 2JoVE Content Production
Here are some highlights from the March 2013 issue of Journal of Visualized Experiments (JoVE).
JoVE Immunology and Infection
A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes
Institute for Bioscience and Biotechnology Research, University of Maryland
A novel directed evolution method specific to the field of thermostability engineering was developed and consequently validated for bacteriolytic enzymes. After only one round of random mutagenesis, an evolved bacteriolytic enzyme, PlyC 29C3, displayed greater than twice the residual activity when compared to the wild-type protein after elevated temperature incubation.
JoVE Neuroscience
Chronic Imaging of Mouse Visual Cortex Using a Thinned-skull Preparation
Neurobiology and Anatomy, University of Rochester
In this video and supplemental material, we show a protocol for chronic in vivo imaging of the intact brain using a thinned-skull preparation.
JoVE General
In vivo Imaging of Deep Cortical Layers using a Microprism
Department of Biomedical Engineering, Yale University
Right-angle microprisms inserted into the mouse neocortex allows for deep imaging of multiple cortical layers with a viewpoint typically found in slice. One-millimeter microprisms offer a wide field-of-view (~900 μm) and spatial resolutions sufficient to resolve dendritic spines. We demonstrate layer V neuronal imaging and neocortical vascular imaging using microprisms.
JoVE Neuroscience
In vivo Imaging of the Mouse Spinal Cord Using Two-photon Microscopy
1Gladstone Institute of Neurological Disease, University of California, San Francisco, 2Department of Neurology, University of California, San Francisco
A minimally invasive protocol to stabilize the mouse spinal column and perform repetitive in vivo spinal cord imaging using two-photon microscopy is described. This method combines a spinal stabilization device and an anesthetic regimen to minimize respiratory-induced movements and produce raw imaging data that require no alignment or other post-processing.
JoVE General
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.
JoVE Immunology and Infection
Analysis of Pulmonary Dendritic Cell Maturation and Migration during Allergic Airway Inflammation
1Stem Cell and Cancer Research Institute, McMaster University, Hamilton, 2Physiology and Experimental Medicine Research Program, Hospital for Sick Children, University of Toronto
We describe a strategy to monitor maturation and migration of pulmonary dendritic cells in response to ovalbumin in the setting of ovalbumin induced allergic airway inflammation. This strategy can be modified to assess migration of pulmonary dendritic cells in settings of infection.
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 General
Time-lapse Imaging of Mitosis After siRNA Transfection
1Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, 2Fluorescence Microscopy Core Facility, University of Utah
Here we describe a basic protocol to image and quantify the mitotic timing of live mammalian tissue culture cells after siRNA transfection.
JoVE General
Fluorescence Activated Cell Sorting of Plant Protoplasts
Center for Genomics and Systems Biology, Department of Biology, New York University
A method for isolating specific cell types from plant material is demonstrated. This technique employs transgenic marker lines expressing fluorescent proteins in particular cell types, cellular dissociation and Fluorescence Activated Cell Sorting. Additionally, a growth setup is established here that facilitates treatment of Arabidopsis thaliana seedlings prior to cell sorting.
JoVE General
Quantitative Real-Time PCR using the Thermo Scientific Solaris qPCR Assay
Thermo Scientific Solaris qPCR Products
The Solaris qPCR Gene Expression Assays are novel pre-designed qPCR primer/probe combinations designed to simplify the qPCR process without sacrificing the specificity and robustness of the assay.
JoVE Neuroscience
In vivo Visualization of Synaptic Vesicles Within Drosophila Larval Segmental Axons
Department of Biological Sciences, SUNY-University at Buffalo
This protocol discusses the live dissection of Drosophila larvae for the purpose of imaging the movement of GFP tagged axonal vesicles on microtubule tracks.
JoVE Immunology and Infection
Transnuclear Mice with Pre-defined T Cell Receptor Specificities Against Toxoplasma gondii Obtained Via SCNT
1 , Whitehead Institute for Biomedical Research, 2Departments of Microbiology and Biological Sciences, National University of Singapore, 3Department of Biology, Massachusetts Institute of Technology
We demonstrate here that epigenetic reprogramming via Somatic Cell Nuclear Transfer (SCNT) can be used as a tool to generate mouse models with pre-defined T cell receptor (TCR) specificities. These transnuclear mice express the corresponding TCR from their endogenous locus under the control of the endogenous promoter.
JoVE General
Substrate Generation for Endonucleases of CRISPR/Cas Systems
Prokaryotic Small RNA Biology, Max-Planck-Institute for Terrestrial Microbiology
CRISPR/Cas systems mediate adaptive immunity in Bacteria and Archaea. Many Cas proteins are proposed to act as endoribonucleases acting on crRNA precursors of varying length. Here we illustrate three different approaches to generate pre-crRNA substrates for the biochemical analysis of Cas endonuclease activity.
JoVE Neuroscience
Appetitive Associative Olfactory Learning in Drosophila Larvae
1Department of Biology, University of Konstanz, 2Department of Biology, University of Fribourg
Drosophila larvae are able to associate odor stimuli with gustatory reward. Here we describe a simple behavioral paradigm that allows the analysis of appetitive associative olfactory learning.
JoVE Applied Physics
Bringing the Visible Universe into Focus with Robo-AO
1Caltech Optical Observatories, California Institute of Technology, 2Department of Astronomy, California Institute of Technology, 3Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 4Inter-University Centre for Astronomy & Astrophysics, 5Observatories of the Carnegie Institution for Science, 6Benoziyo Center for Astrophysics, Weizmann Institute of Science
Light from astronomical objects must travel through the earth's turbulent atmosphere before it can be imaged by ground-based telescopes. To enable direct imaging at maximum theoretical angular resolution, advanced techniques such as those employed by the Robo-AO adaptive-optics system must be used.
JoVE Neuroscience
Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster
1Institute of Genetics, University of Mainz, 2Department of Anatomy and Neuroscience, University of Melbourne
We present a technique for labeling single neurons in the central nervous system (CNS) of Drosophila embryos, which allows the analysis of neuronal morphology by either transmitted light or confocal microscopy.
More Results...
