JoVE General
Purification and Visualization of Influenza A Viral Ribonucleoprotein Complexes
Department of Zoology, University of British Columbia - UBC
The genome of the influenza A virus consists of eight separate complexes of RNA and proteins, termed viral ribonucleoprotein complexes (vRNPs). This paper describes the glycerol gradient purification and transmission electron microscopy visualization of influenza A vRNPs.
JoVE General
Upright Imaging of Drosophila Embryos
1Department of Biology, Case Western Reserve University, 2Department of Genetics, Case Western Reserve University
Here we present a mounting protocol for stained Drosophila embryos in an upright position that allows imaging of cross-sections using Confocal microscopy.
JoVE General
Mutagenesis and Functional Selection Protocols for Directed Evolution of Proteins in E. coli
Department of Microbiology & Environmental Toxicology, University of California Santa Cruz - UCSC
Here we demonstrate a simple protocol to create a random mutant library for a given target sequence. We show how this method, which is performed in vivo in Escherichia coli, can be coupled with functional selections to evolve new enzymatic activities.
JoVE Neuroscience
A Rapid Approach to High-Resolution Fluorescence Imaging in Semi-Thick Brain Slices
1Department of Molecular & Human Genetics, Baylor College of Medicine (BCM), 2Precisionary Instruments Inc., 3Departments of Molecular & Human Genetics and Neuroscience, Baylor College of Medicine (BCM), 4Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital
Here we describe a rapid and simple method to image fluorescently labeled cells in semi-thick brain slices. By fixing, slicing, and optically clearing brain tissue we describe how standard epifluorescent or confocal imaging can be used to visualize individual cells and neuronal networks within intact nervous tissue.
JoVE General
RhoC GTPase Activation Assay
This protocol utilizes a pull down assay to determine the levels of active RhoC GTPase within cells.
JoVE General
Probing for Mitochondrial Complex Activity in Human Embryonic Stem Cells
David Geffen School of Medicine, University of California, Los Angeles
In this video, we will show you how the mitochondrial respiratory chain complexes of human embryonic stem cells can be analyzed using in gel activity assays.
JoVE General
Blue Native Polyacrylamide Gel Electrophoresis (BN-PAGE) for Analysis of Multiprotein Complexes from Cellular Lysates
1Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 2Centre for Biological Signalling Studies (bioss) and Biology III, Faculty of Biology, University of Freiburg, 3Department of Molecular Immunology, Max-Planck-Institute of Immunology and Epigenetics
In this video, we describe the characterization of multiprotein complexes (MPCs) by blue native polyacrylamide gel electrophoresis (BN-PAGE). In a first dimension, dialyzed cellular lysates are separated by BN-PAGE to identify individual MPCs. In a second dimension SDS-PAGE, MPCs of interest are further subdivided to analyze their constituents by immunoblotting.
JoVE Immunology and Infection
Preparation of Viral DNA from Nucleocapsids
Department of Molecular Biology, Princeton University
We describe the process of isolating high purity herpesvirus nucleocapsid DNA from infected cells. The final DNA captured from solution is of high concentration and purity, making it ideally suited for high-throughput sequencing, high fidelity PCR reactions, and transfections to produce new viral recombinants.
JoVE Clinical and Translational Medicine
Isolation of Soluble and Insoluble PrP Oligomers in the Normal Human Brain
1Department of Pathology, National Prion Disease Pathology Surveillance Center, Case Western Reserve University School of Medicine, 2Department of Neurology, National Prion Disease Pathology Surveillance Center, Case Western Reserve University School of Medicine
A new species of cellular prion protein (PrPC) has recently been identified in uninfected human brains using the methods described here. These methods can be used to isolate various PrP species, while some of them are also useful in isolating other misfolded protein aggregates from human brains.
JoVE General
In vitro Reconstitution of the Active T. castaneum Telomerase
Gene Expression and Regulation, The Wistar Institute, University of Pennsylvania
Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.
JoVE Immunology and Infection
Chemoselective Modification of Viral Surfaces via Bioorthogonal Click Chemistry
Department of Chemistry, Stony Brook University
Adenovirus particles are engineered to contain either the unnatural amino acid analogue azidohomoalanine or the azido sugar O-GlcNAz. The azide group of each is chemoselectively ligated via "click" chemistry reactions as a means of viral surface modification.
JoVE Bioengineering
Creating Adhesive and Soluble Gradients for Imaging Cell Migration with Fluorescence Microscopy
1Centre for Vascular Research and Australian Centre for Nanomedicine, The University of New South Wales, 2School of Chemistry and Australian Centre for Nanomedicine, The University of New South Wales
A method for the assembly of adhesive and soluble gradients in a microscopy chamber for live cell migration studies is described. The engineered environment combines antifouling surfaces and adhesive tracks with solution gradients and therefore allows one to determine the relative importance of guidance cues.
JoVE General
Expression and Purification of the Cystic Fibrosis Transmembrane Conductance Regulator Protein in Saccharomyces cerevisiae
Faculty of Life Sciences, University of Manchester
Attempts to express the cystic fibrosis transmembrane conductance regulator (CFTR) in Saccharomyces cerevisiae have, until now, yielded relatively low amounts of protein. This protocol and the associated reagents distributed via the Cystic Fibrosis Foundation should allow the preparation of milligram amounts of this 'difficult' eukaryotic membrane protein.
JoVE Immunology and Infection
Purification of Pathogen Vacuoles from Legionella-infected Phagocytes
Max von Pettenkofer-Institut, Ludwig-Maximilians-Universität
This article describes a method for the isolation and purification of intact Legionella-containing vacuoles (LCVs) from amoeba and macrophages. The two-step protocol comprises LCV enrichment by immuno-magnetic separation using an antibody against a bacterial LCV marker and further purification by density gradient centrifugation.
JoVE Bioengineering
Fluorescence Lifetime Imaging of Molecular Rotors in Living Cells
1Department of Physics, King's College London, 2Department of Chemistry, Imperial College London, 3PhotoBiotics Ltd
Fluorescence Lifetime Imaging (FLIM) has emerged as a key technique to image the environment and interaction of specific proteins and dyes in living cells. FLIM of fluorescent molecular rotors allows mapping of viscosity in living cells.
JoVE General
Isolation of Ribosome Bound Nascent Polypeptides in vitro to Identify Translational Pause Sites Along mRNA
A technique to identify translational pause sites on mRNA is described. This procedure is based on isolation of nascent polypeptides accumulating on ribosomes during in vitro translation of a target mRNA, followed by the size analysis of the nascent chains using a denaturing gel electrophoresis.
JoVE General
Chromatographic Purification of Highly Active Yeast Ribosomes
1Department of Cell Biology and Molecular Genetics, University of Maryland, 2Department of Biotechnology and Microbiology, Vilnius University
Contamination of preparations of eukaryotic ribosomes purified by traditional methods by co-purifying nucleases and proteases negatively impacts on downstream biochemical and structural analyses. A rapid and simple chromatographic purification method is used to solve this problem using yeast ribosomes as a model system.
JoVE General
Purification of Hsp104, a Protein Disaggregase
Department of Biochemistry and Biophysics, University of Pennsylvania
Here, we describe a protocol for the purification of highly active Hsp104, a hexameric AAA+ protein from yeast, which couples ATP hydrolysis to protein disaggregation. This scheme exploits a His6-tagged construct for affinity purification from E. coli followed by anion-exchange chromatography, His6-tag removal with TEV protease, and size-exclusion chromatography.
JoVE General
Isolation of Primary Mouse Trophoblast Cells and Trophoblast Invasion Assay
Obstetrics, Gynecology and Women's Health, University of Missouri
In this protocol, we describe the dissection of placentae from the mouse on pregnancy d10.5, followed by isolation of trophoblast cells using a Percoll gradient. We then demonstrate use of the isolated cells in a matrigel invasion assay.
JoVE Bioengineering
Analyzing Cellular Internalization of Nanoparticles and Bacteria by Multi-spectral Imaging Flow Cytometry
1Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, 2Amnis Corporation, 3Department of Chemical and Biological Engineering, Iowa State University
In this article, we describe a method utilizing multi-spectral imaging flow cytometry to quantify the internalization of polyanhydride nanoparticles or bacteria by RAW 264.7 cells.
JoVE General
Single Particle Electron Microscopy Reconstruction of the Exosome Complex Using the Random Conical Tilt Method
Molecular Biophysics and Biochemistry, Yale University
This article describes a standard method to get a three-dimensional (3D) reconstruction of biological macromolecules using negative staining electron microscopy (EM). In this protocol, we explain how to get the 3D structure of the Saccharomyces cerevisiae exosome complex at medium resolution using the random conical tilt reconstruction method (RCT).
JoVE General
Large Insert Environmental Genomic Library Production
Department of Microbiology and Immunology, University of British Columbia - UBC
Construction of a fosmid library with environmental genomic DNA isolated from the vertical depth continuum of a seasonally hypoxic fjord is described. The resulting clone library is picked into 384-well plates and archived for downstream sequencing and functional screening by the application of an automated colony picking system.
JoVE General
Profiling Thiol Redox Proteome Using Isotope Tagging Mass Spectrometry
1Plant Molecular and Cellular Biology Program, University of Florida, 2Department of Biology, University of Florida, 3Interdisciplinary Center for Biotechnology Research, University of Florida, 4Genetics Institute, University of Florida
Reactive oxygen species level is elevated when cells encounter stress conditions. Here we show the example of 3'-3' diaminobenzidine staining as well as cysTMT labeling and mass spectrometry to profile the redox proteome in Pseudomonas syringae treated tomato leaves.
JoVE General
Cryopreservation of Preimplantation Embryos of Cattle, Sheep, and Goats
Animal Science Department, Iowa State University
Preimplantation embryos may be cryopreserved after placement into a hypertonic cryoprotective solution to cause cellular dehydration. After equilibration, ice crystal formation is induced in the solution surrounding the embryo. Further dehydration occurs as the embryo is slowly cooled to subzero temperatures before plunging into liquid nitrogen for storage.
JoVE Immunology and Infection
Sample Preparation of Mycobacterium tuberculosis Extracts for Nuclear Magnetic Resonance Metabolomic Studies
1School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, 2Department of Chemistry, University of Nebraska-Lincoln
The metabolomic profile of Mycobacterium tuberculosis is determined after growth in broth cultures. Conditions can be varied to test the effects of nutritional supplements, oxidants, and anti-tuberculosis agents on the metabolic profile of this microorganism. Procedure for extract preparation is applicable for both 1D 1H and 2D 1H-13C NMR analyses.
JoVE General
Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels
1Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, 2Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, 3Department of Anesthesiology, Medicine and Physiology, David Geffen School of Medicine, University of California, Los Angeles
We describe a simple protocol to identify brain proteins that bind to the full length C terminus of ATP-gated P2X2 receptors. The extension and systematic application of this approach to all P2X receptors is expected to lead to a better understanding of P2X receptor signaling.
JoVE General
Identification of Protein Complexes in Escherichia coli using Sequential Peptide Affinity Purification in Combination with Tandem Mass Spectrometry
1Banting and Best Department of Medical Research, Donnelly Centre, University of Toronto, 2Deparment of Biochemistry, Research and Innovation Centre, University of Regina, 3Department of Medical Genetics and Microbiology, University of Toronto
Affinity purification of tagged proteins in combination with mass spectrometry (APMS) is a powerful method for the systematic mapping of protein interaction networks and for investigating the mechanistic basis of biological processes. Here, we describe an optimized sequential peptide affinity (SPA) APMS procedure developed for the bacterium Escherichia coli that can be used to isolate and characterize stable multi-protein complexes to near homogeneity even starting from low copy numbers per cell.
JoVE General
Quantitative Phosphoproteomics in Fatty Acid Stimulated Saccharomyces cerevisiae
Description of a quantitative phosphorylation procedure using cryolysis, urea solubilziation, HILIC fractionation and IMAC enrichment of phosphorylated peptides.
JoVE General
Profiling of Methyltransferases and Other S-adenosyl-L-homocysteine-binding Proteins by Capture Compound Mass Spectrometry (CCMS)
1Department of Biochemistry / Analytics, caprotec bioanalytics GmbH, 2Institute of Organic Chemistry, RWTH Aachen University
Capture Compounds are trifunctional small molecules to reduce the complexity of the proteome by functional reversible small molecule-protein interaction followed by photo-crosslinking and purification. Here we use a Capture Compound with S-adenosyl-L-homocysteine-binding as selectivity function to isolate methyltransferases from an Escherichia coli whole cell lysate and identify them by MS.
JoVE General
Identification of Protein Interacting Partners Using Tandem Affinity Purification
Section of Virology, Department of Medicine, Imperial College London
Tandem affinity purification is a robust approach for the identification of protein binding partners. As proof of concept, this methodology was applied to the well-characterized translation initiation factor eIF4E to co-precipitate the host cell factors involved in translation initiation. This method is easily adapted to any cellular or viral protein.
JoVE General
Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Department of Biochemistry and Biomedical Sciences, McMaster University
Crystal structure of protein–DNA complexes can provide insight into protein function, mechanism, as well as, the nature of the specific interaction. Here, we report how to optimize the length, sequence and ends of duplex DNA for co-crystallization with Escherichia coli SeqA, a negative regulator of replication initiation.
JoVE General
Fast and Sensitive Colloidal Coomassie G-250 Staining for Proteins in Polyacrylamide Gels
Biological Medical Research Center (BMFZ), University Duesseldorf
This video shall popularize a colloidal Coomassie G-250 staining protocol according to Kang et al. for the detection of average 4 ng protein in gels. The staining is completed within 2 hours and without any effort. We routinely use Kang's protocol for analytical purposes in gel-based proteomics.
JoVE Immunology and Infection
A Cell Free Assay System Estimating the Neutralizing Capacity of GM-CSF Antibody using Recombinant Soluble GM-CSF Receptor
1Bioscience Medical Research Center, Niigata University Medical and Dental Hospital, 2First department of Internal Medicine, School of Medicine, Kyorin University, 3Neosilk Laboratory, Immuno Biological Laboratories Co., Ltd.
We designed a cell-free receptor binding assay in order to estimate the binding of granulocyte-macrophage colony-stimulating factor (GM-CSF) to the receptors. It enables us to evaluate competitive inhibition of biotinylated GM-CSF binding to soluble GM-CSF receptor alpha by GM-CSF autoantibody with excellent reproducibility.
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 Clinical and Translational Medicine
Skeletal Muscle Gender Dimorphism from Proteomics
1Center for Proteomics, Smith College, 2Department of Molecular Biophysics and Biochemistry, Yale University, 3Department of Chemistry, Smith College, 4Department of Biological Sciences and Center for Proteomics, Smith College
A straight-forward set of methods to isolate and determine the identity of the most abundant proteins expressed in skeletal muscle. About 800 spots are discerned on a two-dimensional gel from 10 mg muscle; this allows for the determination of gender-specific protein expression. These methods will give equivalent results in most tissues.
JoVE General
A Protocol for the Identification of Protein-protein Interactions Based on 15N Metabolic Labeling, Immunoprecipitation, Quantitative Mass Spectrometry and Affinity Modulation
1Max Planck Institute of Molecular Plant Physiology, 2University of Kaiserslautern
We present a variation of the QUICK (QUantitative Immunoprecipitation Combined with Knockdown) approach that was introduced previously to distinguish between true and false protein-protein interactions. Our approach is based on 15N metabolic labeling, the modulation of affinities of protein-protein interactions by the presence/absence of ATP, immunoprecipitation, and quantitative mass spectrometry.
JoVE General
Lentiviral-mediated Knockdown During Ex Vivo Erythropoiesis of Human Hematopoietic Stem Cells
1The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, 2Department of Cellular and Molecular Medicine, University of Ottawa
An ex vivo protocol to generate mature human red blood cells from hematopoietic stem/progenitors is described. Additionally we describe an efficient lentiviral-delivery method to knockdown the transcription factor TAL1 in primary erythroid cells. The efficiency of lentivirus mediated gene delivery is demonstrated using GFP expressing viruses.
JoVE General
Using SecM Arrest Sequence as a Tool to Isolate Ribosome Bound Polypeptides
We describe here a technique that is now routinely used to isolate stably bound ribosome nascent chain complexes (RNCs). This technique takes advantage of the discovery that a 17 amino acid long SecM "arrest sequence" can halt translation elongation in a prokaryotic (E. coli) system, when inserted into (or fused to the C-terminus) of virtually any protein.
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 General
Engineering Cell-permeable Protein
Protein transduction enables the direct delivery of biologically active proteins into cells. In contrast to conventional methods such as DNA transfection or viral transduction this non-invasive paradigm allows highly efficient cellular manipulation in a titratable manner circumventing cellular toxicity and the risk of oncogenic transformation by permanent genetic modification.
JoVE General
Flow Cytometry-based Purification of S. cerevisiae Zygotes
1Department of Pathology, Case Western Reserve University School of Medicine, 2Cell Biology Program, Case Western Reserve University School of Medicine, 3Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine
To purify zygotes of S. cerevisiae, haploid cells of opposite mating type were engineered to express red or green fluorescent proteins, co-incubated to allow zygote formation, and fractionated using a flow cytometry-based protocol. The highly-enriched fraction enables subsequent "-omic" studies, recovery of initial progeny, and systematic investigation of zygote morphogenesis.
JoVE General
Drosophila Larval NMJ Immunohistochemistry
This protocol demonstrates how to perform immunohistochemistry on dissected Drosophila larva.
JoVE Immunology and Infection
Isolation of Brain and Spinal Cord Mononuclear Cells Using Percoll Gradients
The current article describes a rapid protocol to efficiently isolate mononuclear cells from brain and spinal cord tissues that can be effectively utilized for flow cytometric analyses.
JoVE General
A Gradient-generating Microfluidic Device for Cell Biology
We describe a protocol for the microfabrication of the gradient-generating microfluidic device that can generate spatial and temporal gradients in well-defined microenvironment. In this approach, the gradient-generating microfluidic device can be used to study directed cell migration, embryogenesis, wound healing, and cancer metastasis.
JoVE Neuroscience
Dissection of a Mouse Eye for a Whole Mount of the Retinal Pigment Epithelium
A formal demonstration of the dissection of a mouse eye, resulting in a whole mount of the retinal pigment epithelium.
JoVE General
A Technique to Simultaneously Visualize Virus-Specific CD8+ T Cells and Virus-Infected Cells In situ
1Department of Microbiology, Medical School, University of Minnesota, 2Department of Veterinary and Biomedical Sciences, University of Minnesota
A technique combining in situ tetramer staining and in situ hybridization (ISTH) enables visualization, mapping and analysis of the spatial proximity of virus-specific CD8+ T cells to their virus-infected targets, and determination of the quantitative relationships between these immune effectors and targets to infection outcomes.
JoVE General
A Microfluidic Device for Quantifying Bacterial Chemotaxis in Stable Concentration Gradients
1McFerrin Department of Chemical Engineering, Texas A&M University, 2Department of Biology, Texas A&M University, 3Department of Biomedical Engineering, Texas A&M University
This protocol describes the development of a microfluidic device for investigating bacterial chemotaxis in stable concentration gradients of chemoeffectors.
JoVE General
DNA Stable-Isotope Probing (DNA-SIP)
Department of Biology, University of Waterloo
DNA stable-isotope probing is a cultivation-independent method to identify and characterize active communities of microorganisms that are capable of utilizing specific substrates. Assimilation of substrate enriched in heavy isotope leads to incorporation of labelled atoms into microbial biomass. Density gradient ultracentrifugation retrieves labelled DNA for downstream molecular analyses.
JoVE Immunology and Infection
Infection of Zebrafish Embryos with Intracellular Bacterial Pathogens
1Department of Molecular Cell Biology, Institute of Biology, Leiden University, 2Department of Medical Microbiology and Infection Control, VU University Medical Center, 3Australian Regenerative Medicine Institute, Monash University
Transparent zebrafish embryos have proved useful model hosts to visualize and functionally study interactions between innate immune cells and intracellular bacterial pathogens, such as Salmonella typhimurium and Mycobacterium marinum. Micro-injection of bacteria and multi-color fluorescence imaging are essential techniques involved in the application of zebrafish embryo infection models.
JoVE General
High-resolution Measurement of Odor-Driven Behavior in Drosophila Larvae
Laboratory of Neurogenetics and Behavior, Rockefeller University
In this video article, we describe a new method allowing the construction of odorant gradients with stable and controllable geometries. We briefly illustrate how these gradients can be used to screen for olfactory defects (full and partial anosmia) and to study more subtle features of chemotaxis behavior.
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