JoVE General
Metabolic Pathway Confirmation and Discovery Through 13C-labeling of Proteinogenic Amino Acids
1Department of Energy, Environmental and Chemical Engineering, Washington University, 2Department of Biology, Washington University, 3Department of Energy, Environmental and Chemical Engineering and Department of Biology, Washington University
13C-isotope labeling is a useful technique for determining the cell central metabolism for various types of microorganisms. After cells have been cultured with a specific labeled substrate, GC-MS measurement can reveal functional metabolic pathways based on unique labeling patterns in proteinogenic amino acids.
JoVE General
Annotation of Plant Gene Function via Combined Genomics, Metabolomics and Informatics
Molekulare Pflanzenphysiologie, Max-Planck-Institut
Combination of genomics, co-expression gene analysis and the identification of target compounds via metabolism give gene functional annotation.
JoVE General
Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
1Department of Molecular Genetics, University of Toronto, 2Banting and Best Department of Medical Research, Donnelly Centre, University of Toronto, 3Department of Biochemistry, Research and Innovation Centre, University of Regina
Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli.
JoVE General
RNA-seq Analysis of Transcriptomes in Thrombin-treated and Control Human Pulmonary Microvascular Endothelial Cells
Children's Mercy Hospital and Clinics, School of Medicine, University of Missouri-Kansas City
This protocol presents a complete and detailed procedure to apply RNA-seq, a powerful next-generation DNA sequencing technology, to profile transcriptomes in human pulmonary microvascular endothelial cells with or without thrombin treatment. This protocol is generalizable to various cells or tissues affected by different reagents or disease states.
JoVE General
Stable Isotopic Profiling of Intermediary Metabolic Flux in Developing and Adult Stage Caenorhabditis elegans
1Department of Pediatrics, The Children's Hospital of Philadelphia, 2Department of Pediatrics, University of Pennsylvania
Stable isotopic profiling by gas chromatography mass spectrometric analysis of intermediary metabolic flux is described in the nematode, Caenorhabditis elegans. Methods are detailed for assessing isotopic enrichment in carbon dioxide, organic acids, and amino acids following isotope exposure either during development on agar plates or during adulthood in liquid culture.
JoVE Neuroscience
Paired Nanoinjection and Electrophysiology Assay to Screen for Bioactivity of Compounds using the Drosophila melanogaster Giant Fiber System
1Department of Biological Sciences, Florida Atlantic University, 2Department of Chemistry & Biochemistry, Florida Atlantic University
A rapid in vivo assay to test for neuromodulatory compounds using the Giant Fiber System (GFS) of Drosophila melanogaster is described. Nanoinjections in the head of the animal along with electrophysiological recordings of the GFS can reveal bioactivity of compounds on neurons or muscles.
JoVE Bioengineering
A Toolkit to Enable Hydrocarbon Conversion in Aqueous Environments
1Department of Biotechnology, Delft University of Technology, 2Delft Center for Systems and Control, Delft University of Technology
A sustainable auto regulating bacterial system for the remediation of oil pollutions was designed using standard interchangeable DNA parts (BioBricks). An engineered E. coli strain was used to degrade alkanes via β-oxidation in toxic aqueous environments. The respective enzymes from different species showed alkane degradation activity. Additionally, an increased tolerance to n-hexane was achieved by introducing genes from alkane-tolerant bacteria.
JoVE General
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Howard Hughes Medical Institute, Rockefeller University
The fate of the replisome following a collision with a head-on RNA polymerase (RNAP) is unknown. We find that the replisome stalls upon collision with a head-on RNAP, but resumes elongation after displacing the RNAP from DNA. Mfd promotes replication restart by facilitating displacement of the RNAP after the collision.
JoVE General
Rapid and Efficient Generation of Neurons from Human Pluripotent Stem Cells in a Multititre Plate Format
1Max Planck Institute for Molecular Biomedicine, 2Medical Faculty, University of Münster
Protocols for neuronal differentiation of pluripotent human stem cells (hPSCs) are often time-consuming and require substantial cell culture skills. Here, we have adapted a small molecule-based differentiation procedure to a multititre plate format, allowing simple, rapid, and efficient generation of human neurons in a controlled manner.
JoVE General
Profiling of Pre-micro RNAs and microRNAs using Quantitative Real-time PCR (qPCR) Arrays
We will demonstrate the setup and analysis of pre-microRNA 96-well arrays for QPCR using a robot as well as by hand with a Thermo Scientific Matrix multichannel pipette.
JoVE Immunology and Infection
Dissecting Host-virus Interaction in Lytic Replication of a Model Herpesvirus
1Center for Autophagy Research, Department of Internal Medicine, UT Southwestern Medical Center, 2Department of Microbiology, UT Southwestern Medical Center
We describe a protocol to identify key roles of host signaling molecules in lytic replication of a model herpesvirus, gamma herpesvirus 68 (γHV68). Utilizing genetically modified mouse strains and embryonic fibroblasts for γHV68 lytic replication, the protocol permits both phenotypic characterization and molecular interrogation of virus-host interactions in viral lytic replication.
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 Chemistry
Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
ISOF - Bio Free Radicals, Consiglio Nazionale delle Ricerche
Radical-based biomimetic chemistry has been applied to building-up libraries necessary for biomarker development.
JoVE Neuroscience
Experimental Methods for Testing the Effects of Neurotrophic Peptide, ADNF-9, Against Alcohol-induced Apoptosis during Pregnancy in C57BL/6 Mice
Department of Pharmacology, College of Pharmacy and Pharmaceutical Sciences, University of Toledo
The experimental designs proposed here focus on studying the effects of alcohol exposure in apoptosis and the application of neurotrophic peptide during pregnancy in fetal brain. A detailed description from the breeding to the collection of fetal brains is described. Techniques for determination of apoptosis are also described in detail.
JoVE General
Bacterial Delivery of RNAi Effectors: Transkingdom RNAi
Institute of Pathology, Charité Campus Mitte
For development of RNA interference (RNAi)-based therapies, a novel strategy was developed, transkingdom RNAi (tkRNAi). This technology uses non-pathogenic bacteria to produce and deliver therapeutic short hairpin RNA (shRNA) into target cells. Here, tkRNAi was successfully applied for reversal of classical ABCB1-mediated multidrug resistance (MDR) of cancer cells.
JoVE Neuroscience
Isolation, Enrichment, and Maintenance of Medulloblastoma Stem Cells
Department of Cell and Developmental Biology, Vanderbilt University
This protocol describes the isolation, enrichment, and maintenance of medulloblastoma tumor stem cells derived from mutant mice with ectopic Sonic hedgehog pathway activity.
JoVE General
Preparation of Cell-lines for Conditional Knockdown of Gene Expression and Measurement of the Knockdown Effects on E4orf4-Induced Cell Death
Department of Molecular Microbiology, Faculty of Medicine, Technion - Israel Institute of Technology
Contribution of the ACF chromatin remodeling factor to E4orf4-induced cell death was measured. The protocol includes selection of cell clones in which doxycycline treatment induces conditional knockdown of the ACF subunits Acf1 and SNF2h, and use of the DAPI assay to measure E4orf4-induced cell death in the inducible cell lines.
JoVE Neuroscience
Creating Objects and Object Categories for Studying Perception and Perceptual Learning
1Brain and Behavior Discovery Institute, Georgia Health Sciences University, 2Vision Discovery Institute, Georgia Health Sciences University, 3Department of Opthalmology, Georgia Health Sciences University, 4Intelligent Systems Laboratory, Palo Alto Research Center, 5Pattern Recognition Systems, Palo Alto Research Center, 6Department of Psychology, University of Minnesota
We describe a novel methodology for creating naturalistic 3-D objects and object categories with precisely defined feature variations. We use simulations of the biological processes of morphogenesis and phylogenesis to create novel, naturalistic virtual 3-D objects and object categories that can then be rendered as visual images or haptic objects.
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
Agrobacterium-Mediated Virus-Induced Gene Silencing Assay In Cotton
1Department of Biochemistry and Biophysics, Institute of Plant Genomics and Biotechnology, Texas A&M University, 2Department of Plant Pathology and Microbiology, Institute of Plant Genomics and Biotechnology, Texas A&M University
We present the detailed protocol for Agrobacterium-mediated virus-induced gene silencing (VIGS) assay in cotton. The tobacco rattle virus (TRV)-derived VIGS vectors were deployed to induce RNA silencing of cotton GrCLA1, Cloroplastos alterados 1 gene. The albino phenotype caused by silencing GrCLA1 was observed at the seedling stage within 2 weeks after inoculation.
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
Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development
1Department of Biological Sciences, The George Washington University, 2Department of Anatomy and Regenerative Biology, The George Washington University
The fate of an individual embryonic cell can be influenced by inherited molecules and/or by signals from neighboring cells. Utilizing fate maps of the cleavage stage Xenopus embryo, single blastomeres can be identified for culture in isolation to assess the contributions of inherited molecules versus cell-cell interactions.
JoVE Chemistry
Large Scale Non-targeted Metabolomic Profiling of Serum by Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS)
Proteomics and Metabolomics Facility, Colorado State University
Non-targeted metabolite profiling by ultra performance liquid chromatography coupled with mass spectrometry (UPLC-MS) is a powerful technique to investigate metabolism. This article outlines a typical workflow utilized for non-targeted metabolite profiling of serum including sample organization and preparation, data acquisition, data analysis, quality control, and metabolite identification.
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 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
Microgavage of Zebrafish Larvae
Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill
We present a novel method for microgavage of larval zebrafish utilizing standard embryo microinjection and stereomicroscopy equipment. We demonstrate that microgavage is a safe and efficient technique useful for delivering controlled amounts of diverse materials specifically into the larval zebrafish intestinal lumen.
JoVE Neuroscience
In ovo Electroporation of miRNA-based Plasmids in the Developing Neural Tube and Assessment of Phenotypes by DiI Injection in Open-book Preparations
Institute of Molecular Life Sciences, University of Zurich
A method by which gene expression in the neural tube can be downregulated in a cell type-specific, traceable manner is described. We demonstrate how in ovo electroporation of microRNA-based plasmids that elicit spatiotemporally controlled RNA interference can be used to investigate commissural axon guidance in the developing neural tube.
JoVE General
Solid Plate-based Dietary Restriction in Caenorhabditis elegans
1Department of Internal Medicine, Division of Geriatric Medicine, University of Michigan, 2Department of Molecular and Integrative Physiology, University of Michigan
Here we present a protocol for performing solid plate-based dietary restriction in C. elegans with killed bacteria.
JoVE Neuroscience
Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae
Epigenetics and Progenitor Cells Keystone, Fox Chase Cancer Center
In this video, we describe a method for live cell imaging of asymmetrically dividing sensory organ progenitor cells and epidermal cells in intact Drosophila pupae
JoVE General
Affinity Precipitation of Active Rho-GEFs Using a GST-tagged Mutant Rho Protein (GST-RhoA(G17A)) from Epithelial Cell Lysates
1Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 2Department of Surgery, University of Toronto, 3Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill
The method presented here describes an assay to follow activation of RhoA specific GDP/GTP Exchange Factors (GEFs) in cultured cells by making use of a mutant RhoA GST fusion protein that has high affinity for activated GEFs. GEFs are precipitated from cell lysates, detected by Western blotting and quantified by densitometry.
JoVE Neuroscience
Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster
Department of Neurobiology, Stanford University
Genetically encoded optogenetic tools enable noninvasive manipulation of specific neurons in the Drosophila brain. Such tools can identify neurons whose activation is sufficient to elicit or suppress particular behaviors. Here we present a method for activating Channelrhodopsin2 that is expressed in targeted neurons in freely walking flies.
JoVE General
Dissection of the Adult Zebrafish Kidney
Department of Biological Sciences, University of Notre Dame
The zebrafish kidney is home to both renal and hematopoietic adult stem/progenitor cells, and represents an outstanding opportunity to study these cell types and their progeny in a vertebrate model organism. Here, we demonstrate a detailed dissection procedure that enables the researcher to identify and surgically remove the adult zebrafish kidney, which can be used for applications such as cell isolation, transplantation, and expression studies of kidney and/or blood cell populations.
JoVE Neuroscience
Isolating LacZ-expressing Cells from Mouse Inner Ear Tissues using Flow Cytometry
Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine
Flow cytometry is a powerful tool allowing for the isolation and study of specific cell populations. This protocol describes steps for isolating LacZ-expressing cells from cochlear tissues from neonatal transgenic mice. Dissociated cochlear cells were labeled using fluorescent-conjugated substrates of β-galactosidase prior to separation via flow cytometry.
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 Bioengineering
Low Molecular Weight Protein Enrichment on Mesoporous Silica Thin Films for Biomarker Discovery
1Department of Nanomedicine, The Methodist Hospital Research Institute, 2CAS Key Laboratory for Biological Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology
We developed a technology based on mesoporous silica thin film for the selective recovery of low molecular weight proteins and peptides from human serum. The physico-chemical properties of our mesoporous chips were finely tuned to provide substantial control in peptide enrichment and consequently profile the serum proteome for diagnostic purposes.
JoVE Clinical and Translational Medicine
Development of a Unilaterally-lesioned 6-OHDA Mouse Model of Parkinson's Disease
Centre for Neurobiology of Stress, Dept Biological Sciences, University of Toronto at Scarborough
A protocol for performing unilateral 6-OHDA lesions of the medial forebrain bundle in mice is described. This method has a low mortality rate (13.3 %) with 89% of the surviving animals showing >95% loss of striatal dopamine and 90.63±-4.02 % ipsiversive rotational bias towards the side of the lesion.
JoVE Immunology and Infection
Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
1Applied Bioscience Program, Faculty of Science, University of Ontario Institute of Technology, 2Nursing Program, Faculty of Health Sciences, University of Ontario Institute of Technology, 3Medical Laboratory Science Program, Faculty of Health Sciences, University of Ontario Institute of Technology
This study describes a novel microplate assay that measures FV coagulation activity during fibrin clot formation in human plasma which has not been reported previously. The method uses a kinetic microplate reader to continuously measure the change in absorbance at 405nm during fibrin clot formation in human plasma.
JoVE General
4D Imaging of Protein Aggregation in Live Cells
Cellular viability depends on timely and efficient management of protein misfolding. Here we describe a method for visualizing the different potential fates of a misfolded protein: refolding, degradation, or sequestration in inclusions. We demonstrate the use of a folding sensor, Ubc9ts, for monitoring proteostasis and aggregation quality control in live cells using 4D microscopy.
JoVE General
Quantitative and Automated High-throughput Genome-wide RNAi Screens in C. elegans
Centre d’Immunologie de Marseille-Luminy, Université de la Méditerranée
We describe a protocol using C. elegans and RNAi feeding libraries that allows automated measurement of multiple parameters such as fluorescence, size and opacity of individual worms in a population. We give one example of a screen to identify genes involved in anti-fungal innate immunity in C. elegans.
JoVE Clinical and Translational Medicine
Immunohistochemical Staining of B7-H1 (PD-L1) on Paraffin-embedded Slides of Pancreatic Adenocarcinoma Tissue
1The Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, 2Department of Oncology, The Johns Hopkins University School of Medicine, 3Department of Dermatology, The Johns Hopkins University School of Medicine, 4Department of Surgery, Johns Hopkins University School of Medicine, 5The Sol Goldman Pancreatic Cancer Center, The Johns Hopkins University School of Medicine, 6Yale Cancer Center, Yale School of Medicine, 7The Skip Viragh Center for Pancreatic Cancer, The Johns Hopkins University School of Medicine, 8Department of Pathology, The Johns Hopkins University School of Medicine
B7-H1 (PD-L1) and its binding to PD-1 provide a major tumor-induced immunosuppressive signal in the tumor’s microenvironment. An immunohistochemical staining technique to characterize the expression and localization of B7-H1 in pancreatic adenocarcinoma is described here.
JoVE Bioengineering
Bridging the Bio-Electronic Interface with Biofabrication
1Fischell Department of Bioengineering, University of Maryland, 2Institute for Bioscience and Biotechnology Research, University of Maryland, 3Department of Materials Science and Engineering, University of Maryland
This article describes a biofabrication approach: deposition of stimuli-responsive polysaccharides in the presence of biased electrodes to create biocompatible films which can be functionalized with cells or proteins. We demonstrate a bench-top strategy for the generation of the films as well as their basic uses for creating interactive biofunctionalized surfaces for lab-on-a-chip applications.
JoVE Immunology and Infection
An Analytical Tool-box for Comprehensive Biochemical, Structural and Transcriptome Evaluation of Oral Biofilms Mediated by Mutans Streptococci
1Center for Oral Biology, University of Rochester Medical Center, 2State Key Laboratory of Oral Diseases, Sichuan University, 3Department of General Medicine, Glostrup Hospital, Glostrup, Denmark, 4Department of Microbiology and Immunology, University of Rochester Medical Center
Biofilms formed on tooth surfaces are highly complex and exposed to constant innate and exogenous environmental challenges, which modulate their architecture, physiology and transcriptome. We developed a toolbox to examine the composition, structural organization and gene expression of oral biofilms, which can be adapted to other areas of biofilm research.
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 Immunology and Infection
RNA Interference in Ticks
1Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 2(CSIC-UCLM-JCCM), Instituto de Investigación en Recursos Cinegéticos IREC
A method for RNA interference (RNAi) by injection of dsRNA into unfed ticks is described. RNAi is the most widely used gene-silencing technique in ticks where the use of other methods of genetic manipulation has been limited.
JoVE General
Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Department of Biological Sciences, The University of Memphis
Circadian clocks function within individual cells, i.e., they are cell-autonomous. Here, we describe methods for generating cell-autonomous clock models using non-invasive, luciferase-based real-time bioluminescence technology. Reporter cells provide tractable, functional model systems for studying circadian biology.
JoVE Neuroscience
In vivo Laser Axotomy in C. elegans
A protocol to cut neurons in C. elegans with a MicroPoint pulsed laser is presented. We describe setting up the system, immobilizing worms, and severing labeled neurons. Advantages include a relatively low-cost system and the ability to sever neuronal processes or ablate cells in vivo.
JoVE General
A Matrigel-Based Tube Formation Assay to Assess the Vasculogenic Activity of Tumor Cells
1Molecular and Cellular Biology Program, Morrill Science Center, University of Massachusetts, 2Pioneer Valley Life Sciences Institute, University of Massachusetts, 3Department of Veterinary and Animal Sciences, University of Massachusetts
A tube formation assay is used to evaluate vascular activity of tumor cells.
JoVE General
In vivo Electroporation of Morpholinos into the Regenerating Adult Zebrafish Tail Fin
1Department of Biological Sciences, Center for Zebrafish Research, University of Notre Dame, 2Department of Microbiology, Immunology, and Pathology, Colorado State University, 3Departments of Anatomy and Cell Biology and Ophthalmology, Wayne State University School of Medicine
We describe a method to conditionally knockdown the expression of a target protein during adult zebrafish fin regeneration. This technique involves micro-injecting and electroporating antisense oligonucleotide morpholinos into fin tissue, which allows testing the protein’s role in various stages of fin regeneration, including wound healing, blastema formation, and regenerative outgrowth.
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 Bioengineering
Engineering Skeletal Muscle Tissues from Murine Myoblast Progenitor Cells and Application of Electrical Stimulation
Engineered muscle tissue has great potential in regenerative medicine, as disease model and also as an alternative source for meat. Here we describe the engineering of a muscle construct, in this case from mouse myoblast progenitor cells, and the stimulation by electrical pulses.
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