JoVE General
Brain Banking: Making the Most of your Research Specimens
1Department of Physiology, University of Montreal, 2School of Optometry, University of Montreal
Brain banking and systematic sampling of biological material provides the basis for unbiased stereology and maximizes the potential data obtained from each specimen.
JoVE General
Knowing What Counts: Unbiased Stereology in the Non-human Primate Brain
1Department of Physiology, University of Montreal, 2Ecole d’optometrie, University of Montreal, 3Stereology Resource Center
The anatomical organization of the primate brain can provide important insights into normal and pathological conditions in humans. Unbiased stereology is a method for accurately and efficiently estimating the total neuron number (or other cell type) in a given reference space1.
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
Micro-Mechanical Characterization of Lung Tissue Using Atomic Force Microscopy
The stiffness of the extracellular matrix strongly influences multiple behaviors of adherent cells. Matrix stiffness varies spatially throughout a tissue, and undergoes modification in various disease conditions. Here we develop methods to characterize spatial variations in stiffness in normal and fibrotic mouse lung tissue using atomic force microscopy microindentation.
JoVE General
Aseptic Laboratory Techniques: Plating Methods
Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles
When working with media and reagents used to culture microorganisms, aseptic technique must be practiced to ensure contamination is minimized. A variety of plating methods are routinely used to isolate, propagate, or enumerate bacteria and phage, all of which incorporate procedures that maintain the sterility of experimental materials.
JoVE Immunology and Infection
Detection of Bacteria Using Fluorogenic DNAzymes
1Department of Biochemistry and Biomedical Sciences, McMaster University, 2Department of Chemistry and Chemical Biology, McMaster University
We have recently reported a novel approach for generating fluorogenic DNAzyme probes that can be applied to set up a simple, "mix-and-read" fluorescent assay for bacterial detection. These special DNA probes catalyze the cleavage of a chromophore-modified DNA-RNA chimeric substrate in the presence of crude extracellular mixture (CEM) produced by a specific bacterium, thereby translating bacterial detection into fluorescence signal generation. In this report we will describe key experimental procedures where a specific DNAzyme probe denoted "RFD-EC1" is employed for the detection of the model bacterium, Escherichia coli (E. coli).
JoVE General
Mapping the After-effects of Theta Burst Stimulation on the Human Auditory Cortex with Functional Imaging
Auditory processing is the basis of speech and music-related processing. Transcranial Magnetic Stimulation (TMS) has been used successfully to study cognitive, sensory and motor systems but has rarely been applied to audition. Here we investigated TMS combined with functional Magnetic Resonance Imaging to understand the functional organization of auditory cortex.
JoVE General
Single Read and Paired End mRNA-Seq Illumina Libraries from 10 Nanograms Total RNA
1Regenerative Biology, Morgridge Institute for Research, 2Department of Cell & Regenerative Biology, University of Wisconsin, 3Department of Molecular, Cellular, & Regenerative Biology, University of California
Here we describe a method for preparation of both single read and paired end Illumina mRNA-Seq sequencing libraries for gene expression analysis based on T7 linear RNA amplification. This protocol requires only 10 nanograms of starting total RNA and generates highly consistent libraries representing whole transcripts.
JoVE General
Seawater Sampling and Collection
Department of Microbiology and Immunology, University of British Columbia - UBC
This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses.
JoVE Application Notes
Analytical HPLC to Preparative HPLC: Scale Up Techniques using a Natural Product Extract - ADVERTISEMENT
Pharmaceutical Business Operations, Waters Corporation
Using the Waters AutoPurification™ System, separation methods can be developed on an analytical scale and transferred to preparatory scale on the same system.
JoVE General
Do-It-Yourself Device for Recovery of Cryopreserved Samples Accidentally Dropped into Cryogenic Storage Tanks
1Molecular and Microbiology Department and Center for the Study of Genomics in Liver Diseases, George Mason University, 2Translational Research Institute, Inova Health System, 3Research Center for Medical Genetics RAMS
Here we present a low cost, durable cryotolerant device for sample retrieval from Dewar tanks filled with liquid nitrogen. The ease of construction and modular design of the device makes the process of sample retrieval from cryogenic tanks safe and easy.
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 Clinical and Translational Medicine
Automated Midline Shift and Intracranial Pressure Estimation based on Brain CT Images
1Department of Biostatistics, Virginia Commonwealth University, 2Virginia Commonwealth University Reanimation Engineering Science (VCURES) Center, 3Department of Computer Science, Virginia Commonwealth University, 4Department of Radiology, Virginia Commonwealth University, 5Department of Emergency Medicine, Virginia Commonwealth University
An automated midline shift estimation and intracranial pressure (ICP) pre-screening system based on computed tomography (CT) images for patients with traumatic brain injury (TBI) is proposed using image processing and machine learning techniques.
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
Analyzing Large Protein Complexes by Structural Mass Spectrometry
Department of Biological Chemistry, Weizmann Institute of Science
Mass spectrometry has proven to be a valuable tool for analyzing large protein complexes. This method enables insights into the composition, stoichiometry and overall architecture of multi-subunit assemblies. Here, we describe, step-by-step, how to perform a structural mass spectrometry analysis, and characterize macromolecular structures.
JoVE General
Atmospheric-pressure Molecular Imaging of Biological Tissues and Biofilms by LAESI Mass Spectrometry
Department of Chemistry, George Washington University
Laser ablation electrospray ionization (LAESI) is an atmospheric-pressure ion source for mass spectrometry. In the imaging mode, a mid-infrared laser probes the distributions of molecules across a tissue section or a biofilm. This technique presents a new approach for diverse bioanalytical studies carried out under native experimental conditions.
JoVE General
Dissection of Organizer and Animal Pole Explants from Xenopus laevis Embryos and Assembly of a Cell Adhesion Assay
Department of Developmental and Cell Biology, University of California, Irvine (UCI)
This video demonstrates the technique used for preparation of organizer and animal pole explants from Xenopus laevis embryos, including the use of the eyebrow knife - a specialized dissection tool made of one's eyebrow. The protocol for assembling an adhesion assay is also given, which probes for the presence of key adhesion molecules present on the surface organizer or animal pole cells that are critical for proper development.
JoVE Neuroscience
SDS-PAGE/Immunoblot Detection of Aβ Multimers in Human Cortical Tissue Homogenates using Antigen-Epitope Retrieval
1Yerkes National Primate Research Center, Emory University, 2Department of Neurology, Institute of Clinical Medicine, Tsukuba University, 3Department of Pathology, New York University School of Medicine, 4Department of Neurology, Emory University
We describe a technique for the preparation of clarified human cortical homogenates, protein separation by SDS-PAGE, antigen retrieval and immunoblotting with an antibody to the Aβ peptide. Using this protocol, we consistently detect monomeric and multimeric Aβ in cortical tissue from humans with Alzheimer's pathology.
JoVE Neuroscience
Laser Capture Microdissection of Drosophila Peripheral Neurons
1Department of Molecular and Microbiology, George Mason University, 2Krasnow Institute for Advanced Study, George Mason University
In this video-article we present a method for isolating single or multiple Drosophila da neurons from third instar larvae using the infrared capture (IR) class of Laser Capture Microdissection (LCM). RNA obtained from the isolated neurons can be readily used for downstream applications including qRT-PCR or microarray analyses.
JoVE General
Batch Immunostaining for Large-Scale Protein Detection in the Whole Monkey Brain
1Cognitive Neuroscience Unit, Montreal Neurological Institute, 2Ècole d’Optomètrie, Universitè de Montrèal, 3Department of Psychology, McGill University
Large-scale immunodetection of target proteins across the entire primate brain is possible by employing novel tissue embedding and sectioning methods combined with the use of creative apparatus for batch staining of multiple free-floating sections at a given time.
JoVE Neuroscience
A Simple Way to Measure Ethanol Sensitivity in Flies
Department of Psychiatry, University of Texas Southwestern Medical Center
A simple assay to measure the sedating effects of ethanol on Drosophila flies, based on the loss of righting reflex, is described.
JoVE Editorial
October 2011: This Month in JoVE
Here are some highlights from the October 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE Neuroscience
Comprehensive Profiling of Dopamine Regulation in Substantia Nigra and Ventral Tegmental Area
Dopamine is distinctly regulated in the midbrain nuclei, which contain the cell bodies and dendrites of the dopamine neurons. Here we describe a dissection and sample-handling approach to maximize results, and thus conclusions and insights, on dopamine regulation in the midbrain nuclei of the substantia nigra (SN) and ventral tegmental area (VTA) in rodents.
JoVE Bioengineering
Non-contact, Label-free Monitoring of Cells and Extracellular Matrix using Raman Spectroscopy
1Department of Thoracic and Cardiovascular Surgery and Inter-University Centre for Medical Technology Stuttgart-Tübingen (IZST), Eberhard Karls University, Tübingen, 2Department of Cell and Tissue Engineering, Fraunhofer Institute of Interfacial Engineering and Biotechnology (IGB) Stuttgart, Germany, 3Department for Medical Interfacial Engineering (IGVT), University of Stuttgart, Germany, 4Institute of Tissue Engineering and Regenerative Medicine, Julius-Maximillians University, Würzburg, Germany
Raman spectroscopy is a suitable technique for the non-contact, label-free analysis of living cells, tissue-engineered constructs and native tissues. Source-specific spectral fingerprints can be generated and analyzed using multivariate analysis.
JoVE General
MALDI Sample Preparation: the Ultra Thin Layer Method
Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, Rockefeller University
This video demonstrates the preparation of an ultra-thin matrix/analyte layer for analyzing peptides and proteins by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS).
JoVE Applied Physics
Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures
1Institute for Solid State Research, IFW-Dresden, 2Institute of Metal Physics of National Academy of Sciences of Ukraine, 3Diamond Light Source LTD, 4Department of Physics, University of Johannesburg, 5CNR-SPIN, and Dipartimento di Fisica "E. R. Caianiello", Università di Salerno, 6Institute of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne
The overall goal of this method is to determine the low-energy electronic structure of solids at ultra-low temperatures using Angle-Resolved Photoemission Spectroscopy with synchrotron radiation.
JoVE Neuroscience
Scalable Fluidic Injector Arrays for Viral Targeting of Intact 3-D Brain Circuits
Controlling and analyzing neural circuits in vivo would be facilitated by a technology for delivery of viruses and other reagents to desired 3-dimensional sets of brain regions. We demonstrate customized fluidic injector array fabrication, and delivery of virally-encoded optical sensitizers, enabling optical manipulation of complex brain circuits.
JoVE Clinical and Translational Medicine
Use of a Hanging-weight System for Liver Ischemia in Mice
1UCH Transplant Center, University of Colorado, Denver, 2Department of Anesthesiology, University of Colorado, Denver
We established a novel murine model of a hanging weight system for portal triad occlusion. This technique may be useful for future investigations of ischemia in murine hepatic models.
JoVE General
Photo-Induced Cross-Linking of Unmodified Proteins (PICUP) Applied to Amyloidogenic Peptides
1Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, 2Brain Research Institute, Molecular Biology Institute, University of California, Los Angeles, 3Department of Neurology, University of California, Los Angeles
Photo-induced cross-linking of unmodified proteins (PICUP) allows characterization of oligomer size distribution in metastable protein mixtures. We demonstrate application of PICUP to three representative amyloidogenic peptides the 40- and 42-residue forms of amyloid β-protein, and calcitonin, and a control peptide growth-hormone releasing factor.
JoVE General
Competitive Genomic Screens of Barcoded Yeast Libraries
1Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, 2Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 3Donnelly Sequencing Centre, University of Toronto, 4Genetics and Molecular Biology Branch, National Human Genome Research Institute, NIH, 5Stanford Genome Technology Center, Stanford School of Medicine, Stanford University, 6Department of Pharmaceutical Sciences, University of Toronto
We have developed comprehensive, unbiased genome-wide screens to understand gene-drug and gene-environment interactions. Methods for screening these mutant collections are presented.
JoVE General
Olfactory Behavioral Testing in the Adult Mouse
1Department of Pediatric Oncology, Dana Farber Cancer Institute, 2Department of Neurobiology, Harvard Medical School
Fundamental, yet unique properties of the rodent olfactory system have led to its increasing study among biologists. A relatively simple assessment of its function is then also needed. Here we describe sensitive tests for the characterization of mouse olfactory sensitivity and preference.
JoVE General
Microinjection of Medaka Embryos for use as a Model Genetic Organism
Centre for Regenerative Medicine, Department of Biology and Biochemistry, University of Bath
Medaka and zebrafish are complementary for genetic dissection of vertebrate genome functions. This protocol highlights the key points for successful microinjection into medaka embryos, an important technique for embryological and genetic analysis using medaka and zebrafish in a laboratory.
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 Neuroscience
Electrophysiological Measurements and Analysis of Nociception in Human Infants
1Neuroscience, Physiology and Pharmacology, University College London, 2Department of Clinical Neurophysiology, Great Ormond Street Hospital, 3Elizabeth Garrett Anderson Obstetric Hospital, University College Hospital, 4Nuffield Department of Anaesthetics, University of Oxford
The assessment and treatment of pain in infants is difficult because infants cannot verbally report their experience. In this video we describe quantitative electrophysiological methods and analysis techniques that can be used to measure the response to noxious events from the infant nervous system.
JoVE General
Growth Assays to Assess Polyglutamine Toxicity in Yeast
Boston Biomedical Research Institute
This manuscript describes three complementary protocols for assessing the toxicity of polyglutamine (polyQ)-expansion proteins in the yeast Saccharomyces cerevisiae. These protocols can easily be modified to monitor the toxicity of other misfolded proteins in yeast.
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
Automated Microfluidic Blood Lysis Protocol for Enrichment of Circulating Nucleated Cells
1Department of Mechanical Engineering, University of Louisville, 2Department of Bioengineering, University of Louisville
An automated microfluidic device was developed for circulating nucleated cell enrichment from peripheral blood via erythrocyte lysis that ensures isolation of high quality sample without cell loss.
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 General
Eukaryotic Polyribosome Profile Analysis
This article describes a protocol for the extraction of translating ribosomes from eukaryotic cells. Once extracted, ribosomes are separated into monosomes and polyribosomes by sucrose gradient fractionation to allow different ribosomal populations to be analyzed. As such, this method is the gold standard for examining the regulation of translation.
JoVE General
MISSION esiRNA for RNAi Screening in Mammalian Cells
Max Planck Institute of Molecular Cell Biology and Genetics
Here we use a human esiRNA library in a high-throughput screen for genes involved in cell division. We demonstrate how to set up and conduct an esiRNA screens, as well as how to analyze and validate the results.
JoVE Neuroscience
The Culture of Primary Motor and Sensory Neurons in Defined Media on Electrospun Poly-L-lactide Nanofiber Scaffolds
1Department of Biomedical Engineering, University of Michigan, 2State Key Laboratory of Bioelectronics, Southeast University, 3Department of Neurology, University of Michigan, 4Geriatric Research, Education and Clinical Center, Veterans Affairs Ann Arbor Health System
Aligned electrospun fibers direct the growth of neurons in vitro and are a potential component of nerve regeneration scaffolds. We describe a procedure for preparing electrospun fiber substrates and the serum-free culture of primary rat E15 sensory (DRG) and motor neurons. Visualization of neurons by immunocytochemistry is also included.
JoVE General
Performing Custom MicroRNA Microarray Experiments
1Department of Pharmacology, University of Minnesota, 2Masonic Cancer Center, University of Minnesota
A simple procedure of performing custom microRNA microarray experiments is described. The steps include isolating RNA, labeling RNA and reference DNA, hybridizing the samples to microarrays, scanning the microarrays, quantifying and analyzing hybridization signals.
JoVE Clinical and Translational Medicine
How to Measure Cortical Folding from MR Images: a Step-by-Step Tutorial to Compute Local Gyrification Index
1Department of Psychiatry, University of Geneva School of Medicine, 2Signal Processing Laboratory, École Polytechnique Fédérale de Lausanne, 3Department of Radiology, University Hospital Center and University of Lausanne, 4Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital
Measuring gyrification (cortical folding) at any age represents a window into early brain development. Hence, we previously developed an algorithm to measure local gyrification at thousands of points over the hemisphere1. In this paper, we detail the computation of this local gyrification index.
JoVE General
Harvesting and Cryo-cooling Crystals of Membrane Proteins Grown in Lipidic Mesophases for Structure Determination by Macromolecular Crystallography
Herein is described procedures implemented in the Caffrey Membrane Structural and Functional Biology Group to harvest and cryo-cool membrane protein crystals grown in lipidic cubic and sponge phases for use in structure determination using macromolecular X-ray crystallography.
JoVE General
Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter
1School of Forestry and Environmental Studies, Yale University, 2Department of Biological Sciences, Virginia Tech, 3Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem
We present methods to evaluate how predation risk can alter the chemical quality of herbivore prey by inducing dietary changes to meet demands of heightened stress, and how the decomposition of carcasses from these stressed herbivores slows subsequent plant litter decomposition by soil microbes.
JoVE Immunology and Infection
Combination of Adhesive-tape-based Sampling and Fluorescence in situ Hybridization for Rapid Detection of Salmonella on Fresh Produce
1Center for Meat Safety and Quality, Department of Animal Sciences, Colorado State University, 2Rapid Microbial Detection and Control Laboratory, Department of Food Science and Human Nutrition, Iowa State University
This protocol describes a simple adhesive-tape-based approach for sampling of tomato and other fresh produce surfaces, followed by rapid whole cell detection of Salmonella using fluorescence in situ hybridization (FISH).
JoVE General
Diagnostic Necropsy and Selected Tissue and Sample Collection in Rats and Mice
1Research Animal Diagnostic Services, Charles River, 2Research Models and Services, Charles River, 3Department of Comparative Medicine, University of Washington
This article describes the procedures for conducting a basic postmortem examination of a mouse or rat, and the collection of basic organs, as well as more challenging sample types from for histological, microbiological, and PCR evaluation.
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 Clinical and Translational Medicine
Femoral Arterial and Venous Catheterization for Blood Sampling, Drug Administration and Conscious Blood Pressure and Heart Rate Measurements
Department of Pharmacology and Toxicology, Michigan State University
Chronic catheterization of blood vessels in the rat is often required for administration of substances, obtain blood sample over a period of time or for direct conscious blood pressure measurements. Femoral arterial catheterization of the rat and corresponding measurements of blood pressure in the conscious animal will be demonstrated.
JoVE Neuroscience
Targeted Training of Ultrasonic Vocalizations in Aged and Parkinsonian Rats
1Department of Surgery-Division of Otolaryngology, University of Wisconsin, 2Department of Communicative Disorders, University of Wisconsin
Voice disorders are debilitating in aging and Parkinson disease. The ultrasonic vocalizations of rats, also affected by these conditions, can be used to study these voice disorders, their neural substrates, and the nature of functional recovery with behavioral intervention.
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