JoVE Editorial
April 2012: This Month in JoVE
Here are some highlights from the April 2012 Issue of Journal of Visualized Experiments (JoVE).
JoVE General
Establishment of Microbial Eukaryotic Enrichment Cultures from a Chemically Stratified Antarctic Lake and Assessment of Carbon Fixation Potential
Department of Microbiology, Miami University
Microbial eukaryotes are both a source of photosynthetically-derived carbon and top predatory species in permanently ice-covered Antarctic lakes. This report describes an enrichment culture approach to isolate metabolically versatile microbial eukaryotes from the Antarctic lake, Lake Bonney, and assesses inorganic carbon fixation potential using a radioisotope assay for Ribulose-1,5-bisphophate carboxylase oxygenase (RubisCO) activity.
JoVE Editorial
2012: A Year In Review
1Department of Ophthalmology, Massachusetts Eye and Ear, 2JoVE Content Production
Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
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 General
Depletion of Ribosomal RNA for Mosquito Gut Metagenomic RNA-seq
Department of Biology, New Mexico State University
A ribosomal RNA (rRNA) depletion protocol was developed to enrich messenger RNA (mRNA) for RNA-seq of the mosquito gut metatranscriptome. Sample specific rRNA probes, which were used to remove rRNA via subtraction, were created from the mosquito and its gut microbes. Performance of the protocol can result in the removal of approximately 90-99% of rRNA.
JoVE General
Extraction of High Molecular Weight DNA from Microbial Mats
We provide an improved protocol for extracting high molecular weight DNA from hypersaline microbial mats. Microbial cells are separated from the mat matrix prior to DNA extraction and purification. This enhances the concentrations, quality, and size of the DNA. The protocol may be used for other refractory samples.
JoVE Editorial
JoVE 4th Issue
JoVE General
Isolation of Native Soil Microorganisms with Potential for Breaking Down Biodegradable Plastic Mulch Films Used in Agriculture
1Biology Department, Western Washington University, 2Washington State University Northwestern Research and Extension Center, 3Department of Plant and Soil Science, Texas Tech University
Plastic films labeled "biodegradable" are commercially available for agricultural use as mulches. Tillage represents an attractive disposal method, but degradation under field conditions is poorly understood. The purpose of this study was to develop methods for isolating native soil fungi and bacteria that colonize plastic mulch films after field burial.
JoVE General
Genomic Transformation of the Picoeukaryote Ostreococcus tauri
1SynthSys, University of Edinburgh, 2Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Paris 06, 3UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, Banyuls-sur-Mer, Université Pierre et Marie Curie, Paris 06
This article describes genetic transformation of the unicellular marine alga Ostreococcus tauri by electroporation. This eukaryotic organism is an effective model platform for higher plants, possesing greatly reduced genomic and cellular complexity and being readily amenable to both cell culture and chemical biology.
JoVE General
Generation of RNA/DNA Hybrids in Genomic DNA by Transformation using RNA-containing Oligonucleotides
School of Biology, Georgia Institute of Technology
This work shows how to form an RNA/DNA hybrid at the chromosomal level and reveal transfer of genetic information from RNA to genomic DNA in yeast cells.
JoVE Immunology and Infection
Estimating Virus Production Rates in Aquatic Systems
Department of Microbiology, University of Tennessee
The turnover rate of viruses in marine and freshwater systems can be estimated by a reduction and reoccurrence technique. The data allow researchers to infer rates of virus-mediated microbial mortality in aquatic systems.
JoVE General
Chemotactic Response of Marine Micro-Organisms to Micro-Scale Nutrient Layers
Environmental Microfluidics Group, MIT - Massachusetts Institute of Technology
The fabrication of microfluidic channels and their implementation in experiments for studying the chemotactic foraging behaviour of marine microbes within a patchy nutrient seascape and the swimming behaviour of bacteria within shear flow are described.
JoVE Clinical and Translational Medicine
Experimental Human Pneumococcal Carriage
1Respiratory Infection Group, Liverpool School of Tropical Medicine, 2Royal Liverpool and Broadgreen, University Hospital Trust, 3Comprehensive Local Research Network, 4NIHR Biomedical Research Centre in Microbial Diseases, Royal Liverpool and Broadgreen University Hospitals NHS Trust, 5Institute of Lung Health, Respiratory Biomedical Unit, University Hospitals of Leicester NHS Trust & University of Leicester, 6Department of Clinical Infection Microbiology & Immunology, Institute of Infection & Global Health, University of Liverpool
Experimental human pneumococcal carriage offers a natural model of carriage and a potential model for use in vaccine development. This technique is valuable yet complex and involves clinical risk by introducing a pathogen into a human. We have developed a detailed protocol.
JoVE General
Expression of Recombinant Proteins in the Methylotrophic Yeast Pichia pastoris
Department of Microbiology and Immunology, University of British Columbia - UBC
The protocol describes protein expression using the methylotrophic yeast Pichia pastoris. The preparation of electrocompetent yeast cells, transformation of the vector with the gene of interest into P. pastoris and yeast DNA purification are also performed. Western blot analysis and protein purification build the last steps in this protein expression protocol.
JoVE Immunology and Infection
Assessing Hepatic Metabolic Changes During Progressive Colonization of Germ-free Mouse by 1H NMR Spectroscopy
1School of Chemistry, Food and Pharmacy, The University of Reading, 2Department of Nutritional Sciences, The University of Reading
A progressive colonization procedure is described to further assess its impact on the host hepatic metabolism. Colonization is monitored non invasively by evaluating the urinary excretion of microbial co-metabolites by NMR-based metabolic profiling while hepatic metabolism is assessed by High Resolution Magic Angle Spinning (HR MAS) NMR profiling of intact biopsy.
JoVE General
DNA Extraction from 0.22 μM Sterivex Filters and Cesium Chloride Density Gradient Centrifugation
Department of Microbiology and Immunology, University of British Columbia - UBC
We describe a method for extraction of high molecular weight genomic DNA from planktonic biomass concentrated on 0.22 μm Sterivex filters, followed by cesium chloride density gradient centrifugation for purification.
JoVE General
Analyzing Gene Expression from Marine Microbial Communities using Environmental Transcriptomics
Department of Marine Sciences, University of Georgia (UGA)
We present a method for generating cDNA from environmental mRNA. In general, total RNA is first collected from the environment, rRNA is selectively removed, mRNA is selectively amplified, and cDNA synthesized from the enriched mRNA pool is sequenced. Recovered sequences can be annotated using standard bioinformatics techniques to identify the expressed genes.
JoVE Immunology and Infection
Single-cell Analysis of Bacillus subtilis Biofilms Using Fluorescence Microscopy and Flow Cytometry
Institute for Molecular Infection Biology (IMIB), University of Würzburg
Microbial biofilms are generally constituted by distinct subpopulations of specialized cells. Single-cell analysis of these subpopulations requires the use of fluorescent reporters. Here we describe a protocol to visualize and monitor several subpopulationswithin B. subtilis biofilms using fluorescence microscopy and flow cytometry.
JoVE Immunology and Infection
Pseudomonas aeruginosa and Saccharomyces cerevisiae Biofilm in Flow Cells
1Department of Systems Biology, Danish Technical University, 2Department of Biology, University of Copenhagen
Protocol describing the application of a flow cell system for growing and analyzing microbial biofilms for Confocal Laser Scanning Microscopy (CLSM).
JoVE General
GC-based Detection of Aldononitrile Acetate Derivatized Glucosamine and Muramic Acid for Microbial Residue Determination in Soil
1DOE-Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, 2Department of Soil Science, University of Wisconsin, Madison, 3Department of Soil and Water Science, University of Florida
We describe a method protocol for the GC-based analysis of the aldonitrile acetate derivatives of glucosamine and muramic acid extracted from soil. For elucidation of the chemical mechanism, we also present a strategy to confirm the structure of the derivative and the ion fragments formed upon electron ionization.
JoVE General
Yeast Colony Embedding Method
School of Biological Sciences, University of Missouri - Kansas City
A method for embedding yeast colonies allowing sectioning for light and electron microscopy. This protocol allows determination of the distribution of sporulated cells and pseudohyphal cells within colonies providing a new tool toward understanding the organization of cell types within a fungal community.
JoVE Immunology and Infection
Differentiating Functional Roles of Gene Expression from Immune and Non-immune Cells in Mouse Colitis by Bone Marrow Transplantation
Bone marrow transplantation provides a way to change the genotype of the bone marrow derived cells. If the gene of interest is expressed in both bone marrow derived cells and non-bone marrow derived cells, bone marrow transplantation can change the bone marrow derived cells to a different genotype without changing the non-bone marrow derived cell genotype.
JoVE General
Window on a Microworld: Simple Microfluidic Systems for Studying Microbial Transport in Porous Media
1Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, 2Department of Biomedical Engineering, Vanderbilt University, 3Department of Molecular Physiology and Biophysics, Vanderbilt University, 4Department of Physics and Astronomy, Vanderbilt University, 5Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 6Center for Environmental Sciences and Engineering, University of Connecticut
Microfluidic devices can be used to visualize complex natural processes in real time and at the appropriate physical scales. We have developed a simple microfluidic device that mimics key features of natural porous media for studying growth and transport of bacteria in the subsurface.
JoVE General
Extracting DNA from the Gut Microbes of the Termite (Zootermopsis Angusticollis) and Visualizing Gut Microbes
Department of Environmental Science and Engineering, California Institute of Technology - Caltech
This video illustrates the technique for extracting DNA from the species of microbes resident in the termite hindgut. The preparation of a wet mount slide, which is useful for visualizing the gut microbial community is also illustrated, and a tour through the species-rich gut environment is given.
JoVE General
Assay for Adhesion and Agar Invasion in S. cerevisiae
Department of Molecular Biology, Princeton University
We describe a qualitative assay for yeast adhesion and agar invasion as a measure of invasive and pseudohyphal differentiation. This simple assay can be used to assess the invasive phenotype of various mutants as well as the effects environmental cues and signaling pathways on yeast differentiation.
JoVE General
Use of LysoTracker to Detect Programmed Cell Death in Embryos and Differentiating Embryonic Stem Cells
We present a simple protocol to visualize regions of programmed cell death (PCD) in mouse embryos and differentiating embryonic stem (ES) cell cultures using a highly soluble dye called LysoTracker.
JoVE General
Testing Protozoacidal Activity of Ligand-lytic Peptides Against Termite Gut Protozoa in vitro (Protozoa Culture) and in vivo (Microinjection into Termite Hindgut)
Department of Entomology, Louisiana State University Agricultural Center
We present procedures for demonstrating that ligands bind to the surface membrane of the cellulose-digesting protozoa in the gut of Formosan subterranean termites using fluorescent microscopy and that ligands coupled with lytic peptides kill these protozoa in vitro (anaerobic protozoa culture) and in vivo (injection into the termite hindgut).
JoVE Clinical and Translational Medicine
Sequencing of Bacterial Microflora in Peripheral Blood: our Experience with HIV-infected Patients
Our experiment will show how to perform a sequencing analysis of bacterial species translocating in peripheral blood of HIV positive patients.
JoVE General
Visualization of Endoplasmic Reticulum Localized mRNAs in Mammalian Cells
Department of Biochemistry, University of Toronto
Here we describe a method to visualize endoplasmic reticulum-associated mRNAs in mammalian tissue culture cells. This technique involves the selective permeabilization of the plasma membrane with digitonin to remove cytoplasmic contents followed by fluorescent in situ hybridization to detect either bulk poly(A) mRNA or specific transcripts.
JoVE General
Cryosectioning Yeast Communities for Examining Fluorescence Patterns
Division of Basic Sciences, Fred Hutchinson Cancer Research Center
We present a protocol for freezing and cryosectioning yeast communities to observe internal patterns of fluorescent cells. The method relies on methanol-fixing and OCT-embedding to preserve the spatial distribution of cells without inactivating fluorescent proteins within a community.
JoVE Immunology and Infection
Biocontained Carcass Composting for Control of Infectious Disease Outbreak in Livestock
1Agriculture and Agri-Food Canada, Lethbridge Research Centre, 2Department of Bioscience and Biotechnology, Dalian University of Technology, 3Agriculture Centre, Alberta Agriculture and Rural Development
Using readily available materials, this biocontained composting system enables effective on-site disposal of large animal carcasses arising in the event of infectious disease outbreak. This procedure kills most infectious agents in carcasses and contaminated manure. Once infectious agent is confirmed non-viable, mature compost can be spread as fertilizer.
JoVE Application Notes
Orflo Moxi - ADVERTISEMENT
Moxi Z is the only automated cell counter that combines the Coulter Principle typically used in high-end cell counters with a patented thin-film sensor technology to allow for highly accurate (> 95%) and repeatable particle counting and sizing for a broad range of cell types - from mammalian cells to cells as small as wine yeast and more. Since today's workflows demand accurate quality control of samples, determining cell counts precisely has a significant impact on outcomes and downstream costs.
JoVE General
Small Volume (1-3L) Filtration of Coastal Seawater Samples
Department of Microbiology and Immunology, University of British Columbia - UBC
This video documents small volume (~1 L) filtration of microbial biomass from the water column.
JoVE General
Large Volume (20L+) Filtration of Coastal Seawater Samples
Department of Microbiology and Immunology, University of British Columbia - UBC
This video documents large volume (≥20 L) filtration of microbial biomass, ranging between 0.22μm and 2.7μm in diameter, from the water column.
JoVE General
Measuring Replicative Life Span in the Budding Yeast
1Department of Biochemistry, University of Washington, 2Department of Pathology, University of Washington
In this article we present a general protocol for measuring the replicative life span of yeast mother cells.
JoVE General
A Quantitative Assessment of The Yeast Lipidome using Electrospray Ionization Mass Spectrometry
Department of Biology, Concordia University
We describe a new quantitative lipidomics method for identifying numerous lipid species in yeast using survey-scan electrospray ionization mass spectrometry (ESI/MS). This method exceeds currently available methods for lipid identification and quantification in the ability to resolve various molecular forms of lipids, sensitivity, and speed.
JoVE Immunology and Infection
Microtiter Dish Biofilm Formation Assay
Microbiology and Immunology, Dartmouth Medical School
The assay describes a rapid means to measure early biofilm formation in bacteria and fungi. This method uses a microtiter plate as the substratum for microbial biofilm formation, and the biofilm is visualized using crystal violet strain. The assay provides either a qualitative or quantitative assay for early biofilm formation.
JoVE General
Obtaining Hemocytes from the Hawaiian Bobtail Squid Euprymna scolopes and Observing their Adherence to Symbiotic and Non-Symbiotic Bacteria
Department of Molecular and Cell Biology, University of Connecticut
This video will demonstrate how to obtain hemocytes (blood cells) from the Hawaiian bobtail squid, Euprymna scolopes for use in cell biological and bacterial adhesion assays. Hemocytes will be stained with a fluorescent dye and exposed to GFP-labeled bacteria.
JoVE General
Genomic MRI - a Public Resource for Studying Sequence Patterns within Genomic DNA
Department of Medicine, University of Toledo Health Science Campus
We present a public computational web site for the analysis of genomic sequences. It detects DNA sequence patterns with various non-random nucleotide compositions. This resource also generates randomized sequences with diverse levels of complexity.
JoVE General
Preparation of Adult Drosophila Eyes for Thin Sectioning and Microscopic Analysis
Department of Developmental and Molecular Biology, Albert Einstein College of Medicine
A standard approach to prepare adult Drosophila eyes for semi-thin sectioning and light microscopic analysis is presented here. The protocol can be used for gross morphological analysis of eye defects, or with the indicated adjustments can be used to determine genetic requirements of genes in specific cell types of the eye (e.g. clonal analysis of photoreceptors) or for electron microscopic analysis.
JoVE Editorial
The 2009 Lindau Nobel Laureate Meeting: Werner Arber, Physiology or Medicine 1978
Swiss microbial geneticist, Werner Arber shared the 1978 Nobel Prize in Physiology or Medicine with Hamilton Smith and Daniel Nathans for their discovery of restriction endonucleases. Arber found that viral DNA introduced into a non-specific bacterial host was changed, while host DNA was protected by methylation. He theorized that a microbial enzyme cut the DNA into smaller pieces, while at the same time, the methylated host DNA was protected from its own enzymes. Later work done by Nathans and Smith validated his theory, which laid the foundation for recombinant DNA technology.
JoVE Immunology and Infection
Enzyme-linked Immunospot Assay (ELISPOT): Quantification of Th-1 Cellular Immune Responses Against Microbial Antigens
1Department of Medicine, Vanderbilt University School of Medicine, 2Department of Microbiology and Immunology, Vanderbilt University School of Medicine
Identification of microbial targets of adaptive immunity in idiopathic diseases can be accomplished by the use of the enzyme-linked immunospot assay.
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
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 Immunology and Infection
Cost-effective Method for Microbial Source Tracking Using Specific Human and Animal Viruses
The study describes a cost-effective method for the identification of the source of fecal/urine contamination or contamination by nitrates in water using qPCR for the specific quantification of human/porcine/bovine DNA viruses, adenoviruses and polyomaviruses, proposed as MST tools.
JoVE General
Concentration of Metabolites from Low-density Planktonic Communities for Environmental Metabolomics using Nuclear Magnetic Resonance Spectroscopy
1Biosphere Oriented Biology Research Unit, RIKEN Advanced Science Institute, 2Graduate School of Nanobioscience, Yokohama City University, 3Advanced NMR Metabomics Research Team, RIKEN Plant Science Center, 4Graduate School of Bioagricultural Science, Nagoya University
A method for metabolite extraction from microbial planktonic communities is presented. Whole community sampling is achieved by filtration onto specially prepared filters. After lyophilization, aqueous-soluble metabolites are extracted. This approach allows for application of environmental metabolomics to trans-omics investigations of natural or experimental microbial communities.
JoVE General
Bacterial Gene Expression Analysis Using Microarrays
Department of Environmental Toxicology, University of California Santa Cruz - UCSC
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
Making Gynogenetic Diploid Zebrafish by Early Pressure
1Institute of Neuroscience, University of Oregon, 2Division of Basic Science, Fred Hutchinson Cancer Research Center - FHCRC
This is a method for generating gynogenetic diploid zebrafish embryos (embryos whose only genetic contribution comes from the mother) by blocking the second meiotic division immediately after fertilization with ultraviolet light-inactivated sperm. EP embryos are not fully homozygous due to recombination during the first meiotic division, however they are homozygous at all loci that have not been separated from their centromere by recombination.
JoVE General
Investigating the Microbial Community in the Termite Hindgut - Interview
Department of Environmental Science and Engineering, California Institute of Technology - Caltech
Jared Leadbetter explains why the termite-gut microbial community is an excellent system for studying the complex interactions between microbes. The symbiotic relationship existing between the host insect and lignocellulose-degrading gut microbes is explained, as well as the industrial uses of these microbes for degrading plant biomass and generating biofuels.
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