Food:
Any substances taken in by the body that provide nourishment.
JoVE General
Environmentally Induced Heritable Changes in Flax
Department of Biology, Case Western Reserve University
Growing some flax varieties under nutrient stress results in genomic variation within a subset of the genome and phenotypic variation. A complex insertion at a specific site is associated with growth under various nutrient regimes and with changes in gene expression around this site.
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 General
Spatial Multiobjective Optimization of Agricultural Conservation Practices using a SWAT Model and an Evolutionary Algorithm
1School of Environmental and Forest Sciences, University of Washington, 2Center for Agricultural and Rural Development, Department of Economics, Iowa State University, 3Department of Civil, Architectural, and Environmental Engineering, North Carolina A&T University, 4Iowa Geological and Water Survey
This work demonstrates an integration of a water quality model with an optimization component utilizing evolutionary algorithms to solve for optimal (lowest-cost) placement of agricultural conservation practices for a specified set of water quality improvement objectives. The solutions are generated using a multi-objective approach, allowing for explicit quantification of tradeoffs.
JoVE General
Studying Age-dependent Genomic Instability using the S. cerevisiae Chronological Lifespan Model
Here we describe a set of DNA mutation assays that can be combined with the yeast chronological life span model to study the genes/pathways that regulate or contribute to genomic DNA instability during aging.
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 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
Agar-Block Microcosms for Controlled Plant Tissue Decomposition by Aerobic Fungi
Department of Bioproducts and Biosystems Engineering, University of Minnesota
This video demonstrates a controlled environment approach to study degradation of lignocellulosic plant tissues by aerobic fungi. The ability to control nutrient sources and moisture is a key advantage of agar-block microcosms, but the approach often yields mixed success. We address critical pitfalls to yield reproducible, low-variability results.
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 Bioengineering
Microfluidic Device for Recreating a Tumor Microenvironment in Vitro
Department of Chemical Engineering, University Of Massachusetts Amherst
We present the procedure for fabrication and operation of a microfluidic device that recreates heterogeneous tumor microenvironments in vitro. The variability in apoptosis within tumor tissue was quantified using fluorescent stains and the effective diffusion coefficient of the chemotherapeutic drug doxorubicin into tumor tissue was evaluated.
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 Bioengineering
Time-lapse Fluorescence Imaging of Arabidopsis Root Growth with Rapid Manipulation of The Root Environment Using The RootChip
1Department of Plant Biology, Carnegie Institution for Science, 2Howard Hughes Medical Institute, 3Departments of Applied Physics and Bioengineering, Stanford University, 4Department of Microsystems Engineering (IMTEK) and Center for Biological Signaling Studies (BIOSS), University of Freiburg
This article provides a protocol for cultivation of Arabidopsis seedlings in the RootChip, a microfluidic imaging platform that combines automated control of growth conditions with microscopic root monitoring and FRET-based measurement of intracellular metabolite levels.
JoVE General
Long-term, High-resolution Confocal Time Lapse Imaging of Arabidopsis Cotyledon Epidermis during Germination
1Department of Biology, University of Washington, 2Howard Hughes Medical Institute, University of Washington, 3PRESTO, Japan Science and Technology Agency
We describe a protocol using chamber slides and media to immobilize plant cotyledons for confocal imaging of the epidermis over several days of development, documenting stomatal differentiation. Fluorophore-tagged proteins can be tracked dynamically by expression and subcellular localization, increasing understanding of their possible roles during cell division and cell-type differentiation.
JoVE General
Culture and Maintenance of Human Embryonic Stem Cells
Research and Development, Stemgent
This protocol demonstrates how to maintain healthy, undifferentiated human embryonic stem (ES) cells.
JoVE Immunology and Infection
In vitro Biofilm Formation in an 8-well Chamber Slide
Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital
This article describes the procedure for the formation and visualization of a bacterial biofilm grown within an 8-well chamber slide
JoVE Clinical and Translational Medicine
Generation of Alginate Microspheres for Biomedical Applications
1Department of Chemical and Biological Engineering, Illinois Institute of Technology, 2Department of Biomedical Engineering, Illinois Institute of Technology, 3Department of Biomedical Engineering, University of California at Irvine, 4Wake Forest Institute for Regenerative Medicine and Department of Biomedical Engineering, Wake Forest University Health Sciences, 5Research Service, Hines Veterans Administration Hospital
In the following sections, we outline procedures for the preparation of alginate microspheres for use in biomedical applications. We specifically illustrate a technique for creating multilayered alginate microspheres for the dual purpose of cell and protein encapsulation as a potential treatment for type 1 diabetes.
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 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 3D System for Culturing Human Articular Chondrocytes in Synovial Fluid
1Department of Anatomy and Cellular Biology, Tufts University School of Medicine, 2Department of Rheumatology, Tufts Medical Center
A 3D system of culturing human articular chondrocytes in high levels of synovial fluid is described. Synovial fluid reflects the most natural microenvironment for articular cartilage, and can be easily obtained and stored. This system thus can be used for studying cartilage regeneration and for screening therapeutics for treating arthritis.
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
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
Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation
1Institute for Biological Interfaces, Karlsruhe Research Centre, 2Institute for BioMedical Technology, University of Twente, 3Department of Materials Research, Institute for Heavy Ion Research, 4Institute of Microstructure Technology, Karlsruhe Research Centre, 5Institute for Micro Process Engineering, Karlsruhe Research Centre
We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.
JoVE General
Assessing Neural Stem Cell Motility Using an Agarose Gel-based Microfluidic Device
1Biomedical Engineering Department, Cornell University, 2Neurosurgical Laboratory for Translational Stem Cell Research, Weill Cornell Brain Tumor Center, Weill Cornell Medical College of Cornell University, 3Cell Morphology Department, Instituto de Investigacion Principe Felipe, 4Department of Chemical and Biomolecular Engineering, Cornell University
We demonstrate that the over expression of epidermal growth factor receptors (EGFR) enhances the motility of neural stem cells(NSCs) using a novel agarose gel based microfluidic device. This technology can be readily adaptable to other mammalian cell systems where cell sources are scarce, such as human neural stem cells, and the turn around time is critical.
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 Neuroscience
Screening Assay for Oxidative Stress in a Feline Astrocyte Cell Line, G355-5
1College of Veterinary Medicine, Western University of Health Sciences, 2Graduate College of Biomedical Sciences, Western University of Health Sciences, 3ReadiSorb, Products
A screening method to detect oxidative cellular environments is to measure the oxidation of CM-H2DCFDA. Once oxidized within a cell, CM-H2DCFDA changes from non-fluorescent into a fluorescent compound. This change in fluorescence is measured by flow cytometry and indicates the number of cells in an oxidative environment.
JoVE General
Design and Use of Multiplexed Chemostat Arrays
Department of Genome Sciences, University of Washington
We developed and validated a small-footprint array of miniature chemostats built from readily available parts for low cost. Physiological and experimental evolution results were similar to larger volume chemostats. The ministat array provides a compact, inexpensive, and accessible platform for traditional chemostat experiments, functional genomics, and chemical screening applications.
JoVE General
Embryonic Stem Cell-Derived Endothelial Cells for Treatment of Hindlimb Ischemia
1Division of Cardiovascular Medicine, Stanford University, 2Department of Radiology, Stanford University
The surgical procedure for delivery of embryonic stem cell-derived endothelial cells to the ischemic hindlimb is demonstrated, with non-invasive tracking by bioluminescence imaging.
JoVE Bioengineering
Fabrication of Micro-tissues using Modules of Collagen Gel Containing Cells
1Institute of Biomaterials and Biomedical Engineering / Department of Chemical Engineering and Applied Chemistry, University of Toronto, 2Institute of Biomaterials and Biomedical Engineering, University of Toronto
Creation of micro-tissues using cylindrical collagen gels, called modules, that contain embedded cells and which surface is coated with endothelial cells.
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 Clinical and Translational Medicine
Evaluation of Cancer Stem Cell Migration Using Compartmentalizing Microfluidic Devices and Live Cell Imaging
1Department of Biomedical Engineering, University of Wisconsin-Madison, 2Materials Science Program, University of Wisconsin-Madison, 3Department of Neurological Surgery, University of Wisconsin-Madison, 4Carbone Comprehensive Cancer Center and Center for Stem Cell and Regenerative Medicine, University of Wisconsin-Madison
A compartmentalizing microfluidic device for investigating cancer stem cell migration is described. This novel platform creates a viable cellular microenvironment and enables microscopic visualization of live cell locomotion. Highly motile cancer cells are isolated to study molecular mechanisms of aggressive infiltration, potentially leading to more effective future therapies.
JoVE Immunology and Infection
Generation of Multivirus-specific T Cells to Prevent/treat Viral Infections after Allogeneic Hematopoietic Stem Cell Transplant
Center for Cell and Gene Therapy, Baylor College of Medicine
A rapid, simple and cost-effective protocol for the generation of donor-derived multivirus-specific CTLs (rCTL) for infusion to allogeneic hematopoietic stem cell transplant (HSCT) recipients at risk of developing CMV, Adv or EBV infections. This manufacturing process is GMP-compliant and should ensure the broader implementation of T-cell immunotherapy beyond specialized centers.
JoVE General
Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana
1Department of Environmental Quality Monitoring, Institute for Environmental Protection and Research, 2Regional Agency for Environmental Protection in Emilia-Romagna
This study concerns the development and standardization of a valuable methodological protocol to determine long-term (14 days) lethal toxicity exerted by chemical substances, industrial wastewater or sewage and liquid environmental samples on the saltwater crustacean, Artemia franciscana.
JoVE Immunology and Infection
Customization of Aspergillus niger Morphology Through Addition of Talc Micro Particles
Institute of Biochemical Engineering, Technische Universität Braunschweig
A method to precisely generate and to comprehensively characterize morphology of filamentous fungus Aspergillus niger is described, which allows the mathematical correlation of morphological appearance and productivity.
JoVE Bioengineering
Preparation of Intact Bovine Tail Intervertebral Discs for Organ Culture
ARTORG Center for Biomedical Engineering, University of Bern
This protocol illustrates a harvesting technique for coccygeal bovine intervertebral discs for organ culture for in vitro organ culture.
JoVE Bioengineering
Generation and Recovery of β-cell Spheroids From Step-growth PEG-peptide Hydrogels
The following protocol provides techniques for encapsulating pancreatic β-cells in step-growth PEG-peptide hydrogels formed by thiol-ene photo-click reactions. This material platform not only offers a cytocompatible microenvironment for cell encapsulation, but also permits user-controlled rapid recovery of cell structures formed within the hydrogels.
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 Bioengineering
Alginate Microcapsule as a 3D Platform for Propagation and Differentiation of Human Embryonic Stem Cells (hESC) to Different Lineages
1Stem Cell Lab, School of Psychiatry, Faculty of Medicine, The University of New South Wales, 2Siriraj Center of Excellence for Stem cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, 3Neuropsychiatric Institute, Prince of Wales Hospital
We have optimized a microencapsulation technique as an effective 3D platform for propagation and differentiation of embryonic stem cells to endoderm and dopaminergic (DA) neurons. It also provides an opportunity for immune-isolation of cells from the host during transplantation. This platform can be adapted for other cell types.
JoVE Bioengineering
Tracking Hypoxic Signaling within Encapsulated Cell Aggregates
1Biomedical Engineering Program, University of South Carolina, 2Chemical Engineering Department, University of South Carolina
A method for photo-encapsulation of cells in a crosslinked PEG hydrogel is described. Hypoxic signaling within encapsulated murine insulinoma (MIN6) aggregates is tracked using a fluorescent marker system. This system allows serial examination of cells within a hydrogel scaffold and correlation of hypoxic signaling with changes in cell phenotype.
JoVE Immunology and Infection
Expansion, Purification, and Functional Assessment of Human Peripheral Blood NK Cells
Division of Pediatrics, MD Anderson Cancer Center - University of Texas
Here we describe a method to efficiently expand and purify large numbers of human NK cells and assess their function.
JoVE General
Cryopreserving and Recovering of Human iPS Cells using Complete KnockOut Serum Replacement Feeder-Free Medium
This protocol describes the detailed procedure for cryopreserving human iPS cells in KnockOut SR cryopreservation medium and recovering these cells in complete KnockOut SR Feeder Free (KSR-FF) medium or feeder-based KnockOut SR medium.
JoVE General
Measures of Heart and Ventilatory Rates in Freely Moving Crayfish
Department of Biology, University of Kentucky
Invertebrates show an autonomic sympathetic-like response similar to that described for vertebrates. The coordination of the cardio-vascular and ventilatory systems allows for measurement of a biological index in which to assess an organism internal state.
JoVE General
Catheterization of Intestinal Loops in Ruminants
1Department of Agricultural, Food and Nutritional Science, University of Alberta, 2Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge
We describe a novel surgical method for catheterizing 'intestinal loops' within the ileum of sheep. Once animals have recovered from surgery and have cleared antibiotics and analgesics, multiple treatments can be deposited directly in loops via the catheters.
JoVE Bioengineering
Decellularization and Recellularization of Whole Livers
Perfusion decellularization is a novel technique to produce whole liver scaffolds that retains the organ's extracellular matrix composition and microarchitecture. Herein, the method of preparing whole organ scaffolds using perfusion decellularization and subsequent repopulation with hepatocytes is described. Functional and transplantable liver grafts can be generated using this technique.
JoVE Immunology and Infection
Separation of Single-stranded DNA, Double-stranded DNA and RNA from an Environmental Viral Community Using Hydroxyapatite Chromatography
1Department of Microbial and Environmental Genomics, The J. Craig Venter Institute, 2Department of Synthetic Biology and Bioenergy, The J. Craig Venter Institute
We describe an efficient method to separate single-stranded DNA, double-stranded DNA and RNA molecules from environmental viral communities. Nucleic acids are fractionated using hydroxyapatite chromatography with increasing concentrations of phosphate-containing buffers. This method permits the isolation of all viral nucleic acid types from environmental samples.
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
Constructing a Collagen Hydrogel for the Delivery of Stem Cell-loaded Chitosan Microspheres
Department of Regenerative Medicine, United States Army Institute of Surgical Research
A major hurdle in current stem cell therapies is determining the most effective method to deliver these cells to host tissues. Here, we describe a chitosan-based delivery method that is efficient and simple in approach, while allowing adipose-derived stem cells to maintain their multipotency.
JoVE General
A Quantitative Fitness Analysis Workflow
Institute for Cell and Molecular Biosciences, Newcastle University Medical School
Quantitative Fitness Analysis (QFA) is a complementary series of experimental and computational methods for estimating microbial culture fitnesses. QFA estimates the effect of genetic mutations, drugs or other applied treatments on microbe growth. Experiments scaling from focussed analysis of single cultures to thousands of parallel cultures can be designed.
JoVE General
Whole-mount Immunohistochemical Analysis for Embryonic Limb Skin Vasculature: a Model System to Study Vascular Branching Morphogenesis in Embryo
We introduce a whole-mount immunohistochemistry and laser scanning confocal microscopy with multiple labelling for analyzing intricate vascular network formation in mouse embryonic limb skin.
JoVE General
Using High Resolution Computed Tomography to Visualize the Three Dimensional Structure and Function of Plant Vasculature
1U.S. Department of Agriculture, 2Department of Viticulture and Enology, University of California - Davis, 3Hawkesbury Institute for the Environment, University of Western Sydney, 4Advanced Light Source, Lawrence Berkeley National Lab, 5Citrus Research & Education Center, University of Florida
High resolution x-ray computed tomography (HRCT) is a non-destructive diagnostic imaging technique that can be used to study the structure and function of plant vasculature in 3D. We demonstrate how HRCT facilitates exploration of xylem networks across a wide range of plant tissues and species.
JoVE Bioengineering
Micro-particle Image Velocimetry for Velocity Profile Measurements of Micro Blood Flows
1Department of Chemical and Biological Engineering, University of Ottawa, 2Department of Mechanical Engineering, University of Ottawa
Micro-particle image velocimetry (μPIV) is used to visualize paired images of micro particles seeded in blood flows which are cross-correlated to give an accurate velocity profile. Shear rate, maximum velocity, velocity profile shape, and flow rate, each of which has clinical applications, can be derived from these measurements.
JoVE Immunology and Infection
Co-culture Models of Pseudomonas aeruginosa Biofilms Grown on Live Human Airway Cells
1Department of Physiology, Dartmouth College, 2Department of Biology, Indiana University Purdue University Indianapolis
This paper describes different methods of growing Pseudomonas aeruginosa biofilms on cultured human airway epithelial cells. These protocols can be adapted to study different aspects of biofilm formation, including visualization of the biofilm, staining of the biofilm, measuring the colony forming units (CFU) of the biofilm, and studying biofilm cytotoxicity.
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