Microinjections:
The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.
JoVE General
Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c
1Department of Cell and Developmental Biology, Neuroscience Center, University of North Carolina, 2Curriculum in Neurobiology, Neuroscience Center, University of North Carolina
In this protocol, we describe the direct cytoplasmic microinjection of cytochrome c protein into fibroblasts and primary sympathetic neurons. This technique allows for the introduction of cytochrome c protein into the cytoplasm of cells and mimics the release of cytochrome c from mitochondria, which occurs during apoptosis.
JoVE General
Intranuclear Microinjection of DNA into Dissociated Adult Mammalian Neurons
Direct intranuclear injection of cDNA is an effective transfection technique for post-mitotic cells. This method provides high levels of heterologous protein expression from single or multiple cDNA constructs and enables protein function to be studied in a physiologically relevant environment with a variety of single cell assays.
JoVE General
Correlative Light and Electron Microscopy (CLEM) as a Tool to Visualize Microinjected Molecules and their Eukaryotic Sub-cellular Targets
Department of Molecular Microbiology, University of Texas Southwestern Medical Center
The CLEM technique has been adapted to analyze ultrastructural morphology of membranes, organelles, and subcellular structures affected by microinjected molecules. This method combines the powerful techniques of micromanipulation/microinjection, confocal fluorescent microscopy, and electron microscopy to allow millimeter to multi-nanometer resolution. This technique is amenable to a wide variety of applications.
JoVE General
Microinjection of mRNA and Morpholino Antisense Oligonucleotides in Zebrafish Embryos.
Department of Genetics, Yale University School of Medicine
Microinjection is a well-established and effective method for introducing foreign substances into fertilized zebrafish embryos. Here, we demonstrate a robust microinjection technique for performing mRNA overexpression, and morpholino oligonucleotide gene knockdown studies in zebrafish.
JoVE Immunology and Infection
Methods for Rapid Transfer and Localization of Lyme Disease Pathogens Within the Tick Gut
1Department of Veterinary Medicine, University of Maryland, 2Department of Entomology, Connecticut Agricultural Experiment Station
Lyme disease research studies often require generation of ticks infected with the pathogen Borrelia burgdorferi, a process that typically takes several weeks. Here we demonstrate a microinjection-based tick infection procedure that can be accomplished within hours. We also demonstrate an immunofluorescence method for in situ localization of B. burgdorferi within ticks.
JoVE General
Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection
Department of Biochemistry, University of Toronto
Here we describe an assay that employs the power of microinjection coupled with fluorescent in situ hybridization in order to accurately measure the nuclear export kinetics of mRNA in mammalian somatic cells.
JoVE General
Live Cell Imaging of F-actin Dynamics via Fluorescent Speckle Microscopy (FSM)
Department of Cell Biology, Scripps Institute
Selection, microinjection, and imaging of fluorescently-labeled F-actin via fluorescent speckle microscopy (FSM).
JoVE General
Laser Ablation of the Zebrafish Pronephros to Study Renal Epithelial Regeneration
Department of Biological Sciences, University of Notre Dame
Acute kidney injury (AKI) in humans is a common clinical problem caused by damage to the epithelial cells that comprise kidney nephrons, and AKI is associated with high mortality rates of 50-70%1. Following epithelial cell destruction, nephrons have a limited ability to regenerate, though the mechanisms and limitations that guide this phenomenon remain poorly understood. In this video article, we describe our technique for targeted laser ablation of kidney nephron cells in the zebrafish embryo kidney, or pronephros. Our new method can be used to complement nephrotoxicity-induced models of AKI and gain a high-resolution understanding of the cell and molecular alterations that are associated with epithelial regeneration in the kidney nephron.
JoVE Neuroscience
Live-imaging of PKC Translocation in Sf9 Cells and in Aplysia Sensory Neurons
Neurology and Neurosurgery, McGill University
In this video, we demonstrate visualization of PKC translocation in living cells using fluorescently tagged PKCs.
JoVE General
Microinjection of Xenopus Laevis Oocytes
Department of Zoology, University of British Columbia - UBC
Here we demonstrate cytoplasmic microinjection of Xenopus laevis oocytes with a nuclear import substrate, as well as preparation of the injected oocytes for visualization by thin-sectioning electron microscopy.
JoVE Neuroscience
An Assay for Permeability of the Zebrafish Embryonic Neuroepithelium
1Department of Biology, Massachusetts Institute of Technology, 2Whitehead Institute of Biomedical Research
We describe a live whole animal quantitative measurement for permeability of the embryonic zebrafish brain. The technique analyzes the ability to retain cerebrospinal fluid and molecules of different molecular weights within the neural tube lumen and quantifies their movement out of the ventricles. This method is useful for determining differences in epithelial permeability and maturation during development and disease.
JoVE Neuroscience
Manual Drainage of the Zebrafish Embryonic Brain Ventricles
We present a method to collect cerebrospinal fluid (CSF) and to create a system which lacks CSF within the embryonic zebrafish brain ventricular system. This allows for further examination of CSF composition and its requirement during embryonic brain development.
JoVE General
Injection of An. stephensi Embryos to Generate Malaria-resistant Mosquitoes
1Department of Molecular Biology and Biochemistry, University of California, Irvine (UCI), 2Department of Molecular Biology and Biochemistry, Department of Microbiology and Molecular Genetics, University of California, Irvine (UCI)
Anopheles stephensi mosquitoes are vectors for malaria inhabiting India and throughout Asia. This video demonstrates the technique for performing microinjections of this species with transgenes that will confer resistance to the malaria to the mosquito. Much of the methodology demonstrated in this video is applicable to microinjection techniques of other mosquito species.
JoVE General
Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
Department of Biology, University of Pennsylvania
Oocytes are prone to aneuploidy due to errors in chromosome segregation during meiotic maturation. Aneuploid eggs can cause infertility, miscarriages or developmental disorders like Down syndrome. Here, we describe methods to introduce materials of choice into oocytes and methods to study meiotic maturation and assess ploidy.
JoVE General
Measuring Fast Calcium Fluxes in Cardiomyocytes
1Department of Biological Sciences and Geology, Queensborough Community College, 2Department of Physiology & Biophysics, Stony Brook University
We present a method to isolate rapid (microsecond) calcium events from slower fluxes in living cells using laser scanning confocal microscopy. The method measures fluorescence intensity fluctuations of calcium indicators by recording line scans of several hundred pixels in a cell. Histogram analysis allows us to isolate the time scales of different calcium fluxes.
JoVE General
Microinjection of A. aegypti Embryos to Obtain Transgenic Mosquitoes
1Department of Molecular Biology and Biochemistry, University of California, Irvine (UCI), 2Department of Molecular Biology and Biochemistry, Department of Microbiology and Molecular Genetics, University of California, Irvine (UCI)
In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever. The techniques for correctly preparing microinjection needles, dessicating embryos, and performing microinjection are demonstrated.
JoVE General
Tissue Determination Using the Animal Cap Transplant (ACT) Assay in Xenopus laevis
Department of Ophthalmology, SUNY Upstate Medical University
Animal caps overexpressing gene product(s) are transplanted to the flank of developing Xenopus laevis embryos in order to establish whether tissue is determined.
JoVE General
Analyzing the Function of Small GTPases by Microinjection of Plasmids into Polarized Epithelial Cells
Department of Cell and Molecular Biology, Northwestern University
This article details the procedures involved in overexpression and analysis of small GTPases in polarized epithelial cells using microinjection technique.
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 General
An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications
1Department of Biomedical Engineering, Cornell University, 2Current Address: Mechanical Engineering Department, Dogus University
In this article, we present a simple methodology to enable long-term ex-ovo avian embryo culture. This technique is ideal for longitudinal experimentation requiring complete optical accessibility and/or sterile transportation in avian embryos.
JoVE General
Visualizing RNA Localization in Xenopus Oocytes
Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University
Visualization of in vivo RNA transport is accomplished by microinjection of fluorescently labeled RNA transcripts into Xenopus oocytes, followed by confocal microscopy.
JoVE Neuroscience
Labeling and Imaging Cells in the Zebrafish Hindbrain
1Department of Biological Sciences, University of Maryland, Baltimore County, 2Center for Neuroscience, Children's National Medical Center
Key to understanding the morphogenetic processes that shape the early embryo is the ability to image cells at high resolution. We describe here a technique for labeling single cells or small clusters of cells in whole zebrafish embryos with membrane-targeted Green Fluorescent Protein.
JoVE Clinical and Translational Medicine
Evaluation of Nanoparticle Uptake in Tumors in Real Time Using Intravital Imaging
1Department of Medical Biophysics, University of Western Ontario, 2London Regional Cancer Program, London Health Science Centre, 3Department of Pathology, Vanderbilt University, 4Translational Prostate Cancer Research Group, London Health Science Centre
We present a novel approach to quantify nanoparticle localization in the vasculature of human xenografted tumors using dynamic, real-time intravital imaging in an avian embryo model.
JoVE General
Generation of Stable Transgenic C. elegans Using Microinjection
Department of Biological Sciences, University of Alabama
This video demonstrates the technique of microinjection into the gonad of C. elegans to create transgenic animals.
JoVE General
Microinjection of Zebrafish Embryos to Analyze Gene Function
1Department of Genetics, Harvard Medical School, 2Department of Cardiology, Children’s Hospital Boston
This video shows how morpholino or mRNA can be injected into zebrafish embryos at the one-cell stage to decrease or increase the level of specific gene products during subsequent development.
JoVE General
Generation of Transgenic C. elegans by Biolistic Transformation
Department of Medicine, University of Pittsburgh
Transgenic worms are commonly used in C. elegans research. Described is a simple, yet effective, protocol to introduce transgenes into worms using biolistic bombardment with DNA-coated gold particles. The effort involved and results of bombardment compare favorably with microinjection for the generation of transgenic animals.
JoVE General
Intravenous Microinjections of Zebrafish Larvae to Study Acute Kidney Injury
1Department of Developmental Biology, University of Pittsburgh, 2Department of Biological Sciences, University of Pittsburgh, 3Department of Medicine and Genetics, Harvard Medical School
We describe a technique of microinjecting the aminoglycoside, gentamicin, into 2 days post-fetilization (dpf) zebrafish larvae to induce acute kidney injury (AKI). We also describe a method for whole mount immunohistochemistry, plastic embedding and sectioning of zebrafish larvae to visualize the AKI mediated damage.
JoVE General
Vampiric Isolation of Extracellular Fluid from Caenorhabditis elegans
Department of Molecular and Cellular Biology, Harvard University
The model organism C. elegans uses pseudocoelomic fluid as a passive circulatory system. Direct assay of this fluid has not been previously possible. Here we present a novel technique to directly assay the extracellular space, and use systemic silencing signals during an RNAi response as a proof of principle example.
JoVE General
Dechorionation of Medaka Embryos and Cell Transplantation for the Generation of Chimeras
Centre for Regenerative Medicine, Department of Biology and Biochemistry, University of Bath
Due to the hard chorion and soft embryos, manipulation of medaka embryos is more involved than in zebrafish. This video shows step-by-step procedures for how to manipulate medaka embryos, including dechorionation, mounting in agarose for imaging and cell transplantation for the production of chimeras. These procedures are essential to use medaka and zebrafish in a laboratory to take full advantage of their complementary features for the genetic dissection of vertebrate genome functions.
JoVE Neuroscience
Lentivirus-mediated Genetic Manipulation and Visualization of Olfactory Sensory Neurons in vivo
Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis
We present a lentiviral technique for genetic manipulation and visualization of single olfactory sensory neuron axon and its terminal arborization in vivo.
JoVE Neuroscience
Gene Transfer to the Developing Mouse Inner Ear by In Vivo Electroporation
Oregon Hearing Research Center, Oregon Health & Science University
The mouse inner ear is a placode-derived sensory organ whose developmental program is elaborated during gestation. We define an in utero gene transfer technique consisting of three steps: mouse ventral laparotomy, transuterine microinjection, and in vivo electroporation. We use digital video microscopy to demonstrate the critical experimental embryological techniques.
JoVE Neuroscience
Time-lapse Live Imaging of Clonally Related Neural Progenitor Cells in the Developing Zebrafish Forebrain
The present video demonstrates a method which takes advantage of the combination of electroporation and confocal microscopy to perform live imaging on individual neural progenitor cells in the developing zebrafish forebrain. In vivo analysis of the development of forebrain neural progenitor cells at a clonal level can be achieved in this way.
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 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
Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos
Institute for Cell and Molecular Biosciences, University of Newcastle, United Kingdom
The kinetochore is where the SAC initiates its signal monitoring the mitotic segregation of the sister chromatids. A method is described to visualize the recruitment and turnover of one of the kinetochore proteins and its coordination with the chromosome motion in Drosophila embryos using a Leica laser scanning confocal system.
JoVE General
Testing the Physiological Barriers to Viral Transmission in Aphids Using Microinjection
1Plant Pathology, Cornell University, 2Boyce Thompson Institute for Plant Research, Cornell University
Aphids are effective transmitters of plant viruses. Aphid microinjection of virus, the procedure we will show you today, is a technique allowing researchers to inject virus directly into the hemocoel of the aphid, bypassing the gut, one of the 2 major barriers for virus transmission in a circulative manner. The same technique is also used to inject dsRNA for RNAi.
JoVE General
RNAi Mediated Gene Knockdown and Transgenesis by Microinjection in the Necromenic Nematode Pristionchus pacificus
Biology Department, California State University
In model organisms, transgenesis can manipulate gene functions while RNAi can knockdown specific mRNA transcripts 1-2. This protocol aims to illustrate the techniques needed to introduce stably transmitted DNA and transient double stranded RNA into the necromenic nematode Pristionchus pacificus for studies in evolutionary, developmental, and behavioral biology.
JoVE General
Zebrafish Brain Ventricle Injection
1Whitehead Institute for Biochemical Research, 2MIT - Massachusetts Institute of Technology
After neural tube formation, the neuroepithelium constricts and folds while the tube fills with embryonic cerebrospinal fluid (eCSF) to form the embryonic brain ventricles. We developed this ventricle injection technique to better visualize the fluid filled space in contrast to the neuroepithelial shape in a live embryo.
JoVE Neuroscience
Ultrasound-Guided Microinjection into the Mouse Forebrain In Utero at E9.5
1Institute for Cell Engineering Neuroregeneration and Stem Cell Programs, Johns Hopkins University School of Medicine, 2Departments of Neurology, Neuroscience, and Oncology, Johns Hopkins University School of Medicine
In utero survival surgery in mice permits the molecular manipulation of gene expression during development. Here we describe the use of high-frequency ultrasound imaging to guide the injection of retroviral vectors into the mouse brain at embryonic day (E) 9.5.
JoVE General
Single Cell Fate Mapping in Zebrafish
1Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 2Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center
A method is described to photoactivate single cells containing a caged fluorescent protein using two-photon absorption from a Ti:Sapphire femtosecond laser oscillator. To fate map the photoactivated cell, immunohistochemistry is used. This technique can be applied to any cell type.
JoVE General
Injection of dsRNA into Female A. aegypti Mosquitos
1Department of Molecular Biology and Biochemistry, University of California, Irvine (UCI), 2Department of Molecular Biology and Biochemistry, Department of Microbiology and Molecular Genetics, University of California, Irvine (UCI)
Reverse genetic approaches have proven extremely useful for determining which genes underly resistance to vector pathogens in mosquitoes. This video protocol illustrates a method used by the James lab to inject dsRNA into female A. aegypti mosquitoes, which harbor the dengue virus. The technique for calibrating injection needles, manipulating the injection setup, and injecting dsRNA into the thorax is illustrated.
JoVE Neuroscience
Gene Delivery to Postnatal Rat Brain by Non-ventricular Plasmid Injection and Electroporation
1Neuroscience Center, University of Helsinki, 2Faculty of Biological and Enviromental Sciences, University of Helsinki
This protocol describes a non-viral method of delivery of genetic constructs to a certain area of living rodent brain. The method consists of plasmid preparation, micropipette fabrication, neonatal rat pup surgery, microinjection of the construct, and in vivo electroporation.
JoVE General
Application of a C. elegans Dopamine Neuron Degeneration Assay for the Validation of Potential Parkinson's Disease Genes
Department of Biological Sciences, University of Alabama
This video demonstrates how to use C. elegans to assess dopaminergic neuron neurodegeneration as a model for Parkinson's disease. Furthermore, genetic screens are used to identify factors that either enhance degeneration or are neuroprotective.
JoVE General
Combining Peripheral Nerve Grafting and Matrix Modulation to Repair the Injured Rat Spinal Cord
Department of Neurobiology and Anatomy, Drexel University College of Medicine
Traumatic injury to the spinal cord disrupts communication with the brain. To restore lost connectivity we utilize a peripheral nerve graft to provide a substratum for regenerating fibers in combination with neurotrophic factors and matrix-modulating enzymes to remove inhibitory molecules to promote long distance growth.
JoVE General
A Reverse Genetic Approach to Test Functional Redundancy During Embryogenesis
Department of Surgery, Weill Cornell Medical College of Cornell University
Gene function can be obscured in loss-of-function experiments if there is compensation by another gene. The zebrafish model provides a relatively high-throughput means to reveal such functional redundancy in living embryos.
JoVE General
RNAi-mediated Gene Knockdown and In Vivo Diuresis Assay in Adult Female Aedes aegypti Mosquitoes
1Biology Department, New Mexico State University, 2Molecular Biology Department, New Mexico State University
In this protocol we combine RNAi-mediated gene silencing with an in vivo diuresis assay to study the effects knockdown of genes of interest has on mosquito fluid excretion.
JoVE General
Mosaic Zebrafish Transgenesis for Evaluating Enhancer Sequences
Department of Cell and Developmental Biology, University of Pennsylvania
We demonstrate our approach to finding potential enhancer elements from developmentally regulated genes and evaluating their function through mosaic zebrafish transgenesis.
JoVE General
Live Imaging of Cell Extrusion from the Epidermis of Developing Zebrafish
Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah
Dying cells are extruded from epithelial tissues by concerted contraction of neighboring cells without disrupting barrier function. The optical clarity of developing zebrafish provides an excellent system to visualize extrusion in living epithelia. Here we describe methods to induce and image extrusion in the larval zebrafish epidermis at cellular resolution.
JoVE General
Quantifying the Frequency of Tumor-propagating Cells Using Limiting Dilution Cell Transplantation in Syngeneic Zebrafish
1Department of Molecular Pathology, Massachusetts General Hospital, Harvard Medical School, 2Department of Molecular Pathology, Massachusetts General Hospital Cancer Center, Harvard Stem Cell Institute
Limiting dilution cell transplantation assays are used to determine the frequency of tumor-propagating cells. This protocol describes a method for generating syngeneic zebrafish that develop fluorescently-labeled leukemia and details how to isolate and transplant these leukemia cells at limiting dilution into the peritoneal cavity of adult zebrafish.
JoVE General
Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans
1Department of Biological Sciences, University of Alabama in Huntsville, 2NIDDK-National Institutes of Health
This article describes a technique for the visualization of the early events of embryogenesis in the nematode Caenorhabditis elegans.
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