Fluorescence:
The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
JoVE Clinical and Translational Medicine
Multispectral Real-time Fluorescence Imaging for Intraoperative Detection of the Sentinel Lymph Node in Gynecologic Oncology
1Department of Surgery, Division of Surgical Oncology, University Medical Center Groningen, 2Helmholtz Zentrum, Technical University Munich, 3Department of Obstetrics and Gynaecology, University Medical Center Groningen
Fluorescence imaging is a promising innovative modality for image-guided surgery in surgical oncology. In this video we describe the technical procedure for detection of the sentinel lymph node using fluorescence imaging as showcased in gynecologic oncologicy. A multispectral fluorescence camera system, together with the fluorescent agent indocyanine green, is applied.
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 Clinical and Translational Medicine
Computed Tomography-guided Time-domain Diffuse Fluorescence Tomography in Small Animals for Localization of Cancer Biomarkers
1Thayer School of Engineering, Dartmouth College, 2Department of Physics and Astronomy, Dartmouth College, 3Darmouth Medical School, Dartmouth College, 4School of Computer Science, University of Birmingham
Diffuse fluorescence tomography offers a relatively low-cost and potentially high-throughout approach to preclinical in vivo tumor imaging. The methodology of optical data collection, calibration, and image reconstruction is presented for a computed tomography-guided non-contact time-domain system using fluorescent targeting of the tumor biomarker epidermal growth factor receptor in a mouse glioma model.
JoVE Neuroscience
Lateral Diffusion and Exocytosis of Membrane Proteins in Cultured Neurons Assessed using Fluorescence Recovery and Fluorescence-loss Photobleaching
MRC Centre for Synaptic Plasticity, University of Bristol
This report describes the use of live cell imaging and photobleach techniques to determine the surface expression, transport pathways and trafficking kinetics of exogenously expressed, pH-sensitive GFP-tagged proteins at the plasma membrane of neurons.
JoVE Bioengineering
Increasing cDNA Yields from Single-cell Quantities of mRNA in Standard Laboratory Reverse Transcriptase Reactions using Acoustic Microstreaming
1Florey Neuroscience Institutes and Centre for Neuroscience, University of Melbourne, 2Fluid Dynamics Group, CSIRO Materials Science and Engineering, 3Swinburne University of Technology, Faculty of Engineering and Industrial Sciences
We describe a novel method for increasing cDNA yield from single-cell quantities of mRNA in otherwise standard laboratory reverse transcription reactions. The novelty resides in the use of a micromixer, which utilizes the phenomenon of acoustic microstreaming, to mix fluids at microliter scales more effectively than shaking, vortexing or trituration.
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
Determination of Mitochondrial Membrane Potential and Reactive Oxygen Species in Live Rat Cortical Neurons
Department of Molecular Pharmacology and Experimental Therapeutics, Loyola University Chicago
We demonstrate application of the fluorescence indicator, TMRM, in cortical neurons to determine the relative changes in TMRM fluorescence intensity before and after application of a specific stimulus. We also show application of the fluorescence probe H2DCF-DA to assess the relative level of reactive oxygen species in cortical neurons.
JoVE Neuroscience
Optical Recording of Suprathreshold Neural Activity with Single-cell and Single-spike Resolution
Section of Neurobiology, Center for Learning and Memory, The University of Texas at Austin
Understanding the function of the vertebrate central nervous system requires recordings from many neurons because cortical function arises on the level of populations of neurons. Here we describe an optical method to record suprathreshold neural activity with single-cell and single-spike resolution, dithered random-access scanning. This method records somatic fluorescence calcium signals from up to 100 neurons with high temporal resolution. A maximum-likelihood algorithm deconvolves the underlying suprathreshold neural activity from the somatic fluorescence calcium signals. This method reliably detects spikes with high detection efficiency and a low rate of false positives and can be used to study neural populations in vitro and in vivo.
JoVE General
Photoconversion of Purified Fluorescent Proteins and Dual-probe Optical Highlighting in Live Cells
Department of Molecular Physiology and Biophysics, Vanderbilt University
This protocol describes a general approach to perform photoconversion of fluorescent proteins on a confocal laser scanning microscope. We describe procedures for the photoconversion of puried protein samples, as well as for dual-probe optical highlighting in live cells with mOrange2 and Dronpa.
JoVE General
Measuring Intracellular Ca2+ Changes in Human Sperm using Four Techniques: Conventional Fluorometry, Stopped Flow Fluorometry, Flow Cytometry and Single Cell Imaging
1Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología-Universidad Nacional Autónoma de México, 2Math and Sciences Department, Edison State College
Intracellular Ca2+ dynamics are very important in sperm physiology and Ca2+-sensitive fluorescent dyes constitute a versatile tool to study them. Population experiments (fluorometry and stopped flow fluorometry) and single cell experiments (flow cytometry and single cell imaging) are used to track spatio-temporal [Ca2+] changes in human sperm cells.
JoVE General
Techniques for Imaging Ca2+ Signaling in Human Sperm
1School of Biosciences, University of Birmingham, 2School of Medicine, University of Birmingham, 3Centre for Human Reproductive Science, Birmingham Women’s Hospital
Stimulus-evoked [Ca2+]i signals of individual human sperm are assessed. Motile cells are loaded with Ca2+-sensitive fluorescent dye (AM-ester method) and immobilised in a perfusable chamber. Cells are imaged by time-lapse fluorescence microscopy and stimulated via the perfusing medium. Responses of single cells (or regions) are analysed offline using Excel.
JoVE General
A Fluorescence Microscopy Assay for Monitoring Mitophagy in the Yeast Saccharomyces cerevisiae
Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University
A robust approach to monitor the delivery of organelles to the acidic lumen of the yeast vacuole for degradation and recycling is described. The method relies on the specific labeling of target organelles with a genetically encoded dual-emission fluorescence pH-biosensor, and visualization of individual cells using fluorescence microscopy.
JoVE General
Measuring Diffusion Coefficients via Two-photon Fluorescence Recovery After Photobleaching
1Department of Physics and Astronomy, University of Rochester, 2Department of Biomedical Engineering, University of Rochester
In this article we will describe the procedure for measuring diffusion coefficients using multi-photon fluorescence recovery after photobleaching. We will begin by aligning the laser along the optical path to the sample and determining the proper experimental parameters, then continue generating and finally fitting fluorescence recovery curves.
JoVE Immunology and Infection
Immuno-fluorescence Assay of Leptospiral Surface-exposed Proteins
1Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, 2Research service, 151, Veterans Affairs Greater Los Angeles Healthcare System, 3Departments of Medicine, Urology at David Geffen School of Medicine and Department of Microbiology, Immunology and Molecular Gentics, University of California Los Angeles (UCLA), 4Division of Infectious Diseases, 111F, Veterans Affairs Greater Los Angeles Health Care System
An efficient method to assess surface-exposure of leptospiral proteins is described. The method is specifically designed to avoid disruption of the fragile outer membrane of leptospiral cells. This technique requires employment of several negative controls to assess the integrity of the outer membrane and specificity of antibody reaction.
JoVE General
Use of the Protease Fluorescent Detection Kit to Determine Protease Activity
The Protease Fluorescent Detection Kit is designed for the measurement of protease activity using fluorometry. It is also suitable for detection of trace amounts of protease contamination. The method is based on the proteolytic hydroysis of a proprietary formulation of a FITC-labeled casein substrate.
JoVE Neuroscience
Fluorescence Recovery After Photobleaching (FRAP) of Fluorescence Tagged Proteins in Dendritic Spines of Cultured Hippocampal Neurons
FRAP has been used to quantify the mobility of Green Fluorescence Protein (GFP)-tagged proteins in cultured cells. We examined the mobile/immobile fractions of the GFP by analyzing the fluorescence recovery percentage after photobleaching. In this study, FRAP was performed at spines of hippocampal neurons.
JoVE General
Gramicidin-based Fluorescence Assay; for Determining Small Molecules Potential for Modifying Lipid Bilayer Properties
Department of Physiology and Biophysics, Weill Cornell Medical College
We introduce a fast fluorescence-based assay that monitors the rate of fluorescence quenching as a measure of gramicidin channel activity. The gramicidin channels are used as molecular force transducers to monitor changes in lipid bilayer properties as sensed by bilayer spanning proteins.
JoVE Immunology and Infection
Tractable Mammalian Cell Infections with Protozoan-primed Bacteria
Department of Molecular Microbiology & Immunology, Oregon Health & Science University
This technique provides a method to harvest, normalize and quantify intracellular growth of bacterial pathogens that are pre-cultivated in natural protozoan host cells prior to infections of mammalian cells. This method can be modified to accommodate a wide variety of host cells for the priming stage as well as target cell types.
JoVE Neuroscience
Preparation of Living Isolated Vertebrate Photoreceptor Cells for Fluorescence Imaging
Storm Eye Institute, Medical University of South Carolina
A method is described for the preparation of single living photoreceptor cells from different vertebrate species for fluorescence imaging. The method can be used to image the fluorescence of endogenous fluorophores, such as NADH or vitamin A, or that of exogenously added fluorescent dyes sensitive to Ca2+ or other factors.
JoVE General
Determination of Lipid Raft Partitioning of Fluorescently-tagged Probes in Living Cells by Fluorescence Correlation Spectroscopy (FCS)
1Centre de Recherche de l’Institut du Cerveau et de la Moelle Épinière, Hôpital de la Pitié-Salpêtrière, 2Institut des Sciences Moléculaires d'Orsay, Université Paris-Sud, 3Centre de Photonique Biomédicale du Centre Laser, Université Paris-Sud
A technique to probe the lipid raft partitioning of fluorescent proteins at the plasma membrane of living cells is described. It takes advantage of the disparity in diffusion times of proteins located inside or outside of lipid rafts. Acquisition can be performed dynamically in control conditions or after drug addition.
JoVE Bioengineering
Thermodynamics of Membrane Protein Folding Measured by Fluorescence Spectroscopy
Chemistry and Biochemistry, University of California San Diego - UCSD
This video article details the experimental procedure for obtaining the Gibbs free energy of membrane protein folding by tryptophan fluorescence.
JoVE General
Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations
Department of Hematology, Oncology and Stem Cell Transplantation, University Medical Center Freiburg
Metaphase to anaphase transition is triggered through anaphase-promoting complex (APC/C)-dependent ubiquitination and subsequent destruction of cyclin B. Here, we established a system which, following pulse-chase labeling, allows monitoring cyclin B proteolysis in entire cell populations and facilitates the detection of interference by the mitotic checkpoint.
JoVE Immunology and Infection
Live Cell Imaging of Bacillus subtilis and Streptococcus pneumoniae using Automated Time-lapse Microscopy
This protocol provides a step-by-step procedure to monitor single cell behavior of different bacteria in time using automated fluorescence time-lapse microscopy. Furthermore, we provide guidelines how to analyze the microscopy images.
JoVE General
Fluorescence-based Measurement of Store-operated Calcium Entry in Live Cells: from Cultured Cancer Cell to Skeletal Muscle Fiber
1Department of Physiology and Biophysics, Confocal Microscopy and Cell Imaging Core, Robert Wood Johnson Medical School, 2Department of Physiology and Biophysics, Robert Wood Johnson Medical School, 3Muscle Biology Research Group-MUBIG Schools of Nursing & Medicine, University of Missouri-Kansas City
The extent of store-operated Ca2+ entry (SOCE) can be monitored using fluorescent Ca2+ indicators. Mn2+ quenching of such indicators assays SOCE in cultured cells and skeletal muscle fibers. A technique allowing spatial and temporal resolution of SOCE by confocal imaging of mechanically skinned muscle fibers is also described.
JoVE Immunology and Infection
High-throughput Detection Method for Influenza Virus
1Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, 2Department of Microbiology, Mount Sinai School of Medicine, 3Laboratory of Molecular Genetics, Blood Research Institute, 4City of Milwaukee Health Department Laboratory, 5Division of Hematology-Oncology/BMT, Children's Hospital of Wisconsin, Medical College of Wisconsin, 6Division of Hematology and Oncology, Dept Medicine, Medical College of Wisconsin
This method describes the use of Infrared dye based imaging system for detection of H1N1 in bronchioalveolar lavage (BAL) fluid of infected mice at a high sensitivity. This methodology can be performed in a 96- or 384-well plate, requires <10 μl volume of test material and has the potential for concurrent screening of multiple pathogens.
JoVE General
DNA Transfection of Mammalian Skeletal Muscles using In Vivo Electroporation
Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles
We describe detailed procedures for the efficient transfection of plasmid DNA into the fibers of foot muscles of live mice using electroporation and the subsequent visualization of protein expression using fluorescence microscopy.
JoVE General
Born Normalization for Fluorescence Optical Projection Tomography for Whole Heart Imaging
1Center for Systems Biology, Harvard Medical School, 2Center for Systems Biology, MGH - Massachusetts General Hospital, 3Institute for Biological and Medical Imaging, Technical University of Munich and Helmholtz Center Munich
We suggest a Born normalized approach for Optical Projection Tomography (BnOPT) that accounts for the absorption properties of imaged samples to obtain accurate and quantitative fluorescence tomographic reconstructions. We use the proposed algorithm to reconstruct the fluorescence molecular probe distribution within small animal organs.
JoVE General
Measuring the Induced Membrane Voltage with Di-8-ANEPPS
Department of Biomedical Engineering, Faculty of Electrical Engineering, University of Ljubljana
External electric field induces a voltage on the membrane of a cell, termed the induced membrane voltage (ΔΦ). By using the potentiometric dye di-8-ANEPPS, it is possible to measure the ΔΦ noninvasively. This video shows the protocol for measuring ΔΦ using di-8-ANEPPS.
JoVE General
Microiontophoresis and Micromanipulation for Intravital Fluorescence Imaging of the Microcirculation
1Department of Medical Pharmacology and Physiology, University of Missouri, 2Dalton Cardiovascular Research Center, University of Missouri
Microiontophoresis entails movement of ions from a micropipette in response to a difference in electrical potential between the inside and outside of the micropipette. Biologically active molecules are thereby delivered in proportion to electrical current. We illustrate acetylcholine microiontophoresis in conjunction with micromanipulation to study endothelium-dependent vasodilation in the microcirculation.
JoVE General
Quantitative, Real-time Analysis of Base Excision Repair Activity in Cell Lysates Utilizing Lesion-specific Molecular Beacons
1Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, 2Hillman Cancer Center, University of Pittsburgh Cancer Institute, 3Department of Experimental Therapy, The Netherlands Cancer Institute, 4Department of Human Genetics, University of Pittsburgh School of Public Health
We describe a method for the quantitative, real-time measurement of DNA glycosylase and AP endonuclease activities in cell nuclear lysates. The assay yields rates of DNA Repair activity amenable to kinetic analysis and is adaptable for quantification of DNA Repair activity in tissue and tumor lysates or with purified proteins.
JoVE General
Assessment of GFP Expression and Viability Using the Tali Image-Based Cytometer
1Department of Molecular and Cell Biology, Life Technologies, 2Life Technologies
This protocol describes how to perform cell viability and fluorescence expression assays using the Tali Image-Based Cytometer.
JoVE General
Visualization of Vascular Ca2+ Signaling Triggered by Paracrine Derived ROS
1Department of Biochemistry, Temple University, 2Department of Anesthesiology and Pain Medicine, University of Washington
An efficient method to gain insights into visualizing the paracrine-derived ROS induction of endothelial Ca2+ signaling is described. This method takes advantage of measuring paracrine derived ROS triggered Ca2+ mobilization in vascular endothelial cells in a co-culture model.
JoVE General
High-throughput Screening and Biosensing with Fluorescent C. elegans Strains
1Department of Biology, University of Florida, 2Mount Desert Island Biological Laboratory
A procedure for liquid-based culturing and dispensing of C. elegans strains expressing fluorescent reporter proteins is described that does not require expensive sorting equipment. This approach can be applied to numerous inducible C. elegans genes for drug discovery or biosensing of contaminants.
JoVE General
Examining the Conformational Dynamics of Membrane Proteins in situ with Site-directed Fluorescence Labeling
Department of Chemistry and Biochemistry, Worcester Polytechnic Institute
We will describe a method which measures the kinetics of ion transport of membrane proteins alongside site-specific analysis of conformational changes using fluorescence on single cells. This technique is adaptable to ion channels, transporters and ion pumps and can be utilized to determine distance constraints between protein subunits.
JoVE General
Electroporation of Craniofacial Mesenchyme
Department of Craniofacial Development, King's College London
Craniofacial cartilages develop in close contact with other tissues and are difficult to manipulate in live animals. We are using electroporation to deliver molecular tools during growth of the craniofacial skeleton while bypassing early embryonic effects. This approach will allow us to efficiently test candidate molecules in vivo.
JoVE General
Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions
Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University
Vacuolar and cytosolic pH can be measured in live yeast (S. cerevisiae) cells using ratiometric fluorescent dyes localized to specific cellular compartments. We describe procedures for measuring vacuolar pH with BCECF-AM, which localizes to the vacuole in yeast, and cytosolic pH with a cytosolic ratiometric pH-sensitive GFP (yeast pHluorin).
JoVE Bioengineering
Fluorescence detection methods for microfluidic droplet platforms
1Department of Chemistry, Imperial College London, 2Department of Biochemistry, Protein Chip Research Center, Chungbuk National University, 3Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich
Droplet-based microfluidic platforms are promising candidates for high throughput experimentation since they are able to generate picoliter, self-compartmentalized vessels inexpensively at kHz rates. Through integration with fast, sensitive and high resolution fluorescence spectroscopic methods, the large amounts of information generated within these systems can be efficiently extracted, harnessed and utilized.
JoVE Bioengineering
Bridging the Bio-Electronic Interface with Biofabrication
1Fischell Department of Bioengineering, University of Maryland, 2Institute for Bioscience and Biotechnology Research, University of Maryland, 3Department of Materials Science and Engineering, University of Maryland
This article describes a biofabrication approach: deposition of stimuli-responsive polysaccharides in the presence of biased electrodes to create biocompatible films which can be functionalized with cells or proteins. We demonstrate a bench-top strategy for the generation of the films as well as their basic uses for creating interactive biofunctionalized surfaces for lab-on-a-chip applications.
JoVE General
Nano-fEM: Protein Localization Using Photo-activated Localization Microscopy and Electron Microscopy
Department of Biology, Howard Hughes Medical Institute, University of Utah
We describe a method to localize fluorescently tagged proteins in electron micrographs. Fluorescence is first localized using photo-activated localization microscopy on ultrathin sections. These images are then aligned to electron micrographs of the same section.
JoVE General
A Practical Approach to Genetic Inducible Fate Mapping: A Visual Guide to Mark and Track Cells In Vivo
1Department of Neuroscience, Division of Biology and Medicine, Brown University, 2Department of Molecular Biology, Cell Biology and Biochemistry, Division of Biology and Medicine, Brown University
Genetic Inducible Fate Mapping (GIFM) marks and tracks cells with fine spatial and temporal control in vivo and elucidates how cells from a specific genetic lineage contribute to developing and adult tissues. Demonstrated here are the techniques required to fate map E12.5 mouse embryos for epifluorescent and explant analysis.
JoVE General
Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana
1Department of Energy - Plant Research Laboratory, Michigan State University (MSU), 2Department of Biochemistry and Molecular Biology, Michigan State University (MSU)
The molecular basis of spatial-specific phytochrome responses is being investigated using transgenic plants that exhibit tissue- and organ-specific phytochrome deficiencies. The isolation of specific cells exhibiting induced phytochrome chromophore depletion by Fluorescence-Activated Cell Sorting followed by microarray analyses is being utilized to identify genes involved in spatial-specific phytochrome responses.
JoVE Immunology and Infection
Real-time Imaging of Leukotriene B4 Mediated Cell Migration and BLT1 Interactions with β-arrestin
Microbiology and Immunology, James Graham Brown Cancer Center, University of Louisville
This paper describes the methodology to determine the chemotactic response of leukocytes to specific ligands and identify interactions between the cell surface receptors and cytosolic proteins using live cell imaging techniques.
JoVE Bioengineering
Cell-based Calcium Assay for Medium to High Throughput Screening of TRP Channel Functions using FlexStation 3
This video provides a detailed protocol for studying the pharmacological profile of human TRPA1 channels using FlexStation 3. The protocol covers details of cell preparation, dye loading and operation of the microplate reader, FlexStation 3.
JoVE General
Analysis of Gene Function and Visualization of Cilia-Generated Fluid Flow in Kupffer's Vesicle
1Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, 2Department of Neurobiology and Anatomy, Eccles Institute of Human Genetics, University of Utah
Cilia-generated fluid flow in Kupffer’s Vesicle (KV) controls left-right patterning of the zebrafish embryo. Here, we describe a technique to modulate gene function specifically in KV cells. In addition, we show how to deliver fluorescent beads into KV to visualize fluid flow.
JoVE Immunology and Infection
Real-time Imaging of Heterotypic Platelet-neutrophil Interactions on the Activated Endothelium During Vascular Inflammation and Thrombus Formation in Live Mice
1Department of Pharmacology, University of Illinois at Chicago, 2Department of Anesthesiology, University of Illinois at Chicago
Here we report an experimental technique of fluorescence intravital microscopy to visualize heterotypic platelet-neutrophil interactions on the activated endothelium during vascular inflammation and thrombus formation in live mice. This microscopic technology will be valuable to study the molecular mechanism of vascular disease and to test pharmacologic agents under pathophysiological conditions.
JoVE General
Real-time Analyses of Retinol Transport by the Membrane Receptor of Plasma Retinol Binding Protein
Here we describe an optimized technique to produce high-quality vitamin A/RBP complex and two real-time monitoring techniques to study vitamin A transport by STRA6, the RBP receptor.
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 Neuroscience
Cut-loading: A Useful Tool for Examining the Extent of Gap Junction Tracer Coupling Between Retinal Neurons
1Department of Neuroscience, Ohio State University College of Medicine, 2Department of Ophthalmology and Visual Science, University of Texas Medical School
An easy and convenient method to determine the extent of gap junction tracer coupling between retinal neurons is described. This technique enables one to investigate the function of the electrical synapses between neurons in the intact retina under different illumination conditions and at different times of the day and night.
JoVE Applied Physics
Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing
Department of Physics, University of Alberta
Fluorescent-core microcavity sensors employ a high-index quantum-dot coating in the channel of silica microcapillaries. Changes in the refractive index of fluids pumped into the capillary channel cause shifts in the microcavity fluorescence spectrum that can be used to analyze the channel medium.
JoVE General
Mesoscopic Fluorescence Tomography for In-vivo Imaging of Developing Drosophila
1Center for Systems Biology, Massachusetts General Hospital, 2Institute for Biological and Medical Imaging (IBMI), Technical University of Munich and Helmholtz Center Munich, 3Department of Genetics, Harvard Medical School and Howard Hughes Medical Institute
Mesoscopic fluorescence tomography operates beyond the penetration limits of tissue-sectioning fluorescence microscopy. The technique is based on multi-projection illumination and a photon transport description. We demonstrate in-vivo whole-body 3D visualization of the morphogenesis of GFP-expressing wing imaginal discs in Drosophila melanogaster.
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