JoVE Applied Physics
Optical Trapping of Nanoparticles
Electrical and Computer Engineering, University of Victoria
The following setup approach details low power optical trapping of dielectric nanoparticles using a double-nanohole in metal film.
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 General
Concentration Determination of Nucleic Acids and Proteins Using the Micro-volume Bio-spec Nano Spectrophotometer
Shimadzu, Scientific Instruments
This communication presents data on the accuracy and reproducibility of the BioSpec-nano UV-VIS spectrophotometer for dsDNA and protein quantitation. Even with ultra-small volumes (1 to 2 L), reproducibility is excellent, while the automated wiping function improves throughput and results in minimal carryover for more precise results.
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 General
Rapid Homogeneous Detection of Biological Assays Using Magnetic Modulation Biosensing System
1Department of Physical Electronics, Faculty of Engineering, Tel Aviv University, 2Department of Biomedical Engineering, Washington University in St. Louis, 3Department of Biological Sciences, University of Illinois, 4Department of Cell Research and Immunology, Tel Aviv University
Magnetic modulation biosensing system is utilized to rapidly, sensitively and simply detect biological assays, such as DNA molecules and proteins.
JoVE General
Whole-Body Nanoparticle Aerosol Inhalation Exposures
1Department of Physiology and Pharmacology, School of Medicine, West Virginia University, 2Center for Cardiovascular and Respiratory Sciences, West Virginia University, 3National Institute for Occupational Safety and Health
A whole-body nanoparticle aerosol inhalation exposure facility was constructed for nano-sized titanium dioxide (TiO2) inhalation toxicology studies. This system provides nano-TiO2 aerosol test atmospheres that have: 1) a steady mass concentration; 2) a homogenous composition free of contaminants; and 3) a stable particle size distribution during aerosol generation.
JoVE General
Cargo Loading onto Kinesin Powered Molecular Shuttles
1Department of Materials Science and Engineering, University of Florida, 2Department of Biomedical Engineering, Columbia University
Molecular shuttles consisting of functionalized microtubules gliding on surface-adhered kinesin motor proteins can serve as a nanoscale transport system. Here, the assembly of a typical shuttle system is described.
JoVE Bioengineering
Candida albicans Biofilm Chip (CaBChip) for High-throughput Antifungal Drug Screening
1Department of Biomedical Engineering, University of Texas at San Antonio, 2Department of Biology, University of Texas at San Antonio
We have developed a high-density microarray platform consisting of 3D nano-biofilms of C. albicans called CaBChip. The susceptibility profile of drugs tested on a CaBChip is comparable to the conventional 96-well plate model, suggesting that the fungal chip is ideally suited for true high-throughput screening of antifungal drugs.
JoVE Applied Physics
Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy
Materials Sciences Division, Lawrence Berkeley National Laboratory
We have developed a self-contained liquid cell, which allows imaging through liquids using a transmission electron microscope. Dynamic processes of nanoparticles in liquids can be revealed in real time with sub-nanometer resolution.
JoVE Applied Physics
Harvesting Solar Energy by Means of Charge-Separating Nanocrystals and Their Solids
1Department of Physics, Bowling Green State University, 2The Center for Photochemical Sciences, Bowling Green State University, 3Department of Chemistry, Bowling Green State University
A general strategy for the development of charge-separating semiconductor nanocrystal composites deployable for solar energy production is presented. We show that assembly of donor-acceptor nanocrystal domains in a single nanoparticle geometry gives rise to a photocatalytic function, while bulk-heterojunctions of donor-acceptor nanocrystal films can be used for photovoltaic energy conversion.
JoVE Bioengineering
Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation
1Electrical Engineering Department, University of Washington, 2Division of Human Biology, Fred Hutchinson Cancer Research Center, 3Molecular and Cellular Biology Program, University of Washington, 4Clinical Research, Fred Hutchinson Cancer Research Center, 5Public Health Sciences, Fred Hutchinson Cancer Research Center
Plasmonic tweezers and photonic crystal nanostructures are shown to produce useful enhancements in the efficiency and orientation control of optically trapping micro- and nano-particles.
JoVE Applied Physics
Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting
1Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), 2Department of Electrical Engineering and Computer Sciences, University of California, Berkeley
We describe a nanomoulding technique which allows low-cost nanoscale patterning of functional materials, materials stacks and full devices. Nanomoulding can be performed on any nanoimprinting setup and can be applied to a wide range of materials and deposition processes.
JoVE Bioengineering
Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method
1Department of Physics and Astronomy, The University of Texas at San Antonio, 2Centro de Investigaciones en Optica A. C., 3Department of Biology and Neurosciences Institute, The University of Texas at San Antonio
We synthesized star shaped gold nanostars using a silver seed mediated growth method. The diameter of the nanostars ranges from 200 to 300 nm and the number of tips vary from 7 to 10. The nanoparticles have a broad surface plasmon resonance mode centered in the near infrared.
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 Chemistry
Fabricating Nanogaps by Nanoskiving
The fabrication of electrically addressable, high-aspect-ratio (> 1000:1) metal nanowires separated by gaps of single nanometers using either sacrificial layers of aluminum and silver or self-assembled monolayers as templates is described. These nanogap structures are fabricated without a clean room or any photo- or electron-beam lithographic processes by a form of edge lithography known as nanoskiving.
JoVE Applied Physics
Development of Whispering Gallery Mode Polymeric Micro-optical Electric Field Sensors
Mechanical Engineering Department, Southern Methodist University
A high-sensitivity photonic micro sensor was developed for electric field detection. The sensor exploits the optical modes of a dielectric sphere. Changes in the external electric field perturb the sphere morphology leading to shifts in its optical modes. The electric field strength is measured by monitoring these optical shifts.
JoVE Bioengineering
Simultaneous Synthesis of Single-walled Carbon Nanotubes and Graphene in a Magnetically-enhanced Arc Plasma
Department of Mechanical and Aerospace Engineering, The George Washington University
Anodic arc discharge is one of the most practical and efficient methods to synthesize various carbon nanostructures. To increase the arc controllability and flexibility, a non-uniform magnetic field was introduced to process the one-step synthesis of large-scale graphene flakes and high-purity single-walled carbon nanotubes.
JoVE Applied Physics
Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition
1Department of Energy and NEMAS - Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, 2Center for Nano Science and Technology, Instituto Italiano di Tecnologia
We describe the experimental method to deposit nanostructured oxide thin films by nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas. By using this method Al-doped ZnO (AZO) films, from compact to hierarchically structured as nano-tree forests, can be deposited.
JoVE Applied Physics
Measuring Spatially- and Directionally-varying Light Scattering from Biological Material
1Department of Biomedical Science, Cornell University, 2Department of Ecology and Evolutionary Biology, Cornell University, 3Cornell University Museum of Vertebrates, 4Department of Computer Science, Cornell University
We present a non-destructive method for sampling spatial variation in the direction of light scattered from structurally complex materials. By keeping the material intact, we preserve gross-scale scattering behavior, while concurrently capturing fine-scale directional contributions with high-resolution imaging. Results are visualized in software at biologically-relevant positions and scales.
JoVE Bioengineering
Viral Nanoparticles for In vivo Tumor Imaging
1Department of Biomedical Engineering, Case Western Reserve University, 2Department of Biomedical Engineering, Radiology, and Materials Science and Engineering, Case Western Reserve University
Plant viral nanoparticles (VNPs) are promising platforms for applications in biomedicine. Here, we describe the procedures for plant VNP propagation, purification, characterization, and bioconjugation. Finally, we show the application of VNPs for tumor homing and imaging using a mouse xenograft model and fluorescence imaging.
JoVE Bioengineering
Fluorescent Nanoparticles for the Measurement of Ion Concentration in Biological Systems
1Bioengineering Department, Northeastern University, 2Department of Pharmaceutical Sciences, Northeastern University
Fluorescent nanoparticles produced in our lab are used for imaging ion concentrations and ion fluxes in biological systems such as cells during signaling and interstitial fluid during physiological homeostasis.
JoVE General
Assembly, Tuning and Use of an Apertureless Near Field Infrared Microscope for Protein Imaging
1Department of Chemistry, University of Toronto, 2Department of Chemistry, University of Wisconsin, 3Department of Chemistry, Duke University
The assembly of a nearfield infrared microscope for imaging protein aggregates is described.
JoVE Immunology and Infection
Simple and Robust in vivo and in vitro Approach for Studying Virus Assembly
1Department of Plant Pathology and Microbiology, University of California, Riverside, 2Department of Bioengineering, University of California, Riverside
A simple, efficient and robust way to synchronize the delivery of multiple viral components to plant cells via Agrobacterium-mediated transient expression is described. This approach is amenable for studying replication, encapsidation followed by in vitro reassembly of non-viral components into genome depleted optical viral ghosts suitable for biomedical applications.
JoVE General
Synthesis of an In vivo MRI-detectable Apoptosis Probe
1Division of Cardiovascular Medicine, Department of Medicine, Stanford University Medical Center, 2Division of Cardiology, Department of Medicine, University of California, San Francisco, 3San Francisco VAMC
Early detection of apoptosis may identify at-risk cell populations in a variety of diseases. Here we demonstrate a method to link an early apoptosis-detection protein (Annexin V) to a MRI-detectable iron oxide nanoparticle (SPIO). This method may be extended to other proteins of interest to generate MRI-detectable molecular imaging probes.
JoVE General
A Protocol for the Identification of Protein-protein Interactions Based on 15N Metabolic Labeling, Immunoprecipitation, Quantitative Mass Spectrometry and Affinity Modulation
1Max Planck Institute of Molecular Plant Physiology, 2University of Kaiserslautern
We present a variation of the QUICK (QUantitative Immunoprecipitation Combined with Knockdown) approach that was introduced previously to distinguish between true and false protein-protein interactions. Our approach is based on 15N metabolic labeling, the modulation of affinities of protein-protein interactions by the presence/absence of ATP, immunoprecipitation, and quantitative mass spectrometry.
JoVE Bioengineering
Small and Wide Angle X-Ray Scattering Studies of Biological Macromolecules in Solution
Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute
The demonstration of the small and wide angle X-ray scattering (SWAXS) procedure has become instrumental in the study of biological macromolecules. Through the use of the instrumentation and procedures of specific angle methods and preparation, the experimental data from the SWAXS displays the atomic and nano-scale characterization of macromolecules.
JoVE Applied Physics
Synthesis and Functionalization of Nitrogen-doped Carbon Nanotube Cups with Gold Nanoparticles as Cork Stoppers
Department of Chemistry, University of Pittsburgh
We discussed the synthesis of individual graphitic nanocups using a series of techniques including chemical vapor deposition, acid oxidation and probe-tip sonication. By citrate reduction of HAuCl4, the graphitic nanocups were effectively corked with gold nanoparticles due to the chemically reactive edges of the cups.
JoVE Applied Physics
Probing and Mapping Electrode Surfaces in Solid Oxide Fuel Cells
1Center for Innovative Fuel Cells and Battery Technologies, School of Materials Science and Engineering, Georgia Institute of Technology, 2School of Chemistry and Biochemistry, Georgia Institute of Technology
We present a unique platform for characterizing electrode surfaces in solid oxide fuel cells (SOFCs) that allows simultaneous performance of multiple characterization techniques (e.g. in situ Raman spectroscopy and scanning probe microscopy alongside electrochemical measurements). Complementary information from these analyses may help to advance toward a more profound understanding of electrode reaction and degradation mechanisms, providing insights into rational design of better materials for SOFCs.
JoVE Applied Physics
Concurrent Quantitative Conductivity and Mechanical Properties Measurements of Organic Photovoltaic Materials using AFM
1Center for Nanoscale Materials, Argonne National Laboratory, 2Institute for Molecular Engineering, University of Chicago
Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution.
JoVE Applied Physics
Dry Oxidation and Vacuum Annealing Treatments for Tuning the Wetting Properties of Carbon Nanotube Arrays
Graduate Aeronautical Laboratories, California Institute of Technology
This article describes a simple method to fabricate vertically aligned carbon nanotube arrays by CVD and to subsequently tune their wetting properties by exposing them to vacuum annealing or dry oxidation treatment.
JoVE General
Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels
1Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, 2Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, 3Department of Anesthesiology, Medicine and Physiology, David Geffen School of Medicine, University of California, Los Angeles
We describe a simple protocol to identify brain proteins that bind to the full length C terminus of ATP-gated P2X2 receptors. The extension and systematic application of this approach to all P2X receptors is expected to lead to a better understanding of P2X receptor signaling.
JoVE Bioengineering
Soft Lithographic Functionalization and Patterning Oxide-free Silicon and Germanium
1Department of Chemistry, Duke University, 2Hajim School of Engineering and Applied Sciences, University of Rochester, 3Department of Chemical Engineering, University of Rochester
Here we describe a simple method for patterning oxide-free silicon and germanium with reactive organic monolayers and demonstrate functionalization of the patterned substrates with small molecules and proteins. The approach completely protects surfaces from chemical oxidation, provides precise control over feature morphology, and provides ready access to chemically discriminated patterns.
JoVE Bioengineering
Monitoring Protein Adsorption with Solid-state Nanopores
Department of Physics, Syracuse University
A method of using solid-state nanopores to monitor the non-specific adsorption of proteins onto an inorganic surface is described. The method employs the resistive-pulse principle, allowing for the adsorption to be probed in real-time and at the single-molecule level. Because the process of single protein adsorption is far from equilibrium, we propose the employment of parallel arrays of synthetic nanopores, enabling for the quantitative determination of the apparent first-order reaction rate constant of protein adsorption as well as and the Langmuir adsorption constant.
JoVE Chemistry
Template Directed Synthesis of Plasmonic Gold Nanotubes with Tunable IR Absorbance
Department of Chemistry, University of Toronto
Solution-suspendable gold nanotubes with controlled dimensions can be synthesized by electrochemical deposition in porous anodic aluminum oxide (AAO) membranes using a hydrophobic polymer core. Gold nanotubes and nanotube arrays hold promise for applications in plasmonic biosensing, surface-enhanced Raman spectroscopy, photo-thermal heating, ionic and molecular transport, microfluidics, catalysis and electrochemical sensing.
JoVE Bioengineering
Formulation of Diblock Polymeric Nanoparticles through Nanoprecipitation Technique
1Laboratory of Nano- and Translational Medicine, Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, 2Carolina Center for Nanotechnology Excellence, University of North Carolina
This article describes a nanoprecipitation method to synthesize polymer-based nanoparticles using diblock co-polymers. We will discuss the synthesis of diblock co-polymers, the nanoprecipitation technique, and potential applications.
JoVE Bioengineering
Postproduction Processing of Electrospun Fibres for Tissue Engineering
1Materials Science and Engineering, University of Sheffield, 2Department of Biomedical Science, University of Sheffield, 3Department of Chemistry, University of Sheffield
Electrospun scaffolds can be processed post production for tissue engineering applications. Here we describe methods for spinning complex scaffolds (by consecutive spinning), for making thicker scaffolds (by multi-layering using heat or vapour annealing), for achieving sterility (aseptic production or sterilisation post production) and for achieving appropriate biomechanical properties.
JoVE Neuroscience
Antibody Transfection into Neurons as a Tool to Study Disease Pathogenesis
1Research Service, Veterans Administration Medical Center, Memphis, TN, 2Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, 3Department of Anatomy/Neurobiology, University of Tennessee Health Science Center, Memphis, TN
A rapid approach to investigate interactions and effects on molecular mechanisms related to the presence of antibodies in an intracellular environment is described. The method involves transfection of antibodies into live cells using a non-covalent complex formation based on a lipid formulation. The technique is adaptable to immortalized cell lines and primary cells.
JoVE Bioengineering
Multi-analyte Biochip (MAB) Based on All-solid-state Ion-selective Electrodes (ASSISE) for Physiological Research
1Department of Agricultural and Biological Engineering, Birck-Bindley Physiological Sensing Facility, Purdue University, 2NASA Ames Research Center, 3Department of Chemistry, Pennsylvania State University Hazleton, 4Cooley LLP, 5NASA Life and Physical Sciences, Human Exploration and Operations Mission Directorate, NASA Headquarters
All-solid-state ion-selective electrodes (ASSISEs) constructed from a conductive polymer (CP) transducer provide several months of functional lifetime in liquid media. Here, we describe the fabrication and calibration process of ASSISEs in a lab-on-a-chip format. The ASSISE is demonstrated to have maintained a near-Nernstian slope profile after prolonged storage in complex biological media.
JoVE Bioengineering
Bacterial Immobilization for Imaging by Atomic Force Microscopy
1Biological and Nanoscale Systems Group, Biosciences Division, Oak Ridge National Laboratory, 2Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, 3Department of Surgery, Eastern Virginia Medical School, 4Center for Nanophase Materials Sciences Division, Oak Ridge National Laboratory
Live Gram-negative and Gram-positive bacteria can be immobilized on gelatin-coated mica and imaged in liquid using Atomic Force Microscopy (AFM).
JoVE Bioengineering
Studying Cell Rolling Trajectories on Asymmetric Receptor Patterns
1Department of Materials Science and Engineering, MIT - Massachusetts Institute of Technology, 2Department of Mechanical Engineering, MIT - Massachusetts Institute of Technology, 3HST Center for Biomedical Engineering and Harvard Stem Cell Institute, Brigham and Women's Hospital and Harvard Medical School
We describe a protocol to observe and analyze cell rolling trajectories on asymmetric receptor-patterned substrates. The resulting data are useful for engineering of receptor-patterned substrates for label-free cell separation and analysis.
JoVE General
Human Pancreatic Islet Isolation: Part I: Digestion and Collection of Pancreatic Tissue
Department of Surgery, University of Illinois, Chicago
Achieving high quality and appropriate quantity of human islets is one of the prominent prerequisites for successful islet transplantation. In this video, we describe step by step the procedures for human pancreatic islet isolation (part I: digestion and collection of pancreatic tissue) using a modified automated method.
JoVE General
Human Pancreatic Islet Isolation: Part II: Purification and Culture of Human Islets
Department of Surgery, University of Illinois, Chicago
Achieving high quality and appropriate quantity of human islets is one of the prominent prerequisites for successful islet transplantation. In this video, we describe step by step the procedures for human pancreatic islet isolation (part II: purification and culture of human islets) using a modified automated method.
JoVE General
Crystallizing Membrane Proteins for Structure Determination using Lipidic Mesophases
Herein is described the procedure implemented in the Caffrey Membrane Structural and Functional Biology Group to set up manually crystallization trials of membrane proteins in lipidic mesophases.
JoVE General
Measuring the Bending Stiffness of Bacterial Cells Using an Optical Trap
1Department of Molecular Biology, Lewis-Sigler Institute for Integrative Genomics, Princeton University, 2Department of Physics, Lewis-Sigler Institute for Integrative Genomics, Princeton University
We present a protocol for bending filamentous bacterial cells attached to a cover-slip surface with an optical trap to measure the cellular bending stiffness.
JoVE Clinical and Translational Medicine
Sampling Human Indigenous Saliva Peptidome Using a Lollipop-Like Ultrafiltration Probe: Simplify and Enhance Peptide Detection for Clinical Mass Spectrometry
1Sanford-Burnham Medical Research Institute, 2Division of Dermatology, University of California, San Diego, 3VA San Diego Healthcare Center, 4Moores Cancer Center, University of California, San Diego
Considering saliva sampling for future clinical application, a lollipop-like ultrafiltration (LLUF) probe was fabricated to fit in the human oral cavity. Direct analysis of undigested saliva by NanoLC-LTQ mass spectrometry demonstrated the ability of LLUF probes to remove large proteins and high abundance proteins, and make low-abundant peptides more detectable.
JoVE Immunology and Infection
Reverse Genetics Mediated Recovery of Infectious Murine Norovirus
Section of Virology, Imperial College London
Noroviruses are a major cause of gastroenteritis yet molecular techniques for their characterisation are still relatively new. Here we report two different reverse genetics approaches for the efficient recovery of murine norovirus (MNV), the only member of this genus which can be propagated in cell culture.
JoVE Bioengineering
Graphene Coatings for Biomedical Implants
1Department of Physics, Clemson University, 2Department of Pharmacology and Toxicology, East Carolina University, 3Department of Bioengineering, Clemson University, 4Center for Optical Materials Science and Engineering Technologies, Clemson University
Graphene offers potential as a coating material for biomedical implants. In this study we demonstrate a method for coating nitinol alloys with nanometer thick layers of graphene and determine how graphene may influence implant response.
JoVE Neuroscience
The Culture of Primary Motor and Sensory Neurons in Defined Media on Electrospun Poly-L-lactide Nanofiber Scaffolds
1Department of Biomedical Engineering, University of Michigan, 2State Key Laboratory of Bioelectronics, Southeast University, 3Department of Neurology, University of Michigan, 4Geriatric Research, Education and Clinical Center, Veterans Affairs Ann Arbor Health System
Aligned electrospun fibers direct the growth of neurons in vitro and are a potential component of nerve regeneration scaffolds. We describe a procedure for preparing electrospun fiber substrates and the serum-free culture of primary rat E15 sensory (DRG) and motor neurons. Visualization of neurons by immunocytochemistry is also included.
JoVE Bioengineering
Measurement of Bioelectric Current with a Vibrating Probe
Dermatology, University of California, Davis
The manufacture, calibration and use of non-invasive vibrating probes to measure bioelectric current in various biological systems is described.
JoVE General
Analyzing Large Protein Complexes by Structural Mass Spectrometry
Department of Biological Chemistry, Weizmann Institute of Science
Mass spectrometry has proven to be a valuable tool for analyzing large protein complexes. This method enables insights into the composition, stoichiometry and overall architecture of multi-subunit assemblies. Here, we describe, step-by-step, how to perform a structural mass spectrometry analysis, and characterize macromolecular structures.
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