1Department of Chemical and Biomolecular Engineering, Ohio University, 2Biomedical Engineering Program, Russ College of Engineering and Technology, Ohio University, 3Department of Dermatology, Brigham and Women's Hospital, Harvard Medical School
Compared with traditional affinity chromatography using protein A agarose bead-packed columns, protein A membrane adsorbers can significantly speed laboratory-scale isolation of antibodies and other Fc fragment-expressing proteins. Appropriate analysis and quantification methods can further accelerate protein processing, allowing isolation/characterization to be completed in one workday, instead of 20+ work hours.…
Published January 8, 2014. Keywords: Bioengineering, affinity chromatography, membrane adsorber, bioseparations, protein A, galectin-1, Gal-1hFc
1Department of Chemical and Biomolecular Engineering, University of Akron
Developing biotinylatable fusion proteins has many potential applications in various fields of research. Recombinant protein engineering is a straight forward procedure that is cost-effective, providing high yields of custom-designed proteins.
Published January 22, 2014. Keywords: Bioengineering, protein engineering, recombinant protein production, AviTag, BirA, biotinylation, pET vector system, E. coli, inclusion bodies, Ni-NTA, size exclusion chromatography
JoVE Immunology and Infection
1Department of Biomedical Engineering, Vanderbilt University, 2Vanderbilt Institute for Nanoscale Science & Engineering, Vanderbilt University, 3Interdisciplinary Materials Science Program, Vanderbilt University, 4Monroe Carell Jr. Children's Hospital, Vanderbilt University Medical Center, 5Department of Chemical & Biomolecular Engineering, Vanderbilt University, 6Department of Cancer Biology, Vanderbilt University
A hemolysis assay can be used as a rapid, high-throughput screen of drug delivery systems' cytocompatibility and endosomolytic activity for intracellular cargo delivery. The assay measures the disruption of erythrocyte membranes as a function of environmental pH.
Published March 9, 2013. Keywords: Immunology, Cellular Biology, Medicine, Biomedical Engineering, Bioengineering, Cancer Biology, Molecular Biology, Erythrocytes, Endosomes, Small Interfering RNA, Gene Therapy, Nanomedicine, Gene delivery, Nanoparticles, Endosome Escape, Intracellular Trafficking, Cytosolic Drug Delivery, red blood cells, assay
1Department of Chemical and Biomolecular Engineering, Russ College of Engineering and Technology, Ohio University, 2Biomedical Engineering Program, Ohio University
Dual camera emission splitting systems for two-color fluorescence microscopy generate real-time image sequences with exceptional optical and temporal resolution, a requirement of certain live cell assays including parallel plate flow chamber adhesion assays. When software is employed to merge images from simultaneously acquired emission channels, pseudocolored image sequences are produced.…
Published September 4, 2013. Keywords: Bioengineering, Cellular Biology, Biomedical Engineering, Molecular Biology, Biophysics, Biochemistry, Chemical Engineering, Chemistry, Cell Adhesion Molecules, Biological Markers, Antigens, Cell Adhesion Molecules, Microscopy, Fluorescence, Cell Physiological Processes, Cell Adhesion, Cell Physiological Phenomena, Colocalization, cell rolling, two-color fluorescence, cell, imaging
1Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 2Department of Chemistry, The Johns Hopkins University
We describe experimental details of the synthesis of patterned and reconfigurable particles from two dimensional (2D) precursors. This methodology can be used to create particles in a variety of shapes including polyhedra and grasping devices at length scales ranging from the micro to centimeter scale.
Published February 4, 2013. Keywords: Chemistry, Chemical Engineering, Biomolecular Engineering, Materials Science, Physics, Nanotechnology, Molecular Self-assembly, Electrochemistry, Folding, three dimensional, lithography, colloid, patchy particles, particles, nanoparticles, robotics, drug delivery, microfabrication, nanofabrication, nano, assembly, synthesis, reaction, origami
1Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, 2NIST Center for Neutron Research, National Institute of Standards and Technology, 3Institut Laue-Langevin
A shear cell is developed for small-angle neutron scattering measurements in the velocity-velocity gradient plane of shear and is used to characterize complex fluids. Spatially resolved measurements in the velocity gradient direction are possible for studying shear-banding materials. Applications include investigations of colloidal dispersions, polymer solutions, and self-assembled structures.…
Published February 6, 2014. Keywords: Physics, Surfactants, Rheology, Shear Banding, Nanostructure, Neutron Scattering, Complex Fluids, Flow-induced Structure
JoVE Immunology and Infection
1Department of Chemical and Biomolecular Engineering, University of Houston, 2Division of Pediatrics, Research Unit 907, University of Texas MD Anderson Cancer Center
We describe a single-cell high-throughput assay to measure cytotoxicity of T cells when incubated with tumor target cells. This method employs a dense, elastomeric array of sub-nanoliter wells (~100,000 wells/array) to spatially confine the T cells and target cells at defined ratios and is coupled to fluorescence microscopy to monitor effector-target conjugation and subsequent apoptosis.…
Published February 2, 2013. Keywords: Cancer Biology, Immunology, Cellular Biology, Molecular Biology, Medicine, Chemical Engineering, Biomolecular Engineering, Bioengineering, Immunotherapy, Adoptive, Microfluidics, Nanowell arrays, PDMS, BioStation, T Cells, tumor target cells, labeling, cytotoxicity, microscopy, assay
1Department of Physics, University of California at Berkeley, 2Department of Chemistry, University of California at Berkeley, 3Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 4National Institute for Materials Science (Japan), 5Materials Sciences Division, Lawrence Berkeley National Laboratory, 6Kavli Energy NanoSciences Institute, University of California at Berkeley and Lawrence Berkeley National Laboratory
This paper details the fabrication process of a gate-tunable graphene device, decorated with Coulomb impurities for scanning tunneling microscopy studies. Mapping the spatially dependent electronic structure of graphene in the presence of charged impurities unveils the unique behavior of its relativistic charge carriers in response to a local Coulomb potential.
Published July 24, 2015. Keywords: Engineering, Physics, graphene, electrostatic gating, scanning tunneling microscopy (STM), Coulomb impurity, chemical vapor deposition (CVD), poly(methyl methacrylate) (PMMA) transfer, wire bonding
1Experimental Radiology, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital, 2Department of Pharmaceutical Technology, Friedrich-Schiller-University Jena, 3Center for Electron Microscopy, Jena University Hospital
The use of fluorophores for in vivo imaging can be greatly limited by opsonization, rapid clearance, low detection sensitivity and cytotoxic effects on the host. Encapsulation of fluorophores in liposomes by film hydration and extrusion leads to fluorescence quenching and protection which enables in vivo imaging with high detection sensitivity.
Published January 5, 2015. Keywords: Bioengineering, Drug-delivery, Liposomes, Fluorochromes, Fluorescence-quenching, Optical imaging, Inflammation
JoVE Immunology and Infection
1Institute for Bioscience and Biotechnology Research, University of Maryland
A novel directed evolution method specific to the field of thermostability engineering was developed and consequently validated for bacteriolytic enzymes. After only one round of random mutagenesis, an evolved bacteriolytic enzyme, PlyC 29C3, displayed greater than twice the residual activity when compared to the wild-type protein after elevated temperature incubation.
Published November 7, 2012. Keywords: Immunology, Molecular Biology, Genetics, Microbiology, directed evolution, thermal behavior, thermostability, endolysin, enzybiotic, bacteriolytic, antimicrobial, therapeutic, PlyC
1Chemical and Biomolecular Engineering Department, University of Houston
Confocal microscopy is used to image quiescent and flowing colloid-polymer mixtures, which are studied as model systems for attractive suspensions. Image analysis algorithms are used to calculate structural and dynamic metrics for the colloidal particles that measure changes due to geometric confinement.
Published May 20, 2014. Keywords: Chemistry, confocal microscopy, particle tracking, colloids, suspensions, confinement, gelation, microfluidics, image correlation, dynamics, suspension flow
1Department of Materials Science and Engineering, University of California Berkeley, 2Materials Science Division, Lawrence Berkeley National Laboratory, 3Advanced Light Source Division, Lawrence Berkeley National Laboratory, 4Department of Chemical and Biomolecular Engineering, University of California Berkeley, 5Environmental Energy Technology Division, Lawrence Berkeley National Laboratory
Synchrotron-based hard X-ray microtomography is used to image the electrochemical growth of dendrites from a lithium metal electrode through a solid polymer electrolyte membrane.
Published August 26, 2015. Keywords: Engineering, Lithium-ion batteries, lithium dendrite growth, polymer electrolytes, X-ray microtomography, electrochemistry, X-ray imaging
1Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, 2Department of Chemical and Biomolecular Engineering, University of Tennessee
Two techniques for isolating cellular lipid droplets from 1) yeast cells and 2) human placentas are presented. The centerpiece of both procedures is density gradient centrifugation, where the resulting floating layer containing the droplets can be readily visualized by eye, extracted, and quantified by Western Blot analysis for purity.
Published April 1, 2014. Keywords: Bioengineering, Lipid droplet, lipid body, fat body, oil body, Yeast, placenta, placental villous cells, isolation, purification, density gradient centrifugation
1School of Chemistry and Biochemistry, Georgia Institute of Technology, 2School of Chemical and Biomolecular Engineering, Georgia Institute of Technology
The high pressure sapphire cell apparatus is a unique tool to study, without sampling, phase behavior under a wide range of pressures. Using a cathetometer, very precise volume measurements can be recorded to measure liquid expansion and phase composition. Thus, this synthetic method enables the study of (1) phase equilibria of multi-component mixtures and (2) the partition behavior of catalyst or model compounds as a function of pressure. …
Published January 24, 2014. Keywords: Chemistry, Phase equilibria, High-pressure, green chemistry, Green Engineering, Sapphire cell, cathetometer, ternary phase diagrams
1Department of Physics, University of Notre Dame, 2Department of Chemical and Biomolecular Engineering, University of Notre Dame, 3Center of Functional Nano-Ceramics, National University of Science and Technology, "MISIS"
This protocol describes the preparation of gasless nanostructured energetic materials (Ni+Al, Ta+C, Ti+C) using the short-term high-energy ball milling (HEBM) technique. It also describes a high-speed thermal imaging method to study the reactivity of mechanically fabricated nanocomposites. These protocols can be extended to other reactive nanostructured energetic materials.…
Published April 2, 2015. Keywords: Engineering, Reactive composites, Energetic materials, High-Energy Ball Milling, Gasless Combustion, Ignition, Reactivity Enhancement
1Department of Chemistry and Biochemistry, University of Notre Dame, 2Department of Chemical and Biomolecular Engineering, University of Notre Dame, 3Department of Chemistry, Physics, and Engineering Studies, Chicago State University, 4Department of Technology, Ivy Tech Community College, South Bend, Indiana
Reproducible cleaning processes for substrates used in DNA origami research are described, including bench-top RCA cleaning and derivatization of silicon oxide. Protocols for surface preparation, DNA origami deposition, drying parameters, and simple experimental set-ups are illustrated.
Published July 23, 2015. Keywords: Chemistry, Nanostructures, substrate, DNA origami, mica, silicon, biomolecule, self-assembly
1School of Materials Science and Engineering, Clemson University, 2Center for Optical Materials Science and Engineering Technologies, Clemson University
A protocol to construct and test coin cells of lithium ion batteries is described. The specific procedures of making a working electrode, preparing a counter electrode, assembling a cell inside a glovebox and testing the cell are presented.
Published August 2, 2012. Keywords: Materials Science, Chemistry, Chemical Engineering, Electrical Engineering, Physics, Battery, coin cells, CR2032, lithium, lithium ion
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.
Published May 3, 2010. Keywords: Microbiology, Microfluidic device, bacterial transport, porous media, colloid, biofilm, filtration theory, artificial habitat, micromodel, PDMS, GFP
JoVE Immunology and Infection
1Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, 2Department of Mechanical and Aerospace Engineering, The Ohio State University, 3Center for Computational and Integrative Biology, Massachusetts General Hospital, Harvard Medical School, 4Dept. of Chemical and Biomolecular Engineering, Vanderbilt University
A method is described to individually select, manipulate, and image live pathogens using an optical trap coupled to a spinning disk microscope. The optical trap provides spatial and temporal control of organisms and places them adjacent to host cells. Fluorescence microscopy captures dynamic intercellular interactions with minimal perturbation to cells.
Published July 28, 2011. Keywords: Immunology, Optical trapping, optical tweezers, T-cell, pathogen, live cell imaging, spinning disk confocal microscopy, Aspergillus fumigatus, Candida albicans, fungi
1Chemical and Biomolecular Engineering Department, Johns Hopkins University
A procedure for creating and imaging capillary bridges in slit-pore geometry is presented. The creation of capillary bridges relies on the formation of pillars to provide a directional physical and chemical heterogeneity to pin the fluid. Capillary bridges are formed and manipulated using microstages and visualized using a CCD camera.
Published January 9, 2014. Keywords: Physics, Microfluidics, Surface Properties, Capillary Action, Surface Tension, fluid forces, fluidics, polydimethylsiloxane molding, self-assembled monolayers, surface patterning, imprint transfer lithography, surface tension, capillarity, wetting
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.
Published February 11, 2008. Keywords: Cell Biology, Bioengineering, microfluidic device, motility, chemotaxis, EGFR, neural stem cell, brain tumor cell
1Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 2Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign
In this article, we present a microfluidic-based method for particle confinement based on hydrodynamic flow. We demonstrate stable particle trapping at a fluid stagnation point using a feedback control mechanism, thereby enabling confinement and micromanipulation of arbitrary particles in an integrated microdevice.
Published January 21, 2011. Keywords: Bioengineering, hydrodynamic, trap, trapping, confinement, micromanipulation, microfluidics, stagnation point flow
1Department of Chemical and Biomolecular Engineering, Johns Hopkins Physical Sciences Oncology Center and Institute for NanoBioTechnology, Johns Hopkins University
A novel approach that allows the high-resolution analysis of cancer cell interactions with exogenous hyaluronic acid (HA) is described. Patterned surfaces are fabricated by combining carbodiimide chemistry and microcontact printing.
Published December 22, 2010. Keywords: Bioengineering, Hyaluronic acid, microcontact printing, carbodiimide chemistry, cancer, cell adhesion
1Department of Ophthalmology, Massachusetts Eye and Ear, 2JoVE Content Production
Here's a look at what's coming up in the September 2013 issue of JoVE: The Journal of Visualized Experiments.
Published September 3, 2013. Keywords: This Month in JoVE,
1Department of Comparative Medicine, Tulane University, 2Department of Chemical and Biomolecular Engineering, Tulane University
Bladder tumors are established in female mice in a minimally invasive fashion through catheterization, local cauterization, and subsequent adhesion of carcinoma cells to the burn sites.
Published February 6, 2011. Keywords: Medicine, Bladder tumor, orthotopic, mouse, ultrasound
1Department of Ophthalmology, Massachusetts Eye and Ear, 2JoVE Content Production
Here's a look at what's coming up in the February 2013 Issue of Journal of Visualized Experiments (JoVE).
Published February 1, 2013. Keywords: This Month in JoVE