1Materials Engineering Division, Lawrence Livermore National Laboratory, 2UCSF Center for Integrative Neuroscience and the Department of Physiology, University of California, San Francisco
Insertion of flexible neural microelectrode probes is enabled by attaching probes to rigid stiffeners with polyethylene glycol (PEG). A unique assembly process ensures uniform and repeatable attachment. After insertion into tissue, the PEG dissolves and the stiffener is extracted. An in vitro test method evaluates the technique in agarose gel.
Published September 27, 2013. Keywords: Bioengineering, Nervous System Diseases, Surgical Procedures, Operative, Investigative Techniques, Nonmetallic Materials, Engineering (General), neural interfaces, polymer neural probes, surgical insertion, polyethylene glycol, microelectrode arrays, chronic implantation
1Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen
Polymerization of FtsZ is essential for bacterial cell division. In this report, we detail simple protocols to monitor FtsZ polymerization activity and discuss the influence of buffer composition. The protocols can be used to study the interaction of FtsZ with regulatory proteins or antibacterial drugs that affect FtsZ polymerization.
Published November 16, 2013. Keywords: Basic Protocols, FtsZ, protein polymerization, cell division, GTPase, sedimentation assay, light scattering
JoVE Applied Physics
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
1Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem
This paper describes the formation of highly ordered peptide-based structures by the spontaneous process of self-assembly. The method utilizes commercially available peptides and common lab equipment. This technique can be applied to a large variety of peptides and may lead to the discovery of new peptide-based assemblies.
Published November 21, 2013. Keywords: Chemistry, Materials (General), self-assembly, peptides, diphenylalanine, atomatic interactions, coassembly, molecular recognition
1Center for Computational Medicine and Bioinformatics, University of Michigan, 2Center for Bioinformatics and Department of Molecular Bioscience, University of Kansas
Guidelines for computer based structural and functional characterization of protein using the I-TASSER pipeline is described. Starting from query protein sequence, 3D models are generated using multiple threading alignments and iterative structural assembly simulations. Functional inferences are thereafter drawn based on matches to proteins with known structure and functions.
Published November 3, 2011. Keywords: Biochemistry, On-line server, I-TASSER, protein structure prediction, function prediction
1Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation
A protocol is described that uses Illumina's Infinium assays to perform large-scale genotyping. These assays can reliably genotype millions of SNPs across hundreds of individual DNA samples in three days. Once generated, these genotypes can be used to check for associations with a variety of different diseases or phenotypes.
Published November 19, 2013. Keywords: Basic Protocol, genomics, SNP, Genotyping, Infinium, iScan, HiScan, Illumina
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
JoVE Applied Physics
1Organic Chemistry Institute and CeNTech, Westfälische Wilhelms-Universität Münster, 2Laboratory of Macromolecular and Organic Chemistry, Institute for Complex Molecular Systems, Eindhoven University of Technology, 3Laboratory of Materials and Interface Chemistry and Soft Matter Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology
The goal of this experiment is to determine and control the size, shape and stability of self-assembled discotic amphiphiles in water. For aqueous based supramolecular polymers such level of control is very difficult. We apply a strategy using both repulsive and attractive interactions. The experimental techniques applied to characterize this system are broadly applicable.
Published August 2, 2012. Keywords: Chemical Engineering, Chemistry, Physics, Self-assembly, cryogenic transmission electron microscopy, circular dichroism, controlled architecture, discotic amphiphile
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.
Published June 6, 2012. Keywords: Bioengineering, Biomedical Engineering, electrodeposition, biofabrication, chitosan, alginate, lab-on-a-chip, microfluidic, DTRA
JoVE Applied Physics
1Department of Mechanical Engineering, University of Michigan
A procedure for studying transient flows near boundaries using high-resolution, high-speed particle image velocimetry (PIV) is described here. PIV is a non-intrusive measurement technique applicable to any optically accessible flow by optimizing several parameter constraints such as the image and recording properties, the laser sheet properties, and analysis algorithms.
Published June 24, 2013. Keywords: Physics, Mechanical Engineering, Fluid Mechanics, flow measurement, fluid heat transfer, internal flow in turbomachinery (applications), boundary layer flow (general), flow visualization (instrumentation), laser instruments (design and operation), Boundary layer, micro-PIV, optical laser diagnostics, internal combustion engines, flow, fluids, particle, velocimetry, visualization