A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
1Department of Biology, San Diego State University, 2Scripps Institution of Oceanography, University of California San Diego
Here, we present a comprehensive protocol to assess the organic and inorganic nutrient availability and the abundance and structure of microbial and viral communities in remote marine environments.
Published November 5, 2014. Keywords: Environmental Sciences, dissolved organic carbon, particulate organic matter, nutrients, DAPI, SYBR, microbial metagenomics, viral metagenomics, marine environment
JoVE Immunology and Infection
1Department of Chemistry, Stony Brook University
Adenovirus particles are engineered to contain either the unnatural amino acid analogue azidohomoalanine or the azido sugar O-GlcNAz. The azide group of each is chemoselectively ligated via "click" chemistry reactions as a means of viral surface modification.
Published August 19, 2012. Keywords: Chemistry, Virology, Immunology, Genetics, adenovirus, azide-alkyne cycloaddition, azido sugar, azidohomoalanine, bioorthogonal, click chemistry, gene therapy, unnatural amino acid
JoVE Immunology and Infection
1Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch
This method describes the use of click chemistry to measure changes in host cell transcription after infection with the Rift Valley fever virus (RVFV) strain MP-12. Results can be visualized qualitatively via fluorescence microscopy or obtained quantitatively through flow cytometry. This method is adaptable for use with other viruses.
Published August 9, 2013. Keywords: Immunology, Virology, Chemistry, Infectious Diseases, Biochemistry, Genetics, Molecular Biology, Cellular Biology, Medicine, Biomedical Engineering, Arboviruses, Bunyaviridae, RNA, Nuclear, Transcription, Genetic, Rift Valley fever virus, NSs, transcription, click chemistry, MP-12, fluorescence microscopy, flow cytometry, virus, proteins, immunostaining, assay
1Department of Biochemistry, Albert Einstein College of Medicine, Yeshiva University, 2Macromolecular Therapeutics Development Facility, Albert Einstein College of Medicine, Yeshiva University, 3Developmental and Molecular Biology, Albert Einstein College of Medicine, Yeshiva University
A click-chemistry based method that allows for the rapid, noninvasive, and robust labeling of alkyne-tagged glycans in zebrafish embryos is described. Fucosylated glycans in the enveloping layer of zebrafish embryos in the late gastrulation stage were imaged in this study.
Published June 6, 2011. Keywords: Developmental Biology, click chemistry, chemical glycobiology, fucosylated glycans, embryogenesis, microinjection
JoVE Immunology and Infection
1Department of Basic Sciences, Mississippi State University
Here we describe a procedure allowing the labeling of Edwardsiella ictaluri in situ in histological sections from channel catfish Ictalurus punctatus using indirect immunohistochemistry with monoclonal antibodies Ed9 as a primary, and fluorescent FitC labeled antibodies as a secondary. This allowed for the detection of the bacterium using fluorescent microscopy.
Published May 10, 2011. Keywords: Immunology, immunohistochemistry, histology, Edwardsiella ictaluri, enteric septicemia of channel catfish, Fish, Catfish, Ictalurus punctatus
Robert Huber, 1988 Nobel Laureate in Chemistry, looks to the rising generation of scientists for an “Einstein of biology” to solve the folding problem, one of sciences great mysteries.
Published November 25, 2008. Keywords: Cellular Biology, Lindau 2008, Nobel Laureate, Chemistry, Folding Problem, X-ray Crystallography, Transmembrane Protein
Aaron Ciechanover was born in Haifa, Israel in October 1947. Ciechanover shared the Nobel Prize in Chemistry in 2004 with Avram Hershko and Irwin Rose for their discovery of ubiquitin-mediated protein degradation.
Published July 1, 2009. Keywords: Cellular Biology, Ubiquitin, Ubiquitination, Proteosome, Protein Degradation, Nobel Laureate,
American chemist Peter Agre shared the 2003 Nobel Prize in Chemistry for his discovery of aquaporins, the channel proteins that allow water to cross the cell membrane.
Published December 9, 2009. Keywords: Cellular Biology, aquaporins, water-channel, diffusion, renal tubules, red blood cells
American Biologist Martin Chalfie shared the 2008 Nobel Prize in Chemistry with Roger Tsien and Osamu Shimomura for their discovery and development of the Green Fluorescent Protein (GFP). Chalfie subcloned the coding sequence of GFP and expressed it in both E. coli and C. elegans, demonstrating for the first time that no other factor was required for GFP luminescence.
Published February 10, 2010. Keywords: Cellular Biology, GFP, Ghia Euskirchen, E. coli, expression, green fluorescent protein, C. elegans, Nobel Prize, Lindau
American biochemist Roger Tsien shared the 2008 Nobel Prize in Chemistry with Martin Chalfie and Osamu Shimomura for their discovery and development of the Green Fluorescent Protein (GFP). Tsien dramatically improved the wild-type GFP resulting in increased fluorescence, increased photostability, and a shift in the major excitation peak to 488 nm (matching FITC).
Published January 13, 2010. Keywords: Cellular Biology, GFP, Green Fluorescent Protein, IFPs, jellyfish, PKA, Calmodulin
English Chemist Harold Kroto shared the 1996 Nobel Prize in Chemistry with Robert Curl and Richard Smalley for their discovery of Fullerenes (C60), molecules composed completely of carbon that form hollow spheres (also known as Buckyballs), tubes, or ellipsoids. These structures hold the potential for use in future technologies ranging from drug development and antimicrobial agents, to armor and superconductors.
Published April 7, 2010. Keywords: Cellular Biology, Fullerenes, Buckminster, interstellar, carbon chains, atheism, graphic design, C60, Buckyballs
1Department of Chemistry, Virginia Military Institute
A procedure for performing reductive electropolymerization of vinyl-containing compounds onto glassy carbon and fluorine doped tin-oxide coated electrodes is presented. Recommendations on electrochemical cell configurations and troubleshooting procedures are included. Although not explicitly described here, oxidative electropolymerization of pyrrole-containing compounds follows similar procedures to vinyl-based reductive electropolymerization.
Published January 30, 2015. Keywords: Chemistry, electrochemistry, electropolymerization, electrodeposition, fluorine doped tin oxide, glassy carbon, cyclic voltammetry, potentiostat, vinyl, pyrrole, ruthenium, controlled potential electrolysis, 3-compartment cell
1Department of Physics and Astronomy, VU University Amsterdam
This protocol details the reconstitution of light-harvesting complexes in vitro. These integral membrane proteins coordinate chlorophylls and carotenoids and are responsible for harvesting light in higher plants and green algae.
Published October 10, 2014. Keywords: Biochemistry, Reconstitution, Photosynthesis, Chlorophyll, Carotenoids, Light Harvesting Protein, Chlamydomonas reinhardtii, Arabidopsis thaliana
1MESA+ Institute for Nanotechnology, University of Twente
Procedures are outlined to prepare segmented and coaxial nanowires via templated electrodeposition in nanopores. As examples, segmented nanowires consisting of Ag and ZnO segments, and coaxial nanowires consisting of a TiO2 shell and a Ag core were made. The nanowires were used in photocatalytic hydrogen formation experiments.
Published May 2, 2014. Keywords: Physics, Multicomponent nanowires, electrochemistry, sol-gel processes, photocatalysis, photochemistry, H2 evolution
1Physical Sciences Division, Pacific Northwest National Laboratory
Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of novel materials. Coupled with analysis by in situ secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS), soft landing provides unprecedented insights into the interactions of well-defined species with surfaces.
Published June 16, 2014. Keywords: Chemistry, soft landing, mass selected ions, electrospray, secondary ion mass spectrometry, infrared spectroscopy, organometallic, catalysis
1Chemical Sensing & Fuel Technology, Chemistry Division, U.S. Naval Research Laboratory, 2NOVA Research, Inc., 3Bio/Analytical Chemistry, Chemistry Division, U.S. Naval Research Laboratory, 4Navy Technology Center for Safety and Survivability, Chemistry Division, U.S. Naval Research Laboratory
Trace explosive vapors of TNT and RDX collected on sorbent-filled thermal desorption tubes were analyzed using a programmed temperature desorption system coupled to GC with an electron capture detector. The instrumental analysis is combined with direct liquid deposition method to reduce sample variability and account for instrumentation drift and losses.
Published July 25, 2014. Keywords: Chemistry, Gas Chromatography (GC), Electron Capture Detector, Explosives, Quantitation, Thermal Desorption, TNT, RDX
1Combustion Research Facility, Sandia National Laboratories, 2Chemical Sciences Division, Advanced Light Source, Lawrence Berkeley National Laboratory, 3Physikalische Chemie I, Universität Bielefeld
Gas sampling from laboratory-scale flames with online analysis of all species by mass spectrometry is a powerful method to investigate the complex mixture of chemical compounds occurring during combustion processes. Coupled with tunable soft ionization via synchrotron-generated vacuum-ultraviolet radiation, this technique provides isomer-resolved information and potentially fragment-free mass spectra.
Published May 26, 2014. Keywords: Physics, Combustion, Flame, Energy Conversion, Mass Spectrometry, Photoionization, Synchrotron, Hydrocarbon, Soot, Aerosol, Isomer
1Department of Radiology, Memorial Sloan Kettering Cancer Center
The bioorthogonal inverse electron demand Diels-Alder cycloaddition has been harnessed to create an effective and modular pretargeted PET imaging strategy for cancer. In this protocol, the steps of this methodology are described in the context of a model system employing the colorectal cancer targeted antibody huA33 and a 64Cu-labeled radioligand.
Published February 3, 2015. Keywords: Bioengineering, Positron Emission Tomography, Click Chemistry, Pretargeting, Tetrazine, Trans-cyclooctene, Inverse Electron Demand Diels-Alder Cycloaddition
1Diabetes and Islet Biology Group, NHMRC Clinical Trials Centre, Faculty of Medicine, The University of Sydney, 2Biomarkers Laboratory, NHMRC Clinical Trials Centre, Faculty of Medicine, The University of Sydney
Circulating microRNAs have recently emerged as promising and novel biomarkers for various cancers and other diseases. The goal of this article is to discuss three different probe-based real-time PCR platforms and methods that are available to quantify and determine the abundance of circulating microRNAs.
Published April 14, 2015. Keywords: Molecular Biology, microRNA, ncRNA, probe-based assays, high-throughput PCR, Nanofluidics / Open Arrays, reverse-transcription, pre-amplification, qPCR
1Laboratory of Structural Biology, NIEHS, National Institutes of Health
Time courses for the glycosylase activity of 8-oxoguanine DNA glycosylase are biphasic exhibiting a burst of product formation and a linear steady-state phase. Utilizing quench-flow techniques, the burst and the steady-state rates can be measured, which correspond to excision of 8-oxoguanine and release of the glycosylase from the product DNA, respectively.
Published August 19, 2013. Keywords: Chemistry, Biochemistry, Genetics, Molecular Biology, Microbiology, Structural Biology, Chemical Biology, Eukaryota, Amino Acids, Peptides, and Proteins, Nucleic Acids, Nucleotides, and Nucleosides, Enzymes and Coenzymes, Life Sciences (General), enzymology, rapid quench-flow, active site titration, steady-state, pre-steady-state, single-turnover, kinetics, base excision repair, DNA glycosylase, 8-oxo-7, 8-dihydroguanine, 8-oxoG, sequencing
1Department of Bioengineering, Rice University
Provided is a protocol for developing a real-time recombinase polymerase amplification assay to quantify initial concentration of DNA samples using either a thermal cycler or a microscope and stage heater. Also described is the development of an internal positive control. Scripts are provided for processing raw real-time fluorescence data.
Published March 30, 2015. Keywords: Genetics, recombinase polymerase amplification, isothermal amplification, quantitative, diagnostic, HIV-1, viral load
1Department of Chemistry and Chemical Biology, McMaster University
A guided material screening approach to develop sol-gel derived protein doped microarrays using an emerging pin-printing method of fabrication is described. This methodology is demonstrated through the development of acetylcholinesterase and multikinase microarrays, which are used for cost-effective small-molecule screening.
Published August 26, 2013. Keywords: Chemistry, Biochemistry, Chemical Engineering, Molecular Biology, Genetics, Bioengineering, Biomedical Engineering, Chemical Biology, Biocompatible Materials, Siloxanes, Enzymes, Immobilized, chemical analysis techniques, chemistry (general), materials (general), spectroscopic analysis (chemistry), polymer matrix composites, testing of materials (composite materials), Sol-gel, microarray, high-throughput screening, acetylcholinesterase, kinase, drug discovery, assay
1Department of Radiology, Memorial Sloan Kettering Cancer Center
Due to its multi-day radioactive half-life and favorable decay properties, the positron-emitting radiometal 89Zr is extremely well-suited for use in antibody-based radiopharmaceuticals for PET imaging. In this protocol, the bioconjugation, radiosynthesis, and preclinical application of 89Zr-labeled antibodies will be described.
Published February 12, 2015. Keywords: Chemistry, Positron Emission Tomography, Antibody, Bioconjugation, Immunoconjugates, Desferrioxamine, 89Zr
1Department of Cellular and Physiological Sciences, Brain Research Centre, University of British Columbia
The reversible addition of palmitate to proteins is an important regulator of intracellular protein trafficking. This is of particular interest in neurons where many synaptic proteins are palmitoylated. We utilize a simple biochemical method to detect palmitoylated proteins in cultured neurons, which can be adapted for multiple cell types and tissues.
Published February 18, 2013. Keywords: Neuroscience, Biochemistry, Neurobiology, Molecular Biology, Cellular Biology, Physiology, Proteins, synapse, cultured hippocampal neurons, palmitoylation, lipid, immunoprecipitation, western blotting, biotin, Acyl-Biotin Exchange, ABE, neuron, brain, cell culture, rat, mouse, animal model
1Great Lakes Science Center, U. S. Geological Survey, 2Annis Water Resources Institute, Grand Valley State University, 3Daniel P. Haerther Center for Conservation and Research, Shedd Aquarium
A technique for laboratory estimation of net trophic transfer efficiency of polychlorinated biphenyl (PCB) congeners to piscivorous fish from their prey is presented. To maximize applicability of the laboratory results to the field, the piscivorous fish should be fed prey fish that are typically eaten in the field.
Published August 29, 2014. Keywords: Environmental Sciences, trophic transfer efficiency, polychlorinated biphenyl congeners, lake trout, activity, contaminants, accumulation, risk assessment, toxic equivalents
1Division of Nutritional Sciences, Cornell University, 2Field of Biochemistry, and Molecular Cell Biology, Cornell University
Metabolite profiling has been a valuable asset in the study of metabolism in health and disease. Utilizing normal-phased liquid chromatography coupled to high-resolution mass spectrometry with polarity switching and a rapid duty cycle, we describe a protocol to analyze the polar metabolic composition of biological material with high sensitivity, accuracy, and resolution.
Published May 27, 2014. Keywords: Chemistry, high-resolution mass spectrometry, metabolomics, positive/negative switching, low mass calibration, Orbitrap
1Section of Molecular Genetics and Microbiology, The University of Texas at Austin, 2Department of Chemistry and Biochemistry, The University of Texas at Austin, 3The Institute of Cellular and Molecular Biology, The University of Texas at Austin
Isolation and characterization of the lipid A domain of lipopolysaccharide (LPS) from gram-negative bacteria provides insight into cell surface based mechanisms of antibiotic resistance, bacterial survival and fitness, and how chemically diverse lipid A molecular species differentially modulate host innate immune responses.
Published September 16, 2013. Keywords: Chemistry, Membrane Lipids, Toll-Like Receptors, Endotoxins, Glycolipids, Lipopolysaccharides, Lipid A, Microbiology, Lipids, lipid A, Bligh-Dyer, thin layer chromatography (TLC), lipopolysaccharide, mass spectrometry, Collision Induced Dissociation (CID), Photodissociation (PD)
1Department 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.
Published April 1, 2013. Keywords: Chemistry, Chemical Engineering, Materials Science, Physics, Nanotechnology, Chemistry and Materials (General), Composite Materials, Inorganic, Organic and Physical Chemistry, Metals and Metallic Materials, Gold, nanotubes, anodic aluminum oxide templates, surface plasmon resonance, sensing, refractive index, template directed synthesis, nano
1Department of Chemistry, Texas Christian University
The synthesis of asymmetric species of ferrocene is challenging using solution techniques. This report focuses on the methods carried out to produce a ferrocene-biotin bioconjugate using facile and clean reactions accomplished via solid-phase synthesis. Incorporation of a thiolate moiety is shown to impart the ability for immobilization on gold surfaces.
Published March 12, 2015. Keywords: Chemistry, Ferrocene, biotin, bio-conjugate, solid phase peptide synthesis, resin, asymmetric, peptide, amino-acid, gold
1Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University
We genetically-encode the unnatural amino acid, p-azido-L-phenylalanine at various targeted positions in GPCRs and show the versatility of the azido group in different applications. These include a targeted photocrosslinking technology to identify residues in the ligand-binding pocket of a GPCR, and site-specific bioorthogonal modification of GPCRs with a peptide-epitope tag or fluorescent probe.
Published September 13, 2013. Keywords: Genetics, Receptors, G-Protein-Coupled, Protein Engineering, Signal Transduction, Biochemistry, Unnatural amino acid, site-directed mutagenesis, G protein-coupled receptor, targeted photocrosslinking, bioorthogonal labeling, targeted epitope tagging
1School of Chemistry and Biochemistry, Georgia Institute of Technology, 2Earth-Life Science Institute, Tokyo Institute of Technology, 3Institute for Advanced Study, 4Astromaterials Research and Exploration Science Directorate, NASA Johnson Space Center, 5Goddard Center for Astrobiology, NASA Goddard Space Flight Center, 6Geosciences Research Division, Scripps Institution of Oceanography, University of California at San Diego
The Miller-Urey experiment was a pioneering study regarding the abiotic synthesis of organic compounds with possible relevance to the origins of life. Simple gases were introduced into a glass apparatus and subjected to an electric discharge, simulating the effects of lightning in the primordial Earth’s atmosphere-ocean system. The experiment was conducted for one week, after which, the samples collected from it were analyzed for the chemical building blocks of life.
Published January 21, 2014. Keywords: Chemistry, Geosciences (General), Exobiology, Miller-Urey, Prebiotic chemistry, amino acids, spark discharge
1School of Ecology and Environmental Studies, Nalanda University, 2Department of Earth Sciences, Uppsala University
Surface properties of a nanoparticle are important for their interaction with the surrounding medium. Therefore the surface modification of carbon nanotubes can be critical for their transport and retention through porous media. Here, lab scale column experiments are used to understand the possible transport and retention of these nanoparticles.
Published April 2, 2015. Keywords: Chemistry, Carbon nanotubes, functionalization of carbon nanotubes, solution chemistry, flow rate, porous media
1ISOF - Bio Free Radicals, Consiglio Nazionale delle Ricerche
Radical-based biomimetic chemistry has been applied to building-up libraries necessary for biomarker development.
Published April 15, 2013. Keywords: Chemistry, Biochemistry, Chemical Engineering, Chemical Biology, chemical analysis techniques, chemistry (general), life sciences, radiation effects (biological, animal and plant), biomarker, biomimetic chemistry, free radicals, trans lipids, cyclopurine lesions, DNA, chromatography, spectroscopy, synthesis
1Department of Immunology, National Jewish Health, 2Department of Pharmacology, School of Medicine, University of Colorado Denver
The reliability of results in metabolomics experiments depends on the effectiveness and reproducibility of the sample preparation. Described is a rigorous and in-depth method that enables extraction of metabolites from biological fluids with the option of subsequently analyzing up to thousands of compounds, or just the compound classes of interest.
Published July 11, 2014. Keywords: Bioengineering, plasma, chemistry techniques, analytical, solid phase extraction, mass spectrometry, metabolomics, fluids and secretions, profiling, small molecules, lipids, liquid chromatography, liquid-liquid extraction, cerebrospinal fluid, bronchoalveolar lavage fluid
1Graduate 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.
Published April 15, 2013. Keywords: Chemistry, Chemical Engineering, Materials Science, Nanotechnology, Engineering, Nanotubes, Carbon, Oxidation-Reduction, Surface Properties, carbon nanotubes (synthesis and properties), Carbon nanotube, Wettability, Hydrophobic, Hydrophilic, UV/ozone, Oxygen Plasma, Vacuum Annealing
1Center for Systems Biology, Massachusetts General Hospital
We present a method for rapid, reversible immobilization of small molecules and functionalized nanoparticle assemblies for Surface Plasmon Resonance (SPR) studies, using sequential on-chip bioorthogonal cycloaddition chemistry and antibody-antigen capture.
Published September 23, 2013. Keywords: Chemistry, Organic Chemicals, Macromolecular Substances, Chemistry and Materials (General), Surface Plasmon Resonance, Bioorthogonal Chemistry, Diels-Alder Cycloaddition Reaction, Small Molecule Immobilization, Binding Kinetics, Immobilized Nanoparticles
1Department of Chemistry and Biochemistry, University of Notre Dame
We present the high-temperature synthesis of intermetallic precursors K4Ge9, their dissolution in ethylenediamine to form Ge94- deltahedral Zintl ions, and the reaction of the clusters with alkynes to form organo-Zintl ions. The latter are characterized by electrospray mass spectrometry in solutions and by single-crystal X-ray diffraction in the solid state.
Published February 11, 2012. Keywords: Biochemistry, Zintl ions, deltahedral clusters, germanium, intermetallics, alkali metals
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
1Chemistry Department, Elon University, 2Department of Neurobiology and Anatomy, Wake Forest School of Medicine, 3Neuroscience Graduate Program, Wake Forest School of Medicine, 4ALS Center Translational Science Unit, Wake Forest School of Medicine
Comparison of mitochondrial membrane potential between samples yields valuable information about cellular status. Detailed steps for isolating mitochondria and assessing response to inhibitors and uncouplers using fluorescence are described. The method and utility of this protocol are illustrated by use of a cell culture and animal model of cellular stress.
Published March 23, 2015. Keywords: Cellular Biology, Mitochondria, TMRE, cytokines, ALS, HEK cells, fluorescence, mitochondrial dysfunction, mitochondrial membrane potential, cytochrome c
1Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston
Molecular signaling through both estrogen and microRNAs are critical in breast cancer development and growth. Estrogen activates the estrogen receptors, which are transcription factors. Many transcription factors can regulate the expression of microRNAs, and estrogen-regulated microRNAs can be profiled using different large-scale techniques.
Published February 21, 2014. Keywords: Medicine, breast cancer, microRNA, estrogen, estrogen receptor, microarray, qPCR
1Oak Ridge Institute for Science and Education, 2Air Force Research Laboratory, Airbase Technology Division, 3School of Materials Science and Engineering, Clemson University
Silica nanoparticles were prepared using acid-catalysis of a siloxane precursor and microwave-assisted synthetic techniques resulting in the controlled growth of nanomaterials ranging from 30-250 nm in diameter. The growth dynamics can be controlled by varying the initial silicic acid concentration, time of the reaction, and temperature of reaction.
Published December 16, 2013. Keywords: Chemistry, Chemistry, chemical manufacturing, chemistry (general), materials (general), nanocomposites, catalysts (chemical), chemistry of compounds, Chemistry and Materials (General), Composite Materials, Inorganic, Organic and Physical Chemistry, Engineering (General), Microwave, nanoparticle, silica, silicic acid, NP, SiO2, synthesis
1Institute of Structural Biology "J.P. Ebel", UMR5075, Commissariat à L'Energie Atomique et aux Energies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Université J. Fourier
Accurate mass measurement represents an important step during the investigation of proteins. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) can be used for such determination and its key advantage is the tolerance to salts, detergents and contaminants. Here we illustrate an accessible approach for the analysis of proteins larger than 100 kDa by MALDI-MS.
Published September 9, 2013. Keywords: Chemistry, Chemistry Techniques, Analytical, Mass Spectrometry, Analytic Sample Preparation Methods, biochemistry, Analysis of intact proteins, mass spectrometry, matrix-assisted laser desorption ionization, time of flight, sample preparation
1School of Chemistry, University of Sydney, 2Institute for Superconducting & Electronic Materials, University of Wollongong, 3Australian Synchrotron, 4Australian Nuclear Science and Technology Organisation, 5School of Mechanical, Materials, and Mechatronic Engineering, University of Wollongong, 6School of Chemistry, University of New South Wales
We describe the design and construction of an electrochemical cell for the examination of electrode materials using in situ neutron powder diffraction (NPD). We briefly comment on alternate in situ NPD cell designs and discuss methods for the analysis of the corresponding in situ NPD data produced using this cell.
Published November 10, 2014. Keywords: Physics, In operando, structure-property relationships, electrochemical cycling, electrochemical cells, crystallography, battery performance
1Division of Chemistry and Chemical Engineering, California Institute of Technology, 2Department of Molecular Medicine, Beckman Research Institute of the City of Hope
Gallium(III) 5,10,15-(tris)pentafluorophenylcorrole and its freebase analogue exhibit low micromolar cell cytotoxicity. This manuscript describes an RNA transcription reaction, imaging RNA with an ethidium bromide-stained gel, and quantifying RNA with UV-Vis spectroscopy, in order to assess transcription inhibition by corroles and demonstrates a straightforward method of evaluating anticancer candidate properties.
Published March 18, 2015. Keywords: Bioengineering, Corrole, RNA, transcription, inhibition, anti-cancer, DNA, binding, Actinomycin D, triptolide
1Department of Chemistry, Institute of Organic Chemistry, Bielefeld University
This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes which have to be handled using inert conditions, such as the Schlenk technique.
Published September 5, 2014. Keywords: Chemistry, mass spectrometry, electron impact, inlet system, volatile, air sensitive
1Department of Chemistry and Biochemistry, University of Bern
The protocol described herein aims to explain and abridge the numerous obstacles in the way of the intricate route leading to modified nucleoside triphosphates. Consequently, this protocol facilitates both the synthesis of these activated building-blocks and their availability for practical applications.
Published April 3, 2014. Keywords: Chemistry, Nucleic acid analogues, Bioorganic Chemistry, PCR, primer extension reactions, organic synthesis, PAGE, HPLC, nucleoside triphosphates
1Department of Otolaryngology, University of California, San Francisco, 2Department of Chemistry, University of California, Berkeley, 3Materials Science Division, Lawrence Berkeley National Laboratory, 4Department of Pharmaceutical Chemistry, University of California, San Francisco, 5Tetrad Graduate Program, University of California, San Francisco, 6Center for Systems and Synthetic Biology, University of California, San Francisco, 7Chemistry and Chemical Biology Graduate Program, University of California, San Francisco
We provide detailed instructions for the preparation of monovalent targeted quantum dots (mQDs) from phosphorothioate DNA of defined length. DNA wrapping occurs in high yield, and therefore, products do not require purification. We demonstrate the use of the SNAP tag to target mQDs to cell-surface receptors for live-cell imaging applications.
Published October 23, 2014. Keywords: Bioengineering, monovalent quantum dots, single particle tracking, SNAP tag, steric exclusion, phosphorothioate, DNA, nanoparticle bioconjugation, single molecule imaging
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
1Institute of Organic Chemistry, Department of Chemistry, RWTH Aachen University
DNA and proteins are sequence-specifically labeled with affinity or fluorescent reporter groups using DNA or protein methyltransferases and synthetic cofactor analogues. Depending on the cofactor specificity of the enzymes, aziridine or double activated cofactor analogues are employed for one- or two-step labeling.
Published November 22, 2014. Keywords: Biochemistry, S-adenosyl-l-methionine, AdoMet, SAM, aziridine cofactor, double activated cofactor, methyltransferase, DNA methylation, protein methylation, biotin labeling, fluorescence labeling, SMILing, mTAG
1Biochemistry and Molecular Biology, Colorado State University
A method is presented for the reconstitution of model nucleosomal arrays from recombinant core histones and tandemly repeated nucleosome positioning DNA. We also describe how sedimentation velocity experiments in the analytical ultracentrifuge, and atomic force microscopy (AFM) are used to monitor the extent of nucleosomal array saturation after reconstitution.
Published September 10, 2013. Keywords: Cellular Biology, Chromosome Structures, Chromatin, Nucleosomes, Histones, Microscopy, Atomic Force (AFM), Biochemistry, Chromatin, Nucleosome, Nucleosomal Array, Histone, Analytical Ultracentrifugation, Sedimentation Velocity