23,302 research outputs found

    Analysis of biopharma raw materials by electrophoresis microchips with contactless conductivity detection

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    Detailed information concerning the composition of the raw materials employed in the production of biologics is important for the efficient control and optimization of bioprocesses. We demonstrate the application of electrophoresis microchips with capacitively-coupled contactless conductivity detection (C4D) to the analysis of wa-ter-soluble vitamins and metal cations in raw material solutions that are subse-quently fed into bioreactors for the production of biologics

    Time Enough - Consequences of Human Microchip Implantation

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    Dr. Ramesh argues that microchip implantation is both possible and, for some purposes, desirable and suggests that now is the time to consider strategies for preventing potentially grievous intrusion into personal privacy

    Microchip electrophoresis bioanalytical applications

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    Microchip electrophoresis (MCE) is a novel analytical technique resulting from miniaturization of capillary electrophoresis (CE) to a planar microfabricated separation device. The consequences of the transfer of CE to MCE in terms of benefits and drawbacks have been identified and commented. The strategies developed to overcome the unfavourable features of the chip with respect to the capillary are briefly described. A method for simultaneous separation of catecholamines and their cationic metabolites has been developed on the microchip. The addition of three modifiers was required to resolve all analytes. The sensitivity of on-chip amperometric detection has been improved by employing an enzyme-catalyzed reaction on the amperometric electrode, as well as by using a carbon nanotube-modified electrode. The developed analytical methodology has been successfully applied for a direct on-chip determination of catecholamines and their metabolites in a mouse brain homogenate. The feasibility of performing affinity measurements as well as isoelectric focusing on the microchip has been demonstrated and available applications of these two electrophoretic modes on a chip have been reviewed. A commercial Shimadzu microchip station has for the first time been applied for high-throughput microchip isoelectric focusing of therapeutic proteins and obtained results have been compared to conventional capillary isoelectric focusing

    Nucleic acid - protein fingerprints. Novel protein classification based on nucleic acid - protein recognition

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    Protein chemistry uses protein description and classification based on molecular mass and isoelectric point as general features. Enzymes are also compared by enzymatic reaction constants, namely Km and kcat values. Proteins are also studied by binding to different oligonucleotides. Here we suggest a simple experimental method for such a comparison of DNA binding proteins, which we call "nucleic acid-protein fingerprints". The experimental design of the method is based on an use of short oligonucleotides immobilized inside microarray of hydrogel cells - biochip. As a first stage, we solved a simple experimental task: what is the shortest single strand oligonucleotide to be recognized by protein? We tested binding of oligonucleotides from 2 to 12 bases, and we have obtained unexpected result that tetranucleotide one is long enough for specific protein binding. This 4-mer can contain two universal bases - 5-nitroindole nucleoside analogue (Ni) and only two meaningful bases, like A, G, T and C. The result obtained opens a way for constructing the simplest protein binding microarray. This microarray consists of 16 meaningful dinucleotides, like AA, AG, CT, GG etc. Physical sequences of all the nucleotides were NiNiAA, etc, where Ni is bound to gel through the amino linker. We prepared such an array and tested it for specific binding of several DNA/RNA binding proteins, labeled with fluorescent dyes like Texas Red of Bodipy. We tested RNase A and Binase for binding on the simplest microarray. It contains only 16 units, and there is a significant difference in the binding patterns. The microarray based on 3-mers must contains 64 units and must have much more specificity. The new principle of protein classification based on nucleic acid-protein recognition has been proposed and experimentally proved. Such an experimental approach must lead to a universal classification of specific DNA/RNA binding proteins

    The home range of the signal crayfish in a British lowland river

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    The signal crayfish Pacifastacus leniusculus (Dana), a native of north-western North America, is now a common resident in some British fresh waters following its introduction to England in 1976 (Lowery & Holdich 1988). In 1984, signal crayfish were introduced into the River Great Ouse, the major lowland river in southern central England, where they have established a large breeding population. This study examines two sites near Thornborough Weir. For the measurement and description of home range a new eletronic microchip system and a modified capture-mark-recapture method were employed. Signal crayfish were marked or tagged to see if they gradually moved away from their burrows. This method proved to be successful for estimating population densities when a section of river is divided into several equidistant linear ”locations”

    After the SKA - Radio Astronomy in 2049

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    The concept of a Square Kilometre Array was developed to ensure that progress in Radio Astronomy in the early 21st Century continued at the same impressive pace as was achieved during the first 50 years. The SKA telescope is designed to pave that road to greater and greater sensitivity. So what technical challenges does the project face and what key innovations will drive the success of the SKA? What will the next Radio Astronomy mega-science project look like? In this article the author discusses the likely avenues of progress in the coming decades and comments on the status of radio astronomy in 2049 - the author's 70th (and presumably her retirement) year.Comment: Conference Proceedings PoS(RTS2012), 8 pages, 1 figur

    Gold nanodome-patterned microchips for intracellular surface-enhanced Raman spectroscopy

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    While top-down substrates for surface-enhanced Raman spectroscopy (SERS) offer outstanding control and reproducibility of the gold nanopatterns and their related localized surface plasmon resonance, intracellular SERS experiments heavily rely on gold nanoparticles. These nanoparticles often result in varying and uncontrollable enhancement factors. Here we demonstrate the use of top-down gold-nanostructured microchips for intracellular sensing. We develop a tunable and reproducible fabrication scheme for these microchips. Furthermore we observe the intracellular uptake of these structures, and find no immediate influence on cell viability. Finally, we perform a proof-of-concept intracellular SERS experiment by the label-free detection of extraneous molecules. By bringing top-down SERS substrates to the intracellular world, we set an important step towards time-dependent and quantitative intracellular SERS
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