High-Resolution, High-Yield Continuous-Flow Electrophoresis

1986 ◽  
pp. 169-184 ◽  
Author(s):  
William A. Gobie ◽  
Cornelius F. Ivory
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
High Yield

scholarly journals Extreme PCR: Efficient and Specific DNA Amplification in 15–60 Seconds

2015 ◽  
Vol 61 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Jared S Farrar ◽  
Carl T Wittwer
Keyword(s):  
High Resolution ◽  
Single Molecule ◽  
High Resolution Melting ◽  
Dna Amplification ◽  
Temperature Cycling ◽  
High Yield ◽  
Temperature Cycle ◽  
Amplification Efficiency ◽  
Analytical Sensitivity ◽  
Agarose Gels

Abstract BACKGROUND PCR is a key technology in molecular biology and diagnostics that typically amplifies and quantifies specific DNA fragments in about an hour. However, the kinetic limits of PCR are unknown. METHODS We developed prototype instruments to temperature cycle 1- to 5-μL samples in 0.4–2.0 s at annealing/extension temperatures of 62 °C–76 °C and denaturation temperatures of 85 °C–92 °C. Primer and polymerase concentrations were increased 10- to 20-fold above typical concentrations to match the kinetics of primer annealing and polymerase extension to the faster temperature cycling. We assessed analytical specificity and yield on agarose gels and by high-resolution melting analysis. Amplification efficiency and analytical sensitivity were demonstrated by real-time optical monitoring. RESULTS Using single-copy genes from human genomic DNA, we amplified 45- to 102-bp targets in 15–60 s. Agarose gels showed bright single bands at the expected size, and high-resolution melting curves revealed single products without using any “hot start” technique. Amplification efficiencies were 91.7%–95.8% by use of 0.8- to 1.9-s cycles with single-molecule sensitivity. A 60-bp genomic target was amplified in 14.7 s by use of 35 cycles. CONCLUSIONS The time required for PCR is inversely related to the concentration of critical reactants. By increasing primer and polymerase concentrations 10- to 20-fold with temperature cycles of 0.4–2.0 s, efficient (>90%), specific, high-yield PCR from human DNA is possible in <15 s. Extreme PCR demonstrates the feasibility of while-you-wait testing for infectious disease, forensics, and any application where immediate results may be critical.

scholarly journals High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core

2013 ◽  
Vol 9 (6) ◽  
pp. 2579-2593 ◽  
Author(s):  
J. Chappellaz ◽  
C. Stowasser ◽  
T. Blunier ◽  
D. Baslev-Clausen ◽  
E. J. Brook ◽  
...  
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Ice Core ◽  
Rate Of Change ◽  
Atmospheric Methane ◽  
Data Set ◽  
Rate Of Increase ◽  
Concentration Changes ◽  
Cross Dating ◽  
Laser Spectroscopic

Abstract. The Greenland NEEM (North Greenland Eemian Ice Drilling) operation in 2010 provided the first opportunity to combine trace-gas measurements by laser spectroscopic instruments and continuous-flow analysis along a freshly drilled ice core in a field-based setting. We present the resulting atmospheric methane (CH4) record covering the time period from 107.7 to 9.5 ka b2k (thousand years before 2000 AD). Companion discrete CH4 measurements are required to transfer the laser spectroscopic data from a relative to an absolute scale. However, even on a relative scale, the high-resolution CH4 data set significantly improves our knowledge of past atmospheric methane concentration changes. New significant sub-millennial-scale features appear during interstadials and stadials, generally associated with similar changes in water isotopic ratios of the ice, a proxy for local temperature. In addition to the midpoint of Dansgaard–Oeschger (D/O) CH4 transitions usually used for cross-dating, sharp definition of the start and end of these events brings precise depth markers (with ±20 cm uncertainty) for further cross-dating with other palaeo- or ice core records, e.g. speleothems. The method also provides an estimate of CH4 rates of change. The onsets of D/O events in the methane signal show a more rapid rate of change than their endings. The rate of CH4 increase associated with the onsets of D/O events progressively declines from 1.7 to 0.6 ppbv yr−1 in the course of marine isotope stage 3. The largest observed rate of increase takes place at the onset of D/O event #21 and reaches 2.5 ppbv yr−1.

scholarly journals Calculating uncertainty for the RICE ice core continuous flow analysis water isotope record

2018 ◽  
Vol 11 (8) ◽  
pp. 4725-4736 ◽  
Author(s):  
Elizabeth D. Keller ◽  
W. Troy Baisden ◽  
Nancy A. N. Bertler ◽  
B. Daniel Emanuelsson ◽  
Silvia Canessa ◽  
...  
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Ice Core ◽  
Flow Analysis ◽  
Calibration Error ◽  
Data Set ◽  
Total Uncertainty ◽  
Continuous Flow Analysis ◽  
Uncertainty Estimates ◽  
Water Isotope

Abstract. We describe a systematic approach to the calibration and uncertainty estimation of a high-resolution continuous flow analysis (CFA) water isotope (δ2H, δ18O) record from the Roosevelt Island Climate Evolution (RICE) Antarctic ice core. Our method establishes robust uncertainty estimates for CFA δ2H and δ18O measurements, comparable to those reported for discrete sample δ2H and δ18O analysis. Data were calibrated using a time-weighted two-point linear calibration with two standards measured both before and after continuously melting 3 or 4 m of ice core. The error at each data point was calculated as the quadrature sum of three factors: Allan variance error, scatter over our averaging interval (error of the variance) and calibration error (error of the mean). Final mean total uncertainty for the entire record is δ2H=0.74 ‰ and δ18O=0.21 ‰. Uncertainties vary through the data set and were exacerbated by a range of factors, which typically could not be isolated due to the requirements of the multi-instrument CFA campaign. These factors likely occurred in combination and included ice quality, ice breaks, upstream equipment failure, contamination with drill fluid and leaks or valve degradation. We demonstrate that our methodology for documenting uncertainty was effective across periods of uneven system performance and delivered a significant achievement in the precision of high-resolution CFA water isotope measurements.

scholarly journals Polymorphonuclear Leukocytes Prepared by Continuous-Flow Filtration Leukapheresis: Viability and Function

Blood ◽  
1974 ◽  
Vol 44 (5) ◽  
pp. 707-713 ◽  
Author(s):  
Michael B. Harris ◽  
Isaac Djerassi ◽  
Elias Schwartz ◽  
Richard K. Root
Keyword(s):  
Continuous Flow ◽  
Polymorphonuclear Leukocytes ◽  
Cell Types ◽  
High Yield ◽  
Trypan Blue Exclusion ◽  
Flow Filtration ◽  
And Function ◽  
Combating Infection

Abstract Preparation of granulocytes for transfusion in high yield and relatively free of contamination by other cell types has been made possible by the technique of continuous-flow filtration leukapheresis (CFFL). Since previous work suggested that granulocytes collected in this manner may have impaired viability and function, a detailed study of the bactericidal, metabolic, and chemotactic properties of such cells was performed and compared to control cells obtained from the same donors prior to CFFL. The granulocyte percentage of the cell suspensions obtained by CFFL averaged 94.5% ± 1.5% compared to 82.5% ± 1.8% for the controls (p < 0.001) with viability of the PMNs determined by trypan blue exclusion being 97.5% ± 0.9% and 98.2% ± 0.5%, respectively. The phogocytic, metabolic (14C-I-glucose oxidation and protein iodination) and chemotactic properties of both cell types were equivalent in suspensions equalized for granulocyte content. These findings indicate that CFFL technique employed does not impair granulocyte viability or function in vitro. Studies of the in vivo survival and function of CFFL granulocytes are necessary to evaluate their efficacy in combating infection in severely leukopenic patients.

Continuous flow biodiesel production from wet microalgae using a hybrid thin film microfluidic platform

2018 ◽  
Vol 54 (85) ◽  
pp. 12085-12088 ◽  
Author(s):  
Eko K. Sitepu ◽  
Darryl B. Jones ◽  
Youhong Tang ◽  
Sophie C. Leterme ◽  
Kirsten Heimann ◽  
...  
Keyword(s):  
Thin Film ◽  
Continuous Flow ◽  
Room Temperature ◽  
Biodiesel Production ◽  
High Yield ◽  
Hybrid Thin Film ◽  
Microfluidic Platform ◽  
Thin Film Device ◽  
Wet Microalgae

A novel continuous flow turbo-thin film device (T2FD) is effective in producing biodiesel in high yield from wet microalgae at room temperature.

THE USE OF AN ULTRASONIC PROBE IN SOIL DISPERSION AND IN THE BULK ISOLATION OF ORGANO-MINERAL COMPLEXES

1980 ◽  
Vol 60 (2) ◽  
pp. 389-392 ◽  
Author(s):  
A. A. HINDS ◽  
L. E. LOWE
Keyword(s):  
Particle Size ◽  
Continuous Flow ◽  
Rest Period ◽  
Soil Samples ◽  
High Yield ◽  
Ultrasonic Dispersion ◽  
Ultrasonic Probe ◽  
Average Recovery ◽  
Soil Dispersion

Conditions were investigated for using a Biosonic BP-III ultrasonic probe for reproducible soil dispersion. The importance of probe-tip conditions and an instrument rest period between successive dispersions is emphasized. A procedure for bulk isolation of particle size separates is described, based on ultrasonic dispersion and continuous flow centrifugation. For 500-g soil samples, average recovery of soil solids was 98%. The procedure is relatively rapid and should be useful where high yield of size separates is needed for characterization or mineralization studies on organo-mineral complexes.

Synthesis of one-dimensional structured metal phthalocyanine in an ionic liquid

2007 ◽  
Vol 11 (10) ◽  
pp. 713-718 ◽  
Author(s):  
David S. Jacob ◽  
Somashekarappa Mallenahalli ◽  
Aharon Gedanken ◽  
Leonid A. Solovyov ◽  
Evangelia Xenogiannopoulou ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Electron Microscope ◽  
High Resolution ◽  
High Yield ◽  
Metal Phthalocyanine ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Nickel Phthalocyanine ◽  
Transmission Electron

Nickel phthalocyanine is synthesized in an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) giving a high yield of one-dimensional structures. The morphology of the synthesized material is detected by a high-resolution scanning electron microscope, a high-resolution transmission electron microscope, characterized by powder X-ray diffraction, and a CHN analyzer. The nonlinear optical properties of the synthesized phthalocyanine are also investigated.

Preliminary Results from High-Resolution Analyses of Ultraviolet-Absorbing and Carbohydrate Constituents in Several Pathologic Body Fluids

1970 ◽  
Vol 16 (8) ◽  
pp. 687-696 ◽  
Author(s):  
Robert L Jolley ◽  
Charles D Scott
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Body Fluid ◽  
National Laboratory ◽  
Ultraviolet Spectrophotometry ◽  
Maple Syrup ◽  
Oak Ridge ◽  
Urine Disease ◽  
Carbohydrate Components ◽  
Phenol Sulfuric Acid

Abstract Human urine, blood serum, cerebrospinal fluid, and amniotic fluid have been analyzed by high-resolution chromatographic systems under development at the Oak Ridge National Laboratory. These systems, or analyzers, consist of heated, high-pressure anion-exchange columns for chromatographic separation of the constituents and continuous-flow ultraviolet spectrophotometry or phenol-sulfuric acid colorimetry for detection of the separated ultraviolet-absorbing or carbohydrate components. Quantification of the resulting chromatograms has revealed significant differences in the concentrations of body-fluid constituents for the normal state and for various pathologic states such as hereditary nephritis, Lesch-Nyhan syndrome, gout, alkaptonuria, and maple syrup urine disease. Some changes in urinary chromatographic patterns resulting from nicotinic acid and allopurinol therapies have also been detected.

High resolution remote and proximal sensing to assess low and high yield areas in a wheat field

2015 ◽  
pp. 191-198 ◽  
Author(s):  
F.A. Rodrigues ◽  
I. Ortiz-Monasterio ◽  
P.J. Zarco-Tejada ◽  
U. Schulthess ◽  
B. Gérard
Keyword(s):  
High Resolution ◽  
High Yield ◽  
Proximal Sensing ◽  
Wheat Field

Forty years later: High resolution continuous flow analysis of the Dye3 ice core

2021 ◽  
Author(s):  
Helle Astrid Kjær ◽  
Margaret Harlan ◽  
Paul Vallelonga ◽  
Anders Svensson ◽  
Thomas Blunier ◽  
...  
Keyword(s):  
High Resolution ◽  
Forest Fires ◽  
Continuous Flow ◽  
Ice Core ◽  
Flow Analysis ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
The Core ◽  
Continuous Flow Analysis

&lt;div&gt;&lt;span&gt;&lt;span&gt;The Dye-3 ice core was drilled to bedrock at the Southern part of the central Greenland ice sheet (65&amp;#176;11'N, 43&amp;#176;50'W) in 1979-1981. The southern location is characterized by high accumulation rates compared to more central locations of the ice sheet. Since its drilling, numerous analyses of the core have been performed, and the ice has since been in freezer storage both in the USA and in Denmark.&lt;/span&gt;&lt;/span&gt;&lt;/div&gt;&lt;div&gt;&lt;span&gt;In October and November 2019, the remaining ice, two mostly complete sections covering the depths of 1753&amp;#8211;1820m and 1865&amp;#8211;1918m of the Dye-3 core, were melted during a continuous flow analysis (CFA) campaign at the Physics of Ice, Climate, and Earth (PICE) group at the University of Copenhagen. The data represents both Holocene, Younger Dryas and Glacial sections (GS 5 to 12).&lt;/span&gt;&lt;/div&gt;&lt;div&gt;&amp;#160;&lt;/div&gt;&lt;div&gt;&lt;span&gt;&lt;span&gt;The measured data consist chemistry and impurities contained in the ice, isotopes, as well as analysis of methane and other atmospheric gases.&amp;#160;&lt;/span&gt;&lt;/span&gt;&lt;/div&gt;&lt;div&gt;&lt;span&gt;&lt;span&gt;The chemistry measurements include NH&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;&lt;sup&gt;+&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;, Ca&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;&lt;sup&gt;2+&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;, and Na&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;&lt;sup&gt;+&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;&amp;#160;ions, which besides being influenced by transport, provide information about forest fires, wind-blown dust, and sea ice, respectively, as well as acidity, which aids in the identification of volcanic events contained in the core. The quantity and grain size distribution of insoluble particles was analyzed by means of an Abakus laser particle counter.&lt;/span&gt;&lt;/span&gt;&lt;/div&gt;&lt;div&gt;&amp;#160;&lt;/div&gt;&lt;div&gt;&lt;span&gt;We compare the new high-resolution CFA record of dye3 with previous analysis and thus evaluate the progress made over 40 years. Further we compare overlapping time periods with other central Greenland ice cores and discuss spatial patterns in relation to the presented climate proxies.&lt;/span&gt;&lt;/div&gt;

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