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Sample records for acetate membrane electrophoresis

  1. A simple cellulose acetate membrane-based small lanes technique for protein electrophoresis.

    PubMed

    Na, Na; Liu, Tingting; Yang, Xiaojun; Sun, Binjie; Ouyang, Jenny; Ouyang, Jin

    2012-08-01

    Combining electrophoresis with a cellulose acetate membrane-based technique, we developed a simple and low-cost method, named cellulose acetate membrane-based small lanes (CASL), for protein electrophoresis. A home-made capillary plotter controlled by a 3D moving stage was used to create milli-to-micro channels by printing poly(dimethylsiloxane) on to a hydrophilic cellulose acetate membrane. In the hydrophilic channels, 5 nL protein mixture was separated on the basis of electro-migration under an electric field. Compared with polyacrylamide gel electrophoresis (PAGE), CASL resulted in higher protein signal intensity for separation of mixtures containing the same mass of protein. The platform was easily fabricated at low cost (approx. $0.005 for each 1-mm-wide channel), and separation of three protein mixtures was completed in 15 min. Both electrophoresis time and potential affected the separation. Rather than chromatographic separation, this method accomplished application of microchannel techniques for cellulose acetate membrane-based protein electrophoresis. It has potential in proteomic analysis, especially for rapid, low-cost, and low-volume sample analysis in clinical diagnosis. PMID:22752445

  2. Silver stain for proteins on a cellulose acetate membrane.

    PubMed

    Fujita, T; Toda, T; Ohashi, M

    1984-06-01

    A rapid and sensitive silver staining method to detect proteins on a cellulose acetate membrane has been established. This method is achieved by modification of the silver-based color staining for detection of proteins in polyacrylamide gels [D. W. Sammons, L. D. Adams, and E. E. Nishizawa, Electrophoresis 2, 135-141 (1981)] and applied to our new type of two-dimensional electrophoresis for analysis of proteins on a cellulose acetate sheet [T. Toda, T. Fujita, and M. Ohashi, Anal. Biochem. 119, 167-176 (1982)]. Maximal sensitivity of silver stain for proteins on a cellulose acetate membrane can be obtained by an optimal balance between deposition of silver on the protein and on the background. Certain kinds of proteins are colored red, orange, or grayish-blue. The silver stain is 20-80 times more sensitive than Coomassie blue and some spots are visualized reproducibly by silver only. Densitometric evaluation of standard proteins stained with silver and Coomassie blue is also demonstrated. The method takes only 50 min to perform and is sensitive, simple, and reproducible. PMID:6206749

  3. Fabricating PFPE Membranes for Capillary Electrophoresis

    NASA Technical Reports Server (NTRS)

    Lee, Michael C.; Willis, Peter A.; Greer, Frank; Rolland, Jason

    2009-01-01

    A process has been developed for fabricating perfluoropolyether (PFPE) membranes that contain microscopic holes of precise sizes at precise locations. The membranes are to be incorporated into laboratory-on-a-chip microfluidic devices to be used in performing capillary electrophoresis. The present process is a modified version of part of the process, described in the immediately preceding article, that includes a step in which a liquid PFPE layer is cured into solid (membrane) form by use of ultraviolet light. In the present process, one exploits the fact that by masking some locations to prevent exposure to ultraviolet light, one can prevent curing of the PFPE in those locations. The uncured PFPE can be washed away from those locations in the subsequent release and cleaning steps. Thus, holes are formed in the membrane in those locations. The most straightforward way to implement the modification is to use, during the ultraviolet-curing step, an ultraviolet photomask similar to the photomasks used in fabricating microelectronic devices. In lieu of such a photomask, one could use a mask made of any patternable ultraviolet-absorbing material (for example, an ink or a photoresist).

  4. Rapid electrophoresis and quantitation of haemoglobins on cellulose acetate

    PubMed Central

    Marengo-Rowe, A. J.

    1965-01-01

    A rapid and reproducible electrophoretic method for the separation and quantitation of haemoglobins on cellulose acetate is described. The accuracy of the method and its possible sources of error are discussed. The normal range for haemoglobin A2 by this method is 1% to 3% of the total haemoglobin concentration. Blood samples from 32 thalassaemic patients showed haemoglobin A2 values of 35% to 7%. Images PMID:5844210

  5. Use of cellulose acetate electrophoresis in the taxonomy of steinernematids (rhabditida, nematoda).

    PubMed

    Jagdale, G B; Gordon, R; Vrain, T C

    1996-09-01

    A steinernematid nematode was isolated from soil samples collected near St. John's, Newfoundland, Canada. On the basis of its morphometry and RFLPs in ribosomal DNA spacer, it was designated as a new strain, NF, of Steinernema feltiae. Cellulose acetate electrophoresis was used to separate isozymes of eight enzymes in infective juveniles of S. feltiae NF as well as four other isolates: S. feltiae Ume strain, S. feltiae L1C strain, Steinernema carpocapsae All strain, and Steinernema riobravis TX strain. Based on comparisons of the relative electrophoretic mobilities (mu) of the isozymes, one of the eight enzymes (arginine kinase) yielded zymograms that were distinctive for each of the isolates, except for the Ume and NF strains of S. feltiae, which had identical banding patterns. Four enzymes (fumarate hydratase, phosphoglucoisomerase, phosphoglucomutase, and 6-phosphogluconate dehydrogenase) yielded isozyme banding patterns that were characteristic for all isolates, except for the L1C and NF strains of S. feltiae, which were identical. Two enzymes (aspartate amino transferase and glycerol-3-phosphate dehydrogenase) yielded zymograms that permitted S. carpocapsae All strain to be discriminated from the other four isolates, while the remaining enzyme (mannose-6-phosphate isomerase) was discriminatory for S. riobravis TX strain. Except for one enzyme, the isozyme banding pattern of the NF isolate of S. feltiae was the same as in the L1C strain, isolated 13 years previously from Newfoundland. Cellulose acetate electrophoresis could prove invaluable for taxonomic identification of isolates of steinernematids, provided that a combination of enzymes is used. PMID:19277147

  6. Use of Cellulose Acetate Electrophoresis in the Taxonomy of Steinernematids (Rhabditida, Nematoda)

    PubMed Central

    Jagdale, G. B.; Gordon, R.; Vrain, T. C.

    1996-01-01

    A steinernematid nematode was isolated from soil samples collected near St. John's, Newfoundland, Canada. On the basis of its morphometry and RFLPs in ribosomal DNA spacer, it was designated as a new strain, NF, of Steinernema feltiae. Cellulose acetate electrophoresis was used to separate isozymes of eight enzymes in infective juveniles of S. feltiae NF as well as four other isolates: S. feltiae Ume strain, S. feltiae L1C strain, Steinernema carpocapsae All strain, and Steinernema riobravis TX strain. Based on comparisons of the relative electrophoretic mobilities (?) of the isozymes, one of the eight enzymes (arginine kinase) yielded zymograms that were distinctive for each of the isolates, except for the Ume and NF strains of S. feltiae, which had identical banding patterns. Four enzymes (fumarate hydratase, phosphoglucoisomerase, phosphoglucomutase, and 6-phosphogluconate dehydrogenase) yielded isozyme banding patterns that were characteristic for all isolates, except for the L1C and NF strains of S. feltiae, which were identical. Two enzymes (aspartate amino transferase and glycerol-3-phosphate dehydrogenase) yielded zymograms that permitted S. carpocapsae All strain to be discriminated from the other four isolates, while the remaining enzyme (mannose-6-phosphate isomerase) was discriminatory for S. riobravis TX strain. Except for one enzyme, the isozyme banding pattern of the NF isolate of S. feltiae was the same as in the L1C strain, isolated 13 years previously from Newfoundland. Cellulose acetate electrophoresis could prove invaluable for taxonomic identification of isolates of steinernematids, provided that a combination of enzymes is used. PMID:19277147

  7. Continuous-flow electrophoresis: Membrane-associated deviations of buffer pH and conductivity

    NASA Technical Reports Server (NTRS)

    Smolka, A. J. K.; Mcguire, J. K.

    1978-01-01

    The deviations in buffer pH and conductivity which occur near the electrode membranes in continuous-flow electrophoresis were studied in the Beckman charged particle electrophoresis system and the Hanning FF-5 preparative electrophoresis instrument. The nature of the membranes separating the electrode compartments from the electrophoresis chamber, the electric field strength, and the flow rate of electrophoresis buffer were all found to influence the formation of the pH and conductivity gradients. Variations in electrode buffer flow rate and the time of electrophoresis were less important. The results obtained supported the hypothesis that a combination of Donnan membrane effects and the differing ionic mobilities in the electrophoresis buffer was responsible for the formation of the gradients. The significance of the results for the design and stable operation of continuous-flow electrophoresis apparatus was discussed.

  8. Comparative analysis of cellulose acetate hemoglobin electrophoresis and high performance liquid chromatography for quantitative determination of hemoglobin A2

    PubMed Central

    Khosa, Shafi Mohammad; Moinuddin, Moinuddin; Mehmood, Hassan Osman; Qamar, Khansa

    2015-01-01

    Background The present study is designed to evaluate the reliability and cost effectiveness of cellulose acetate Hb electrophoresis and high performance liquid chromatography (HPLC) in the determination of HbA2 levels. Methods The test population comprised 160 individuals divided into four groups: normal individuals, ?-thalassemia trait (BTT) patients, iron deficiency anemia (IDA) patients, and co-morbid patients (BTT with IDA). HbA2 levels determined using cellulose acetate Hb electrophoresis and HPLC were compared. Results HbA2 levels were found to be diagnostic for classical BTT using either method. In co-morbid cases, both techniques failed to diagnose all cases of BTT. The sensitivity, specificity, and Youden's index for detection of the co-morbid condition was 69% and 66% for HPLC and cellulose acetate Hb electrophoresis, respectively. Conclusion This study revealed that semi-automated cellulose acetate Hb electrophoresis is more suitable for use in ?-thalassemia prevention programs in low-income countries like Pakistan. This technique is easily available, simple and cost effective. PMID:25830130

  9. Dissolution control of Mg by cellulose acetate-polyelectrolyte membranes.

    PubMed

    Yliniemi, Kirsi; Wilson, Benjamin P; Singer, Ferdinand; Höhn, Sarah; Kontturi, Eero; Virtanen, Sannakaisa

    2014-12-24

    Cellulose acetate (CA)-based membranes are used for Mg dissolution control: the permeability of the membrane is adjusted by additions of the polyelectrolyte, poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA). Spin-coated films were characterized with FT-IR, and once exposed to an aqueous solution the film distends and starts acting as a membrane which controls the flow of ions and H2 gas. Electrochemical measurements (linear sweep voltammograms, open-circuit potential, and polarization) show that by altering the CA:PDMAEMA ratio the dissolution rate of Mg can be controlled. Such a control over Mg dissolution is crucial if Mg is to be considered as a viable, temporary biomedical implant material. Furthermore, the accumulation of corrosion products between the membrane and the sample diminishes the undesirable effects of high local pH and H2 formation which takes place during the corrosion process. PMID:25426707

  10. Ion selective permeation through cellulose acetate membranes in forward osmosis.

    PubMed

    Irvine, Gavin J; Rajesh, Sahadevan; Georgiadis, Michael; Phillip, William A

    2013-12-01

    Solute-solute interactions can have a dramatic impact on the permeation of solutes through dense polymeric membranes. In particular, understanding how solute-solute interactions can affect the design of osmotically driven membrane processes (ODMPs) is critical to the successful development of these emerging water treatment and energy generation processes. In this work, we investigate the influence that solute-solute interactions have on nitrate permeation through an asymmetric cellulose acetate forward osmosis membrane. A series of experiments that included systematic modifications to the cation paired with nitrate, the identity of the draw solute, and the solution pH were conducted. These experiments reveal that in the unique operating geometry of ODMPs, where solute containing solutions are present on both sides of the membrane, nitrate fluxes are significantly higher (>15 times in some cases) than predicted by existing models for solute permeation in ODMPs. The identity of the cation paired with nitrate influences the flux of nitrate; the identity of the cation in the draw solution does not affect the flux of nitrate; however, the identity of the anion in the draw solution has the most significant impact on the flux of nitrate. These results suggest that an ion exchange mechanism, which allows nitrate to switch rapidly with anions from the draw solution, is present when cellulose acetate based membranes are used in ODMPs. PMID:24152190

  11. Membrane interfaces for sample introduction in capillary zone electrophoresis

    SciTech Connect

    Bao, L.; Dasgupta, P.K.

    1992-05-01

    Small lengths of narrow-bore tubular membranes can be interposed in the separation capillary in capillary electrophoretic separation systems. These membrane segments can be used as sampling interfaces; a jacket is built outside the membrane, and the sample is introduced by diffusion/permeation through the membrane. Various examples are shown; the determination of gaseous samples through a porous membrane, the determination of ionizable/nonionic solutes by permeation through a silicone rubber membrane, and the separation of low MW constituents in blood plasma by transport through a dialysis membrane. In the first two cases, significant preconcentration is possible, thus permitting attractive detection limits. 23 refs., 10 figs., 2 tabs.

  12. Thiosulphate conversion in a methane and acetate fed membrane bioreactor.

    PubMed

    Suarez-Zuluaga, Diego A; Timmers, Peer H A; Plugge, Caroline M; Stams, Alfons J M; Buisman, Cees J N; Weijma, Jan

    2016-02-01

    The use of methane and acetate as electron donors for biological reduction of thiosulphate in a 5-L laboratory membrane bioreactor was studied and compared to disproportionation of thiosulphate as competing biological reaction. The reactor was operated for 454days in semi-batch mode; 30% of its liquid phase was removed and periodically replenished (days 77, 119, 166, 258, 312 and 385). Although the reactor was operated under conditions favourable to promote thiosulphate reduction coupled to methane oxidation, thiosulphate disproportionation was the dominant microbial process. Pyrosequencing analysis showed that the most abundant microorganisms in the bioreactor were phototrophic green sulphur bacteria (GSB) belonging to the family Chlorobiaceae and thiosulphate-disproportionating bacteria belonging to the genus Desulfocapsa. Even though the reactor system was surrounded with opaque plastic capable of filtering most of the light, the GSB used it to oxidize the hydrogen sulphide produced from thiosulphate disproportionation to elemental sulphur. Interrupting methane and acetate supply did not have any effect on the microbial processes taking place. The ultimate goal of our research was to develop a process that could be applied for thiosulphate and sulphate removal and biogenic sulphide formation for metal precipitation. Even though the system achieved in this study did not accomplish the targeted conversion using methane as electron donor, it does perform microbial conversions which allow to directly obtain elemental sulphur from thiosulphate. PMID:26423279

  13. Surface modification of cellulose acetate membrane using thermal annealing to enhance produced water treatment

    NASA Astrophysics Data System (ADS)

    Kusworo, T. D.; Aryanti, N.; Firdaus, M. M. H.; Sukmawati, H.

    2015-12-01

    This study is performed primarily to investigate the effect of surface modification of cellulose acetate using thermal annealing on the enhancement of membrane performance for produced water treatment. In this study, Cellulose Acetate membranes were casted using dry/wet phase inversion technique. The effect of additive and post-treatment using thermal annealing on the membrane surface were examined for produced water treatment. Therma annealing was subjected to membrane surface at 60 and 70 C for 5, 10 and 15 second, respectively. Membrane characterizations were done using membrane flux and rejection with produced water as a feed, Scanning Electron Microscopy (SEM) and Fourier Transform Infra Red (FTIR) analysis. Experimental results showed that asymmetric cellulose acetate membrane can be made by dry/wet phase inversion technique. The results from the Scanning Electron Microscopy (FESEM) analysis was also confirmed that polyethylene glycol as additivie in dope solution and thermal annealing was affected the morphology and membrane performance for produced water treatment, respectively. Scanning electron microscopy micrographs showed that the selective layer and the substructure of membrane became denser and more compact after the thermal annealing processes. Therefore, membrane rejection was significantly increased while the flux was slighty decreased, respectively. The best membrane performance is obtained on the composition of 18 wt % cellulose acetate, poly ethylene glycol 5 wt% with thermal annealing at 70 C for 15 second.

  14. Continuous Ethanol Production with a Membrane Bioreactor at High Acetic Acid Concentrations

    PubMed Central

    Ylitervo, Päivi; Franzén, Carl Johan; Taherzadeh, Mohammad J.

    2014-01-01

    The release of inhibitory concentrations of acetic acid from lignocellulosic raw materials during hydrolysis is one of the main concerns for 2nd generation ethanol production. The undissociated form of acetic acid can enter the cell by diffusion through the plasma membrane and trigger several toxic effects, such as uncoupling and lowered intracellular pH. The effect of acetic acid on the ethanol production was investigated in continuous cultivations by adding medium containing 2.5 to 20.0 g·L−1 acetic acid at pH 5.0, at a dilution rate of 0.5 h−1. The cultivations were performed at both high (~25 g·L−1) and very high (100–200 g·L−1) yeast concentration by retaining the yeast cells inside the reactor by a cross-flow membrane in a membrane bioreactor. The yeast was able to steadily produce ethanol from 25 g·L−1 sucrose, at volumetric rates of 5–6 g·L−1·h−1 at acetic acid concentrations up to 15.0 g·L−1. However, the yeast continued to produce ethanol also at a concentration of 20 g·L−1 acetic acid but at a declining rate. The study thereby demonstrates the great potential of the membrane bioreactor for improving the robustness of the ethanol production based on lignocellulosic raw materials. PMID:25028956

  15. Adsorptive Membranes vs. Resins for Acetic Acid Removal from Biomass Hydrolysates

    SciTech Connect

    Han, B.; Carvalho, W.; Canilha, L.; da Silva, S. S.; e Silva, J. B. A.; McMillan, J. D.; Wickramasinghe, S. R.

    2006-01-01

    Acetic acid is a compound commonly found in hemicellulosic hydrolysates. This weak acid strongly influences the bioconversion of sugar containing hydrolysates. Previous investigators have used anion exchange resins for acetic acid removal from different hemicellulosic hydrolysates. In this study, the efficiency of an anion exchange membrane was compared to that of an anion exchange resin, for acetic acid removal from a DI water solution and an acidic hemicellulose hydrolysate pretreated using two different methods. Ion exchange membranes and resins have very different geometries. Here the performance of membranes and resins is compared using two dimensionless parameters, the relative mass throughput and chromatographic bed number. The relative mass throughput arises naturally from the Thomas solution for ion exchange. The results show that the membrane exhibit better performance in terms of capacity, and loss of the desired sugars. In addition acetic acid may be eluted at a higher concentration from the membrane thus leading to the possibility of recovery and re-use of the acetic acid.

  16. Performance of cellulose acetate butyrate membranes in hyperfiltration of sodium chloride and urea feed solution

    NASA Technical Reports Server (NTRS)

    Wydeven, T.; Leban, M.

    1973-01-01

    Cellulose acetate butyrate (CAB) membranes are shown to give high salt and urea rejection with water flux of about 3 gallons/sq ft per day at 600 psig. Membranes prepared from a formulation containing glyoxal show a significant increase in flux and decrease in salt and urea rejection with drying time. Zero drying time gives maximum urea and salt rejection and is therefore most suitable for hyperfiltration of sodium chloride and urea feed solution.

  17. Impact of membrane immobilization on particle formation and trichloroethylene dechlorination for bimetallic Fe/Ni nanoparticles in cellulose acetate membranes.

    PubMed

    Meyer, D E; Bhattacharyya, D

    2007-06-28

    The use of membrane immobilization to carry out the batch dechlorination of trichloroethylene (TCE) using bimetallic Fe/Ni (4:1, Fe to Ni) nanoparticles in cellulose acetate membranes is examined using modeling of transport phenomenon based on experimental results. Membranes are synthesized using both gelation and solvent evaporation techniques for phase inversion. The reduction of metal ions within cellulose acetate phase-inversion membranes was accomplished using sodium borohydride reduction to obtain up to 2 wt % total metals. Characterization of the mixed-matrix structure reveals a bimodal particle distribution ranging between 18 and 80 nm within the membrane cross section. The distribution is the result of changes in the morphology of the cellulose acetate support. The diffusivity and linear partitioning coefficient for the chlorinated organic were measured and are 2.0 x 10(-8) cm2.s-1 and 3.5 x 10(-2) L.g-1, respectively. An unsteady-state model for diffusion through a membrane with reaction was developed to predict experimental results with an error of only 7.2%. The error can be attributed to the lack of the model to account for loss of reactivity through pH effects, alloy effects (bimetallic ratio), and oxidation of nanoparticles. Simulations were run to vary the major transport variables, partitioning and diffusivity, and determine their impact on reaction kinetics. Of the two, diffusivity was less significant because it really only influences the time required for maximum TCE partitioning to the membrane to be achieved and has no effect on the limiting capacity of the membrane for TCE. Therefore, selection of an appropriate support material is crucial for development of highly reactive mixed-matrix membrane systems. PMID:17530798

  18. Non-denaturing gel electrophoresis system for the purification of membrane bound proteins

    SciTech Connect

    Cavinato, A.G.; Macleod, R.M.; Ahmed, M.S.

    1988-01-01

    A new method is described for the purification of a membrane bound glycoprotein, the kappa opioid receptor from human placental tissue. The method uses preparative slab-gel electrophoresis in the presence of the non-denaturing detergent CHAPS. A linear relationship between log molecular weight and SDS PAGE electrophoretic mobility of known molecular weight markers, in the presence of CHAPS, is observed. Using this method, we were able partially to purify an /sup 3/H-etorphine binding glycoprotein, from placental villus tissue, with an apparent molecular weight range of 60-70,000. The iodinated glycoprotein migrates in SDS PAGE with an apparent molecular weight of 63,000. This method may be useful for the isolation of membrane bound proteins, especially when an affinity ligand is not available.

  19. Study of ABO blood types by combining membrane electrophoresis with surface-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Lin, Juqiang; Huang, Zufang; Sun, Liqing; Shao, Yonghong; Lu, Peng; Shi, Wei; Lin, Jinyong; Chen, Rong

    2012-12-01

    The molecular characterization of ABO blood types, which is clinically significant in blood transfusion, has clinical and anthropological importance. Polymerase chain reaction sequence-based typing (PCR-SBT) is one of the most commonly used methods for the analysis of genetic bases of ABO blood types. However, such methods as PCR-SBT are time-consuming and are high in demand of equipments and manipulative skill. Here we showed that membrane electrophoresis based SERS method employed for studying the molecular bases of ABO blood types can provide rapidand easy-operation with high sensitivity and specificity. The plasma proteins were firstly purified by membrane electrophoresis and then mixed with silver nanoparticles to perform SERS detection. We use this method to classify different blood types, including blood type A (n=13), blood type B (n=9) and blood type O (n=10). Combination of principal component analysis (PCA) and liner discriminant analysis (LDA) was then performed on the SERS spectra of purified albumin, showing good classification results among different blood types. Our experimental outcomes represent a critical step towards the rapid, convenient and accurate identification of ABO blood types.

  20. Electrospinning of silver nanoparticles loaded highly porous cellulose acetate nanofibrous membrane for treatment of dye wastewater

    NASA Astrophysics Data System (ADS)

    Wang, Ke; Ma, Qian; Wang, Shu-Dong; Liu, Hua; Zhang, Sheng-Zhong; Bao, Wei; Zhang, Ke-Qin; Ling, Liang-Zhong

    2016-01-01

    In this paper, silver nanoparticles (NPs) were reduced form silver nitrate. Morphology and distribution of the synthesized silver NPs were characterized. In order to obtain cellulose acetate (CA), nanofibrous membrane with high effective adsorption performance to carry silver NPs for treatment of dye wastewater, different solvent systems were used to fabricate CA nanofibrous membranes with different morphologies and porous structures via electrospinning. Morphologies and structures of the obtained CA nanofibrous membranes were compared by scanning electron microscopy (SEM), which showed that CA nanofibrous membrane obtained from acetone/dichloromethane (1/2, v/v) was with the highly porous structure. SEM, energy-dispersive spectrometry and Fourier transform infrared spectrometry showed that the silver NPs were effectively incorporated in the CA nanofibrous membrane and the addition of silver NPs did not damage the porous structure of the CA nanofibrous membrane. Adsorption of dye solution (rhodamine B aqueous solution) revealed that the highly porous CA nanofibrous membrane exhibited effective adsorption performance and the addition of silver NPs did not affect the adsorption of the dye. Antibacterial property of the CA nanofibrous membrane showed that the silver-loaded highly porous CA nanofibrous membrane had remarkable antibacterial property when compared to the CA nanofibrous membrane without silver NPs. The silver-loaded highly porous CA nanofibrous membrane could be considered as an ideal candidate for treatment of the dye wastewater.

  1. Study of polydimethylsiloxane/aromatic polyamide laminated membranes for separation of acetic acid/water mixtures by pervaporation process

    SciTech Connect

    Deng, S.; Sourirajan, S.; Matsuura, T. )

    1994-06-01

    Separation of acetic acid/water mixtures by pervaporation was attempted over a range of compositions using polydimethylsiloxane (PDMS), aromatic polyamide (PA), and laminated polydimethylsiloxane-aromatic polyamide membranes. PDMS membranes are hydrophobic and acetic acid selective, whereas PA membranes are hydrophilic and water selective. When PDMS and PA membranes were laminated, with PDMS on the top side and in contact with the feed, water selectivity of the bottom PA membrane was intensified. On the other hand, when the PA membrane was on the top side and in contact with the feed, the selectivity was lowered. 10 refs., 4 figs.

  2. Western Blotting Using Microchip Electrophoresis Interfaced to a Protein Capture Membrane

    PubMed Central

    Jin, Shi; Anderson, Gwendolyn J.; Kennedy, Robert T.

    2013-01-01

    Western blotting is a commonly used assay for proteins. Despite the utility of the method, it is also characterized by long analysis times, manual operation, and lack of established miniaturized counterpart. We report a new way to Western blot which addresses these limitations. In the method, sodium dodecyl sulfate (SDS)-protein complexes are separated by sieving electrophoresis in a microfluidic device or chip. The chip is interfaced to a moving membrane so that proteins are captured in discrete zones as they migrate from the chip. Separations of SDS-protein complexes in the molecular weight range of 11 to 155 kDa were completed in 2 min with 4 104 theoretical plates at 460 V/cm. Migration time and peak area relative standard deviations were 36% and 0.2% respectively. Detection limit for actin was 0.7 nM. Assays for actin, AMP-kinase, carbonic anhydrase, and lysozyme are shown to demonstrate versatility of the method. Total analysis time including immunoassay was 2232 min for a single sample. Because processing membrane for immunoassay is the slow step of the assay, sequential injections from different reservoirs on the chip and capture in different tracks on the same membrane allow increased throughput. As a demonstration, 9 injections were collected on one membrane and analyzed in 43 min (~5 min/sample). Further improvements in throughput are possible with more reservoirs or parallel channels. PMID:23672369

  3. Alginate fouling reduction of functionalized carbon nanotube blended cellulose acetate membrane in forward osmosis.

    PubMed

    Choi, Hyeon-Gyu; Son, Moon; Yoon, SangHyeon; Celik, Evrim; Kang, Seoktae; Park, Hosik; Park, Chul Hwi; Choi, Heechul

    2015-10-01

    Functionalized multi-walled carbon nanotube blended cellulose acetate (fCNT-CA) membranes were synthesized for forward osmosis (FO) through phase inversion. The membranes were characterized through SEM, FTIR, and water contact angle measurement. AFM was utilized to investigate alginate fouling mechanism on the membrane. It reveals that the fCNT contributes to advance alginate fouling resistance in FO (57% less normalized water flux decline for 1% fCNT-CA membrane was observed than that for bare CA membrane), due to enhanced electrostatic repulsion between the membrane and the alginate foulant. Furthermore, it was found that the fCNT-CA membranes became more hydrophilic due to carboxylic groups in functionalized carbon nanotube, resulting in approximately 50% higher water-permeated flux than bare CA membrane. This study presents not only the fabrication of fCNT-CA membrane and its application to FO, but also the quantification of the beneficial role of fCNT with respect to alginate fouling in FO. PMID:26022283

  4. Cellulose Acetate 398-10 Asymmetric Membrane Capsules for Osmotically Regulated Delivery of Acyclovir

    PubMed Central

    Sonkar, Alka; Kumar, Anil; Pathak, Kamla

    2016-01-01

    The study was aimed at developing cellulose acetate asymmetric membrane capsules (AMCs) of acyclovir for its controlled delivery at the absorption site. The AMCs were prepared by phase inversion technique using wet process. A 23 full factorial design assessed the effect of independent variables (level(s) of polymer, pore former, and osmogen) on the cumulative drug release from AMCs. The buoyant optimized formulation F7 (low level of cellulose acetate; high levels of both glycerol and sodium lauryl sulphate) displayed maximum drug release of 97.88 ± 0.77% in 8 h that was independent of variation in agitational intensity and intentional defect on the cellulose acetate AMC. The in vitro data best fitted zero-order kinetics (r2 = 0.9898). SEM micrograph of the transverse section confirmed the asymmetric nature of the cellulose acetate capsular membrane. Statistical analysis by Design Expert software indicated no interaction between the independent variables confirming the efficiency of the design in estimating the effects of variables on drug release. The optimized formulation F7 (desirability = 0.871) displayed sustenance of drug release over the drug packed in AMC in pure state proving the superiority of osmotically active formulation. Conclusively the AMCs have potential for controlled release of acyclovir at its absorption site. PMID:26981319

  5. Removal of acetic acid from simulated hemicellulosic hydrolysates by emulsion liquid membrane with organophosphorus extractants.

    PubMed

    Lee, Sang Cheol

    2015-09-01

    Selective removal of acetic acid from simulated hemicellulosic hydrolysates containing xylose and sulfuric acid was attempted in a batch emulsion liquid membrane (ELM) system with organophosphorus extractants. Various experimental variables were used to develop a more energy-efficient ELM process. Total operation time of an ELM run with a very small quantity of trioctylphosphine oxide as the extractant was reduced to about a third of those required to attain almost the same extraction efficiency as obtained in previous ELM works without any extractant. Under specific conditions, acetic acid was selectively separated with a high degree of extraction and insignificant loss of xylose, and its purity and enrichment ratio in the stripping phase were higher than 92% and 6, respectively. Also, reused organic membrane solutions exhibited the extraction efficiency as high as fresh organic solutions did. These results showed that the current ELM process would be quite practical. PMID:26056774

  6. Transport of lactate and acetate through the energized cytoplasmic membrane of Escherichia coli

    SciTech Connect

    Axe, D.D.; Bailey, J.E.

    1995-07-05

    Escherichia coli produces lactate and acetate in significant amounts during both aerobic and anaerobic glycolysis. A model describing the mechanism of protein-mediated lactate transport has previously been proposed. A simple theoretical analysis here indicates that the proposed model would drain cellular energy resources by catalytically dissipating the proton-motive force. An experimental analysis of lactate and acetate transport employs nuclear magnetic resonance (NMR) spectroscopy to measure the relative concentrations of these end products on the two sides of the cytoplasmic membrane of anaerobically glycolyzing cells. Comparison of measured concentration ratios of those expected at equilibrium for various transport modes indicates that acetate is a classical uncoupling agent, permeating the membrane at comparable rates in the dissociated and undissociated forms. The lactate concentration ratio changes markedly after an initial period of sustained glycolysis. This change is most readily explained as resulting from a lactate transport system that responds to an indicator of glycolytic activity. The data further indicate that lactate permeates the membrane in both dissociated and undissociated forms. Both acids, then, are capable of catalytically dissipating the proton-motive force.

  7. Dehydration of water/pyridine mixtures by pervaporation using cellulose acetate/ polyacrylonitrile blend membrane.

    PubMed

    Lv, J H; Xiao, G M

    2011-01-01

    Cellulose acetate/ polyacrylonitrile (CA/PAN) membranes were prepared and used to separate pyridine / water mixtures by pervaporation. The membranes were characterized through SEM. The effects of feed concentration, operation temperature and downstream pressure on the separation performance were evaluated. Experimental results indicated the increase of operation temperature could raise the permeation flux and the separation factor, while increasing feed concentration and downstream pressure would raise the separation factor and decrease the permeation flux. Under the conditions that pyridine solution was 99 wt.%, operation temperature was 323 K and downstream pressure was 20 mmHg, the CA/PAN blend membrane showed its best separation performance that the permeation flux was 56.g.m-2 h-1 and the separation factor was 182. PMID:21866770

  8. Pervaporation of water and ethanol using a cellulose acetate butyrate membrane

    SciTech Connect

    Wu, W.S.; Lau, W.W.Y.; Rangaiah, G.P.; Sourirajan, S. . Dept. of Chemical Engineering)

    1993-10-15

    Okada and Matsuura's transport equations for pervaporation give rise to three fundamental parameters, namely, interfacial saturation vapor pressure P*, liquid transport parameter A/[delta], and vapor transport parameter B/[delta]. The effects of the chemical nature of the membrane material and the upstream operating pressures of 101.3 and 303.9 kPa on the above parameters were investigated from the pervaporation data at laboratory temperature (24 C) for water and ethanol using a cellulose acetate butyrate membrane. The results show that the P. values are essentially unaffected by the upstream pressure, and that they are generally higher than the literature values of saturation vapor pressure at 24 C. Further, the values for A/[delta] and B/[delta] tend to increase with increased upstream pressure for both systems studied. These results are discussed.

  9. Rapid and sensitive determination of phosphoamino acids in phosvitin by N-hydroxysuccinimidyl fluorescein-O-acetate derivatization and capillary zone electrophoresis with laser-induced fluorescence detection.

    PubMed

    Deng, Ying-Hua; Zhang, Hua-Shan; Wang, Hong

    2008-09-01

    A method was developed for the determination of phosphoamino acids by capillary zone electrophoresis-laser-induced fluorescence detection (argon ion laser, excitation at 488 nm and emission at 520 nm) using derivatization with N-hydroxysuccinimidyl fluorescein-O-acetate (SIFA). Different variables affecting the derivatization (SIFA concentration, derivatization pH, reaction temperature and reaction time) and the separation (type, pH and concentration of buffer, applied voltage and injection mode) were investigated in detail. The optimized separation conditions were 40 mM boric acid buffer (pH 9.2) for background electrolyte, 25 kV for the separation voltage, 25 degrees C for the capillary temperature and 5 s at 0.5 psi for the sample injection. Under the optimal conditions, the SIFA-labeled phosphoamino acids were fully separated within 7 min. The detection limits ranged from 0.1 to 0.3 nM, which are the lowest values reported for capillary electrophoresis (CE) methods. The proposed methodology allowed the rapid, sensitive and selective determination of phosphoamino acids in hen egg yolk phosvitin by the standard addition method. The recovery of these compounds in real sample was 94.0-103.5%. The developed method surpasses previously published CE methods in terms of detection limit, separation time, stability and simplicity of the electrophoretic procedure. PMID:18648781

  10. Low cost hydrogen/novel membrane technology for hydrogen separation from synthesis gas, Phase 1. [Polyetherimide, cellulose acetate and ethylcellulose

    SciTech Connect

    Not Available

    1986-01-01

    The goal of this program is to develop polymer membranes useful in the preparation of hydrogen from coal-derived synthesis gas. During this quarter the first experiment were aimed at developing high performance composite membranes for the separation of hydrogen from nitrogen and carbon monoxide. Three polymers have been selected as materials for these membranes: polyetherimide cellulose acetate and ethylcellulose. This quarter the investigators worked on polyetherimide and cellulose acetate membranes. The overall structure of these membranes is shown schematically in Figure 1. As shown, a microporous support membrane is first coated with a high flux intermediate layer then with an ultrathin permselective layer and finally, if necessary, a thin protective high flux layer. 1 fig., 4 tabs.

  11. Synthesis of polymer electrolyte membranes from cellulose acetate/poly(ethylene oxide)/LiClO4 for lithium ion battery application

    NASA Astrophysics Data System (ADS)

    Nurhadini, Arcana, I. Made

    2015-09-01

    This study was conducted to determine the effect of cellulose acetate on poly(ethylene oxide)-LiClO4 membranes as the polymer electrolyte. Cellulose acetate is used as an additive to increase ionic conductivity and mechanical property of polymer electrolyte membranes. The increase the percentage of cellulose acetate in membranes do not directly effect on the ionic conductivity, and the highest ionic conductivity of membranes about 5,7 10-4 S/cm was observed in SA/PEO/LiClO4 membrane with cellulose ratio of 10-25% (w/w). Cellulose acetate in membranes increases mechanical strength of polymer electrolyte membranes. Based on TGA analysis, this polymer electrolyte thermally is stable until 270 C. The polymer electrolyte membrane prepared by blending the cellulose acetate, poly(ethylene oxide), and lithium chlorate could be potentially used as a polymer electrolyte for lithium ion battery application.

  12. A novel, post-column micro-membrane reactor for fluorescent analysis of protein in capillary electrophoresis.

    PubMed

    Liu, Fan; Zhang, Lingyi; Qian, Junhong; Ren, Jun; Gao, Fangyuan; Zhang, Weibing

    2013-11-01

    Based on the semipermeability of hollow fiber membranes, a post-column membrane reactor was developed for capillary electrophoresis (CE)-laser induced fluorescence (LIF) analysis of proteins by using a hollow fiber membrane to connect the separation and detection capillaries. The membrane length between the separation and detection capillaries was 1 mm. Driven by the chemical potential difference between the separation buffer inside the membrane and the fluorescence derivatization solution outside the membrane, the derivatization reagent can be easily drawn into hollow fiber membrane to react with proteins. Also, the separation buffer can be adjusted by the derivatization solution to match the conditions of derivatization without sample loss. The effect of the separation buffer on the derivatization reaction was investigated and the results showed that even a strong acidic solution and multiple additives can be adopted in the separation buffer without destroying the post-column derivatization of proteins. Under the optimized conditions, the highly sensitive detection of BSA was achieved with a detection limit of 3.3 nmol L(-1) and a linear calibration range from 0.007 to 0.1 mg mL(-1). The proposed CE-LIF system with a post-column membrane reactor was also successfully applied to the separation and detection of proteins in rat liver and loach muscle. PMID:24015400

  13. Composite membrane of niobium(V) oxide and cellulose acetate: Preparation and characterization

    SciTech Connect

    Campos, E.A.; Gushikem, Y.

    1997-09-01

    Composite membranes of niobium(V) oxide and cellulose acetate (Cel/Nb{sub 2}O{sub 5}) were prepared with the following Nb{sub 2}O{sub 5} loadings (in wt%): 1.1, 6.1, 9.8, 15.6, and 20.9. The thermal stability of the membranes slightly decreased in relation to the pure membrane on incorporation of the metal oxide into the matrix. Scanning electron microscopy and niobium mapping with an X-ray EDS microprobe showed that the metal oxide particles are homogeneously dispersed in the matrix. The electronic absorption bands indicated that the oxide particle size varies from that of the monomer to those of oligomer species on increased Nb{sub 2}O{sub 5} loading in the matrix. The dispersed oxide possesses mainly Lewis acid character, a clear indication that on increasing the oxide loading in the matrix, the coordination number of the metal is not saturated by formation of the Nb-O-Nb bond. These materials can be useful in ion-exchange process, as supports for enzymes, in catalytic reactions, and in reverse osmosis experiments.

  14. Investigation of the pore structure and morphology of cellulose acetate membranes using small-angle neutron scattering. 2: Ultrafiltration and reverse-osmosis membranes

    SciTech Connect

    Kulkarni, S.; Krause, S. ); Wignall, G.D. . Solid State Div.)

    1994-11-07

    Pore structure in cellulose acetate ultrafiltration (UF) and reverse-osmosis (RO) membranes has been studied using small-angle neutron scattering. Scattering experiments were carried out on dry membranes as well as on membranes swollen with deuterated solvents (D[sub 2]O and CD[sub 3]OD). In addition, the RO membranes were studied both before and after annealing (a process of heating a membrane in a water bath at [approximately]75 C to improve its separation properties). The pore surface in UF membranes was found to be smooth and nonfractal, as evidenced by the fourth power law behavior at high Q. Values of average pore sizes obtained for dry and solvent swollen membranes agree well with pore sizes obtained by other methods. For cellulose acetate RO membranes in their dry state, the unannealed membrane appears to consist of two discrete pore size distributions in the intermediate and high Q region while the annealed membrane contains a much wider distribution of pore sizes. These results give a good account of the changes occurring in the structure of RO membranes as a result of annealing, and agree well with the prediction of other authors.

  15. Improved membrane protein solubilization and clean-up for optimum two-dimensional electrophoresis utilizing GLUT-1 as a classic integral membrane protein.

    PubMed

    Devraj, K; Geguchadze, R; Klinger, M E; Freeman, W M; Mokashi, A; Hawkins, R A; Simpson, I A

    2009-10-30

    Two-dimensional (2-D) electrophoresis remains a primary resolving tool for proteomic analyses. The final number of proteins resolved by 2-D electrophoresis depends on their respective solubility, size, charge, and isoelectric point. While water-soluble cytosolic proteins have often been well represented in 2-D maps, the same is not true with membrane proteins. Highly hydrophobic in nature, membrane proteins are poorly resolved in 2-D gels due to problems associated primarily with sample preparation. This is of especial concern in neuroscience studies where many proteins of interest are membrane bound. In the current work, we present a substantially improved sample preparation protocol for membrane proteins utilizing the GLUT-1 glucose transporter from brain microvessels as an example of a typical membrane protein. GLUT-1 (SLC2A1; solute carrier family 2 (facilitated glucose transporter), member 1) is a 55kD glycoprotein that contains 12 membrane-spanning alpha helices that impart the protein its characteristic hydrophobicity. GLUT-1 based on its amino acid sequence has a theoretical isoelectric point (pI) of 8.94. Using a combination of the non-ionic detergents, n-dodecyl-beta-maltoside (DDM) and amido sulphobetaine-14 (ASB-14) for sample solubilization, and a modification of the Bio-Rad 2-D clean-up protocol involving trichloroacetic acid (TCA)/acetone, we obtained near complete solubilization of GLUT-1 and greater than 90% recovery of this membrane protein in 1-D and 2-D Western blots. The total number of proteins resolved also increased dramatically in Deep Purple total protein stains using our improved protocol. PMID:19631691

  16. Membrane-supported liquid-liquid-liquid microextraction combined with anion-selective exhaustive injection capillary electrophoresis-ultraviolet detection for sensitive analysis of phytohormones.

    PubMed

    Huang, Linfang; He, Man; Chen, Beibei; Hu, Bin

    2014-05-23

    A novel method based on off-line membrane-supported liquid-liquid-liquid microextraction (MS-LLLME) combined with on-column anion-selective exhaustive injection (ASEI) capillary electrophoresis-ultraviolet (CE-UV) detection was established for the analysis of seven phytohormones (abscisic acid (ABA), jasmonic acid (JA), 2,4-dichlorophenoxyacetic acid (2,4-D), 1-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), salicylic acid (SA) and gibberellic acid (GA)). In MS-LLLME, the target phytohormones were extracted from the acid donor phase to the alkaline acceptor phase, and the acceptor solutions were directly analyzed by ASEI-CE-UV. Under the optimal experimental conditions, the analytical performance of the method was evaluated. The limits of detection (LODs) of ABA, JA, 2,4-D, NAA, IAA, SA and GA were determined to be 1.00, 2.21, 0.33, 0.17, 0.67, 0.05 and 16.5ng/mL, respectively. The relative standard deviations (RSDs, n=7) ranged from 4.7% to 12.9%, and the enrichment factors were in the range of 307 to 20,160. The proposed method was successfully applied for the determination of multiple phytohormones in banana, cabbage and cucumber extracts, and ABA, IAA and SA were detected in these samples. The recoveries for the spiked samples were in the range of 79.0 to 116.4%. The proposed method was demonstrated to be suitable for the simultaneous quantification of multiple phytohormones with high sensitivity and good sample cleanup ability. PMID:24720904

  17. Sensitivity enhancement in direct coupling of supported liquid membrane extractions to capillary electrophoresis by means of transient isotachophoresis and large electrokinetic injections.

    PubMed

    Pant??kov, Pavla; Kub?, Pavel; Bo?ek, Petr

    2015-04-10

    Enhanced sensitivity for determination of basic drugs in body fluids was achieved by in-line coupling of extraction across supported liquid membrane (SLM) to large electrokinetic injection and transient isotachophoresis-capillary zone electrophoresis (tITP-CZE) in commercial CZE instrument. Twelve cm long tITP plug of 300mM ammonium acetate was formed in the separation capillary just before the electrokinetic injection of acceptor solution containing nortriptyline, haloperidol and loperamide extracted across the SLM. The tITP plug ensured efficient stacking and preconcentration of the injected basic drugs due to the tITP action of ammonium and the drugs were then separated by CZE using 5.2M acetic acid as background electrolyte. No interferences were observed from highly-abundant body fluid species (NaCl and human serum albumin) due to the excellent clean-up properties of SLMs and analytical sensitivity increased up to 340 times compared to SLM extractions coupled in-line to CZE with standard hydrodynamic injections. The SLM-tITP-CZE method was characterized by good repeatability (RSDs of peak areas below 7.8%), linearity over two orders of magnitude (r(2) better than 0.994) and limits of detection (defined as 3S/N) between 3 and 45?g/L. Interfacing of SLM extractions to CZE instrumentation was achieved by low-cost, disposable micro-extraction devices, which can be routinely prepared in every analytical laboratory. These devices eliminated sample carry-over, minimized the need for manual sample handling and ensured fully automated determination (including extraction, injection, preconcentration and separation) of the three basic drugs in 20?L of untreated body fluids. PMID:25747667

  18. A green approach to ethyl acetate: quantitative conversion of ethanol through direct dehydrogenation in a Pd-Ag membrane reactor.

    PubMed

    Zeng, Gaofeng; Chen, Tao; He, Lipeng; Pinnau, Ingo; Lai, Zhiping; Huang, Kuo-Wei

    2012-12-01

    Pincers do the trick: The conversion of ethanol to ethyl acetate and hydrogen was achieved using a pincer-Ru catalyst in a Pd-Ag membrane reactor. Near quantitative conversions and yields could be achieved without the need for acid or base promoters or hydrogen acceptors (see scheme). PMID:23136053

  19. Development and optimization of a capillary zone electrophoresis technique for simultaneous determination of miconazole nitrate and hydrocortisone acetate in a cream pharmaceutical formulation.

    PubMed

    Korany, Mohamed A; Maher, Hadir M; Galal, Shereen M; Ragab, Marwa A A

    2013-01-01

    A simple, fast, inexpensive, and reliable capillary zone electrophoresis (CZE) method for the determination of a mixture of miconazole nitrate (MCZ) and hydrocortisone acetate (HCZ) in a cream formulation has been developed and validated. Optimum conditions were sodium dihydrogen phosphate buffer (50 mM, pH 4) and 30 kV applied voltage in a 85 cm x 75 pm id capillary. Direct UV detection at 230 nm led to adequate sensitivity without interference from the sample excipients. MCZ and HCZ migrated in approximately 165 and 415 s, respectively. The analytical curves had a coefficient of correlation, r, of 0.9999 and 0.9996 for MCZ and HCZ, respectively. The LOD and LOQ were 0.28 and 0.93 microg/mL for MCZ and 0.38 and 1.27 microg/mL for HCZ, respectively. Thus, excellent accuracy and precision were obtained. Recoveries varied from 98 to 102%, and intraday and interday precision, calculated as the RSD, were less than 2.0% for each drug. The proposed CZE method displayed advantageous performance characteristics and can be considered suitable for QC of the MCZ and HCZ cream formulation. PMID:24645507

  20. Magnetic Targeted Delivery of Dexamethasone Acetate across the Round Window Membrane in Guinea Pigs

    PubMed Central

    Du, Xiaoping; Chen, Kejian; Kuriyavar, Satish; Kopke, Richard D.; Grady, Brian P.; Bourne, David H.; Li, Wei; Dormer, Kenneth J.

    2012-01-01

    Hypothesis Magnetically susceptible PLGA nanoparticles will effectively target the round window membrane (RWM) for delivery of dexamethasone-acetate (Dex-Ac) to the scala tympani. Background Targeted delivery of therapeutics to specific tissues can be accomplished using different targeting mechanisms. One technology includes iron oxide nanoparticles, susceptible to external magnetic fields. If a nanocomposite composed of biocompatible polymer (PLGA), magnetite, and Dex-Ac can be pulled into and across the mammalian RWM, drug delivery can be enhanced. Method In vitro targeting and release kinetics of PLGA-magnetite-Dex-Ac nanoparticles first were measured using a RWM model. Next, these optimized nanocomposites were targeted to the RWM by filling the niche in anesthetized guinea pigs. A permanent magnet was placed opposite the RWM for 1 hour. Cochlear soft tissues, perilymph, and RWM were harvested after euthanasia and steroid levels were measured using HPLC. Results Membrane transport, in vitro, proved optimal targeting using a lower particle magnetite concentration (1 versus 5 or 10 mg/ml). In vivo targeted PLGA-magnetite-Dex-Ac particles had an average size of 482.8 158 nm (DLS) and an average zeta potential ?19.9 3.3 mV. In 1 hour, there was significantly increased cochlear targeted delivery of Dex or Dex-Ac, compared with diffusion alone. Conclusion Superparamagnetic PLGA-magnetite-Dex-Ac nanoparticles under an external magnetic field (0.26 mT) for 1 hour significantly increased Dex-Ac delivery to the inner ear. The RWM was not completely permeated and also became loaded with nanocomposites, indicating that delivery to the cochlea would continue for weeks by PLGA degradation and passive diffusion. PMID:23187928

  1. Fouling propensity and separation efficiency of epoxidated polyethersulfone incorporated cellulose acetate ultrafiltration membrane in the retention of proteins

    NASA Astrophysics Data System (ADS)

    Jayalakshmi, A.; Rajesh, S.; Mohan, D.

    2012-10-01

    Epoxidated polyethersulfone (EPES) incorporated cellulose acetate (CA) ultrafiltration membranes were prepared by diffusion induced precipitation technique in the absence and presence of pore former polyethyleneglycol-600. Effect of blend ratio on the compatibility, thermal stability, mechanical strength, hydrophilicity, morphology, pure water flux, protein adsorption resistance, protein separation efficiency and fouling propensity of the CA/EPES blend membranes was evaluated. Addition of EPES results in the formation of thin separating layer and spongy sub layer in CA/EPES blend membranes. The efficiency of these membranes in the separation of commercially important proteins such as bovine serum albumin, egg albumin, pepsin and trypsin was studied and found to be enhanced as compared to CA membranes. The fouling-resistant capability of the membranes was studied by bovine serum albumin as the model foulant and flux recovery ratio of the membranes were calculated. Attempts have been made to correlate the changes in membrane morphology with pure water flux, hydraulic resistance, thermal and mechanical stability, separation efficiency and antifouling property of the CA/EPES membranes. The optimal combination of CA and EPES, thus allows the preparation of high performance UF membranes which are sufficiently dense to retain proteins and at the same time give economically viable fluxes.

  2. Bidimensional electrophoresis in the diagnosis of mucopolysaccharidosis.

    PubMed

    Sato, C S; Gyorkey, F

    1977-08-01

    Using the modified bidimensional electrophoresis method, characteristic patterns of urinary glycosaminoglycans were obtained for nine different syndromes of mucopolysaccharidoses and normal. Each pattern, portrayed on a 55 mm square cellulose acetate membrane, was visualized by staining the electrophoretically separated GAGs with alcian blue. The method, tested with 38 cases, was precise and sensitive; the first direction of electrophoresis was run for 25 min and the second direction for 60 min. Because the method is qualitative, the usual quantitative measurements and calculations are circumvented. Moreover, any irregular pattern can readily be verified by repeating the bidimensional electrophoresis. Thus, the clarity of the pattern itself offers assurance of its diagnostic reliabilty; consequently, false negative and false positive results should be minimized. PMID:407038

  3. Application of zwitterionic detergent to the solubilization of Klebsiella pneumoniae outer membrane proteins for two-dimensional gel electrophoresis.

    PubMed

    Bednarz-Misa, I; Serek, P; Dudek, B; Pawlak, A; Bugla-P?osko?ska, G; Gamian, A

    2014-12-01

    Klebsiella pneumoniae is a frequent cause of nosocomial respiratory, urinary and gastrointestinal tract infections and septicemia with the multidrug-resistant K. pneumoniae being a major public health concern. Outer membrane proteins (OMPs) are important virulence factors responsible for the appropriate adaptation to the host environment. They constitute of the antigens being the first in contact with infected organism. However, K. pneumoniae strains are heavily capsulated and it is important to establish the OMPs isolation procedure prior to proteomics extensive studies. In this study we used Zwittergent Z 3-14 as a detergent to isolate the OMPs from K. pneumoniae cells and resolve them using two-dimensional electrophoresis (2-DE). As a result we identified 134 protein spots. The OMPs identified in this study are possible candidates for the development of a protein-based vaccine against K. pneumoniae infections. PMID:25261774

  4. An improved sodium dodecyl sulfate-polyacrylamide gel electrophoresis system for the analysis of membrane protein complexes.

    PubMed

    Kashino, Y; Koike, H; Satoh, K

    2001-04-01

    Membrane protein complexes such as the reaction center complexes of oxygenic photosynthesis or the complex I of mitochondira are composed of many subunit polypeptides. To analyze their polypeptide compositions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), a wide range of molecular sizes has to be resolved, especially in the low molecular mass range. We have improved the traditional Tris/HCI buffer systems adopting a Tris/2-(N-morpholino)ethanesulfonic acid (MES) buffer system containing 6 M urea. This gel system was used with an 18-24% acrylamide gradient for the separation of polypeptides with molecular masses from below 5 kDa to over 100 kDa. This buffer system can also be applied to the usual uniform concentration of acrylamide gel and also to minislab gels. PMID:11358120

  5. Electrophoresis and isoelectric focusing of whole cell and membrane proteins from the extremely halophilic archaebacteria

    NASA Technical Reports Server (NTRS)

    Stan-Lotter, Helga; Lang, Frank J., Jr.; Hochstein, Lawrence I.

    1989-01-01

    The subunits from two purified halobacterial membrane enzymes (ATPase and nitrate reductase) behaved differently with respect to isoelectric focusing, silver staining and interaction with ampholytes. Differential behavior was also observed in whole cell proteins from Halobacterium saccharovorum regarding resolution in two-dimensional gels and silver staining. It is proposed that these differences reflect the existence of two classes of halobacterial proteins.

  6. Diffusive transfer to membranes as an effective interface between gel electrophoresis and mass spectrometry

    NASA Astrophysics Data System (ADS)

    Ogorzalek Loo, Rachel R.; Mitchell, Charles; Stevenson, Tracy I.; Loo, Joseph A.; Andrews, Philip C.

    1997-12-01

    Diffusive transfer was examined as a blotting method to transfer proteins from polyacrylamide gels to membranes for ultraviolet matrix-assisted laser desorption ionization (MALDI) mass spectrometry. The method is well-suited for transfers from isoelectric focusing (IEF) gels. Spectra have been obtained for 11 pmol of 66 kDa albumin loaded onto an IEF gel and subsequently blotted to polyethylene. Similarly, masses of intact carbonic anhydrase and hemoglobin were obtained from 14 and 20 pmol loadings. This methodology is also compatible with blotting high molecular weight proteins, as seen for 6 pmol of the 150 kDa monoclonal antibody anti-[beta]-galactosidase transferred to Goretex. Polypropylene, Teflon, Nafion and polyvinylidene difluoride (PVDF) also produced good spectra following diffusive transfer. Only analysis from PVDF required that the membrane be kept wet prior to application of matrix. Considerations in mass accuracy for analysis from large-area membranes with continuous extraction and delayed extraction were explored, as were remedies for surface charging. Vapor phase CNBr cleavage was applied to membrane-bound samples for peptide mapping.

  7. Fabrication of tethered carbon nanotubes in cellulose acetate/polyethylene glycol-400 composite membranes for reverse osmosis.

    PubMed

    Sabir, Aneela; Shafiq, Muhammad; Islam, Atif; Sarwar, Afsheen; Dilshad, Muhammad Rizwan; Shafeeq, Amir; Zahid Butt, Muhammad Taqi; Jamil, Tahir

    2015-11-01

    In this study pristine multi-walled carbon nanotubes (MWCNTs) were surface engineered (SE) in strong acidic medium by oxidation purification method to form SE-MWCNT. Five different amount of SE-MWCNT ranging from 0.1 to 0.5 wt% were thoroughly and uniformly dispersed in cellulose acetate/polyethylene glycol (CA/PEG400) polymer matrix during synthesis of membrane by dissolution casting method. The structural analysis, surface morphology and roughness was carried out by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively, which showed that the dispersed SE-MWCNT was substantially tethered in CA/PEG400 polymer matrix membrane. The thermogravimetric analysis (TGA) of membranes also suggested some improvement in thermal properties with the addition of SE-MWCNT. Finally, the performance of these membranes was assessed for suitability in drinking water treatment. The permeation flux and salt rejection were determined by using indigenously fabricated reverse osmosis pilot plant with 1000 ppm NaCl feed solution. The results showed that the tethered SE-MWCNT/CA/PEG400 polymer matrix membrane, with strong SE-MWCNTs/polymer matrix interaction, improved the salt rejection performance of the membrane with the salt rejection of 99.8% for the highest content of SE-MWCNT. PMID:26256386

  8. Development of cellulose acetate propionate membrane for separation of ethanol and ethyl tert-butyl ether mixtures

    SciTech Connect

    Luo, G.S.; Niang, M.; Schaetzel, P.

    1997-04-01

    For pervaporation separation of ethanol and ethyl tert-butyl ether mixtures, a cellulose acetate propionate membrane was chosen as the experimental membrane because of its high selectivity and good mass fluxes. The properties of the membranes were evaluated by the pervaporation separation of mixtures of ethyl tert-butyl ether/ethanol and the sorption experiments. The experimental results showed that the selectivity and the permeates depend on the ethanol concentration in the feed and the experimental temperature. With increases of the ethanol weight fraction in the feed and the temperature, the total and partial mass fluxes increased. With respect to the temperature, ethanol mass flux obeys the Arrhenius equation. The selectivity of this membrane decreases as the temperature and the ethanol concentration in the feed increase. This membrane shows special characteristics at the azeotropic composition. In the vicinity of the azeotropic point, minimum values of ethanol concentration in the permeate and in sorption solution are obtained. The swelling ratios increase when temperature and the ethanol concentration in the feed are increasing. The ethanol concentration in the sorption solution is also influenced by the temperature and the mixture`s composition. When the temperature increases, the sorption selectivity of the membrane decreases.

  9. Development of Low Cost Membranes (Ta, Nb & Cellulose Acetate) for H2/CO2 Separation in WGS Reactors

    SciTech Connect

    Seetala, Naidu; Siriwardane, Upali

    2011-12-15

    The main aim of this work is to synthesize low temperature bimetallic nanocatalysts for Water Gas Shift reaction (WGS) for hydrogen production from CO and steam mixture; and develop low-cost metal (Nb/Ta)/ceramic membranes for H2 separation and Cellulose Acetate membranes for CO2 separation. .

  10. Free-Flow Electrophoresis of Plasma Membrane Vesicles Enriched by Two-Phase Partitioning Enhances the Quality of the Proteome from Arabidopsis Seedlings.

    PubMed

    de Michele, Roberto; McFarlane, Heather E; Parsons, Harriet T; Meents, Miranda J; Lao, Jeemeng; Gonzlez Fernndez-Nio, Susana M; Petzold, Christopher J; Frommer, Wolf B; Samuels, A Lacey; Heazlewood, Joshua L

    2016-03-01

    The plant plasma membrane is the interface between the cell and its environment undertaking a range of important functions related to transport, signaling, cell wall biosynthesis, and secretion. Multiple proteomic studies have attempted to capture the diversity of proteins in the plasma membrane using biochemical fractionation techniques. In this study, two-phase partitioning was combined with free-flow electrophoresis to produce a population of highly purified plasma membrane vesicles that were subsequently characterized by tandem mass spectroscopy. This combined high-quality plasma membrane isolation technique produced a reproducible proteomic library of over 1000 proteins with an extended dynamic range including plasma membrane-associated proteins. The approach enabled the detection of a number of putative plasma membrane proteins not previously identified by other studies, including peripheral membrane proteins. Utilizing multiple data sources, we developed a PM-confidence score to provide a value indicating association to the plasma membrane. This study highlights over 700 proteins that, while seemingly abundant at the plasma membrane, are mostly unstudied. To validate this data set, we selected 14 candidates and transiently localized 13 to the plasma membrane using a fluorescent tag. Given the importance of the plasma membrane, this data set provides a valuable tool to further investigate important proteins. The mass spectrometry data are available via ProteomeXchange, identifier PXD001795. PMID:26781341

  11. Effect of gossypol-acetic acid on calcium transport and ATPase activity in plasma membranes from ram and bull spermatozoa.

    PubMed

    Breitbart, H; Rubinstein, S; Nass-Arden, L

    1984-10-01

    The effects of gossypol acetic acid on the activity of Mg-ATPase and Ca-Mg-ATPase and on calcium uptake by plasma membranes from ram and bull spermatozoa were examined. The three parameters were almost completely inhibited by 10 microM gossypol for both ram and bull sperm. In order to assess the effects of higher gossypol concentrations isolated membrane vesicles were loaded with calcium by operating the ATP-dependent calcium pump after which gossypol was added and calcium uptake followed. At 10 microM gossypol, additional calcium uptake was 85% inhibited while at 40 microM a release of the accumulated calcium was observed. The inhibitory effect of 10 microM gossypol was almost completely reversible by simple dilution of gossypol-treated membranes, whilst at 40 microM the effect was only 50% reversible. The data show a high degree of similarity between bull and ram, suggesting minimal differences between the two species as far as the structure and function of the sperm plasma membrane is concerned. PMID:6151940

  12. ADSORPTION AND MEMBRANE SEPARATION MEASUREMENTS WITH MIXTURES OF ETHANOL, ACETIC ACID, AND WATER

    EPA Science Inventory

    Biomass fermentation produces ethanol and other renewable biofuels. Pervaporation using hydrophobic membranes is potentially a cost-effective means of removing biofuels from fermentation broths for small- to medium-scale applications. Silicalite-filled polydimethylsiloxane (PDMS)...

  13. Removal of chromium from aqueous solution using cellulose acetate and sulfonated poly(ether ether ketone) blend ultrafiltration membranes.

    PubMed

    Arthanareeswaran, G; Thanikaivelan, P; Jaya, N; Mohan, D; Raajenthiren, M

    2007-01-01

    A process for purifying aqueous solutions containing heavy and toxic metals such as chromium has been investigated. Chromium salts are largely used in various industries including leather-manufacturing industry. Ultrafiltration processes are largely being applied for macromolecular and heavy metal ion separation from aqueous streams. Cellulose acetate and sulfonated poly(ether ether ketone) blend ultrafiltration membranes were prepared by precipitation phase inversion technique in 100/0, 90/10, 80/20 and 70/30% polymer blend compositions and subjected to the rejection of chromium at different concentrations such as 200, 400, 600, 800 and 1000 ppm with a water-soluble macroligand (polyvinylalcohol). Factors affecting the percentage rejection and permeate flux such as pH, concentration of solute, concentration of PVA, transmembrane pressure and composition of blend membranes were investigated. It was found that percentage rejection improved at a pH 6 and a macroligand concentration of 2 wt.%. The transmembrane pressure and concentration of solute also have an effect on the separation and product rate efficiencies of the blend membranes. PMID:16860465

  14. Effect of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) upon membrane ionic exchanges in sea urchin eggs

    SciTech Connect

    Ciapa, B.; Payan, P. ); Allemand, D. )

    1989-12-01

    The effect of TPA (12-O-tetradecanoylphorbol-13-acetate) upon ionic exchanges was investigated in eggs of the sea urchin Arbacia lixula. Ouabain-sensitive {sup 86}Rb uptake and amiloride-sensitive {sup 24}Na influx were dramatically stimulated after TPA addition, indicating an enhancement of total ionic permeabilities. Stimulation by TPA of both Na{sup +}/H{sup +} and Na{sup +}/K{sup +} exchanges was canceled by amiloride, suggesting that activation of protein kinase C elicits, via Na{sup +}/H{sup +} activity, stimulation of the sodium pump. However, TPA did not stimulate sodium pump activity and Na{sup +}/H{sup +} exchange at the same rate as fertilization, probably because of an absence of calcium-dependent events. Further fertilization of TPA pretreated eggs triggered an enhancement of sodium pump activity when the TPA treatment duration did not exceed 10 minutes. It is suggested that TPA activates preexisting transporting mechanisms in plasma membranes of unfertilized eggs (Na{sup +} stat, pH stat).

  15. Electrophoresis-Enhanced Detection of Deoxyribonucleic Acids on a Membrane-Based Lateral Flow Strip Using Avian Influenza H5 Genetic Sequence as the Model

    PubMed Central

    Wu, Jui-Chuang; Chen, Chih-Hung; Fu, Ja-Wei; Yang, Huan-Ching

    2014-01-01

    This study reports a simple strategy to detect a deoxyribonucleic acid (DNA) on a membrane-based lateral flow (MBLF) strip without tedious gel preparation, gel electrophoresis, and EtBr-staining processes. The method also enhances the detection signal of the genetic sample. A direct electric field was applied over two ends of the MBLF strips to induce an electrophoresis of DNAs through the strips. The signal enhancement was demonstrated by the detection of the H5 subtype of avian influenza virus (H5 AIV). This approach showed an excellent selectivity of H5 AIV from other two control species, Arabidopsis thaliana and human PSMA5. It also showed an effective signal repeatability and sensitivity over a series of analyte concentrations. Its detection limit could be enhanced, from 40 ng to 0.1 ng by applying 12 V. The nano-gold particles for the color development were labeled on the capture antibody, and UV-VIS and TEM were used to check if the labeling was successful. This detection strategy could be further developed to apply on the detection of drug-allergic genes at clinics or detection of infectious substances at incident sites by a simple manipulation with an aid of a mini-PCR machine and auxiliary kits. PMID:24603637

  16. Analysis of Streptomyces coelicolor membrane proteome using two-dimensional native/native and native/sodium dodecyl sulfate gel electrophoresis.

    PubMed

    Li, Fuhou; Liang, Jingdan; Wang, Weixia; Zhou, Xiufen; Deng, Zixin; Wang, Zhijun

    2014-11-15

    Analysis of the oligomeric state of a protein may provide insights into its physiological functions. Because membrane proteins are considered to be the workhorses of energy generation and polypeptide and nutrient transportation, in this study we characterized the membrane-associated proteome of Streptomyces coelicolor by two-dimensional (2D) blue native/sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), high-resolution clear native/native PAGE, and native/SDS-PAGE. A total of 77 proteins were identified, and 20 proteins belonging to 15 complexes were characterized. Moreover, the resolution of high-resolution clear native/SDS-PAGE is much higher than that of blue native/SDS-PAGE. OBP (SCO5477) and BldKB (SCO5113) were identified as the main protein spots from the membrane fractions of S. coelicolor M145, suggesting that these two proteins are involved in extracellular peptide transportation. These two transporters exhibited multiple oligomeric states in the native PAGE system, which may suggest their multiple physiological functions in the development of S. coelicolor. PMID:25150108

  17. Bargain Electrophoresis.

    ERIC Educational Resources Information Center

    Maderia, Vitor M. C.; Pires, Euclides M. V.

    1986-01-01

    Discusses the value of electrophoresis in the fields of protein chemistry and biochemistry. Describes how to build an inexpensive electrophoresis setup for use in either research or teaching activities. Details the construction of both the separating device and the power supply. (TW)

  18. Conjugation of silica nanoparticles with cellulose acetate/polyethylene glycol 300 membrane for reverse osmosis using MgSO4 solution.

    PubMed

    Sabir, Aneela; Shafiq, Muhammad; Islam, Atif; Jabeen, Faiza; Shafeeq, Amir; Ahmad, Adnan; Zahid Butt, Muhammad Taqi; Jacob, Karl I; Jamil, Tahir

    2016-01-20

    Thermally-induced phase separation (TIPS) method was used to synthesize polymer matrix (PM) membranes for reverse osmosis from cellulose acetate/polyethylene glycol (CA/PEG300) conjugated with silica nanoparticles (SNPs). Experimental data showed that the conjugation of SNPs changed the surface properties as dense and asymmetric composite structure. The results were explicitly determined by the permeability flux and salt rejection efficiency of the PM-SNPs membranes. The effect of SNPs conjugation on MgSO4 salt rejection was more significant in magnitude than on permeation flux i.e. 2.38 L/m(2)h. FTIR verified that SNPs were successfully conjugated on the surface of PM membrane. DSC of PM-SNPs shows an improved Tg from 76.2 to 101.8 °C for PM and PM-S4 respectively. Thermal stability of the PM-SNPs membranes was observed by TGA which was significantly enhanced with the conjugation of SNPs. The micrographs of SEM and AFM showed the morphological changes and increase in the valley and ridges on membrane surface. Experimental data showed that the PM-S4 (0.4 wt% SNPs) membrane has maximum salt rejection capacity and was selected as an optimal membrane. PMID:26572387

  19. Versatile microanalytical system with porous polypropylene capillary membrane for calibration gas generation and trace gaseous pollutants sampling applied to the analysis of formaldehyde, formic acid, acetic acid and ammonia in outdoor air.

    PubMed

    Coelho, Lúcia H G; Melchert, Wanessa R; Rocha, Flavio R; Rocha, Fábio R P; Gutz, Ivano G R

    2010-11-15

    The analytical determination of atmospheric pollutants still presents challenges due to the low-level concentrations (frequently in the μg m(-3) range) and their variations with sampling site and time. In this work, a capillary membrane diffusion scrubber (CMDS) was scaled down to match with capillary electrophoresis (CE), a quick separation technique that requires nothing more than some nanoliters of sample and, when combined with capacitively coupled contactless conductometric detection (C(4)D), is particularly favorable for ionic species that do not absorb in the UV-vis region, like the target analytes formaldehyde, formic acid, acetic acid and ammonium. The CMDS was coaxially assembled inside a PTFE tube and fed with acceptor phase (deionized water for species with a high Henry's constant such as formaldehyde and carboxylic acids, or acidic solution for ammonia sampling with equilibrium displacement to the non-volatile ammonium ion) at a low flow rate (8.3 nL s(-1)), while the sample was aspirated through the annular gap of the concentric tubes at 2.5 mL s(-1). A second unit, in all similar to the CMDS, was operated as a capillary membrane diffusion emitter (CMDE), generating a gas flow with know concentrations of ammonia for the evaluation of the CMDS. The fluids of the system were driven with inexpensive aquarium air pumps, and the collected samples were stored in vials cooled by a Peltier element. Complete protocols were developed for the analysis, in air, of NH(3), CH(3)COOH, HCOOH and, with a derivatization setup, CH(2)O, by associating the CMDS collection with the determination by CE-C(4)D. The ammonia concentrations obtained by electrophoresis were checked against the reference spectrophotometric method based on Berthelot's reaction. Sensitivity enhancements of this reference method were achieved by using a modified Berthelot reaction, solenoid micro-pumps for liquid propulsion and a long optical path cell based on a liquid core waveguide (LCW). All techniques and methods of this work are in line with the green analytical chemistry trends. PMID:21035648

  20. STABILITY OF MFI ZEOLITE-FILLED PDMS MEMBRANES DURING PERVAPORATIVE ETHANOL RECOVERY FROM AQUEOUS MIXTURES CONTAINING ACETIC ACID

    EPA Science Inventory

    Pervaporation is a potential process for recovering bioethanol produced from biomass fermentation. Fermentation broths contain ethanol, water, and a variety of other compounds, often including carboxylic acids. The effects of acetic acid on long-term pervaporation of aqueous et...

  1. Gypsum (CaSO42H2O) Scaling on Polybenzimidazole and Cellulose Acetate Hollow Fiber Membranes under Forward Osmosis.

    PubMed

    Chen, Si Cong; Su, Jincai; Fu, Feng-Jiang; Mi, Baoxia; Chung, Tai-Shung

    2013-01-01

    We have examined the gypsum (CaSO42H2O) scaling phenomena on membranes with different physicochemical properties in forward osmosis (FO) processes. Three hollow fiber membranes made of (1) cellulose acetate (CA), (2) polybenzimidazole (PBI)/polyethersulfone (PES) and (3) PBI-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) were studied. For the first time in FO processes, we have found that surface ionic interactions dominate gypsum scaling on the membrane surface. A 70% flux reduction was observed on negatively charged CA and PBI membrane surfaces, due to strong attractive forces. The PBI membrane surface also showed a slightly positive charge at a low pH value of 3 and exhibited a 30% flux reduction. The atomic force microscopy (AFM) force measurements confirmed a strong repulsive force between gypsum and PBI at a pH value of 3. The newly developed PBI-POSS/PAN membrane had ridge morphology and a contact angle of 51.42 14.85 after the addition of hydrophilic POSS nanoparticles and 3 min thermal treatment at 95 C. Minimal scaling and an only 1.3% flux reduction were observed at a pH value of 3. Such a ridge structure may reduce scaling by not providing a locally flat surface to the crystallite at a pH value of 3; thus, gypsum would be easily washed away from the surface. PMID:24957062

  2. Gypsum (CaSO42H2O) Scaling on Polybenzimidazole and Cellulose Acetate Hollow Fiber Membranes under Forward Osmosis

    PubMed Central

    Chen, Si Cong; Su, Jincai; Fu, Feng-Jiang; Mi, Baoxia; Chung, Tai-Shung

    2013-01-01

    We have examined the gypsum (CaSO42H2O) scaling phenomena on membranes with different physicochemical properties in forward osmosis (FO) processes. Three hollow fiber membranes made of (1) cellulose acetate (CA), (2) polybenzimidazole (PBI)/polyethersulfone (PES) and (3) PBI-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) were studied. For the first time in FO processes, we have found that surface ionic interactions dominate gypsum scaling on the membrane surface. A 70% flux reduction was observed on negatively charged CA and PBI membrane surfaces, due to strong attractive forces. The PBI membrane surface also showed a slightly positive charge at a low pH value of 3 and exhibited a 30% flux reduction. The atomic force microscopy (AFM) force measurements confirmed a strong repulsive force between gypsum and PBI at a pH value of 3. The newly developed PBI-POSS/PAN membrane had ridge morphology and a contact angle of 51.42 14.85 after the addition of hydrophilic POSS nanoparticles and 3 min thermal treatment at 95 C. Minimal scaling and an only 1.3% flux reduction were observed at a pH value of 3. Such a ridge structure may reduce scaling by not providing a locally flat surface to the crystallite at a pH value of 3; thus, gypsum would be easily washed away from the surface. PMID:24957062

  3. Analysis of electrophoresis performance

    NASA Technical Reports Server (NTRS)

    Roberts, G. O.

    1984-01-01

    The SAMPLE computer code models electrophoresis separation in a wide range of conditions. Results are included for steady three dimensional continuous flow electrophoresis (CFE), time dependent gel and acetate film experiments in one or two dimensions and isoelectric focusing in one dimension. The code evolves N two dimensional radical concentration distributions in time, or distance down a CFE chamber. For each time or distance increment, there are six stages, successively obtaining the pH distribution, the corresponding degrees of ionization for each radical, the conductivity, the electric field and current distribution, and the flux components in each direction for each separate radical. The final stage is to update the radical concentrations. The model formulation for ion motion in an electric field ignores activity effects, and is valid only for low concentrations; for larger concentrations the conductivity is, therefore, also invalid.

  4. Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation

    PubMed Central

    Casado-Coterillo, Clara; López-Guerrero, María del Mar; Irabien, Ángel

    2014-01-01

    Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials. PMID:24957178

  5. Analysis of diazinon pesticide using potentiometric biosensor based on enzyme immobilized cellulose acetate membrane in gold electrode

    NASA Astrophysics Data System (ADS)

    Mashuni; Ramadhan, L. O. A. N.; Jahiding, M.; Herniati

    2016-02-01

    Biosensor for analysis of diazinon pesticide using Potentiometric transducer has been developed. The basic element of this biosensor was a gold electrode modified with an immobilized acetylcholinesterase enzyme layer formed by entrapment with glutaraldehyde crosslinked-cellulose acetate. The aim of the research is to determine the composition of glutaraldehyde crosslinked-cellulose acetate in the gold electrode which provide optimum performance of biosensors of diazinon pesticide analysis on characterization include a range of working concentration, sensitivity, and detection limit. The results showed the composition of the cellulose acetate 15% and glutaraldehyde 25% that obtain optimum performance in the measurement of diazinon pesticide with a range of working concentration of 10-6 ppm to 1 ppm, the value of sensitivity 20.275 mV/decade and detection limit 10-6 ppm. The use of cellulose acetate provides highly sensitive devices allowing the efficient analysis of pesticides. The response time of electrode is on the measurement of pesticide diazinon with concentration variation of 10-6 ppm to 1 ppm with response time is about 5 minutes.

  6. Micromanipulation of adhesion of phorbol 12-myristate-13-acetate-stimulated T lymphocytes to planar membranes containing intercellular adhesion molecule-1.

    PubMed Central

    Tzeren, A; Mackie, L H; Lawrence, M B; Chan, P Y; Dustin, M L; Springer, T A

    1992-01-01

    This paper presents an analytical and experimental methodology to determine the physical strength of cell adhesion to a planar membrane containing one set of adhesion molecules. In particular, the T lymphocyte adhesion due to the interaction of the lymphocyte function associated molecule 1 on the surface of the cell, with its counter-receptor, intercellular adhesion molecule-1 (ICAM-1), on the planar membrane, was investigated. A micromanipulation method and mathematical analysis of cell deformation were used to determine (a) the area of conjugation between the cell and the substrate and (b) the energy that must be supplied to detach a unit area of the cell membrane from its substrate. T lymphocytes stimulated with phorbol 12-myristate-13-acetate (PMA) conjugated strongly with the planar membrane containing purified ICAM-1. The T lymphocytes attached to the planar membrane deviated occasionally from their round configuration by extending pseudopods but without changing the size of the contact area. These adherent cells were dramatically deformed and then detached when pulled away from the planar membrane by a micropipette. Detachment occurred by a gradual decrease in the radius of the contact area. The physical strength of adhesion between a PMA-stimulated T lymphocyte and a planar membrane containing 1,000 ICAM-1 molecules/micron 2 was comparable to the strength of adhesion between a cytotoxic T cell and its target cell. The comparison of the adhesive energy density, measured at constant cell shape, with the model predictions suggests that the physical strength of cell adhesion may increase significantly when the adhesion bonds in the contact area are immobilized by the actin cytoskeleton. Images FIGURE 2 FIGURE 4 FIGURE 5 FIGURE 8 FIGURE 9 PMID:1358239

  7. Electrophoresis technology

    NASA Technical Reports Server (NTRS)

    Snyder, R. S.

    1985-01-01

    A new high resolution apparatus designed for space was built as a laboratory prototype. Using a moving wall with a low zeta potential coating, the major sources of flow distortion for an electrophoretic sample stream are removed. Highly resolved fractions, however, will only be produced in space because of the sensitivity of this chamber to buoyancy-induced convection in the laboratory. The second and third flights of the McDonnell Douglas Astronautics Corporation continuous flow electrophoresis system carried samples developed at MSFC intended to evaluate the broad capabilities of free flow electrophoresis in a reduced gravity environment. Biological model materials, hemoglobin and polystyrene latex microspheres, were selected because of their past use as electrophoresis standards and as visible markers for fluid flow due to electroosmosis, spacecraft acceleration or other factors. The dependence of the separation resolution on the properties of the sample and its suspension solution was assessed.

  8. In-line coupling of microextractions across polymer inclusion membranes to capillary zone electrophoresis for rapid determination of formate in blood samples.

    PubMed

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2015-08-01

    Polymer inclusion membranes (PIMs) have several important features, i.e., PIMs are dry and non-porous membranes, which can be prepared ahead of use and stored without noticeable deterioration in extraction performance. In this contribution, in-line coupling of microextractions across PIMs to a separation method for clinical purposes was demonstrated for the first time. Formate (the major metabolite in methanol poisoning) was determined in undiluted human serum and whole blood by capillary zone electrophoresis (CZE) with simultaneous capacitively coupled contactless conductivity detection (C(4)D) and UV-Vis detection. A purpose-made microextraction device with PIM was coupled to a commercial CZE instrument in order to ensure complete automation of the entire analytical procedure, i.e., of formate extraction, injection, CZE separation and quantification. PIMs for formate extractions consisted of 60% (w/w) cellulose triacetate as base polymer and 40% (w/w) Aliquat™ 336 as anion carrier. The method was characterized by good repeatability of peak areas (≤7.0%) and migration times (≤0.8%) and by good linearity of calibration curves (r(2) = 0.993-0.999). Limits of detection in various matrices ranged from 15 to 54 μM for C(4)D and from 200 to 635 μM for UV-Vis detection and were sufficiently low to clearly distinguish between endogenous and toxic levels of formate in healthy and methanol intoxicated individuals. In addition, PIMs proved that they may act as phase interfaces with excellent long-term stability since once prepared, they retained their extractions properties for, at least, two months of storage. PMID:26320792

  9. Parallel characterization of anaerobic toluene- and ethylbenzene-degrading microbial consortia by PCR-denaturing gradient gel electrophoresis, RNA-DNA membrane hybridization, and DNA microarray technology

    NASA Technical Reports Server (NTRS)

    Koizumi, Yoshikazu; Kelly, John J.; Nakagawa, Tatsunori; Urakawa, Hidetoshi; El-Fantroussi, Said; Al-Muzaini, Saleh; Fukui, Manabu; Urushigawa, Yoshikuni; Stahl, David A.

    2002-01-01

    A mesophilic toluene-degrading consortium (TDC) and an ethylbenzene-degrading consortium (EDC) were established under sulfate-reducing conditions. These consortia were first characterized by denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR-amplified 16S rRNA gene fragments, followed by sequencing. The sequences of the major bands (T-1 and E-2) belonging to TDC and EDC, respectively, were affiliated with the family Desulfobacteriaceae. Another major band from EDC (E-1) was related to an uncultured non-sulfate-reducing soil bacterium. Oligonucleotide probes specific for the 16S rRNAs of target organisms corresponding to T-1, E-1, and E-2 were designed, and hybridization conditions were optimized for two analytical formats, membrane and DNA microarray hybridization. Both formats were used to characterize the TDC and EDC, and the results of both were consistent with DGGE analysis. In order to assess the utility of the microarray format for analysis of environmental samples, oil-contaminated sediments from the coast of Kuwait were analyzed. The DNA microarray successfully detected bacterial nucleic acids from these samples, but probes targeting specific groups of sulfate-reducing bacteria did not give positive signals. The results of this study demonstrate the limitations and the potential utility of DNA microarrays for microbial community analysis.

  10. Simulating Electrophoresis.

    ERIC Educational Resources Information Center

    Moertel, Cheryl; Frutiger, Bruce

    1996-01-01

    Describes a DNA fingerprinting simulation that uses vegetable food coloring and plastic food containers instead of DNA and expensive gel electrophoresis chambers. Allows students to decipher unknown combinations of dyes in a method similar to that used to decipher samples of DNA in DNA fingerprint techniques. (JRH)

  11. Proteins Induced during Adaptation of Acetobacter aceti to High Acetate Concentrations

    PubMed Central

    Steiner, Peter; Sauer, Uwe

    2001-01-01

    As a typical product of microbial metabolism, the weak acid acetate is well known for its cytotoxic effects. In contrast to most other microbes, the so-called acetic acid bacteria can acquire significant resistance to high acetate concentrations when properly adapted to such hostile conditions. To characterize the molecular events that are associated with this adaptation, we analyzed global protein expression levels during adaptation of Acetobacter aceti by two-dimensional gel electrophoresis. Adaptation was achieved by using serial batch and continuous cultivations with increasing acetate supplementation. Computer-aided analysis revealed a complex proteome response with at least 50 proteins that are specifically induced by adaptation to acetate but not by other stress conditions, such as heat or oxidative or osmotic stress. Of these proteins, 19 were significantly induced in serial batch and continuous cultures and were thus noted as acetate adaptation proteins (Aaps). Here we present first microsequence information on such Aaps from A. aceti. Membrane-associated processes appear to be of major importance for adaptation, because some of the Aap bear N-terminal sequence homology to membrane proteins and 11 of about 40 resolved proteins from membrane protein-enriched fractions are significantly induced. PMID:11722895

  12. Expression of the AZR1 gene (ORF YGR224w), encoding a plasma membrane transporter of the major facilitator superfamily, is required for adaptation to acetic acid and resistance to azoles in Saccharomyces cerevisiae.

    PubMed

    Tenreiro, S; Rosa, P C; Viegas, C A; S-Correia, I

    2000-12-01

    In this work, we report results on the functional analysis of Saccharomyces cerevisiae ORF YGR224w, predicted to code for an integral membrane protein, with 14 potential transmembrane segments, belonging to the major facilitator superfamily (MFS) of transporters which are required for multiple-drug resistance (MDR). This MFS-MDR homologue is required for yeast adaptation to high stress imposed by low-chain organic acids, in particular by acetic acid, and for resistance to azoles, especially to ketoconazole and fluconazole; the encoding gene was thus named the AZR1 gene. These conclusions were based on the higher susceptibility to these compounds of an azr1Delta deletion mutant strain compared with the wild-type and on the increased resistance of both azr1Delta and wild-type strains upon increased expression of the AZR1 gene from a centromeric plasmid clone. AZR1 gene expression reduces the duration of acetic acid-induced latency, although the growth kinetics of adapted cells under acetic acid stress is apparently independent of AZR1 expression level. Fluorescence microscopy observation of the distribution of the Azr1-GFP fusion protein in yeast living cells indicated that Azr1 is a plasma membrane protein. Studies carried out to gain some understanding of how this plasma membrane putative transporter facilitates yeast adaptation to acetic acid did not implicate Azr1p in the alteration of acetic acid accumulation into the cell through the active efflux of acetate. PMID:11113970

  13. STABILITY OF MFI ZEOLITE-FILLED PDMS MEMBRANES DURING PERVAPORATIVE ETHANOL RECOVERY FROM AQUEOUS MIXTURES CONTAINING ACETIC ACID

    EPA Science Inventory

    Pervaporation is potentially a cost-effective means of recovering biofuels, such as ethanol, from biomass fermentation broths for small- to medium-scale applications (~2 - 20 million liters per year). Hydrophobic zeolite-filled polydimethylsiloxane (PDMS) membranes have been sho...

  14. Flecainide acetate acetic acid solvates.

    PubMed

    Veldre, Kaspars; Acti?s, Andris; Eglite, Zane

    2011-02-01

    Flecainide acetate forms acetic acid solvates with 0.5 and 2 acetic acid molecules. Powder X-ray diffraction, differential thermal analysis/thermogravimetric, infrared, and potentiometric titration were used to determine the composition of solvates. Flecainide acetate hemisolvate with acetic acid decomposes to form a new crystalline form of flecainide acetate. This form is less stable than the already known polymorphic form at all temperatures, and it is formed due to kinetic reasons. Both flecainide acetate nonsolvated and flecainide acetate hemisolvate forms crystallize in monoclinic crystals, but flecainide triacetate forms triclinic crystals. Solvate formation was not observed when flecainide base was treated with formic acid, propanoic acid, and butanoic acid. Only nonsolvated flecainide salts were obtained in these experiments. PMID:21249720

  15. Fluid flow electrophoresis in space

    NASA Technical Reports Server (NTRS)

    Griffin, R. N.

    1975-01-01

    Four areas relating to free-flow electrophoresis in space were investigated. The first was the degree of improvement over earthbound operations that might be expected. The second area of investigation covered the problems in developing a flowing buffer electrophoresis apparatus. The third area of investigation was the problem of testing on the ground equipment designed for use in space. The fourth area of investigation was the improvement to be expected in space for purification of biologicals. The results of some ground-based experiments are described. Other studies included cooling requirements in space, fluid sealing techniques, and measurement of voltage drop across membranes.

  16. Effect of K+ and Ca2+ on the indole-3-acetic acid- and fusicoccin-induced growth and membrane potential in maize coleoptile cells

    PubMed Central

    Siemieniuk, Agnieszka; Karcz, Waldemar

    2015-01-01

    The role of potassium (K+) and calcium (Ca2+) in the regulation of plant growth and development is complex and needs a diverse range of physiological studies. Both elements are essential for satisfactory crop production. Here, the effects of K+ and Ca2+ ions on endogenous growth and growth in the presence of either indole-3-acetic acid (IAA) or fusicoccin (FC) were studied in maize (Zea mays) coleoptiles. Membrane potentials of coleoptile parenchymal cells, incubated in media containing IAA, FC and different concentrations of K+ and Ca2+, were also determined. Growth experiments have shown that in the absence of K+ in the incubation medium, both endogenous and IAA- or FC-induced growth were significantly inhibited by 0.1 and 1 mM Ca2+, respectively, while in the presence of 1 mM K+ they were inhibited only by 1 mM Ca2+. At 10 mM K+, endogenous growth and growth induced by either IAA or FC did not depend on Ca2+ concentration. TEA-Cl, a potassium channel blocker, added 1 h before IAA or FC, caused a reduction of growth by 59 or 45 %, respectively. In contrast to TEA-Cl, verapamil, the Ca2+ channel blocker, did not affect IAA- and FC-induced growth. It was also found that in parenchymal cells of maize coleoptile segments, membrane potential (Em) was strongly affected by the medium K+, independently of Ca2+. However, lack of Ca2+ in the incubation medium significantly reduced the IAA- and FC-induced membrane potential hyperpolarization. TEA-Cl applied to the control medium in the same way as in growth experiments caused Em hyperpolarization synergistic with hyperpolarization produced by IAA or FC. Verapamil did not change either the Em of parenchymal cells incubated in the control medium or the IAA- and FC-induced membrane hyperpolarization. The data presented here have been discussed considering the role of K+ uptake channels in regulation of plant cell growth. PMID:26134122

  17. Mesoxalaldehyde acetals

    SciTech Connect

    Gordeeva, G.N.; Kalashnikov, S.M.; Popov, Yu.N.; Kruglov, E.A.; Imashev, U.B.

    1987-11-10

    The treatment of methylglyoxal acetals by alkyl nitrites in the presence of the corresponding aliphatic alcohols and hydrochloric acid leads to the formation of linear mesoxalaldehyde acetals, whose structure was established by NMR spectroscopy and mass spectrometry. The major pathways for the decomposition of these molecules upon electron impact were established.

  18. Glycosaminoglycan blotting and detection after electrophoresis separation.

    PubMed

    Volpi, Nicola; Maccari, Francesca

    2015-01-01

    Separation of glycosaminoglycans (GAGs) by electrophoresis and their characterization to the microgram level are integral parts of biochemical research. Their blotting on membranes after electrophoresis offers the advantage to perform further analysis on single separated species such as identification with antibodies and/or recovery of single band. A method for the blotting and immobilizing of several nonsulfated and sulfated complex GAGs on membranes made hydrophilic and positively charged by cationic detergent after their separation by conventional agarose-gel electrophoresis is illustrated. This approach to the study of these complex macromolecules utilizes the capacity of agarose-gel electrophoresis to separate single species of polysaccharides from mixtures and the membrane technology for further preparative and analytical uses. Nitrocellulose membranes are derivatized with the cationic detergent cetylpyridinium chloride (CPC) and mixtures of GAGs are capillary blotted after their separation in agarose-gel electrophoresis. Single purified species of variously sulfated polysaccharides are transferred on derivatized membranes with an efficiency of 100 % and stained with alcian blue (irreversible staining) and toluidine blue (reversible staining). This enables a lower amount limit of detection of 0.1 ?g. Nonsulfated polyanions, for example hyaluronic acid (HA), may also be transferred to membranes with a limit of detection of approximately 0.1-0.5 ?g after irreversible or reversible staining. The membranes may be stained with reversible staining and the same lanes used for immunological detection or other applications. PMID:26043997

  19. Using linoleic acid embedded cellulose acetate membranes to in situ monitor polycyclic aromatic hydrocarbons in lakes and predict their bioavailability to submerged macrophytes.

    PubMed

    Tao, Yuqiang; Xue, Bin; Yao, Shuchun

    2015-05-19

    To date no passive sampler has been used to predict bioavailability of contaminants to macrophytes. Here a novel passive sampler, linoleic acid embedded cellulose acetate membrane (LAECAM), was developed and used to in situ measure the freely dissolved concentrations of ten polycyclic aromatic hydrocarbons in the sediment porewaters and the water columns of two lakes in both winter and summer and predict their bioavailability to the shoots of resident submerged macrophytes (Potamogeton malainus, Myriophyllum spicata, Najas minor All., and Vallisneria natans (Lour.) Hara). PAH sampling by LAECAMs could reach equilibrium within 21 days. The influence of temperature on LAECAM-water partition coefficients was 0.0008-0.0116 log units/C. The method of LAECAM was comparable with the active sampling methods of liquid-liquid extraction combined with fDOC adjustment, centrifugation/solid-phase extraction (SPE), and filtration/SPE but had several advantages. After lipid normalization, concentrations of the PAHs in LAECAMs were not significantly different from those in the macrophytes. In contrast, concentrations of the PAHs in the triolein containing passive sampler (TECAM) deployed simultaneously with LAECAM were much higher. The results suggest that linoleic acid is more suitable than triolein as the model lipid for passive samplers to predict bioavailability of PAHs to submerged macrophytes. PMID:25877046

  20. Electrophoresis. [in microgravity environment

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1977-01-01

    Ground-based techniques for electrophoresis take account of the need either to circumvent the effects of gravity to prevent convection, or to use gravity for fluid stabilization through artificial density gradients. The microgravity environments of orbiting spacecraft provides a new alternative for electrophoresis by avoiding the need for either of these two approaches. The paper presents some theoretical considerations concerning electrophoresis, examines certain experimental techniques (zone and high density gel electrophoresis, isoelectric focusing and isotachophoresis), and examines the electrophoresis of living cells.

  1. Thallium acetate

    Integrated Risk Information System (IRIS)

    Jump to main content . Integrated Risk Information System Recent Additions | Contact Us Search : All EPA IRIS You are here : EPA Home Research Environmental Assessment IRIS IRIS Summaries Redirect Page As of September 30 , 2009 , the assessment summary for Thallium acetate is included in t

  2. Ammonium acetate

    Integrated Risk Information System (IRIS)

    Ammonium acetate ; CASRN 631 - 61 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  3. Phenylmercuric acetate

    Integrated Risk Information System (IRIS)

    Phenylmercuric acetate ; CASRN 62 - 38 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  4. Vinyl acetate

    Integrated Risk Information System (IRIS)

    Vinyl acetate ; CASRN 108 - 05 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  5. Ethyl acetate

    Integrated Risk Information System (IRIS)

    Ethyl acetate ; CASRN 141 - 78 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  6. Thallium acetate

    Integrated Risk Information System (IRIS)

    Jump to main content . Integrated Risk Information System Recent Additions | Contact Us Search : All EPA IRIS • You are here : EPA Home • Research • Environmental Assessment • IRIS • IRIS Summaries Redirect Page As of September 30 , 2009 , the assessment summary for Thallium acetate is included in t

  7. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1979-01-01

    A kidney cell electrophoresis technique is described in four parts: (1) the development and testing of electrophoresis solutions; (2) optimization of freezing and thawing; (3) procedures for evaluation of separated kidney cells; and (4) electrophoretic mobility characteristics of kidney cells.

  8. Protein electrophoresis - serum

    MedlinePLUS

    This lab test measures the types of protein in the fluid (serum) part of a blood sample. Other electrophoresis tests that measure proteins in the serum include: Immunoelectrophoresis Immunofixation Globulin electrophoresis

  9. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1980-01-01

    The following aspects of kidney cell electrophoresis are discussed: (1) the development and testing of electrophoresis solutions; (2) optimization of freezing and thawing; (3) procedures for evaluation of separated kidney cells; and (4) electrophoretic mobility characterization of kidney cells.

  10. An Economical Electrophoresis Apparatus

    ERIC Educational Resources Information Center

    Andrews, I. M.

    1975-01-01

    Describes the production of an electrophoresis apparatus from commonly discarded articles. Outlines paper and gel electrophoresis and its application to the separation of amino acids and intestinal enzymes. (GS)

  11. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P. W.

    1985-01-01

    Tasks were undertaken in support of two objectives. They are: (1) to carry out electrophoresis experiments on cells in microgravity; and (2) assess the feasibility of using purified kidney cells from embryonic kidney cultures as a source of important cell products. Investigations were carried out in the following areas: (1) ground based electrophoresis technology; (2) cell culture technology; (3) electrophoresis of cells; (4) urokinase assay research; (5) zero-g electrophoresis; and (6) flow cytometry.

  12. Combining blue native polyacrylamide gel electrophoresis with liquid chromatography tandem mass spectrometry as an effective strategy for analyzing potential membrane protein complexes of Mycobacterium bovis bacillus Calmette-Gurin

    PubMed Central

    2011-01-01

    Background Tuberculosis is an infectious bacterial disease in humans caused primarily by Mycobacterium tuberculosis, and infects one-third of the world's total population. Mycobacterium bovis bacillus Calmette-Gurin (BCG) vaccine has been widely used to prevent tuberculosis worldwide since 1921. Membrane proteins play important roles in various cellular processes, and the protein-protein interactions involved in these processes may provide further information about molecular organization and cellular pathways. However, membrane proteins are notoriously under-represented by traditional two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and little is known about mycobacterial membrane and membrane-associated protein complexes. Here we investigated M. bovis BCG by an alternative proteomic strategy coupling blue native PAGE to liquid chromatography tandem mass spectrometry (LC-MS/MS) to characterize potential protein-protein interactions in membrane fractions. Results Using this approach, we analyzed native molecular composition of protein complexes in BCG membrane fractions. As a result, 40 proteins (including 12 integral membrane proteins), which were organized in 9 different gel bands, were unambiguous identified. The proteins identified have been experimentally confirmed using 2-D SDS PAGE. We identified MmpL8 and four neighboring proteins that were involved in lipid transport complexes, and all subunits of ATP synthase complex in their monomeric states. Two phenolpthiocerol synthases and three arabinosyltransferases belonging to individual operons were obtained in different gel bands. Furthermore, two giant multifunctional enzymes, Pks7 and Pks8, and four mycobacterial Hsp family members were determined. Additionally, seven ribosomal proteins involved in polyribosome complex and two subunits of the succinate dehydrogenase complex were also found. Notablely, some proteins with high hydrophobicity or multiple transmembrane helixes were identified well in our work. Conclusions In this study, we utilized LC-MS/MS in combination with blue native PAGE to characterize modular components of multiprotein complexes in BCG membrane fractions. The results demonstrated that the proteomic strategy was a reliable and reproducible tool for analysis of BCG multiprotein complexes. The identification in our study may provide some evidence for further study of BCG protein interaction. PMID:21241518

  13. Kidney Cell Electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1985-01-01

    Materials and procedures for microgravity electrophoresis of living human embryonic kidney cells were evaluated, ground support in the form of analytical cell electrophoresis and flow cytometry was provided and cells returned from space flight were analyzed. Preflight culture media, electrophoresis buffer, fraction collection media, temperature profiles, and urokinase assay procedures were tested prior to flight. Electrophoretic mobility distributions of aliquots of the cell population to be fractionated in flight were obtained. The protocol established and utilized is given.

  14. Electrophoresis of biological materials

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The selection of biological products was studied for electrophoresis in space. Free flow electrophoresis, isoelectric focusing, and isotachophoresis are described. The candidates discussed include: immunoglobulins and gamma globulins; isolated islet of langerhans from pancreas; bone marrow; tumor cells; kidney cells, cryoprecipitate; and column separated cultures.

  15. Electrophoresis experiments for space

    NASA Astrophysics Data System (ADS)

    Snyder, Robert S.; Rhodes, Percy H.

    2000-01-01

    It has long been hoped that space could alleviate the problems of large-scale, high-capacity electrophoresis. Support media and reduced chamber dimensions of capillary electrophoresis have established the physical boundaries for Earth-based systems. Ideally, electrophoresis conducted in a virtual weightless environment in an unrestricted ``free'' fluid should have great potential. The electrophoresis and isoelectric focusing experiments done in the reduced gravity over the past twenty-five years have demonstrated the absence of thermal convection and sedimentation as well as the presence of electrohydrodynamics that requires careful control. One commercial venture produced gram amounts of an electrophoretically purified protein during seven Space Shuttle flights but the market disappeared in the six years between experiment conception and performance on the Space Shuttle. Our accumulated experience in microgravity plus theoretical models predict improvements that should be possible with electrophoresis if past problems are considered and both invention of new technologies and innovation of procedures on the Space Station are encouraged. .

  16. Preparative electrophoresis experiment design

    NASA Technical Reports Server (NTRS)

    Thiehler, A.

    1972-01-01

    A multifaceted study supporting the NASA programs to develop a space electrophoresis capability has been conducted. The study involved principally the technique of continuous free electrophoresis. It comprised a critical review of the art, study of new techniques for enhancing resolution and stability, and construction and initial testing of a high resolution cell. The effort resulted in a significant advance in free electrophoresis technique. It has provided also a much improved base for developments exploiting the added advantages of a zero-gravity environment.

  17. Electrophoresis operations in space

    NASA Technical Reports Server (NTRS)

    Richman, D. W.

    1982-01-01

    Application of electrophoresis in space processing is described. Spaceborne experiments in areas such as biological products and FDA approved drugs are discussed. These experiments will be carried on shuttle payloads.

  18. Sphingolipids contribute to acetic acid resistance in Zygosaccharomyces bailii.

    PubMed

    Lindahl, Lina; Genheden, Samuel; Eriksson, Leif A; Olsson, Lisbeth; Bettiga, Maurizio

    2016-04-01

    Lignocellulosic raw material plays a crucial role in the development of sustainable processes for the production of fuels and chemicals. Weak acids such as acetic acid and formic acid are troublesome inhibitors restricting efficient microbial conversion of the biomass to desired products. To improve our understanding of weak acid inhibition and to identify engineering strategies to reduce acetic acid toxicity, the highly acetic-acid-tolerant yeast Zygosaccharomyces bailii was studied. The impact of acetic acid membrane permeability on acetic acid tolerance in Z. bailii was investigated with particular focus on how the previously demonstrated high sphingolipid content in the plasma membrane influences acetic acid tolerance and membrane permeability. Through molecular dynamics simulations, we concluded that membranes with a high content of sphingolipids are thicker and more dense, increasing the free energy barrier for the permeation of acetic acid through the membrane. Z. bailii cultured with the drug myriocin, known to decrease cellular sphingo-lipid levels, exhibited significant growth inhibition in the presence of acetic acid, while growth in medium without acetic acid was unaffected by the myriocin addition. Furthermore, following an acetic acid pulse, the intracellular pH decreased more in myriocin-treated cells than in control cells. This indicates a higher inflow rate of acetic acid and confirms that the reduction in growth of cells cultured with myriocin in the medium with acetic acid was due to an increase in membrane permeability, thereby demonstrating the importance of a high fraction of sphingolipids in the membrane of Z. bailii to facilitate acetic acid resistance; a property potentially transferable to desired production organisms suffering from weak acid stress. Biotechnol. Bioeng. 2016;113: 744-753. © 2015 Wiley Periodicals, Inc. PMID:26416641

  19. Recent advances in preparative electrophoresis

    NASA Technical Reports Server (NTRS)

    Mosher, Richard A.; Thormann, Wolfgang; Egen, Ned B.; Couasnon, Pascal; Sammons, David W.

    1987-01-01

    Various approaches for preparative electrophoresis, and three new instruments for preparative electrophoresis are discussed. Consideration is given to isoelectric focusing, isotachophoresis, and zone electrophoresis, three gel-based electrophoresis methods. The design, functions, and performance of the Elphor VaP 21 device of Hannig (1982), the shear-stabilized BIOSTREAM separator of Thompson (1983), and the recycling isoelectric focusing device are described.

  20. Using capillary electrophoresis for failure analysis

    SciTech Connect

    Kelly, R.G.; Scully, H.S.; Stoner, G.E. . Center for Electrochemical Science and Engineering)

    1993-07-01

    Capillary electrophoresis (CE), an advanced solution analysis technique, can be used for failure analysis of corroded components. It has high sensitivity (concentrations as low as parts-per-trillion) and can detect quantitatively a large number of ionic species. CE determined the vapor-phase attack by organic acids, mainly acetic acid, on an electrical equipment enclosure. These acids most likely originated from the seasoning of the oak pallets used to transport the manufactured items, accumulating inside the shrink-wrap film used to bind packages to the pallet.

  1. Capillary electrophoresis-mass spectrometry of carbohydrates

    PubMed Central

    Zaia, Joseph

    2014-01-01

    The development of methods for capillary electrophoresis (CE) with on-line mass spectrometric detection (CE/MS) is driven by the need for accurate, robust and sensitive glycomics analysis for basic biomedicine, biomarker discovery, and analysis of recombinant protein therapeutics. One important capability is to profile glycan mixtures with respect to the patterns of substituents including sialic acids, acetate, sulfate, phosphate, and other groups. There is additional need for an MS-compatible separation system capable of resolving carbohydrate isomers. This review summarizes applications of CS/MS to analysis of carbohydrates, glycoproteins and glycopeptides that have appeared since 2008. Readers are referred to recent comprehensive reviews covering earlier publications. PMID:23386333

  2. In-gel digestion of proteins for internal sequence analysis after one- or two-dimensional gel electrophoresis.

    PubMed

    Rosenfeld, J; Capdevielle, J; Guillemot, J C; Ferrara, P

    1992-05-15

    We examined the different steps necessary for the enzymatic digestion of proteins in the polyacrylamide matrix after gel electrophoresis. As a result, we developed an improved method for obtaining peptides for internal sequence analysis from 1-2 micrograms of in-gel-digested proteins. The long washing-lyophilization-equilibration steps necessary to eliminate the dye, sodium dodecyl sulfate, and other gel-associated contaminants that perturb protein digestion in Coomassie blue-stained gels have been replaced by washing for 40 min with 50% acetonitrile, drying for 10 min at room temperature, and then rehydrating with a protease solution. The washing and drying steps result in a substantial reduction of the gel slice volume that, when next swollen in the protease solution, readily absorbs the enzyme, facilitating digestion. The Coomassie blue staining procedure has also been modified by reducing acetic acid and methanol concentrations in the staining solution and by eliminating acetic acid in the destaining solution. The peptides resulting from the in-gel digestion are easily recovered by passive elution, in excellent yields for structural characterization. This simple and rapid method has been successfully applied for the internal sequence analysis of membrane proteins from the rat mitochondria resolved in preparative two-dimensional gel electrophoresis. PMID:1524213

  3. Electrophoresis in space.

    PubMed

    Bauer, J; Hymer, W C; Morrison, D R; Kobayashi, H; Seaman, G V; Weber, G

    1999-01-01

    Programs for free flow electrophoresis in microgravity over the past 25 years are reviewed. Several studies accomplished during 20 spaceflight missions have demonstrated that sample throughput is significantly higher in microgravity than on the ground. Some studies have shown that resolution is also increased. However, many cell separation trials have fallen victim to difficulties associated with experimenting in the microgravity environment such as microbial contamination, air bubbles in electrophoresis chambers, and inadequate facilities for maintaining cells before and after separation. Recent studies suggest that the charge density of cells at their surface may also be modified in microgravity. If this result is confirmed, a further cellular mechanism of "sensing" the low gravity environment will have been found. Several free fluid electrophoresis devices are now available. Most have been tried at least once in microgravity. Newer units not yet tested in spaceflight have been designed to accommodate problems associated with space processing. The USCEPS device and the Japanese FFEU device are specifically designed for sterile operations, whereas the Octopus device is designed to reduce electroosmotic and electrohydrodynamic effects, which become dominant and detrimental in microgravity. Some of these devices will also separate proteins by zone electrophoresis, isotachophoresis, or isoelectric focusing in a single unit. Separation experiments with standard test particles are useful and necessary for testing and optimizing new space hardware. A cohesive free fluid electrophoresis program in the future will obviously require (1) flight opportunities and funding, (2) identification of suitable cellular and macromolecular candidate samples, and (3) provision of a proper interface of electrophoresis processing equipment with biotechnological facilities--equipment like bioreactors and protein crystal growth chambers. The authors feel that such capabilities will lead to the production of commercially useful quantities of target products and to an accumulation of new knowledge relating to the complexities of electrostatic phenomena at the cell surface. PMID:10660776

  4. Pulse Field Gel Electrophoresis.

    PubMed

    Sharma-Kuinkel, Batu K; Rude, Thomas H; Fowler, Vance G

    2016-01-01

    Pulse Field Gel Electrophoresis (PFGE) is a powerful genotyping technique used for the separation of large DNA molecules (entire genomic DNA) after digesting it with unique restriction enzymes and applying to a gel matrix under the electric field that periodically changes direction. PFGE is a variation of agarose gel electrophoresis that permits analysis of bacterial DNA fragments over an order of magnitude larger than that with conventional restriction enzyme analysis. It provides a good representation of the entire bacterial chromosome in a single gel with a highly reproducible restriction profile, providing clearly distinct and well-resolved DNA fragments. PMID:25682374

  5. Fraction collector for electrophoresis

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1977-01-01

    Rotating-tube electrophoresis apparatus employs rotating jet of eluting buffer to reduce effects of convection during separation. Designed for separation of microorganisms and biological species, system combines gravity/gradient compensating of lumen with buffer flush at fraction outlet to increase separation efficiency.

  6. DNA ELECTROPHORESIS AT SURFACES

    SciTech Connect

    RAFAILOVICH, MIRIAM; SOKOLOV, JONATHAN; GERSAPPE, DILIP

    2003-09-01

    During this year we performed two major projects: I. We developed a detailed theoretical model which complements our experiments on surface DNA electrophoresis. We found that it was possible to enhance the separation of DNA chains by imposing a chemical nanoscale pattern on the surface. This approach utilized the surface interaction effect of the DNA chains with the substrate and is a refinement to our previous method in which DNA chains were separated on homogeneous flat surfaces. By introducing the nano-patterns on the surface, the conformational changes of DNA chains of different lengths can be amplified, which results in the different friction strengths with the substrate surface. Our results also show that, when compared to the DNA electrophoresis performed on homogeneous flat surfaces, nanopatterned surfaces offer a larger window in choosing different surface interactions to achieve separation. II. In collaboration with a large international manufacturer of skin care products we also embarked on a project involving photo toxicity of titanium dioxide nanoparticles, which are a key ingredient in sunscreen and cosmetic lotions. The results clearly implicated the nanoparticles in catalyzing damage to chromosomal DNA. We then used this knowledge to develop a polymer/anti-oxidant coating which prevented the photocatalytic reaction on DNA while still retaining the UV absorptive properties of the nanoparticles. The standard gel electrophoresis was not sufficient in determining the extent of the DNA damage. The conclusions of this study were based predominantly on analysis obtained with the surface electrophoresis method.

  7. Ultra-trace determination of lead(II) in water using electrothermal atomic absorption spectrometry after preconcentration by solid-phase extraction to a small piece of cellulose acetate type membrane filter.

    PubMed

    Mizuguchi, Hitoshi; Ishida, Mirai; Takahashi, Tomohiro; Sasaki, Atsushi; Shida, Junichi

    2011-01-01

    A simple and inexpensive preconcentration technique has been developed for the ultra-trace determination of lead(II) using electrothermal atomic absorption spectrometry (ETAAS). The lead(II) complex with dicyclohexano-18-crown 6-ether (DC18C6) was extracted to a small piece of cellulose acetate-type membrane filter (2 5 mm) merely by vigorously eccentric stirring for 120 min under the coexistence of sodium dodecyl sulfate (SDS) at around pH 7. The extraction medium was inserted into a graphite cuvette for the determination of lead(II) by ETAAS. A linear relation was obtained for the range of 0.1-5.0 ng in 10 ml of lead(II) standard solution (r = 0.998). The detection limit was found to be 0.03 ng of lead(II) in 10 ml (0.003 g l(-1)) of water sample. The proposed method was applied to the ultra-trace determination of lead(II) in river water, underground water, tap water, and snow fall samples. PMID:21233566

  8. Automatic multiple-sample applicator and electrophoresis apparatus

    NASA Technical Reports Server (NTRS)

    Grunbaum, B. W. (Inventor)

    1977-01-01

    An apparatus for performing electrophoresis and a multiple-sample applicator is described. Electrophoresis is a physical process in which electrically charged molecules and colloidal particles, upon the application of a dc current, migrate along a gel or a membrane that is wetted with an electrolyte. A multiple-sample applicator is provided which coacts with a novel tank cover to permit an operator either to depress a single button, thus causing multiple samples to be deposited on the gel or on the membrane simultaneously, or to depress one or more sample applicators separately by means of a separate button for each applicator.

  9. Happy bicentennial, electrophoresis!

    PubMed

    Righetti, Pier Giorgio

    2009-12-01

    A short survey of electrophoresis and a celebration of its bicentennial, with some remarkable mementos and a list of books that shaped the field. Where one also learns of a secret production plant with a huge-scale electrophoretic apparatus for skimming of latex from Hevea brasiliensis and keeping the wheels of the Ally Army running during World War II. And of cyber (mammoth) 2D gels of 1.5 x 1 m in size accommodating >12,000 spots. PMID:19938305

  10. Preparative electrophoresis for space

    NASA Technical Reports Server (NTRS)

    Rhodes, Percy H.; Snyder, Robert S.

    1987-01-01

    A premise of continuous flow electrophoresis is that removal of buoyancy-induced thermal convection caused by axial and lateral temperature gradients results in ideal performance of these instruments in space. Although these gravity dependent phenomena disturb the rectilinear flow in the separation chamber when high voltage gradients or thick chambers are used, distortion of the injected sample stream due to electrohydrodynamic effects cause major broadening of the separated bands. The electrophoresis separation process is simple, however flow local to the sample filament produced by the applied electric field have not been considered. These electrohydrodynamic flows distort the sample stream and limit the separation. Also, electroosmosis and viscous flow combine to further distort the process. A moving wall concept is being proposed for space which will eliminate and control the disturbances. The moving wall entrains the fluid to move as a rigid body and produces a constant residence time for all samples distributed across the chamber thickness. The moving wall electrophoresis chamber can only be operated in space because there is no viscous flow in the chamber to stabilize against thermal convection.

  11. Preparative electrophoresis for space

    NASA Technical Reports Server (NTRS)

    Rhodes, Percy H.; Snyder, Robert S.

    1988-01-01

    A premise of continuous flow electrophoresis is that removal of buoyance-induced thermal convection caused by axial and lateral temperature gradients results in ideal performance of these instruments in space. Although these gravity dependent phenomena disturb the rectilinear flow in the separation chamber when high voltage gradients or thick chamber are used, distortion of the injected sample stream due to electrodynamic effects cause major broadening of the separated bands. The electrophoresis separation process is simple, however flow local to the sample filament produced by the applied electric field were not considered. These electrohydrodynamic flows distort the sample stream and limit the separation. Also, electroosmosis and viscous flow combine to further distort the process. A moving wall concept is being proposed for space which will eliminate and control the disturbances. The moving wall entrains the fluid to move as a rigid body and produces a constant residence time for all samples distributed across the chamber thickness. The moving wall electrophoresis chamber can only be operated in space because there is no viscous flow in the chamber to stabilize against thermal convection.

  12. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, E.S.; Chang, H.T.; Fung, E.N.; Li, Q.; Lu, X.

    1996-12-10

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.

  13. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, E.S.; Li, Q.; Lu, X.

    1998-04-21

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.

  14. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, Edward S. (Ames, IA); Chang, Huan-Tsang (Silver Spring, MD); Fung, Eliza N. (Ames, IA); Li, Qingbo (Ames, IA); Lu, Xiandan (Ames, IA)

    1996-12-10

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.

  15. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, Edward S. (Ames, IA); Li, Qingbo (Ames, IA); Lu, Xiandan (Ames, IA)

    1998-04-21

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.

  16. Temperature effects on electrophoresis.

    PubMed

    Rogacs, Anita; Santiago, Juan G

    2013-05-21

    We present a model capturing the important contributors to the effects of temperature on the observable electrophoretic mobilities of small ions, and on solution conductivity and pH. Our temperature model includes relations for temperature-dependent viscosity, ionic strength corrections, degree of ionization (pK), and ion solvation effects on mobility. We incorporate thermophysical data for water viscosity, temperature-dependence of the Onsager-Fuoss model for finite ionic strength effects on mobility, temperature-dependence of the extended Debye-Huckel theory for correction of ionic activity, the Clarke-Glew approach and tabulated thermodynamic quantities of ionization reaction for acid dissociation constants as a function of temperature, and species-specific, empirically evaluated correction terms for temperature-dependence of Stokes' radii. We incorporated our model into a MATLAB-based simulation tool we named Simulation of Temperature Effects on ElectroPhoresis (STEEP). We validated our model using conductivity and pH measurements across a temperature variation of 25-70 °C for a set of electrolytes routinely used in electrophoresis. The model accurately captures electrolyte solution pH and conductivity, including important effects not captured by simple Walden-type relations. PMID:23627294

  17. Possibility of Microchip Electrophoresis for Biological Application

    NASA Astrophysics Data System (ADS)

    Kataoka, Masatoshi; Kido, Jun-Ichi; Shinohara, Yasuo

    Microchip electrophoresis has recently attracted much attention in the field of nuclear acid analysis due to its high efficiency, ease of operation, low consumption of samples and reagents, and relatively low costs. Nucleic acid fragments are separated by capillary electrophoresis in a chip with microfabricated channels, with automated detection as well as on-line data evaluation. Microfabricated devices are forecast to be fundamental to the postgenome era, especially in the field of genetics and medicine. However, although there are many reports of the use of these instruments to evaluate standard DNA, DNA ladders, PCR products, and commercially available plasmid digests, little information is available their use with biological material. In this report, we showed the accuracy of sizing and quantification of endonuclease-digested plasmid DNA. We also showed the feasibility of on-microchip endonuclease treatment of plasmid DNA and sequential analysis as an additional application for DNA analysis. Furthermore, to evaluate the possibility of microchip electrophoresis for biological application, the results of the examination of blood sugar in human plasma and mitochondrial membrane potential were shown.

  18. Preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles (Kingsport, TN); Zoeller, Joseph Robert (Kingsport, TN); Depew, Leslie Sharon (Kingsport, TN)

    1998-01-01

    This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

  19. Preparation of vinyl acetate

    DOEpatents

    Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

    1998-03-24

    This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

  20. Electrophoresis experiment for space

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; Micale, F. J.

    1976-01-01

    The Apollo 16 electrophoresis experiment was analyzed, demonstrating that the separation of the two different-size monodisperse latexes did indeed take place, but that the separation was obscured by the pronounced electroosmotic flow of the liquid medium. The results of this experiment, however, were dramatic since it is impossible to carry out a similar separation on earth. It can be stated unequivocally from this experiment that any electrophoretic separation will be enhanced under microgravity conditions. The only question is the degree of this enhancement, which can be expected to vary from one experimental technique to another. The low-electroosmotic-mobility coating (Z6040-MC) developed under this program was found to be suitable for a free-fluid electrophoretic separation such as the experiment designed for the ASTP flight. The problem with this coating, however, is that its permanency is limited because of the slow desorption of the methylcellulose from the coated surface.

  1. Static continuous electrophoresis device

    NASA Technical Reports Server (NTRS)

    Rhodes, P. H. (inventor)

    1982-01-01

    An apparatus is disclosed for carrying out a moving wall type electrophoresis process for separation of cellular particles. The apparatus includes a water-tight housing containing an electrolytic buffer solution. A separation chamber in the housing is defined by spaced opposed moving walls and spaced opposed side walls. Substrate assemblies, which support the moving wall include vacuum ports for positively sealing the moving walls against the substrate walls. Several suction conduits communicate with the suction ports and are arranged in the form of valleys in a grid plate. The raised land portion of the grid plat supports the substrate walls against deformation inwardly under suction. A cooling chamber is carried on the back side of plate. The apparatus also has tensioner means including roller and adjustment screws for maintaining the belts in position and a drive arrangement including an electric motor with a gear affixed to its output shaft. Electrode assemblies are disposed to provide the required electric field.

  2. Electrophoresis demonstration on Apollo 16

    NASA Technical Reports Server (NTRS)

    Snyder, R. S.

    1972-01-01

    Free fluid electrophoresis, a process used to separate particulate species according to surface charge, size, or shape was suggested as a promising technique to utilize the near zero gravity condition of space. Fluid electrophoresis on earth is disturbed by gravity-induced thermal convection and sedimentation. An apparatus was developed to demonstrate the principle and possible problems of electrophoresis on Apollo 14 and the separation boundary between red and blue dye was photographed in space. The basic operating elements of the Apollo 14 unit were used for a second flight demonstration on Apollo 16. Polystyrene latex particles of two different sizes were used to simulate the electrophoresis of large biological particles. The particle bands in space were extremely stable compared to ground operation because convection in the fluid was negligible. Electrophoresis of the polystyrene latex particle groups according to size was accomplished although electro-osmosis in the flight apparatus prevented the clear separation of two particle bands.

  3. Kidney cell electrophoresis, continuing task

    NASA Technical Reports Server (NTRS)

    Todd, P. W.

    1985-01-01

    Materials and procedures for microgravity electrophoresis of living human embryonic kidney cells were evaluated to provide ground support in the form of analytical cell electrophoresis and flow cytometry. Preflight culture media, electrophoresis buffer, fraction collection media, temperature profiles, and urokinase assay procedures were tested prior to flight. Electrophoretic mobility distributions of aliquots of the cell population to be fractionated in flight were obtained. Cells were prepared in suspension prior to flight in electrophoresis buffer and 10% calf serum. Electrophoretic separation proceeded in electrophoresis buffer without serum in the Continuous Flow Electrophoretic Separator, and fractions were collected into sample bags containing culture medium and concentrated serum. Fractions that yielded enough progeny cells were analyzed for morphology and electrophoretic mobility distributions. It is noted that the lowest mobility fraction studied produced higher mobility progeny while the other fractions produced progeny cells with mobilities related to the fractions from which they were collected.

  4. Diagnostic use of an analysis of urinary proteins by a practicable sodium dodecyl sulfate-electrophoresis method and rapid two-dimensional electrophoresis.

    PubMed

    Lapin, A; Gabl, F; Kopsa, H

    1989-01-01

    Two methods suitable for routine clinical analyses of urinary proteins are presented and compared. The first is a horizontal sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique, suitable for simultaneous analysis of 20 native urinary samples. This method uses polyacrylamide gradient gels, prepared with a laboratory-built gel casting device. The second method is a rapid two-dimensional electrophoresis procedure, combining cellulose acetate electrophoresis and sodium dodecyl sulfate-electrophoresis. The first step uses a routine system (Chemetron), the second separation step followed by staining with Coomassie Brilliant Blue R is performed on the PhastSystem. The resulting two-dimensional patterns reveal urinary proteins distributed according to the 5-zone pattern of native proteins (albumin, alpha-1, alpha-2, beta, gamma-globulin) as well as to the logarithm of their molecular weights. Examples of (routine) diagnoses with a special interest in the monitoring of kidney transplant patients are shown. PMID:2806208

  5. Surface Charge Measurement of SonoVue, Definity and Optison: A Comparison of Laser Doppler Electrophoresis and Micro-Electrophoresis.

    PubMed

    Ja'afar, Fairuzeta; Leow, Chee Hau; Garbin, Valeria; Sennoga, Charles A; Tang, Meng-Xing; Seddon, John M

    2015-11-01

    Microbubble (MB) contrast-enhanced ultrasonography is a promising tool for targeted molecular imaging. It is important to determine the MB surface charge accurately as it affects the MB interactions with cell membranes. In this article, we report the surface charge measurement of SonoVue, Definity and Optison. We compare the performance of the widely used laser Doppler electrophoresis with an in-house micro-electrophoresis system. By optically tracking MB electrophoretic velocity in a microchannel, we determined the zeta potentials of MB samples. Using micro-electrophoresis, we obtained zeta potential values for SonoVue, Definity and Optison of -28.3, -4.2 and -9.5 mV, with relative standard deviations of 5%, 48% and 8%, respectively. In comparison, laser Doppler electrophoresis gave -8.7, +0.7 and +15.8 mV with relative standard deviations of 330%, 29,000% and 130%, respectively. We found that the reliability of laser Doppler electrophoresis is compromised by MB buoyancy. Micro-electrophoresis determined zeta potential values with a 10-fold improvement in relative standard deviation. PMID:26318559

  6. Binary Oscillatory Crossflow Electrophoresis

    NASA Technical Reports Server (NTRS)

    Molloy, Richard F.; Gallagher, Christopher T.; Leighton, David T., Jr.

    1997-01-01

    Electrophoresis has long been recognized as an effective analytic technique for the separation of proteins and other charged species, however attempts at scaling up to accommodate commercial volumes have met with limited success. In this report we describe a novel electrophoretic separation technique - Binary Oscillatory Crossflow Electrophoresis (BOCE). Numerical simulations indicate that the technique has the potential for preparative scale throughputs with high resolution, while simultaneously avoiding many problems common to conventional electrophoresis. The technique utilizes the interaction of an oscillatory electric field and a transverse oscillatory shear flow to create an active binary filter for the separation of charged protein species. An oscillatory electric field is applied across the narrow gap of a rectangular channel inducing a periodic motion of charged protein species. The amplitude of this motion depends on the dimensionless electrophoretic mobility, alpha = E(sub o)mu/(omega)d, where E(sub o) is the amplitude of the electric field oscillations, mu is the dimensional mobility, omega is the angular frequency of oscillation and d is the channel gap width. An oscillatory shear flow is induced along the length of the channel resulting in the separation of species with different mobilities. We present a model that predicts the oscillatory behavior of charged species and allows estimation of both the magnitude of the induced convective velocity and the effective diffusivity as a function of a in infinitely long channels. Numerical results indicate that in addition to the mobility dependence, the steady state behavior of solute species may be strongly affected by oscillating fluid into and out of the active electric field region at the ends of the cell. The effect is most pronounced using time dependent shear flows of the same frequency (cos((omega)t)) flow mode) as the electric field oscillations. Under such conditions, experiments indicate that solute is drawn into the cell from reservoirs at both ends of the cell leading to a large mass build up. As a consequence, any initially induced mass flux will vanish after short times. This effect was not captured by the infinite channel model and hence numerical and experimental results deviated significantly. The revised model including finite cell lengths and reservoir volumes allowed quantitative predictions of the time history of the concentration profile throughout the system. This latter model accurately describes the fluxes observed for both oscillatory flow modes in experiments using single protein species. Based on the results obtained from research funded under NASA grant NAG-8-1080.S, we conclude that binary separations are not possible using purely oscillatory flow modes because of end effects associated with the cos((omega)t) mode. Our research shows, however, that a combination of cos(2(omega)t) and steady flow should lead to efficient separation free of end effects. This possibility is currently under investigation.

  7. The Acetate Switch

    PubMed Central

    Wolfe, Alan J.

    2005-01-01

    To succeed, many cells must alternate between life-styles that permit rapid growth in the presence of abundant nutrients and ones that enhance survival in the absence of those nutrients. One such change in life-style, the “acetate switch,” occurs as cells deplete their environment of acetate-producing carbon sources and begin to rely on their ability to scavenge for acetate. This review explains why, when, and how cells excrete or dissimilate acetate. The central components of the “switch” (phosphotransacetylase [PTA], acetate kinase [ACK], and AMP-forming acetyl coenzyme A synthetase [AMP-ACS]) and the behavior of cells that lack these components are introduced. Acetyl phosphate (acetyl∼P), the high-energy intermediate of acetate dissimilation, is discussed, and conditions that influence its intracellular concentration are described. Evidence is provided that acetyl∼P influences cellular processes from organelle biogenesis to cell cycle regulation and from biofilm development to pathogenesis. The merits of each mechanism proposed to explain the interaction of acetyl∼P with two-component signal transduction pathways are addressed. A short list of enzymes that generate acetyl∼P by PTA-ACKA-independent mechanisms is introduced and discussed briefly. Attention is then directed to the mechanisms used by cells to “flip the switch,” the induction and activation of the acetate-scavenging AMP-ACS. First, evidence is presented that nucleoid proteins orchestrate a progression of distinct nucleoprotein complexes to ensure proper transcription of its gene. Next, the way in which cells regulate AMP-ACS activity through reversible acetylation is described. Finally, the “acetate switch” as it exists in selected eubacteria, archaea, and eukaryotes, including humans, is described. PMID:15755952

  8. Electrophoresis of Ferroelectric Nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, Xiya; Davidovic, Dragomir

    2006-03-01

    We have studied the electrophoresis of ferroelectric nanoparticles(Ba1-xSrxTiO3). We used de-ionized (DI) water as solvent and an optical microscope to observe the motion of suspended ferroelectric nanoparticles driven by AC electric fields. The immediate start and stop of motion were noticed when the driving electric field was turned on and off, which was similar to dielectricphoresis. Higher voltage generated higher speed as expected. In some instances, the dielectric constant ɛ of ferroelectric materials can increase greatly, which makes it possible that a low driving voltage (no larger than 10V) could induce a relatively high speed. At room temperature, we studied the frequency dependence of the motion speed. By comparing a serial of captured motion movies, we found that higher speeds were corresponding to lower frequencies of driving AC electric field. Further, we use well defined electrodes made by electron-beam lithography and high-vacuum deposition, which may regulate the electric field distribution. Consequently, we can characterize the electric force applied on those nanoparticles.

  9. Biomedical applications of capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Kartsova, L. A.; Bessonova, E. A.

    2015-08-01

    The review deals with modern analytical approaches used in capillary electrophoresis for solving medical and biological problems: search for biomarkers of various diseases and rapid diagnosis based on characteristic profiles of biologically active compounds by capillary electrophoresis with mass spectrometric detection; monitoring of the residual drugs in biological fluids for evaluating the efficiency of drug therapy; testing of the enantiomeric purity of pharmaceutical products; the use of novel materials as components of stationary and pseudo-stationary phases in capillary electrophoresis and capillary electrochromatography to increase the selectivity of separation of components of complex matrices; and identification of various on-line preconcentration techniques to reduce the detection limits of biologically active analytes. A topical trend in capillary electrophoresis required in clinical practice, viz., the design of microfluidic systems, is discussed. The bibliography includes 173 references.

  10. Copolymers For Capillary Gel Electrophoresis

    SciTech Connect

    Liu, Changsheng; Li, Qingbo

    2005-08-09

    This invention relates to an electrophoresis separation medium having a gel matrix of at least one random, linear copolymer comprising a primary comonomer and at least one secondary comonomer, wherein the comonomers are randomly distributed along the copolymer chain. The primary comonomer is an acrylamide or an acrylamide derivative that provides the primary physical, chemical, and sieving properties of the gel matrix. The at least one secondary comonomer imparts an inherent physical, chemical, or sieving property to the copolymer chain. The primary and secondary comonomers are present in a ratio sufficient to induce desired properties that optimize electrophoresis performance. The invention also relates to a method of separating a mixture of biological molecules using this gel matrix, a method of preparing the novel electrophoresis separation medium, and a capillary tube filled with the electrophoresis separation medium.

  11. Electrophoresis for Under Five Dollars.

    ERIC Educational Resources Information Center

    Lumetta, Vincent J.; Doktycz, Mitchel J.

    1994-01-01

    Equipped with a little more than batteries, food-dye, and sieving media, teachers can demonstrate an essential process used in biochemical research. An activity is provided to aid in helping students to understand electrophoresis. (ZWH)

  12. DNA typing by capillary electrophoresis

    SciTech Connect

    Zhang, N.

    1997-10-08

    Capillary electrophoresis is becoming more and more important in nucleic acid analysis including DNA sequencing, typing and disease gene measurements. This work summarized the background of DNA typing. The recent development of capillary electrophoresis was also discussed. The second part of the thesis showed the principle of DNA typing based on using the allelic ladder as the absolute standard ladder in capillary electrophoresis system. Future work will be focused on demonstrating DNA typing on multiplex loci and examples of disease diagnosis in the on-line format of PCR-CE. Also capillary array electrophoresis system should allow high throughput, fast speed DNA typing. Only the introduction and conclusions for this report are available here. A reprint was removed for separate processing.

  13. Automated dual capillary electrophoresis system with hydrodynamic injection for the concurrent determination of cations and anions.

    PubMed

    Pham, Thi Thanh Thuy; Mai, Thanh Duc; Nguyen, Thanh Dam; Siz, Jorge; Pham, Hung Viet; Hauser, Peter C

    2014-09-01

    The capillary electrophoresis instrument developed for the concurrent determination of cations and anions features two separate capillaries and individual detectors to allow independent optimization for each group of ions. The capillaries are joined in a common injector block. The sample is drawn into the injector with a small membrane pump and automated simultaneous injection into both capillaries is achieved by pressurization of the fluid with compressed air. Flushing of the injector and of the capillaries with the background electrolyte is also carried out automatically by the same means. The buffer consisted of 12mM histidine and 2mM 18-crown-6 adjusted to pH 4 with acetic acid and was suitable for the contactless conductivity detection employed. The system was optimized for the determination of cationic NH4(+) and anionic NO3(-) and NO2(-), and linear calibration curves from about 20?M up to about 1.5mM were obtained for these ions. In a test run over 8h, the reproducibility for the peak areas was within 7%. For demonstration, the instrument was successfully applied to the concurrent monitoring of the concentrations of the three ions during the biological removal of ammonium from contaminated groundwater in a sequencing batch reactor, where NO3(-) and NO2(-) are formed as intermediate products. PMID:25109864

  14. Antibody enhancement of free-flow electrophoresis

    NASA Technical Reports Server (NTRS)

    Cohly, H. H. P.; Morrison, Dennis R.; Atassi, M. Zouhair

    1988-01-01

    Specific T cell clones and antibodies (ABs) were developed to study the efficiency of purifying closely associated T cells using Continuous Flow Electrophoresis System. Enhanced separation is accomplished by tagging cells first with ABs directed against the antigenic determinants on the cell surface and then with ABs against the Fc portion of the first AB. This second AB protrudes sufficiently beyond the cell membrane and glycocalyx to become the major overall cell surface potential determinant and thus causes a reduction of electrophoretic mobility. This project was divided into three phases. Phase one included development of specific T cell clones and separation of these specific clones. Phase two extends these principles to the separation of T cells from spleen cells and immunized lymph node cells. Phase three applies this double antibody technique to the separation of T cytotoxic cells from bone marrow.

  15. Electrophoresis as a management tool

    USGS Publications Warehouse

    Morgan, R.P., II; Chapman, J.A.; Noe, L.A.; Henny, C.J.

    1974-01-01

    The theme of this 1974 Northeast Fish and Wildlife Conference is 'A New Era'. Indeed, it is a new era for improved techniques to assist in management of our fish and wildlife resources for the maximum benefit of all. In some cases, the new techniques are primarily used in research.on fish and wildlife, and the results from the research are used to aid management and enforcement agencies in the decision-making process. One of the newer techniques that is being applied to problems in fisheries and wildlife is electrophoresis. In this paper, we review briefly the techniques of electrophoresis and illustrate research problems in wildlife and fisheries where the use of electrophoresis is now assisting or may potentially aid in management decisions.

  16. PNEUMATIC MICROVALVE FOR ELECTROKINETIC SAMPLE PRECONCENTRATION AND CAPILLARY ELECTROPHORESIS INJECTION

    SciTech Connect

    Cong, Yongzheng; Rausch, Sarah J.; Geng, Tao; Jambovane, Sachin R.; Kelly, Ryan T.

    2014-10-27

    Here we show that a closed pneumatic microvalve on a PDMS chip can serve as a semipermeable membrane under an applied potential, enabling current to pass through while blocking the passage of charged analytes. Enrichment of both anionic and cationic species has been demonstrated, and concentration factors of ~70 have been achieved in just 8 s. Once analytes are concentrated, the valve is briefly opened and the sample is hydrodynamically injected onto an integrated microchip or capillary electrophoresis (CE) column. In contrast to existing preconcentration approaches, the membrane-based method described here enables both rapid analyte concentration as well as high resolution separations.

  17. Contactless conductivity detector for microchip capillary electrophoresis

    NASA Technical Reports Server (NTRS)

    Pumera, Martin; Wang, Joseph; Opekar, Frantisek; Jelinek, Ivan; Feldman, Jason; Lowe, Holger; Hardt, Steffen; Svehla, D. (Principal Investigator)

    2002-01-01

    A microfabricated electrophoresis chip with an integrated contactless conductivity detection system is described. The new contactless conductivity microchip detector is based on placing two planar sensing aluminum film electrodes on the outer side of a poly(methyl methacrylate) (PMMA) microchip (without contacting the solution) and measuring the impedance of the solution in the separation channel. The contactless route obviates problems (e.g., fouling, unwanted reactions) associated with the electrode-solution contact, offers isolation of the detection system from high separation fields, does not compromise the separation efficiency, and greatly simplifies the detector fabrication. Relevant experimental variables, such as the frequency and amplitude of the applied ac voltage or the separation voltage, were examined and optimized. The detector performance was illustrated by the separation of potassium, sodium, barium, and lithium cations and the chloride, sulfate, fluoride, acetate, and phosphate anions. The response was linear (over the 20 microM-7 mM range) and reproducible (RSD = 3.4-4.9%; n = 10), with detection limits of 2.8 and 6.4 microM (for potassium and chloride, respectively). The advantages associated with the contactless conductivity detection, along with the low cost of the integrated PMMA chip/detection system, should enhance the power and scope of microfluidic analytical devices.

  18. Fragrance material review on 2-phenylpropyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-phenylpropyl acetate when used as a fragrance ingredient is presented. 2-Phenylpropyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-phenylpropyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22421639

  19. Fragrance material review on piperonyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of piperonyl acetate when used as a fragrance ingredient is presented. Piperonyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for piperonyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, toxicokinetics, and genotoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22445840

  20. Fragrance material review on phenethyl acetate.

    PubMed

    McGinty, D; Vitale, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of phenethyl acetate when used as a fragrance ingredient is presented. Phenethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for phenethyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, toxicokinetics, repeated dose, genotoxicity, and carcinogenicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414644

  1. Electrophoretic Characterization of a Detergent-Treated Plasma Membrane Fraction from Corn Roots 1

    PubMed Central

    Gallagher, Sean R.; Leonard, Robert T.

    1987-01-01

    Experiments were conducted to determine conditions essential for electrophoretic characterization of a detergent-extracted plasma membrane fraction from corn (Zea mays L.) roots. Sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) initially gave poor resolution of polypeptides in the plasma membrane fraction and, upon detergent treatment for purification of the proton-pumping adenosine triphosphatase (ATPase), showed no enrichment for a 100 kilodalton catalytic subunit characteristic of the ATPase. In contrast to SDS-PAGE, phenol urea acetic acid (PAU)-PAGE clearly resolved two polypeptides in the 100 kilodalton region that were enriched during detergent treatment and indicated at least one polypeptide forms a phosphorylated intermediate characteristic of the ATPase. Problems with SDS-PAGE were found to be caused, in part, by a combination of endogenous proteases and heat-induced aggregation of high molecular weight proteins. The usually standard procedure of boiling the sample prior to SDS-PAGE caused the aggregation of the 100 kilodalton polypeptides. By controlling for proteases using chymostatin and/or phenylmethane sulfonyl floride, and not boiling the sample prior to electrophoresis, two polypeptides were clearly resolved by SDS-PAGE in the 100 kilodalton region of Triton X-114-extracted membranes from corn, oat, barley, and tomato. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:16665234

  2. Kallolide A acetate pyrazoline

    PubMed Central

    Rodrguez-Escudero, Idaliz; Marrero, Jeffrey; Rodrguez, Abimael D.

    2012-01-01

    In the crystal structure of kallolide A acetate pyrazoline [systematic name: 7-methyl-16-oxo-4,10-bis(prop-1-en-2-yl)-17,18-dioxa-14,15-diazatetracyclo[9.4.2.16,9.01,12]octadeca-6,8,14-trien-5-yl acetate], C23H28N2O5, there is a 12-membered carbon macrocyclic structure. In addition, there is a trisubstituted furan ring, an approximately planar ?-lactone ring [maximum deviation of 0.057?(3)?] and a pyrazoline ring, the latter in an envelope conformation. The pyrazoline and the ?-lactone rings are fused in a cis configuration. In the crystal, molecules are linked by weak CH?O interactions, forming a two-dimensional network parallel to (001). An intramolecular CH?O hydrogen bond is also present. PMID:22259545

  3. Acetate Dependence of Tumors

    PubMed Central

    Comerford, Sarah A.; Huang, Zhiguang; Du, Xinlin; Wang, Yun; Cai, Ling; Witkiewicz, Agnes; Walters, Holly; Tantawy, Mohammed N.; Fu, Allie; Manning, H. Charles; Horton, Jay D.; Hammer, Robert E.; McKnight, Steven L.; Tu, Benjamin P.

    2014-01-01

    SUMMARY Acetyl-CoA represents a central node of carbon metabolism that plays a key role in bioenergetics, cell proliferation and the regulation of gene expression. How highly glycolytic or hypoxic tumors are able to produce sufficient quantities of this metabolite to support cell growth and survival under nutrient-limiting conditions remains poorly understood. Here we show that the nucleocytosolic acetyl-CoA synthetase enzyme, ACSS2, supplies a key source of acetyl-CoA for tumors by capturing acetate as a carbon source. Despite exhibiting no gross deficits in growth or development, adult mice lacking ACSS2 exhibit a significant reduction in tumor burden in two different models of hepatocellular carcinoma. ACSS2 is expressed in a large proportion of human tumors and its activity is responsible for the majority of cellular acetate uptake into both lipids and histones. These observations may qualify ACSS2 as a targetable metabolic vulnerability of a wide spectrum of tumors. PMID:25525877

  4. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    PubMed

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided. PMID:25575804

  5. DNA electrophoresis in microfabricated devices

    NASA Astrophysics Data System (ADS)

    Dorfman, Kevin D.

    2010-10-01

    Picking up at the conclusion of Viovy’s review of the physics of gel electrophoresis [J.-L. Viovy, Rev. Mod. Phys. 72, 813 (2000)10.1103/RevModPhys.72.813], this review synthesizes the experimental data, theoretical models, and simulation results for DNA electrophoresis in microfabricated and nanofabricated devices appearing since the seminal paper by Volkmuth and Austin [Nature (London) 358, 600 (1992)10.1038/358600a0]. Prototype versions of these devices separate DNA by molecular weight at a rate far superior to gel electrophoresis. After providing an overview of the requisite background material in polymer physics, electrophoresis, and microfluidic device fabrication, the focus is on the following three generic problems: (i) collision with an isolated post, (ii) transport in an array of posts, and (iii) entropic trapping and filtration in the slit-well motif. The transport phenomena are examined here in the context of the length and time scales characterizing the DNA, the device, and the applied electric field.

  6. Techniques For Focusing In Zone Electrophoresis

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Twitty, Garland E.; Sammons, David W.

    1994-01-01

    In two techniques for focusing in zone electrophoresis, force of applied electrical field in each charged particle balanced by restoring force of electro-osmosis. Two techniques: velocity-gradient focusing (VGF), suitable for rectangular electrophoresis chambers; and field-gradient focusing (FGF), suitable for step-shaped electrophoresis chambers.

  7. [Erythrocyte membrane proteins].

    PubMed

    Delaunay, J

    1977-01-01

    Proteins are important constituents of the red blood cell plasma membrane. Several important breakthroughs have occurred in their analysis over the past few years. SDS-polyacrylamide gel electrophoresis lead to the separation of the major proteins and glycoproteins. Location of most of these proteins -- either on the external, the internal or both surfaces of the membrane -- was determined. The strenght of the binding of the protein to the membrane was established. Hydrophobicity of membrane proteins has so far hindered their purification. However, the major glycoprotein (glycophorin A) was isolated and recently sequenced. The description of several membrane-associated enzyme activities has been followed by some understanding of their specific role in the red blood cell physiology. Abnormalities of glycoproteins, Ca2+-ATPase and of membrane protein phosphorylation have been reported under various conditions: sickle cell disease, hereditary spherocytoses, progressive muscular dystrophy. PMID:146451

  8. The clinical use of PET with (11)C-acetate.

    PubMed

    Grassi, Ilaria; Nanni, Cristina; Allegri, Vincenzo; Morigi, Joshua James; Montini, Gian Carlo; Castellucci, Paolo; Fanti, Stefano

    2012-01-01

    The aim of this review is to evaluate clinical applications of (11)C-acetate positron emission tomography (PET). Acetate is quickly metabolized into acetyl-CoA in human cells. In this form it can either enter into the tricarboxylic acid cycle, thus producing energy, as happens in the myocardium, or participate in cell membrane lipid synthesis, as happens in tumor cells. (11)C-acetate PET was originally employed in cardiology, to study myocardial oxygen metabolism. More recently it has also been used to evaluate myocardial perfusion, as well as in oncology. The first studies of (11)C-acetate focused on its use in prostate cancer. Subsequently, (11)C-acetate was studied in other urological malignancies, as well as renal cell carcinoma and bladder cancer. Well differentiated hepatocellular carcinoma represents an (18)F-fluoro-deoxyglucose ((18)F-FDG) PET pitfall, so many authors have proposed to use (11)C-acetate in addition to (18)F-FDG in studying this tumor. (11)C-acetate PET has also been used in other malignancies, such as brain tumors and lung carcinoma. Some authors reported a few cases in which (11)C-acetate PET incidentally found multiple myeloma or rare tumors, such as thymoma, multicentric angiomyolipoma of the kidney and cerebellopontine angle schwannoma. Lastly, (11)C-acetate PET was also employed in a differential diagnosis case between glioma and encephalitis. The numerous studies on (11)C-acetate have demonstrated that it can be used in cardiology and oncology with no contraindications apart from pregnancy and the necessity of a rapid scan. Despite its limited availability, this tracer can surely be considered to be a promising one, because of its versatility and capacity to even detect non (18)F-FDG-avid neoplasm, such as differentiated lung cancer or hepatocellular carcinoma. PMID:23133801

  9. Gas separation membranes

    DOEpatents

    Schell, William J.

    1979-01-01

    A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.

  10. Acetate oxidation by syntrophic association between Geobacter sulfurreducens and a hydrogen-utilizing exoelectrogen

    PubMed Central

    Kimura, Zen-ichiro; Okabe, Satoshi

    2013-01-01

    Anodic microbial communities in acetate-fed microbial fuel cells (MFCs) were analyzed using stable-isotope probing of 16S rRNA genes followed by denaturing gradient gel electrophoresis. The results revealed that Geobacter sulfurreducens and Hydrogenophaga sp. predominated in the anodic biofilm. Although the predominance of Geobacter sp. as acetoclastic exoelectrogens in acetate-fed MFC systems has been often reported, the ecophysiological role of Hydrogenophaga sp. is unknown. Therefore, we isolated and characterized a bacterium closely related to Hydrogenophaga sp. (designated strain AR20). The newly isolated strain AR20 could use molecular hydrogen (H2), but not acetate, with carbon electrode as the electron acceptor, indicating that the strain AR20 was a hydrogenotrophic exoelectrogen. This evidence raises a hypothesis that acetate was oxidized by G. sulfurreducens in syntrophic cooperation with the strain AR20 as a hydrogen-consuming partner in the acetate-fed MFC. To prove this hypothesis, G. sulfurreducens strain PCA was cocultivated with the strain AR20 in the acetate-fed MFC without any dissolved electron acceptors. In the coculture MFC of G. sulfurreducens and strain AR20, current generation and acetate degradation were the highest, and the growth of strain AR20 was observed. No current generation, acetate degradation and cell growth occurred in the strain AR20 pure culture MFC. These results show for the first time that G. sulfurreducens can oxidize acetate in syntrophic cooperation with the isolated Hydrogenophaga sp. strain AR20, with electrode as the electron acceptor. PMID:23486252

  11. Electrophoresis technology experiment MA-011

    NASA Technical Reports Server (NTRS)

    Allen, R. E.; Barlow, G. H.; Bier, M.; Bigazzi, P. E.; Knox, R. J.; Micale, F. J.; Seaman, G. V. F.; Vanderhoff, J. W.; Vanoss, C. J.; Patterson, W. J.

    1976-01-01

    Experiment MA-011, electrophoresis technology, was designed to test electrophoresis hardware that would continue the development of technology for electrophoretic separation of materials in the near zero g environment of space. The experimental hardware generally functioned as planned. Frozen live cells were successfully transported into space, electrophoretic processing was performed, and viable cells were returned to earth. A separation of the three types of fixed red blood cells (rabbit, human, and horse) was demonstrated. The human lymphocytes, however, showed no apparent migration. The separation of human kidney cells produced the most exciting data. Analysis shows electrophoretic separation throughout the entire column with at least four bands of viable cells. The isotachophoresis experiment definitely demonstrated the isotachophoretic separation of biological cells in a near zero g environment.

  12. Fast separation and analysis of reduced monoclonal antibodies with capillary zone electrophoresis coupled to mass spectrometry.

    PubMed

    Zhao, Yimeng; Sun, Liangliang; Knierman, Michael D; Dovichi, Norman J

    2016-02-01

    Capillary zone electrophoresis-electrospray ionization-mass spectrometry (CZE-ESI-MS) was used for analysis of reduced antibodies. We first developed a simple protocol to condition commercial linear-polyacrylamide coated capillaries for use in top-down proteomics. We then suspended reduced antibodies in a solution of 35% acetic acid, 50% acetonitrile in water. Heavy and light chains were baseline resolved within 10 min and with 3-30 µg/mL detection limits using a 0.1% aqueous formic acid background electrolyte. Quintuplicate runs of a two-antibody mixture produced relative standard deviations of ∼1% in migration time and 10% in peak amplitudes. Resolution was further improved for the two-antibody mixture by using 5% acetic acid as the background electrolyte, highlighting the potential of capillary electrophoresis-mass spectrometry for analysis of antibody mixtures. PMID:26653481

  13. Capillary electrophoresis systems and methods

    DOEpatents

    Dorairaj, Rathissh (Hillsboro, OR); Keynton, Robert S. (Louisville, KY); Roussel, Thomas J. (Louisville, KY); Crain, Mark M. (Georgetown, IN); Jackson, Douglas J. (New Albany, IN); Walsh, Kevin M. (Louisville, KY); Naber, John F. (Goshen, KY); Baldwin, Richard P. (Louisville, KY); Franco, Danielle B. (Mount Washington, KY)

    2011-08-02

    An embodiment of the invention is directed to a capillary electrophoresis apparatus comprising a plurality of separation micro-channels. A sample loading channel communicates with each of the plurality of separation channels. A driver circuit comprising a plurality of electrodes is configured to induce an electric field across each of the plurality of separation channels sufficient to cause analytes in the samples to migrate along each of the channels. The system further comprises a plurality of detectors configured to detect the analytes.

  14. Vinegar as a burn-down herbicide: Acetic acid concentrations, application volumes, and adjuvants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acetic acid acts as a contact herbicide, injuring and killing plants by first destroying the cell membranes, which causes the rapid desiccation of the plant tissues. Vinegars with acetic acid concentrations of 11% or greater can burn the skin and cause serious to severe eye injury, including blindn...

  15. Antigenic distinctions of glycoproteins in plasma and mitochondrial membranes of lymphoid cells neoplastically transformed by simian virus 40.

    PubMed Central

    Schmidt-Ullrich, R; Thompson, W S; Wallach, D F

    1977-01-01

    Highly purified plasma membranes from hamster lymphocytes transformed by simian virus 40 (GD 248) were compared with the membranes of normal cells by crossed immune electrophoresis, crossed-line immune electrophoresis, and bidimensional isoelectric focusing-immune electrophoresis. Antiserum raised by inoculation of guinea pigs with GD 248 membranes was used as serologic reagent, either directly or after absorption with membranes from normal cells. Bidimensional immune electrophoresis reveals the presence in the plasma membranes of GD 248 cells of at least three antigens not detectable in the membranes from the normal cell population. At least two of these are also present in the mitochondrial membranes of GD 248 cells, but none could be detected in membranes of embryonic fibroblasts. Bidimensional isoelectric focusing-immune electrophoresis indicates that the distinctive antigens of the GD 248 membranes are glycoproteins. Images PMID:66678

  16. Stemofoline ethyl acetate solvate

    PubMed Central

    Mungkornasawakul, Pitchaya; Pyne, Stephen G.; Ung, Alison T.; Jatisatienr, Araya; Willis, Anthony C.

    2009-01-01

    Crystals of the title compound, C22H29NO5C4H8O2, {[systematic name: (2R,3R,5R,5aS,6R,8aR,9S)-(5Z)-5-[3-butyltetrahydro-6-methyl-2,5-methano-4,3,8a-[1]propanyl[3]ylidenefuro[3,2-f][1,4]oxazepin-7(5H)-ylidene]-4-methoxy-3-methylfuran-2(5H)-one ethyl acetate solvate} were isolated from the root extracts of Stemona aphylla (Stemonaceae). The structure closely resembles those of stemofoline derivatives which have previously been reported. Intermolecular contacts are observed between some C-bonded H atoms and nearby O atoms, perhaps indicating weak interactions which could influence the packing of species within the unit cell. PMID:21583572

  17. [Nomegestrol acetate: clinical pharmacology].

    PubMed

    Lello, S

    2009-10-01

    Progestogens are used in clinical practice in some conditions. Their effects depend on their chemical structure, pharmacokinetics, pharmacodynamics, with important differences among various progestogens. Generally, progestins are classified according to their parent molecule, of which often they keep some features. Derivatives of 19-nor-progesterone are characterized by high selectivity of action on progestin receptor. In particular, nomegestrol acetate (NomAc) shows an important progestational potency, neutral gluco-lipid profile, and antigonadotropic activity. It is used for treating menstrual cycle disorders and for hormone replacement therapy in menopause in association with an estrogen. In future, thanks to its antigonadotropic activity, NomAc will be used in estroprogestin combinations in fertile women, thus taking advantage of its tolerability profile and obtaining numerous non-contraceptive benefits as well. PMID:19749678

  18. Membranes and Films from Polymers.

    ERIC Educational Resources Information Center

    Blumberg, Avrom A.

    1986-01-01

    Provides background information on polymeric films and membranes including production methods, special industrial and medical applications, laboratory preparation, and an experimental investigation of a porous cellulose acetate membrane. Presents a demonstration to distinguish between high- and low-density polyethylene. (JM)

  19. Membrane humidity control investigation

    NASA Technical Reports Server (NTRS)

    Elam, J.; Ruder, J.; Strumpf, H.

    1974-01-01

    The basic performance data on a hollow fiber membrane unit that removes water from a breathing gas loop by diffusion is presented. Using available permeability data for cellulose acetate, a preliminary design was made of a dehumidifier unit that would meet the problem statement.

  20. Mathematical models of continuous flow electrophoresis: Electrophoresis technology

    NASA Technical Reports Server (NTRS)

    Saville, Dudley A.

    1986-01-01

    Two aspects of continuous flow electrophoresis were studied: (1) the structure of the flow field in continuous flow devices; and (2) the electrokinetic properties of suspended particles relevant to electrophoretic separations. Mathematical models were developed to describe flow structure and stability, with particular emphasis on effects due to buoyancy. To describe the fractionation of an arbitrary particulate sample by continuous flow electrophoresis, a general mathematical model was constructed. In this model, chamber dimensions, field strength, buffer composition, and other design variables can be altered at will to study their effects on resolution and throughput. All these mathematical models were implemented on a digital computer and the codes are available for general use. Experimental and theoretical work with particulate samples probed how particle mobility is related to buffer composition. It was found that ions on the surface of small particles are mobile, contrary to the widely accepted view. This influences particle mobility and suspension conductivity. A novel technique was used to measure the mobility of particles in concentrated suspensions.

  1. Integrated multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, Edward S. (Ames, IA); Tan, Hongdong (Ames, IA)

    2002-05-14

    The present invention provides an integrated multiplexed capillary electrophoresis system for the analysis of sample analytes. The system integrates and automates multiple components, such as chromatographic columns and separation capillaries, and further provides a detector for the detection of analytes eluting from the separation capillaries. The system employs multiplexed freeze/thaw valves to manage fluid flow and sample movement. The system is computer controlled and is capable of processing samples through reaction, purification, denaturation, pre-concentration, injection, separation and detection in parallel fashion. Methods employing the system of the invention are also provided.

  2. Capillary electrophoresis for drug analysis

    NASA Astrophysics Data System (ADS)

    Lurie, Ira S.

    1999-02-01

    Capillary electrophoresis (CE) is a high resolution separation technique which is amenable to a wide variety of solutes, including compounds which are thermally degradable, non-volatile and highly polar, and is therefore well suited for drug analysis. Techniques which have been used in our laboratory include electrokinetic chromatography (ECC), free zone electrophoresis (CZE) and capillary electrochromatography (CEC). ECC, which uses a charged run buffer additive which migrates counter to osmotic flow, is excellent for many applications, including, drug screening and analyses of heroin, cocaine and methamphetamine samples. ECC approaches include the use of micelles and charged cyclodextrins, which allow for the separation of complex mixtures. Simultaneous separation of acidic, neutral and basic solutes and the resolution of optical isomers and positional isomers are possible. CZE has been used for the analysis of small ions (cations and anions) in heroin exhibits. For the ECC and CZE experiments performed in our laboratory, uncoated capillaries were used. In contrast, CEC uses capillaries packed with high performance liquid chromatography stationary phases, and offers both high peak capacities and unique selectivities. Applications include the analysis of cannabinoids and drug screening. Although CE suffers from limited concentration sensitivity, it is still applicable to trace analysis of drug samples, especially when using injection techniques such as stacking, or detection schemes such as laser induced fluorescence and extended pathlength UV.

  3. DNA electrophoresis in microlithographic arrays

    NASA Astrophysics Data System (ADS)

    Volkmuth, W. D.; Austin, R. H.

    1992-08-01

    WE have used optical microlithography to fabricate capped quasi-two-dimensional obstacle courses in SiO2. We report here observations using epifluorescence microscopy of the electrophoresis and length fractionation of large DNA molecules confined in arrays. Simple reptation theory, based on the work of deGennes1, predicts that at low electric fields the electrophoretic mobility of a polymer of length L much greater than the persistence length p scales inversely with L (ref. 2). But elongation of the coil in the matrix at sufficiently strong electric fields3 results in a length-independent electrophoretic mobility4,5. The application of suitably timed pulsed electric fields restores the fractionating power of gels for long molecules6 but the protocols of pulsed-field electrophoresis are semi-empirical because the complex and ill-understood gel matrix plays a critical role in fractionation. Microlithographically constructed obstacle arrays, with their low dimensionality, small volume and extremely reproducible topography, will make it possible to understand the motion and fractionation of large polymer molecules in complex but well characterized topologies.

  4. Regulation of membrane associated protein kinase C activity by guanine nucleotide in rabbit peritoneal neutrophils

    SciTech Connect

    Huang, C.K.; Devanney, J.F.

    1986-03-05

    Addition of phorbol myristate acetate (PMA) (0.1 ..mu..g/ml) or guanosine-5'-0-(3-thiotriphosphate) (GTP..gamma..S) (10..mu..M) to the membrane fraction from rabbit peritoneal neutrophils results in an increase of phosphorylation of several membrane proteins. To test whether membrane associated protein kinase C is involved in the activation, histone is added to the membrane as a substrate for protein kinase C. Phosphorylation of histone is determined by counting the gel pieces containing histone IIIS after separation from other membrane components by SDS-gel electrophoresis. In the presence of CaC12 (20 ..mu..M), GTP..gamma..S (10 ..mu..M) or PMA (0.1 ..mu..g/ml) stimulates the phosphorylation of histone IIIS (40% to 70% increase). To achieve this effect calcium is required for GTP..gamma..S but not for PMA. The effect of GTP..gamma..S but not PMA is inhibited in membranes obtained from cells pretreated with pertussis toxin. Membrane protein kinase C is solubilized with Triton X-100 (1%) and then applied to a DEAE-52 cellulose column chromatography. Two peaks of protein kinase C activity are observed. Peak one is eluted at 40 mM NaCl, peak two is eluted at 140 mM NaCl. The activity of peak one is stimulated with phosphatidylserine (PS) and PMA but not with PS and calcium. The activity of peak two is stimulated with either PS and PMA or PS and calcium. The results suggest that GTP binding protein is involved in the activation of membrane associated protein kinase C and the kinase may exist in two forms, calcium sensitive and calcium insensitive.

  5. Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.

    SciTech Connect

    Snyder, S. W.; Energy Systems

    2010-02-08

    Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4) Moderate ammonia flux. The advantages of producing acetic acid by fermentation include its appropriateness for small-scale production, lower cost feedstocks, low energy membrane-based purification, and lower temperature and pressure requirements. Potential energy savings of using fermentation are estimated to be approximately 14 trillion Btu by 2020 from a reduction in natural gas use. Decreased transportation needs with regional plants will eliminate approximately 200 million gallons of diesel consumption, for combined savings of 45 trillion Btu. If the fermentation process captures new acetic acid production, savings could include an additional 5 trillion Btu from production and 7 trillion Btu from transportation energy.

  6. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be produced by the calcium hydroxide neutralization of acetic acid. (b) The ingredient meets...

  7. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be produced by the calcium hydroxide neutralization of acetic acid. (b) The ingredient meets the specifications of the...

  8. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be produced by the calcium hydroxide neutralization of acetic acid. (b) The ingredient meets...

  9. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be produced by the calcium hydroxide neutralization of acetic acid. (b) The ingredient meets...

  10. Non-Aqueous Capillary Electrophoresis

    NASA Astrophysics Data System (ADS)

    Szumski, Michał; Buszewski, Bogusław

    Non-aqueous capillary electrophoresis and capillary electrochromatography are special variants of these techniques. Here, organic solvents or their mixtures with or without dissolved electrolytes are used as separation buffer or mobile phase, respectively. The most important features of non-aqueous systems are: better solubility of more hydrophobic ionic substances (many natural products) than in water, much less current and Joule heating allows for using highly concentrated buffers and/or larger capillary internal diameters, polar interactions are enhanced in organic solvents which is often highly advantageous in chiral separation systems. This chapter presents most frequently used solvents, their properties, as well as shows pH* scale which is often used in non-aqueous systems.

  11. Electrophoresis-mass spectrometry probe

    DOEpatents

    Andresen, B.D.; Fought, E.R.

    1987-11-10

    The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface. 8 figs.

  12. Electrophoresis-mass spectrometry probe

    DOEpatents

    Andresen, Brian D. (Pleasanton, CA); Fought, Eric R. (Livermore, CA)

    1987-01-01

    The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface.

  13. Getting the Most out of Electrophoresis Units

    ERIC Educational Resources Information Center

    Mulvihill, Charlotte

    2007-01-01

    At Oklahoma City Community College, they have developed gel electrophoresis activities that support active learning of many scientific concepts, including: pH, electrolysis, oxidation reduction, electrical currents, potentials, conductivity, molarity, gel electrophoresis, DNA and protein separation, and DNA fingerprinting. This article presents

  14. Fluorescence detection for gel and capillary electrophoresis

    SciTech Connect

    Hogan, B.

    1992-07-21

    First, an indirect fluorescence detection system for the separation of proteins via gel electrophoresis. Quantities as low as 50 nanograms of bovine serum albumin and soybean trypsin inhibitor are separated and detected visually without the need for staining of the analytes. This is very similar to levels of protein commonly separated with gel electrophoresis.

  15. Compensating for Electro-Osmosis in Electrophoresis

    NASA Technical Reports Server (NTRS)

    Rhodes, Percy H.; Snyder, Robert S.

    1987-01-01

    Simple mechanical adjustment eliminates transverse velocity component. New apparatus for moving-wall electrophoresis increases degree of collimation of chemical species in sample stream. Electrophoresis chamber set at slight angle in horizontal plane to adjust angle between solution flow and wall motion. Component of velocity created cancels electro-osmotic effect.

  16. A method for demonstrating prophenoloxidase after electrophoresis.

    PubMed

    Nellaiappan, K; Vinayakam, A

    1993-07-01

    The demonstration of prophenoloxidase after electrophoresis is based on its activation by sodium dodecyl sulfate (SDS) or sodium oleate and staining the activated phenoloxidase with dopamine and 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH). A rapid method is presented for demonstrating the presence of activated phenoloxidase using polyacrylamide gel electrophoresis followed by staining in the presence of SDS or sodium oleate. PMID:7692984

  17. Getting the Most out of Electrophoresis Units

    ERIC Educational Resources Information Center

    Mulvihill, Charlotte

    2007-01-01

    At Oklahoma City Community College, they have developed gel electrophoresis activities that support active learning of many scientific concepts, including: pH, electrolysis, oxidation reduction, electrical currents, potentials, conductivity, molarity, gel electrophoresis, DNA and protein separation, and DNA fingerprinting. This article presents…

  18. Improvement of productivity in acetic acid fermentation with Clostridium thermoaceticum

    SciTech Connect

    Shah, M.M.; Cheryan, M.

    1995-12-31

    Production of acetic acid by a mutant strain of Clostridium thermoaceticum was compared in three types of membrane cell-recycle bioreactors. A modified fed-batch bioreactor (where the product is partially removed at the end of fermentation, but the cells are retained), and a two-stage CSTR (with product being removed continuously and the cells being recycled from the second to the first stage) resulted in better performance than a one-stage CSTR or batch fermenter. The difference in performance was greater at higher acetate concentration. With 45 g/L of glucose in the feed, productivity was 0.75-1.12 g/L-h and acetic acid concentrations were 34-38 g/L. This is more than double the batch system. The nutrient supply rate also appeared to have a strong influence on productivity of the microorganism.

  19. Antibiofilm Properties of Acetic Acid

    PubMed Central

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup; Nielsen, Anne K.; Johansen, Helle Krogh; Homøe, Preben; Høiby, Niels; Givskov, Michael; Kirketerp-Møller, Klaus

    2015-01-01

    Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms. PMID:26155378

  20. Tris-acetate polyacrylamide gradient gels for the simultaneous electrophoretic analysis of proteins of very high and low molecular mass.

    PubMed

    Cubillos-Rojas, Monica; Amair-Pinedo, Fabiola; Tato, Irantzu; Bartrons, Ramon; Ventura, Francesc; Rosa, Jose Luis

    2012-01-01

    Polyacrylamide gel electrophoresis (PAGE) is one of the most powerful tools used for protein analysis. We describe the use of Tris-acetate buffer and 3-15% polyacrylamide gradient gels to simultaneously separate proteins in the mass range of 10-500 kDa. We show that this system is highly sensitive, it has good resolution and high reproducibility, and that it can be used for general applications of PAGE such as Coomassie Brilliant Blue staining and immunoblotting. Moreover, we describe how to generate mini Tris-acetate polyacrylamide gels to use them in miniprotein electrophoresis systems. These economical gels are easy to generate and to manipulate and allow a rapid analysis of proteins. All these features make the Tris-acetate-PAGE system a very helpful tool for protein analysis. PMID:22585488

  1. Two Electrophoresis Experiments for Freshmen in the Health Professions.

    ERIC Educational Resources Information Center

    Brabson, G. Dana; Waugh, David S.

    1986-01-01

    Describes procedures involved with paper electrophoresis separation of amino acids, gel electrophoresis separation of DNA, and design of an electrophoresis tank. Describes experiments using paper (amino acids) and gel (deoxyribonucleic acid fragments). Provides material lists, procedures, and discussion. (JM)

  2. DNA Sequencing Using capillary Electrophoresis

    SciTech Connect

    Dr. Barry Karger

    2011-05-09

    The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other application papers of sequencing up to this level were also published in the mid 1990's. A major interest of the sequencing community has always been read length. The longer the sequence read per run the more efficient the process as well as the ability to read repeat sequences. We therefore devoted a great deal of time to studying the factors influencing read length in capillary electrophoresis, including polymer type and molecule weight, capillary column temperature, applied electric field, etc. In our initial optimization, we were able to demonstrate, for the first time, the sequencing of over 1000 bases with 90% accuracy. The run required 80 minutes for separation. Sequencing of 1000 bases per column was next demonstrated on a multiple capillary instrument. Our studies revealed that linear polyacrylamide produced the longest read lengths because the hydrophilic single strand DNA had minimal interaction with the very hydrophilic linear polyacrylamide. Any interaction of the DNA with the polymer would lead to broader peaks and lower read length. Another important parameter was the molecular weight of the linear chains. High molecular weight (> 1 MDA) was important to allow the long single strand DNA to reptate through the entangled polymer matrix. In an important paper, we showed an inverse emulsion method to prepare reproducibility linear polyacrylamide polymer with an average MWT of 9MDa. This approach was used in the polymer for sequencing the human genome. Another critical factor in the successful use of capillary electrophoresis for sequencing was the sample preparation method. In the Sanger sequencing reaction, high concentration of salts and dideoxynucleotide remained. Since the sample was introduced to the capillary column by electrokinetic injection, these salt ions would be favorably injected into the column over the sequencing fragments, thus reducing the signal for longer fragments and hence reading read length. In two papers, we examined the role of individual components from the sequencing reaction and then developed a protocol to reduce the deleterious salts. We demonstrated a robust method for achieving long read length DNA sequencing. Continuing our advances, we next demonstrated the achievement of over 1000 bases in less than one hour with a base calling accuracy of between 98 and 99%. In this work, we implemented energy transfer dyes which allowed for cleaner differentiation of the 4 dye labeled terminal nucleotides. In addition, we developed improved base calling software to help read sequencing when the separation was only minimal as occurs at long read lengths. Another critical parameter we studied was column temperature. We demonstrated that read lengths improved as the column temperature was increased from room temperature to 60 C or 70 C. The higher temperature relaxed the DNA chains under the influence of the high electric field.

  3. Comparison of non-electrophoresis grade with electrophoresis grade BIS in NIPAM polymer gel preparation

    PubMed Central

    Khodadadi, Roghayeh; Khajeali, Azim; Farajollahi, Ali Reza; Hajalioghli, Parisa; Raeisi, Noorallah

    2015-01-01

    Introduction:The main objective of this study was to investigate the possibility of replacing electrophoresis cross-linker with non-electrophoresis N, N′-methylenebisacrylamide (BIS) in N-isopropyl acrylamide (NIPAM) polymer gel and its possible effect on dose response. Methods: NIPAM polymer gel was prepared from non-electrophoresis grade BIS and the relaxation rate (R2) was measured by MR imaging after exposing the gel to gamma radiation from Co-60 source. To compare the response of this gel with the one that contains electrophoresis grade BIS, two sets of NIPAM gel were prepared using electrophoresis and non-electrophoresis BIS and irradiated to different gamma doses. Results: It was found that the dose–response of NIPAM gel made from the non-electrophoresis grade BIS is coincident with that of electrophoresis grade BIS. Conclusion:Taken all, it can be concluded that the non-electrophoresis grade BIS not only is a suitable alternative for the electrophoresis grade BIS but also reduces the cost of gel due to its lower price. PMID:26457250

  4. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethyl acetate. 173.228 Section 173.228 Food and..., Lubricants, Release Agents and Related Substances 173.228 Ethyl acetate. Ethyl acetate (CAS Reg. No. 141-78... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which...

  5. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethyl acetate. 173.228 Section 173.228 Food and..., Lubricants, Release Agents and Related Substances 173.228 Ethyl acetate. Ethyl acetate (CAS Reg. No. 141-78... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which...

  6. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl acetate. 173.228 Section 173.228 Food and..., Lubricants, Release Agents and Related Substances 173.228 Ethyl acetate. Ethyl acetate (CAS Reg. No. 141-78... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which...

  7. Capillary electrophoresis of phytochemical substances.

    PubMed

    Suntornsuk, Leena

    2002-02-01

    Applications of capillary electrophoresis (CE) for analysis of phytochemical substances (e.g. flavonoids, alkaloids, terpenoids, phenolic acid, quinones and coumarins) are reviewed. For example, CE analysis of sixteen tea ingredients were achieved within 10 min with the good precision (RSDs% <1% for intra-day and 2% for inter-day) and linearity (R(2)>0.990). Quantitation of sanguinarine and chelerythrine, alkaloids from Sanguinaria canadensis L. or Macleaya cordata (Wild) Br. R. by CE showed excellent linearity (R(2)>0.998), precision (RSD%=1.8%) and detection limit (2.4-3.0 microM). Determination of antraquinone-1-sulphonate was also obtained by this technique with good linearity (R(2)>0.9999), precision (RSD%=2%) and detection limit (0.7 microg/ml). Results of CE analysis from several studies are comparable to those of high performance liquid chromatography (HPLC), but the former is more useful for complex mixture samples where the analysis demands higher resolving power. Advantages of CE are high efficiency, low cost, short analysis time and simplicity, whereas disadvantages include low sensitivity comparing to HPLC and limitation of the preparative scale. PMID:11814710

  8. Nonlinear waves in capillary electrophoresis

    PubMed Central

    Ghosal, Sandip; Chen, Zhen

    2011-01-01

    Electrophoretic separation of a mixture of chemical species is a fundamental technique of great usefulness in biology, health care and forensics. In capillary electrophoresis the sample migrates in a microcapillary in the presence of a background electrolyte. When the ionic concentration of the sample is sufficiently high, the signal is known to exhibit features reminiscent of nonlinear waves including sharp concentration shocks. In this paper we consider a simplified model consisting of a single sample ion and a background electrolyte consisting of a single co-ion and a counterion in the absence of any processes that might change the ionization states of the constituents. If the ionic diffusivities are assumed to be the same for all constituents the concentration of sample ion is shown to obey a one dimensional advection diffusion equation with a concentration dependent advection velocity. If the analyte concentration is sufficiently low in a suitable non-dimensional sense, Burgers equation is recovered, and thus, the time dependent problem is exactly solvable with arbitrary initial conditions. In the case of small diffusivity either a leading edge or trailing edge shock is formed depending on the electrophoretic mobility of the sample ion relative to the background ions. Analytical formulas are presented for the shape, width and migration velocity of the sample peak and it is shown that axial dispersion at long times may be characterized by an effective diffusivity that is exactly calculated. These results are consistent with known observations from physical and numerical simulation experiments. PMID:20238181

  9. Mesoscale modelling of polyelectrolyte electrophoresis.

    PubMed

    Grass, Kai; Holm, Christian

    2010-01-01

    The electrophoretic behaviour of flexible polyelectrolyte chains ranging from single monomers up to long fragments of a hundred repeat units is studied by a mesoscopic simulation approach. Abstracting from the atomistic details of the polyelectrolyte and the fluid, a coarse-grained molecular dynamics model connected to a mesoscopic fluid described by the Lattice-Boltzmann approach is used to investigate free-solution electrophoresis. Our study demonstrates the importance of hydrodynamic interactions for the electrophoretic motion of polyelectrolytes and quantifies the influence of surrounding ions. The length-dependence of the electrophoretic mobility can be understood by evaluating the scaling behavior of the effective charge and the effective friction. The perfect agreement of our results with experimental measurements shows that all chemical details and fluid structure can be safely neglected, and a suitable coarse-grained approach can yield an accurate description of the physics of the problem, provided that electrostatic and hydrodynamic interactions between all entities in the system, i.e., the polyelectrolyte, dissociated counterions, additional salt and the solvent, are properly accounted for. Our model is able to bridge the single molecule regime of a few nm up to macromolecules with contour lengths of more than 100 nm, a length scale that is currently not accessible to atomistic simulations. PMID:20158023

  10. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium acetate. 184.1185 Section 184.1185 Food and... Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may...

  11. Acid diffusion through polyaniline membranes

    SciTech Connect

    Su, T.M.; Huang, S.C.; Conklin, J.A.

    1995-12-01

    Polyaniline membranes in the undoped (base) and doped (acid) forms are studied for their utility as pervaporation membranes. The separation of water from mixtures of propionic acid, acetic acid and formic acid have been demonstrated from various feed compositions. Doped polyaniline displays an enhanced selectivity of water over these organic acids as compared with undoped polyaniline. For as-cast polyaniline membranes a diffusion coefficient (D) on the order of 10{sup -9} cm{sup 2}/sec has been determined for the flux of protons through the membranes using hydrochloric acid.

  12. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. 721.10001 Section 721.10001 Protection of...-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. (a) Chemical substances and significant...-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and...

  13. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. 721.10001 Section 721.10001 Protection of...-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. (a) Chemical substances and significant...-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and...

  14. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. 721.10001 Section 721.10001 Protection of...-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. (a) Chemical substances and significant...-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and...

  15. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. 721.10001 Section 721.10001 Protection of...-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. (a) Chemical substances and significant...-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and...

  16. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. 721.10001 Section 721.10001 Protection of...-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. (a) Chemical substances and significant...-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and...

  17. Capillary electrophoresis electrospray ionization mass spectrometry interface

    DOEpatents

    Smith, Richard D. (Richland, WA); Severs, Joanne C. (Hayward, CA)

    1999-01-01

    The present invention is an interface between a capillary electrophoresis separation capillary end and an electrospray ionization mass spectrometry emitter capillary end, for transporting an anolyte sample from a capillary electrophoresis separation capillary to a electrospray ionization mass spectrometry emitter capillary. The interface of the present invention has: (a) a charge transfer fitting enclosing both of the capillary electrophoresis capillary end and the electrospray ionization mass spectrometry emitter capillary end; (b) a reservoir containing an electrolyte surrounding the charge transfer fitting; and (c) an electrode immersed into the electrolyte, the electrode closing a capillary electrophoresis circuit and providing charge transfer across the charge transfer fitting while avoiding substantial bulk fluid transfer across the charge transfer fitting. Advantages of the present invention have been demonstrated as effective in providing high sensitivity and efficient analyses.

  18. High-performance capillary electrophoresis of histones

    SciTech Connect

    Gurley, L.R.; London, J.E.; Valdez, J.G.

    1991-01-01

    A high performance capillary electrophoresis (HPCE) system has been developed for the fractionation of histones. This system involves electroinjection of the sample and electrophoresis in a 0.1M phosphate buffer at pH 2.5 in a 50 {mu}m {times} 35 cm coated capillary. Electrophoresis was accomplished in 9 minutes separating a whole histone preparation into its components in the following order of decreasing mobility; (MHP) H3, H1 (major variant), H1 (minor variant), (LHP) H3, (MHP) H2A (major variant), (LHP) H2A, H4, H2B, (MHP) H2A (minor variant) where MHP is the more hydrophobic component and LHP is the less hydrophobic component. This order of separation is very different from that found in acid-urea polyacrylamide gel electrophoresis and in reversed-phase HPLC and, thus, brings the histone biochemist a new dimension for the qualitative analysis of histone samples. 27 refs., 8 figs.

  19. Acetate and Formate Stress: Opposite Responses in the Proteome of Escherichia coli

    PubMed Central

    Kirkpatrick, Christopher; Maurer, Lisa M.; Oyelakin, Nikki E.; Yoncheva, Yuliya N.; Maurer, Russell; Slonczewski, Joan L.

    2001-01-01

    Acetate and formate are major fermentation products of Escherichia coli. Below pH 7, the balance shifts to lactate; an oversupply of acetate or formate retards growth. E. coli W3110 was grown with aeration in potassium-modified Luria broth buffered at pH 6.7 in the presence or absence of added acetate or formate, and the protein profiles were compared by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Acetate increased the steady-state expression levels of 37 proteins, including periplasmic transporters for amino acids and peptides (ArtI, FliY, OppA, and ProX), metabolic enzymes (YfiD and GatY), the RpoS growth phase regulon, and the autoinducer synthesis protein LuxS. Acetate repressed 17 proteins, among them phosphotransferase (Pta). An ackA-pta deletion, which nearly eliminates interconversion between acetate and acetyl-coenzyme A (acetyl-CoA), led to elevated basal levels of 16 of the acetate-inducible proteins, including the RpoS regulon. Consistent with RpoS activation, the ackA-pta strain also showed constitutive extreme-acid resistance. Formate, however, repressed 10 of the acetate-inducible proteins, including the RpoS regulon. Ten of the proteins with elevated basal levels in the ackA-pta strain were repressed by growth of the mutant with formate; thus, the formate response took precedence over the loss of the ackA-pta pathway. The similar effects of exogenous acetate and the ackA-pta deletion, and the opposite effect of formate, could have several causes; one possibility is that the excess buildup of acetyl-CoA upregulates stress proteins but excess formate depletes acetyl-CoA and downregulates these proteins. PMID:11591692

  20. Affinity Electrophoresis Using Ligands Attached To Polymers

    NASA Technical Reports Server (NTRS)

    Van Alstine, James M.; Snyder, Robert S.; Harris, J. M.; Brooks, D. E.

    1990-01-01

    In new technique, reduction of electrophoretic mobilities by addition of polyethylene glycol to ligands increases electrophoretic separabilities. In immuno-affinity electrophoresis, modification of ligands extends specificity of electrophoretic separation to particles having surface electric-charge structures otherwise making them electrophoretically inseparable. Modification of antibodies by polyethylene glycol greatly reduces ability to aggregate while enhancing ability to affect electrophoretic mobilities of cells. In hydrophobic-affinity electrophoresis, addition of polyethylene glycol reduces tendency toward aggregation of cells or macromolecules.

  1. Effects of acetic acid/acetic anhydride ratios on the properties of corn starch acetates.

    PubMed

    Diop, Cherif Ibrahima Khalil; Li, Hai Long; Xie, Bi Jun; Shi, John

    2011-06-15

    Corn starch was pre-treated with acetic acid and then acetylated by acetic anhydride under microwave irradiation. The effects of molar ratios of these two reagents on the acetylation of starch were investigated. Starch acetate with a high degree of substitution (DS, 2.93) was obtained at a molar ratio (acetic acid/acetic anhydride) of 1:1. However, the DS should tend to decrease with a change of this ratio. The FT-IR analysis indicated characteristic absorption peaks, with increasing DS materialised by an increase of the carbonyl CO group and a decrease of the hydroxyl O-H group, at about 1750cm(-1) and 3450cm(-1), respectively. The X-ray diffraction patterns of acetylated starch showed an amorphous structure. Degree of crystallinity, surface morphology, water solubility and water absorption index of corn starch were also affected by the changes in reagent ratios. The glass transition (Tg) and melting (Tm) temperatures of acetylated starches also decreased after acetylation. PMID:25213942

  2. Micelles Protect and Concentrate Activated Acetic Acid

    NASA Astrophysics Data System (ADS)

    Todd, Zoe; House, C.

    2014-01-01

    As more and more exoplanets are discovered and the habitability of such planets is considered, one can turn to searching for the origin of life on Earth in order to better understand what makes a habitable planet. Activated acetic acid, or methyl thioacetate, has been proposed to be central to the origin of life on Earth, and also as an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about three orders of magnitude faster (K = 0.00663 s^-1; 100C, pH 7.5, concentration = 0.33mM) than published rates for its catalyzed production making it unlikely to accumulate under prebiotic conditions. However, we also observed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. We found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid micelles. Thus, the hydrophobic regions of prebiotic micelles and early cell membranes could have offered a refuge for this energetic molecule increasing its lifetime in close proximity to the reactions for which it would be needed. Methyl thioacetate could thus be important for the origin of life on Earth and perhaps for better understanding the potential habitability of other planets.

  3. Biodegradable cellulose acetate nanofiber fabrication via electrospinning.

    PubMed

    Christoforou, Theopisti; Doumanidis, Charalabos

    2010-09-01

    Nanofiber manufacturing is one of the key advancements in nanotechnology today. Over the past few years, there has been a tremendous growth of research activities to explore electrospinning for nanofiber formation from a rich variety of materials. This quite simple and cost effective process operates on the principle that the solution is extracted under the action of a high electric field. Once the voltage is sufficiently high, a charged jet is ejected following a complicated looping trajectory. During its travel, the solvent evaporates leaving behind randomly oriented nanofibers accumulated on the collector. The combination of their nanoscale dimensionality, high surface area, porosity, flexibility and superior strength makes the electrospun fibers suitable for several value-added applications, such as filters, protecting clothes, high performance structures and biomedical devices. In this study biodegradable cellulose acetate (CA) nanofibrous membranes were produced using electrospinning. The device utilized consisted of a syringe equipped with a metal needle, a microdialysis pump, a high voltage supply and a collector. The morphology of the yielded fibers was determined using SEM. The effect of various parameters, including electric field strength, tip-to-collector distance, solution feed rate and composition on the morphological features of the electrospun fibers was examined. The optimum operating conditions for the production of uniform, non-beaded fibers with submicron diameter were also explored. The biodegradable CA nanofiber membranes are suitable as tissue engineering scaffolds and as reinforcements of biopolymer matrix composites in foils by ultrasonic welding methods. PMID:21133179

  4. [Comparison of different buffer systems for separation of 15 nucleosides by capillary electrophoresis].

    PubMed

    Shi, Qian; Chen, Junhui; Li, Xin; Cao, Wei; Zheng, Li; Zang, Jiaye; Wang, Xiaoru

    2011-06-01

    The most suitable background electrolytes (BGEs) for simultaneous separation of 15 nucleosides by different modes of capillary electrophoresis (CE) were obtained. Various modes of CE were performed including capillary zone electrophoresis (CZE), capillary electrophoresis-electrospray ionization-time of flight mass spectrometry (CE-ESI-TOF/MS) and micellar electrokinetic chromatography (MEKC). The electrolyte buffers using sodium tetraborate decahydrate, disodium hydrogen phosphate, sodium acetate, sodium bicarbonate, ammonium acetate or 1, 2-diamino-ethane (DEA) were tested, and the best of them were systematically optimized. In CZE mode, the nucleosides could not be separated completely with sodium tetraborate decahydrate or disodium hydrogen phosphate as BGEs, demonstrating the limited applicability of the two buffer systems for complex samples. However, with 300 mmol/L DEA (containing 2% acetone) as BGE, 15 nucleosides could be separated with good resolution and peak shape, which proved that the DEA buffer was most suitable in CZE. The best buffer system in MEKC mode was 25 mmol/L disodium hydrogen phosphate with 70 mmol/L sodium dodecyl sulfate (SDS), and it was successfully applied for the separation of the nucleosides in Chinese Anthopleura lanthogrammica Berkly. The optimum buffer system for CE-ESI-TOF/MS analysis was 20 mmol/L ammonium acetate (pH 10.0). In the positive ion mode, the MS signals of each compound were better than those in the literature using DEA as BGE. The results of this study demonstrated the applicability of different buffer systems for the simultaneous separation of 15 nucleosides, and were helpful for the development of CE method in complex sample separation. PMID:22032157

  5. Sodium chloride in separation medium enhances cell compatibility of free flow electrophoresis.

    PubMed

    Bondy, B; Bauer, J; Seuffert, I; Weber, G

    1995-01-01

    Free flow electrophoresis of cell suspensions in buffers containing sodium chloride was investigated using a modified procedure and the new apparatus Octopus PZE. The major methodical innovations are upward fluid flow, margin buffers flowing through the electrophoresis chamber at both sides of a central cell suspension buffer, adjacent to the electrode membranes, and a sample injection device which focuses the cells hydrodynamically to the middle of the chamber thickness. Mononuclear leukocytes, suspended in a buffer containing 35 mM NaCl, could be fractionated with the same accuracy as by conventional free flow electrophoresis, operated with a single NaCl-free chamber buffer. However, testing the vitality of separated cells with the help of the calcium indicator FURA2-AM clearly demonstrated the biological importance of the presence of a minimum amount of sodium chloride during cell electrophoresis. Only if at least 35 mM NaCl were present could an undisturbed cytosolic Ca2+ metabolism be maintained for the time of a free flow electrophoresis cell separation experiment. PMID:7737096

  6. Reductive opening of carbohydrate phenylsulfonylethylidene (PSE) acetals.

    PubMed

    Chry, Florence; Cabianca, Elena; Tatibout, Arnaud; De Lucchi, Ottorino; Lindhorst, Thisbe K; Rollin, Patrick

    2015-11-19

    The phenylsulfonylethylidene (PSE) acetal is a relatively new protecting group in carbohydrate chemistry. However, carbohydrate-derived phenylsulfonylethylidene (PSE) acetals show a different behavior in reductive desulfonylation than simple symmetrical acetals. Here we have investigated various SET-type reaction conditions in order to open PSE acetals regioselectively and to produce chiral ?-hydroxyethenyl ethers. Whereas sodium amalgam leads to a mixture of regioisomeric vinyl ethers besides the ethylidene acetal, samarium iodide is suited for regioselective ring opening. This is shown with seven different carbohydrate PSE acetals, both of the 1,3-dioxane and the 1,3-dioxolane type. PMID:26469209

  7. Vibrational spectroscopy and electrophoresis as a "golden means" in monitoring of polysaccharides in medical plant and gels.

    PubMed

    Pielesz, A

    2012-07-01

    In recent years, some bioactive polysaccharides isolated from natural sources have attracted much attention in the field of biochemistry and pharmacology. Of them, polysaccharides or their glycoconjugates were shown to exhibit multiple biological activities including anticarcinogenic, anticoagulant, immunostimulating, antioxidant, etc. Pharmacotherapy using plant-derived substances can be currently regarded as a very promising future alternative to conventional therapy. The advanced biotechnologies available today enable chemical investigation of well-defined bioactive plant components as sources of novel drugs. The need for safer drugs without side effects has led to the use of natural ingredients with proven safety. Special interest is focused on plant polysaccharides. This article attempts to review the current structural and conformational characterization of some importantly bioactive monosaccharides isolated from following plant cell-wall: Symphytum officinale (comfrey), Thymus pulegioides (thyme), Trigonella foenum-graecum L. (fenugreek), Tussilago farfara L. (coltsfoot), Hyssopus officinalis (hyssop), Althaea officinalis L. (marshmallow) and Equisetum arvense L. (horsetail). The chemical structures of monosaccharides were analysed using FTIR and Raman spectroscopies as well as cellulose acetate membrane electrophoresis (CAE). The dried plant samples were gently hydrolysed with sulphuric acid. The presence of glucuronic acid, galacturonic acid, alginic acid, glucose, mannose and xylose in the hydrolysates of reference substances and non-defatted plant films was proved. The possibility of a taxonomic classification of plant cell walls based on infrared and Raman spectroscopies and the use of spectral fingerprinting for authentication and detection of adulteration of products rich in cell-wall materials are discussed. Individual bands were selected to monitor the sugar content in medical plant cell walls and to confirm the identity of the analysed plants. PMID:22465769

  8. Vibrational spectroscopy and electrophoresis as a "golden means" in monitoring of polysaccharides in medical plant and gels

    NASA Astrophysics Data System (ADS)

    Pielesz, A.

    In recent years, some bioactive polysaccharides isolated from natural sources have attracted much attention in the field of biochemistry and pharmacology. Of them, polysaccharides or their glycoconjugates were shown to exhibit multiple biological activities including anticarcinogenic, anticoagulant, immunostimulating, antioxidant, etc. Pharmacotherapy using plant-derived substances can be currently regarded as a very promising future alternative to conventional therapy. The advanced biotechnologies available today enable chemical investigation of well-defined bioactive plant components as sources of novel drugs. The need for safer drugs without side effects has led to the use of natural ingredients with proven safety. Special interest is focused on plant polysaccharides. This article attempts to review the current structural and conformational characterization of some importantly bioactive monosaccharides isolated from following plant cell-wall: Symphytum officinale (comfrey), Thymus pulegioides (thyme), Trigonella foenum-graecum L. (fenugreek), Tussilago farfara L. (coltsfoot), Hyssopus officinalis (hyssop), Althaea officinalis L. (marshmallow) and Equisetum arvense L. (horsetail). The chemical structures of monosaccharides were analysed using FTIR and Raman spectroscopies as well as cellulose acetate membrane electrophoresis (CAE). The dried plant samples were gently hydrolysed with sulphuric acid. The presence of glucuronic acid, galacturonic acid, alginic acid, glucose, mannose and xylose in the hydrolysates of reference substances and non-defatted plant films was proved. The possibility of a taxonomic classification of plant cell walls based on infrared and Raman spectroscopies and the use of spectral fingerprinting for authentication and detection of adulteration of products rich in cell-wall materials are discussed. Individual bands were selected to monitor the sugar content in medical plant cell walls and to confirm the identity of the analysed plants.

  9. Preparation of Electrically Conductive Polymeric Membranes

    NASA Astrophysics Data System (ADS)

    Encinas, J. C.; Castillo-Ortega, M. M.; Rodríguez, F.; Castaño, V. M.

    2015-10-01

    Cellulose acetate porous membranes, coated with polyaniline, were chemically modified with polyelectrolytes to produce films of varying and controlled porosity and electrical conductivity. The highest electrical conductivity was obtained in membranes prepared with poly(styrene sulfonate) with large pore sizes. The electrical properties as well as scanning electron microscopy (SEM) images are discussed.

  10. Fragrance material review on p-anisyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of p-anisyl acetate when used as a fragrance ingredient is presented. p-Anisyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for p-anisyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, and genotoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22417777

  11. Carbon-isotopic analysis of dissolved acetate

    NASA Technical Reports Server (NTRS)

    Gelwicks, J. T.; Hayes, J. M.

    1990-01-01

    Heating of dried, acetate-containing solids together with oxalic acid dihydrate conveniently releases acetic acid for purification by gas chromatography. For determination of the carbon-isotopic composition of total acetate, the acetate-containing zone of the chromatographic effluent can be routed directly to a combustion furnace coupled to a vacuum system allowing recovery, purification, and packaging of CO2 for mass-spectrometric analysis. For analysis of methyl carbon, acetic acid can be cryogenically trapped from the chromatographic effluent, then transferred to a tube containing excess NaOH. The tube is evacuated, sealed, and heated to 500 degrees C to produce methane by pyrolysis of sodium acetate. Subsequent combustion of the methane allows determination of the 13C content at the methyl position in the parent acetate. With typical blanks, the standard deviation of single analyses is less than 0.4% for acetate samples larger than 5 micromoles. A full treatment of uncertainties is outlined.

  12. Ozone decomposition in aqueous acetate solutions

    SciTech Connect

    Sehested, K.; Holcman, J.; Bjergbakke, E.; Hart, E.J.

    1987-01-01

    The acetate radical ion reacts with ozone with a rate constant of k = (1.5 +/- 0.5) x 10Z dmT mol s . The products from this reaction are CO2, HCHO, and O2 . By subsequent reaction of the peroxy radical with ozone the acetate radical ion is regenerated through the OH radical. A chain decomposition of ozone takes place. It terminates when the acetate radical ion reacts with oxygen forming the unreactive peroxy acetate radical. The chain is rather short as oxygen is developed, as a result of the ozone consumption. The inhibiting effect of acetate on the ozone decay is rationalized by OH scavenging by acetate and successive reaction of the acetate radical ion with oxygen. Some products from the bimolecular disappearance of the peroxy acetate radicals, however, react further with ozone, reducing the effectiveness of the stabilization.

  13. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and....1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3 or C2H3O2Na·3H2O, CAS Reg. No. 6131-90-4) is the sodium salt of acetic acid and occurs naturally in plant and animal tissues....

  14. Free flow cell electrophoresis using zwitterionic buffer

    NASA Technical Reports Server (NTRS)

    Rodkey, R. Scott

    1990-01-01

    Studies of a zwitterionic buffer formulated for cell electrophoresis were done using the McDonnell-Douglas Continuous Flow Electrophoresis System. Standard buffers were analyzed for their stability in the electrical field and the results showed that both buffers tested were inherently unstable. Further, titration studies showed that the standards buffers buffered poorly at the pH employed for electrophoresis. The zwitterionic buffer buffered well at its nominal pH and was shown to be stable in the electrical field. Comparative studies of the buffer with standard cell separation buffers using formalin fixed rabbit and goose red blood cells showed that the zwitterionic buffer gave better resolution of the fixed cells. Studies with viable hybridoma cells showed that buffer Q supported cell viability equal to Hank's Balanced Salt Solution and that hybridoma cells in different stages of the growth cycle demonstrated reproducible differences in electrophoretic mobility.

  15. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  16. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  17. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  18. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  19. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  20. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  1. 27 CFR 21.107 - Ethyl acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....107 Ethyl acetate. (a) 85 percent ester: (1) Acidity (as acetic acid). Not more than 0.015 percent by... 80 °C. (b) 100 percent ester: (1) Acidity (as acetic acid). Not more than 0.010 percent by weight....

  2. 27 CFR 21.107 - Ethyl acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....107 Ethyl acetate. (a) 85 percent ester: (1) Acidity (as acetic acid). Not more than 0.015 percent by... 80 °C. (b) 100 percent ester: (1) Acidity (as acetic acid). Not more than 0.010 percent by weight....

  3. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acetic acid. 184.1005 Section 184.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD....1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It...

  4. 27 CFR 21.107 - Ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....107 Ethyl acetate. (a) 85 percent ester: (1) Acidity (as acetic acid). Not more than 0.015 percent by... 80 °C. (b) 100 percent ester: (1) Acidity (as acetic acid). Not more than 0.010 percent by weight....

  5. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+)...

  6. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  7. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582.1005 Acetic acid. (a) Product. Acetic acid....

  8. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  9. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  10. 27 CFR 21.107 - Ethyl acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....107 Ethyl acetate. (a) 85 percent ester: (1) Acidity (as acetic acid). Not more than 0.015 percent by... 80 °C. (b) 100 percent ester: (1) Acidity (as acetic acid). Not more than 0.010 percent by weight....

  11. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  12. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  13. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  14. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  15. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  16. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  17. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  18. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  19. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Trenbolone acetate. 522.2476 Section 522.2476 Food... Trenbolone acetate. (a) Sponsors. See sponsors in 510.600(c) of this chapter for use as in paragraph (d) of... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each...

  20. 21 CFR 182.8892 - ?-Tocopherol acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false α-Tocopherol acetate. 182.8892 Section 182.8892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...-Tocopherol acetate. (a) Product. ?-Tocopherol acetate. (b) Conditions of use. This substance is...

  1. 21 CFR 182.8892 - ?-Tocopherol acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false α-Tocopherol acetate. 182.8892 Section 182.8892...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients 182.8892 ?-Tocopherol acetate. (a) Product. ?-Tocopherol acetate. (b) Conditions of use. This substance is generally recognized as safe when used in...

  2. 21 CFR 522.1073 - Gonadorelin acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Gonadorelin acetate. 522.1073 Section 522.1073... Gonadorelin acetate. (a) Specifications. Each milliliter of solution contains 100 micrograms (g) of gonadorelin as gonadorelin acetate. (b) Sponsor. See No. 068504 in 510.600(c) of this chapter....

  3. 21 CFR 182.8892 - ?-Tocopherol acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true α-Tocopherol acetate. 182.8892 Section 182.8892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...-Tocopherol acetate. (a) Product. ?-Tocopherol acetate. (b) Conditions of use. This substance is...

  4. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food... Tolerances for Residues of New Animal Drugs 556.380 Melengestrol acetate. A tolerance of 25 parts per billion is established for residues of the parent compound, melengestrol acetate, in fat of cattle....

  5. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food... Tolerances for Residues of New Animal Drugs 556.380 Melengestrol acetate. A tolerance of 25 parts per billion is established for residues of the parent compound, melengestrol acetate, in fat of cattle....

  6. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food... Tolerances for Residues of New Animal Drugs 556.380 Melengestrol acetate. A tolerance of 25 parts per billion is established for residues of the parent compound, melengestrol acetate, in fat of cattle....

  7. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Trenbolone acetate. 522.2476 Section 522.2476 Food... Trenbolone acetate. (a) Sponsors. See sponsors in 510.600(c) of this chapter for use as in paragraph (d) of... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each...

  8. 21 CFR 182.8892 - ?-Tocopherol acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false α-Tocopherol acetate. 182.8892 Section 182.8892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...-Tocopherol acetate. (a) Product. ?-Tocopherol acetate. (b) Conditions of use. This substance is...

  9. 21 CFR 182.8892 - ?-Tocopherol acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false α-Tocopherol acetate. 182.8892 Section 182.8892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...-Tocopherol acetate. (a) Product. ?-Tocopherol acetate. (b) Conditions of use. This substance is...

  10. 21 CFR 522.1073 - Gonadorelin acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Gonadorelin acetate. 522.1073 Section 522.1073... Gonadorelin acetate. (a) Specifications. Each milliliter of solution contains 100 micrograms (g) of gonadorelin as gonadorelin acetate. (b) Sponsor. See No. 068504 in 510.600(c) of this chapter....

  11. A new injection method for soil nutrient analysis in capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Smolka, M.; Puchberger-Enengl, D.; Bipoun, M.; Fercher, G.; Klasa, A.; Krutzler, C.; Keplinger, F.; Vellekoop, M. J.

    2013-05-01

    We present a new method for the direct injection of liquid sample into a capillary electrophoresis (CE) device. Instead of a double-T injection mechanism, a single inlet provided with a membrane filter is used. From a reservoir on top of this inlet, the liquid directly enters the separation channel through the membrane. The driving force is a short electrical pulse. This avoids an additional sample channel, so that the chip needs only three microfluidic connects and no mechanical sample pumping is demanded. The high injection reproducibility and the comparatively simple setup open up the way for mobile application of soil analysis.

  12. Undergraduate physics laboratory: Electrophoresis in chromatography paper

    NASA Astrophysics Data System (ADS)

    Hyde, Alexander; Batishchev, Oleg

    2015-12-01

    An experiment studying the physical principles of electrophoresis in liquids was developed for an undergraduate laboratory. We have improved upon the standard agarose gel electrophoresis experimental regime with a straightforward and cost-effective procedure, in which drops of widely available black food coloring were separated by electric field into their dye components on strips of chromatography paper soaked in a baking soda/water solution. Terminal velocities of seven student-safe dyes were measured as a function of the electric potential applied along the strips. The molecular mobility was introduced and calculated by analyzing data for a single dye. Sources of systematic and random errors were investigated.

  13. Application of Microchip Electrophoresis for Clinical Tests

    NASA Astrophysics Data System (ADS)

    Yatsushiro, Shouki; Kataoka, Masatoshi

    Microchip electrophoresis has recently attracted much attention in the field of nuclear acid analysis due to its high efficiency, ease of operation, low consumption of samples and reagents, and relatively low costs. In addition, the analysis has expanded to an analytical field like not only the analysis of DNA but also the analysis of RNA, the protein, the sugar chain, and the cellular function, etc. In this report, we showed that high-performance monitoring systems for human blood glucose levels and α-amylase activity in human plasma using microchip electrophoresis.

  14. Role of gravity in preparative electrophoresis

    NASA Technical Reports Server (NTRS)

    Bier, M.; Hinckley, J. O. N.; Smolka, A. J. K.; Binder, M. J.; Coxon, M.; Nee, T. W.; Scully, M. O.; Shih, H. S. T.; Snyder, R. S.

    1974-01-01

    Electrophoresis has contributed significantly to the methodology of biological sciences, and shows the potential for large scale fractionation of a wide range of medically important substances, including living cells. Gravity plays an important role in the electrophoretic process, and hence the importance of the NASA effort to develop a zero-gravity separation facility as part of its shuttle program. The current state of art in electrophoresis is reviewed with particular emphasis on the role of gravity and the possible use of istachophoresis. This technique utilizes a discontinuous buffer system, and appears to be the only high resolution electrophoretic technique currently available for separation of living cells.

  15. Effect of membrane polymeric materials on relationship between surface pore size and membrane fouling in membrane bioreactors

    NASA Astrophysics Data System (ADS)

    Miyoshi, Taro; Yuasa, Kotaku; Ishigami, Toru; Rajabzadeh, Saeid; Kamio, Eiji; Ohmukai, Yoshikage; Saeki, Daisuke; Ni, Jinren; Matsuyama, Hideto

    2015-03-01

    We investigated the effect of different membrane polymeric materials on the relationship between membrane pore size and development of membrane fouling in a membrane bioreactor (MBR). Membranes with different pore sizes were prepared using three different polymeric materials, cellulose acetate butyrate (CAB), polyvinyl butyral (PVB), and polyvinylidene fluoride (PVDF), and the development of membrane fouling in each membrane was evaluated by batch filtration tests using a mixed liquor suspension obtained from a laboratory-scale MBR. The results revealed that the optimal membrane pore size to mitigate membrane fouling differed depending on membrane polymeric material. For PVDF membranes, the degree of membrane fouling decreased as membrane pore size increased. In contrast, CAB membranes with smaller pores had less fouling propensity than those with larger ones. Such difference can be attributed to the difference in major membrane foulants in each membrane; in PVDF, they were small colloids or dissolved organics in which proteins are abundant, and in CAB, microbial flocs. The results obtained in this study strongly suggested that optimum operating conditions of MBRs differ depending on the characteristics of the used membrane.

  16. A Simple Vertical Slab Gel Electrophoresis Apparatus.

    ERIC Educational Resources Information Center

    Carter, J. B.; And Others

    1983-01-01

    Describes an inexpensive, easily constructed, and safe vertical slab gel kit used routinely for sodium dodecyl sulphate-polyacrylamide gel electrophoresis research and student experiments. Five kits are run from a single transformer. Because toxic solutions are used, students are given plastic gloves and closely supervised during laboratory…

  17. Role of gravity in preparative electrophoresis

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1975-01-01

    The fundamental formulas of electrophoresis are derived microscopically and applied to the problem of isotachophoresis. A simple physical model of the isotachophoresis front is proposed. The front motion and structure are studied in the simplified case without convection, diffusion and non-electric external forces.

  18. Planetary In Situ Capillary Electrophoresis System (PISCES)

    NASA Astrophysics Data System (ADS)

    Willis, P. A.; Stockton, A. M.; Mora, M. F.; Cable, M. L.; Bramall, N. E.; Jensen, E. C.; Jiao, H.; Lynch, E.; Mathies, R. A.

    2012-10-01

    We propose to develop PISCES, a 3-kg, 2W, flight-capable microfluidic lab-on-a-chip capillary electrophoresis analyzer capable of ingesting solid, liquid, or gas samples and performing a suite of chemical analyses with parts per trillion sensitivity.

  19. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    SciTech Connect

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  20. A Simple Vertical Slab Gel Electrophoresis Apparatus.

    ERIC Educational Resources Information Center

    Carter, J. B.; And Others

    1983-01-01

    Describes an inexpensive, easily constructed, and safe vertical slab gel kit used routinely for sodium dodecyl sulphate-polyacrylamide gel electrophoresis research and student experiments. Five kits are run from a single transformer. Because toxic solutions are used, students are given plastic gloves and closely supervised during laboratory

  1. Increasing Sensitivity In Continuous-Flow Electrophoresis

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Sensitivity of continuous-flow electrophoresis (CFE) chamber increased by introducing lateral gradients in concentration of buffer solution and thickness of chamber. Such gradients, with resulting enhanced separation, achieved in CFE chamber with wedge-shaped cross section and collateral flow. Enables improved separations of homogeneous components of mixtures of variety of biologically important substances.

  2. Plasmodium falciparum Polypeptides Associated with the Infected Erythrocyte Plasma Membrane

    NASA Astrophysics Data System (ADS)

    Stanley, Harold A.; Reese, Robert T.

    1986-08-01

    Plasmodium falciparum proteins associated with plasma membranes of infected erythrocytes were identified by using three techniques: (i) isolated plasma membranes from infected and uninfected erythrocytes were compared by gel electrophoresis and silver staining; (ii) isolated plasma membranes from cells metabolically labeled with [35S]methionine were assayed by gel electrophoresis; and (iii) uninfected and infected intact erythrocytes were surface-labeled by lactoperoxidase iodination, and the labeled polypeptides were compared by gel electrophoresis. The results from these experiments indicate that at least six parasite-derived polypeptides (Mr = > 240,000, 150,000, 55,000, 45,000, 35,000, and 20,000) are associated with the infected erythrocyte plasma membrane. At least four of these peptides (Mr = 55,000, 45,000, 35,000, and 20,000) may be exposed on the surface of the infected erythrocytes.

  3. Using Gel Electrophoresis To Illustrate Protein Diversity and Isoelectric Point.

    ERIC Educational Resources Information Center

    Browning, Mark; Vanable, Joseph

    2002-01-01

    Demonstrates the differences in protein structures by focusing on isoelectric point with an experiment that is observable under certain pH levels in gel electrophoresis. Explains the electrophoresis procedure and reports results of the experiments. (YDS)

  4. Membrane controlled anaerobic digestion

    NASA Astrophysics Data System (ADS)

    Omstead, D. R.

    In response to general shortages of energy, examination of the anaerboic digestion process as a potential source of a combustible, methane-rich fuel has intensified in recent years. It has been suggested that orgaic intermediates (such as fatty acids), produced during digestion, might also be recovered for use as chemical feedstocks. This investigation has been concerned with combining ultrafiltration separation techniques with anaerobic digestion for the development of a process in which the total production of acetic acid (the most valuable intermediate in anaerobic digestion) and methane are optimized. Enrichment cultures, able to utilize glucose as a sole carbon source, were adapted from sewage digesting cultures using conventional techniques. An ultrafiltration system was constructed and coupled to an anaerobic digester culture vessel which contained the glucose enrichment. The membrane controlled anaerobic digester appears to show promise as a means of producing high rates of both methane gas and acetic acid.

  5. Phorbol myristate acetate receptors in human polymorphonuclear neutrophils

    SciTech Connect

    Nishihira, J.; O'Flaherty, J.T.

    1985-11-01

    Resting or phorbol myristate acetate (PMA)-pretreated neutrophils were disrupted by nitrogen cavitation and were fractionated on Percoll density gradients to identify the subcellular location of PMA receptors. Receptors were found in the cytoplasm of resting cells; neither primary nor secondary granules bound (/sup 3/H)PMA, and the few binding sites located in non-granule membrane fractions appeared to reflect cytosolic contamination. Contrastingly, PMA-pretreated cells lost cytosolic receptors; > 80% of PMA-binding sites were associated with non-granule membranes. Protein kinase C activity similarly shifted from cytosol to membranes after PMA treatment. Indeed, protein kinase C and PMA receptors co-sedimented on Percoll gradients, co-eluted from Ultragel AcA 44 columns loaded with neutrophil cytoplasm, and were identically influenced by various phospholipids. Finally, PMA, mezerein, diacylglycerol, and dialkylglycerol activated protein kinase C with potencies that paralleled their respective abilities to stimulate neutrophil aggregation responses and inhibit (/sup 3/H)PMA binding to whole cells or cytosol. These results fit a model of stimulus-response coupling wherein exogenous PMA or endogenous diacylglycerol solvate in cellular membranes. Cytosolic protein kinase C binds to the intramembranous ligand, forming an active, membrane-associated complex that phosphorylates nearby elements involved in triggering aggregation and other responses.

  6. Development of nanofibrous cellulose acetate/gelatin skin substitutes for variety wound treatment applications.

    PubMed

    Vatankhah, Elham; Prabhakaran, Molamma P; Jin, Guorui; Mobarakeh, Laleh Ghasemi; Ramakrishna, Seeram

    2014-02-01

    The major component of fibrous extracellular matrix of dermis is composed of a complex combination of proteins and polysaccharides. Electrospun cellulose acetate/gelatin might be an effective simulator of the structure and composition of native skin and during this study, we electrospun cellulose acetate/gelatin membranes in various compositions and their performance as a scaffold for either skin tissue engineering or as a wound dressing was evaluated. Skin treatment products, whether tissue-engineered scaffolds or wound dressings, should be sufficiently hydrophilic to allow for gas and fluid exchange and absorb excess exudates while controlling the fluid loss. However, a wound dressing should be easily removable without causing tissue damage and a tissue-engineered scaffold should be able to adhere to the wound, and support cell proliferation during skin regeneration. We showed that these distinct adherency features are feasible just by changing the composition of cellulose acetate and gelatin in composite cellulose acetate/gelatin scaffolds. High proliferation of human dermal fibroblasts on electrospun cellulose acetate/gelatin 25:75 confirmed the capability of cellulose acetate/gelatin 25:75 nanofibers as a tissue-engineered scaffold, while the electrospun cellulose acetate/gelatin 75:25 can be a potential low-adherent wound dressing. PMID:23640859

  7. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrophoresis apparatus for clinical use. 862... Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including...

  8. Acetic acid induces pH-independent cellular energy depletion in Salmonella enterica.

    PubMed

    Tan, Sin Mei; Lee, Sui Mae; Dykes, Gary A

    2015-03-01

    Weak organic acids are widely used as preservatives and disinfectants in the food industry. Despite their widespread use, the antimicrobial mode of action of organic acids is still not fully understood. This study investigated the effect of acetic acid on the cell membranes and cellular energy generation of four Salmonella strains. Using a nucleic acid/protein assay, it was established that acetic acid did not cause leakage of intracellular components from the strains. A scanning electron microscopy study further confirmed that membrane disruption was not the antimicrobial mode of action of acetic acid. Some elongated Salmonella cells observed in the micrographs indicated a possibility that acetic acid may inhibit DNA synthesis in the bacterial cells. Using an ATP assay, it was found that at a neutral pH, acetic acid caused cellular energy depletion with an ADP/ATP ratio in the range between 0.48 and 2.63 (p<0.05) that was apparent for the four Salmonella strains. We suggest that this effect was probably due solely to the action of undissociated acid molecules. The antimicrobial effect of acetic acid was better under acidic conditions (ADP/ATP ratio of 5.56 ± 1.27; p<0.05), where the role of both pH and undissociated acid molecules can act together. We concluded that the inhibitory effect of acetic acid is not solely attributable to acidic pH but also to undissociated acid molecules. This finding has implication for the use of acetic acid as an antimicrobial against Salmonella on food products, such as chicken meat, which can buffer its pH. PMID:25562466

  9. Tonoplast Vesicles of Opposite Sidedness from Soybean Hypocotyls by Preparative Free-Flow Electrophoresis 1

    PubMed Central

    Canut, Herv; Brightman, Andrew; Boudet, Alain M.; Morr, D. James

    1990-01-01

    Tonoplast vesicles were purified from a microsomal fraction isolated from etiolated soybean hypocotyls (Glycine max L.) by preparative free-flow electrophoresis. Marker enzyme determinations and immunoblot analysis against the vacuolar-ATPase confirmed the nature and the purity of the isolated membranes. A purified tonoplast fraction also was obtained by consecutive sucrose and glycerol centrifugation which was further resolved into two different populations of vesicles (TA and TB) by free-flow electrophoresis. The determination of the sidedness of these different vesicles included concanavalin A binding as an imposed label, NADH-ferricyanide oxidoreductase cytochemistry, and ATPase latency. The tonoplast fractions, obtained by consecutive sucrose and glycerol gradient centrifugations, were found to consist of a mixture of two populations of vesicles of opposite sidedness. The least electronegative fraction obtained by free-flow electrophoresis (TB) consisted predominantly of cytoplasmic side out tonoplast vesicles while a fraction of greater electronegativity (TA) contained the cytoplasmic side in tonoplast vesicles. The relative amounts of each type of vesicle varied with the method of homogenization. Razor blade chopping, Polytron, and Waring Blendor homogenization gave predominantly cytoplasmic side out vesicles, whereas mashing with a mortar and pestle gave nearly equal amounts of the two populations of membrane vesicles of different orientation. Images Figure 3 Figure 6 Figure 7 PMID:16667810

  10. Enzymatic production of glycerol acetate from glycerol.

    PubMed

    Oh, Seokhyeon; Park, Chulhwan

    2015-02-01

    In this study, we report the enzymatic production of glycerol acetate from glycerol and methyl acetate. Lipases are essential for the catalysis of this reaction. To find the optimum conditions for glycerol acetate production, sequential experiments were designed. Type of lipase, lipase concentration, molar ratio of reactants, reaction temperature and solvents were investigated for the optimum conversion of glycerol to glycerol acetate. As the result of lipase screening, Novozym 435 (Immobilized Candida antarctica lipase B) was turned out to be the optimal lipase for the reaction. Under the optimal conditions (2.5 g/L of Novozym 435, 1:40 molar ratio of glycerol to methyl acetate, 40 °C and tert-butanol as the solvent), glycerol acetate production was achieved in 95.00% conversion. PMID:25640720

  11. Membrane stabilizer

    DOEpatents

    Mingenbach, William A. (P.O. Box 49, Taos, NM 87571)

    1988-01-01

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material.

  12. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  13. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  14. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  15. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  16. Numerical simulation of electrophoresis separation processes

    NASA Technical Reports Server (NTRS)

    Ganjoo, D. K.; Tezduyar, T. E.

    1986-01-01

    A new Petrov-Galerkin finite element formulation has been proposed for transient convection-diffusion problems. Most Petrov-Galerkin formulations take into account the spatial discretization, and the weighting functions so developed give satisfactory solutions for steady state problems. Though these schemes can be used for transient problems, there is scope for improvement. The schemes proposed here, which consider temporal as well as spatial discretization, provide improved solutions. Electrophoresis, which involves the motion of charged entities under the influence of an applied electric field, is governed by equations similiar to those encountered in fluid flow problems, i.e., transient convection-diffusion equations. Test problems are solved in electrophoresis and fluid flow. The results obtained are satisfactory. It is also expected that these schemes, suitably adapted, will improve the numerical solutions of the compressible Euler and the Navier-Stokes equations.

  17. Sampling techniques for single-cell electrophoresis

    PubMed Central

    Cecala, Christine; Sweedler, Jonathan V.

    2013-01-01

    Cells are extraordinarily complex, containing thousands of different analytes with concentrations spanning at least nine orders of magnitude. Analyzing single cells instead of tissue homogenates provides unique insights into cell-to-cell heterogeneity and aids in distinguishing normal cells from pathological ones. The high sensitivity and low sample consumption of capillary and on-chip electrophoresis, when integrated with fluorescence, electrochemical, and mass spectrometric detection methods, offer an ideal toolset for examining single cells and even subcellular organelles; however, the isolation and loading of such small samples into these devices is challenging. Recent advances have addressed this issue by interfacing a variety of enhanced mechanical, microfluidic, and optical sampling techniques to capillary and on-chip electrophoresis instruments for single-cell analyses. PMID:22288071

  18. Fish Muscle Proteins: Extraction, Quantitation, and Electrophoresis

    NASA Astrophysics Data System (ADS)

    Smith, Denise

    Electrophoresis can be used to separate and visualize proteins. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), proteins are separated based on size. When protein samples are applied to such gels, it is usually necessary to know the protein content of the sample. This makes it possible to apply a volume of sample to the gel such that samples have a comparable amount of total protein. While it is possible to use an official method of protein analysis (e.g., Kjeldahl, N combustion) for such an application, it often is convenient to use a rapid spectroscopic protein analysis that requires only a small amount of sample. The bicinchoninic acid (BCA) assay method will be used for this purpose.

  19. DNA electrophoresis in a nanofence array

    PubMed Central

    Park, Sung-Gyu; Olson, Daniel W.

    2012-01-01

    We present the design and implementation of an oxidized silicon nanofence array for long DNA electrophoresis. The device consists of a periodic array of post-filled regions (the nanofences) alternating with empty channel regions. Even in this prototype version, the nanofence array provides the resolving power of a hexagonal nanopost array without requiring any direct-write nanopatterning steps such as electron-beam lithography. Through detailed single molecule investigations, we demonstrate that the origin of the resolving power of the nanofence array is not a reduction in band broadening, which might be expected from the theories for DNA electrophoresis in post arrays. Rather, the enhanced stretching of the hooked DNA by the uniform electric field between nanofences increases the efficiency of the collisions. PMID:22388662

  20. A method and apparatus for continuous electrophoresis

    SciTech Connect

    Watson, J.S.

    1990-01-01

    A method and apparatus for conducting continuous separation of substances by electrophoresis are disclosed. The process involves electrophoretic separation combined with couette flow in a thin volume defined by opposing surfaces. By alternating the polarity of the applied potential and producing reciprocating short rotations of at least on of the surfaces relative to the other, small increments of separation accumulate to cause substantial, useful segregation of electrophoretically separable components in a continuous flow system.

  1. Portable electrophoresis apparatus using minimum electrolyte

    NASA Technical Reports Server (NTRS)

    Stevens, M. R.; Vickers, J. M. (Inventor)

    1976-01-01

    An electrophoresis unit for use in conducting electrophoretic analysis of specimens is described. The unit includes a sealable container in which a substrate mounted specimen is suspended in an electrolytic vapor. A heating unit is employed to heat a supply of electrolyte to produce the vapor. The substrate is suspended within the container by being attached between a pair of clips which also serve as electrodes to which a direct current power source may be connected.

  2. Method and apparatus for continuous electrophoresis

    DOEpatents

    Watson, Jack S. (Knoxville, TN)

    1992-01-01

    A method and apparatus for conducting continuous separation of substances by electrophoresis are disclosed. The process involves electrophoretic separation combined with couette flow in a thin volume defined by opposing surfaces. By alternating the polarity of the applied potential and producing reciprocating short rotations of at least one of the surfaces relative to the other, small increments of separation accumulate to cause substantial, useful segregation of electrophoretically separable components in a continuous flow system.

  3. Capillary zone electrophoresis-mass spectrometer interface

    DOEpatents

    D'Silva, Arthur

    1996-08-06

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conducts is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer.

  4. Capillary zone electrophoresis-mass spectrometer interface

    DOEpatents

    D`Silva, A.

    1996-08-06

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conductors is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer. 1 fig.

  5. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, Edward S. (Ames, IA); Taylor, John A. (Nevada, IA)

    1996-03-12

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.

  6. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, Edward S. (Ames, IA); Taylor, John A. (Nevada, IA)

    1994-06-28

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.

  7. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, E.S.; Taylor, J.A.

    1994-06-28

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis. 14 figures.

  8. Determination of protein association constants by electrophoresis.

    PubMed

    Matejec, R; Schnert, H

    1998-08-24

    An electrophoresis cell with scanning UV-absorption optics is presented. It allows the measurement of moving reaction boundaries of dilute protein solutions with a high-resolution. The protein profiles in the boundaries can be extrapolated to infinite time after an appropriate transformation of space and time coordinates and then evaluated with respect to association constants. This is demonstrated for the dimer-tetramer equilibrium of haemoglobin. PMID:17029737

  9. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, E.S.; Taylor, J.A.

    1996-03-12

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis. 14 figs.

  10. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3 or C2H3O2Na·3H2O, CAS Reg. No. 6131-90-4) is the sodium salt of acetic acid and occurs naturally in plant...

  11. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3 or C2H3O2Na·3H2O, CAS Reg. No. 6131-90-4) is the sodium salt of acetic acid and occurs naturally in plant...

  12. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3 or C2H3O2Na·3H2O, CAS Reg. No. 6131-90-4) is the sodium salt of acetic acid and occurs naturally in plant...

  13. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3 or C2H3O2Na·3H2O, CAS Reg. No. 6131-90-4) is the sodium salt of acetic acid and occurs naturally in plant...

  14. Neuronal network analysis of serum electrophoresis.

    PubMed Central

    Kratzer, M. A.; Ivandic, B.; Fateh-Moghadam, A.

    1992-01-01

    AIMS: To advise a system of neuronal networks which can classify the densitometric patterns of serum electrophoresis. METHODS: Digitised data containing 83 normal and 132 pathological serum protein electrophoresis patterns were presented to four neuronal networks containing 1900 neurons. Network 1 evaluates the integrated values of the albumin, alpha 1, alpha 2, beta and gamma fractions together with total protein (Biuret method). Networks 2, 3, and 4 analyse the shape of the albumin, beta and gamma fractions. To increase the sensitivity for the detection of monoclonal gammopathies a Fourier transformation was applied to the beta and gamma fractions. RESULTS: After a learning period of 20 minutes (back-propagation learning algorithm) the system was tested with a set of electrophoresis patterns comprising 446 routinely collected samples. It differentiated between physiological and pathological curves with a sensitivity of 97.5% and a specificity of 98.8%, with 86% correct diagnoses. All monoclonal gammopathies were recognised by the Fourier detector. CONCLUSIONS: Neuronal networks could be useful for certain medical uses. Unlike rule based systems, neuronal networks do not have to be programmed but have the capacity to "learn" quickly. PMID:1517463

  15. Detection of telomerase activity using microchip electrophoresis.

    PubMed

    Karasawa, Koji; Arakawa, Hidetoshi

    2015-07-01

    Telomerase participates in malignant transformation or immortalization of cells and thus has attracted attention as an anticancer drug target and diagnostic tumor marker. The telomeric repeat amplification protocol (TRAP) and improved TRAP methods (TRAP-fluorescence, TRAP-hybridization, etc.) are widely used forms of this telomerase assay. However, these approaches generally employ acrylamide gel electrophoresis after amplification of telomeric repeats by polymerase chain reaction (PCR), making these TRAP methods time consuming and technically demanding. In this study we developed a novel telomerase assay using microchip electrophoresis for rapid and highly sensitive detection of telomerase activity in cancer cells. The mixed gel of 0.8% hydroxypropyl methylcellulose (HPMC) and 0.3% polyethylene oxide (PEO) with SYBR Gold (fluorescent reagent) was used for microchip electrophoresis. As a result, the product amplified by a telomerase-positive cell could be measured in one cell per assay and detected with high reproducibility (CV=0.67%) in the short time of 100s. PMID:25980765

  16. Detection of biclonal gammopathy by capillary zone electrophoresis in a cat and a dog with plasma cell neoplasia.

    PubMed

    Facchini, Roberto Vailati; Bertazzolo, Walter; Zuliani, Davide; Bonfanti, Ugo; Caldin, Marco; Avallone, Giancarlo; Roccabianca, Paola

    2010-12-01

    Gammopathies associated with plasma cell neoplasms in a 15-year-old female spayed domestic shorthaired cat and a 9-year-old female spayed Rottweiler dog were evaluated by serum protein electrophoresis. In the cat, the plasma cell neoplasm was found in the liver and spleen, and an evaluable sample of bone marrow was not obtained. Some of the plasma cells had the morphologic appearance of flame cells. The paraprotein was confirmed as IgG based on agar gel immunodiffusion precipitation and both immunocytochemical and immunohistochemical staining. The dog had multiple myeloma with production of IgG and IgA paraproteins. In both cases, serum proteins were evaluated by 2 methods of protein electrophoresis: cellulose acetate electrophoresis (CAE) and capillary zone electrophoresis (CZE). In the cat and the dog, CAE showed a single large oligoclonal-like peak, which occurred in the γ-region in the cat and the β-γ-region in the dog, whereas CZE showed a biclonal gammopathy with 2 very close narrow spikes in the γ- and β-γ-regions in the cat and dog, respectively. In selected cases, CZE may be more effective than routine CAE in distinguishing oligoclonal from monoclonal or biclonal paraproteinemia. PMID:21039713

  17. Enhancement of acetyl xylan esterase activity on cellulose acetate through fusion to a family 3 cellulose binding module.

    PubMed

    Mai-Gisondi, Galina; Turunen, Ossi; Pastinen, Ossi; Pahimanolis, Nikolaos; Master, Emma R

    2015-11-01

    The current study investigates the potential to increase the activity of a family 1 carbohydrate esterase on cellulose acetate through fusion to a family 3 carbohydrate binding module (CBM). Specifically, CtCBM3 from Clostridium thermocellum was fused to the carboxyl terminus of the acetyl xylan esterase (AnAXE) from Aspergillus nidulans, and active forms of both AnAXE and AnAXE-CtCBM3 were produced in Pichia pastoris. CtCBM3 fusion had negligible impact on the thermostability or regioselectivity of AnAXE; activities towards acetylated corncob xylan, 4-methylumbelliferyl acetate, p-nitrophenyl acetate, and cellobiose octaacetate were also unchanged. By contrast, the activity of AnAXE-CtCBM3 on cellulose acetate increased by two to four times over 24 h, with greater differences observed at earlier time points. Binding studies using microcrystalline cellulose (Avicel) and a commercial source of cellulose acetate confirmed functional production of the CtCBM3 domain; affinity gel electrophoresis using acetylated xylan also verified the selectivity of CtCBM3 binding to cellulose. Notably, gains in enzyme activity on cellulose acetate appeared to exceed gains in substrate binding, suggesting that fusion to CtCBM3 increases functional associations between the enzyme and insoluble, high molecular weight cellulosic substrates. PMID:26320711

  18. Extractive fermentation of acetic acid

    SciTech Connect

    Busche, R.M.

    1991-12-31

    In this technoeconomic evaluation of the manufacture of acetic acid by fermentation, the use of the bacterium: Acetobacter suboxydans from the old vinegar process was compared with expected performance of the newer Clostridium thermoaceticum bacterium. Both systems were projected to operate as immobilized cells in a continuous, fluidized bed bioreactor, using solvent extraction to recover the product. Acetobacter metabolizes ethanol aerobically to produce acid at 100 g/L in a low pH medium. This ensures that the product is in the form of a concentrated extractable free acid, rather than as an unextractable salt. Unfortunately, yields from glucose by way of the ethanol fermentation are poor, but near the biological limits of the organisms involved. Conversely, C. thermoaceticum is a thermophilic anaerobe that operates at high fermentation rates on glucose at neutral pH to produce acetate salts directly in substantially quantitative yields. However, it is severely inhibited by product, which restricts concentration to a dilute 20 g/L. An improved Acetobacter system operating with recycled cells at 50 g/L appears capable of producing acid at $0.38/lb, as compared with a $0.29/lb price for synthetic acid. However, this system has only a limited margin for process improvement. The present Clostridium system cannot compete, since the required selling price would be $0.42/lb. However, if the organism could be adapted to tolerate higher product concentrations at acid pH, selling price could be reduced to $0.22/lb, or about 80% of the price of synthetic acid.

  19. Automated extraction of direct, reactive, and vat dyes from cellulosic fibers for forensic analysis by capillary electrophoresis.

    PubMed

    Dockery, C R; Stefan, A R; Nieuwland, A A; Roberson, S N; Baguley, B M; Hendrix, J E; Morgan, S L

    2009-08-01

    Systematic designed experiments were employed to find the optimum conditions for extraction of direct, reactive, and vat dyes from cotton fibers prior to forensic characterization. Automated microextractions were coupled with measurements of extraction efficiencies on a microplate reader UV-visible spectrophotometer to enable rapid screening of extraction efficiency as a function of solvent composition. Solvent extraction conditions were also developed to be compatible with subsequent forensic characterization of extracted dyes by capillary electrophoresis with UV-visible diode array detection. The capillary electrophoresis electrolyte successfully used in this work consists of 5 mM ammonium acetate in 40:60 acetonitrile-water at pH 9.3, with the addition of sodium dithionite reducing agent to facilitate analysis of vat dyes. The ultimate goal of these research efforts is enhanced discrimination of trace fiber evidence by analysis of extracted dyes. PMID:19536528

  20. Aurantiamide acetate suppresses the growth of malignant gliomas in vitro and in vivo by inhibiting autophagic flux

    PubMed Central

    Yang, Yi; Zhang, Li-hui; Yang, Bing-xian; Tian, Jin-kui; Zhang, Lin

    2015-01-01

    We aim to investigate the effect of aurantiamide acetate isolated from the aerial parts of Clematis terniflora DC against gliomas. Human malignant glioma U87 and U251 cells were incubated with different concentrations (0100?M) of aurantiamide acetate. Aurantiamide acetate greatly decreased the cell viability in a dose- and time-dependent manner. It induced moderate mitochondrial fragmentation and the loss of mitochondrial membrane potential. No significant difference was found in the alternation of other intracellular organelles, although F-actin structure was slightly disturbed. Apparent ultrastructure alternation with increased autophagosome and autolysosome accumulation was observed in aurantiamide acetate-treated cells. The expression of LC3-II was greatly up-regulated in cells exposed to aurantiamide acetate (P<0.05 compared with control). The cytoplasmic accumulation of autophagosomes and autolysosomes induced by aurantiamide acetate treatment was confirmed by fluorescent reporter protein labelling. Administration of chloroquine (CQ), which inhibits the fusion step of autophagosomes, further increased the accumulation of autophagosomes in the cytoplasm of U87 cells. Autophagy inhibition by 3-methyladenine, Bafilomycin A1 or CQ had no influence on aurantiamide acetate-induced cytotoxicity, whereas autophagy stimulator rapamycin significantly suppressed aurantiamide acetate-induced cell death. The anti-tumour effects of aurantiamide acetate were further evaluated in tumour-bearing nude mice. Intratumoural injection of aurantiamide acetate obviously suppressed tumour growth, and increased number of autophagic vacuoles was observed in tumour tissues of animals receiving aurantiamide acetate. Our findings suggest that aurantiamide acetate may suppress the growth of malignant gliomas by blocking autophagic flux. PMID:25704599

  1. Electrophoretic extraction of proteins from two-dimensional electrophoresis gel spots

    DOEpatents

    Zhang, Jian-Shi (Shanghai, CN); Giometti, Carol S. (Glenview, IL); Tollaksen, Sandra L. (Montgomery, IL)

    1989-01-01

    After two-dimensional electrophoresis of proteins or the like, resulting in a polyacrylamide gel slab having a pattern of protein gel spots thereon, an individual protein gel spot is cored out from the slab, to form a gel spot core which is placed in an extraction tube, with a dialysis membrane across the lower end of the tube. Replicate gel spots can be cored out from replicate gel slabs and placed in the extraction tube. Molten agarose gel is poured into the extraction tube where the agarose gel hardens to form an immobilizing gel, covering the gel spot cores. The upper end portion of the extraction tube is filled with a volume of buffer solution, and the upper end is closed by another dialysis membrane. Upper and lower bodies of a buffer solution are brought into contact with the upper and lower membranes and are provided with electrodes connected to the positive and negative terminals of a DC power supply, thereby producing an electrical current which flows through the upper membrane, the volume of buffer solution, the agarose, the gel spot cores and the lower membrane. The current causes the proteins to be extracted electrophoretically from the gel spot cores, so that the extracted proteins accumulate and are contained in the space between the agarose gel and the upper membrane. A high percentage extraction of proteins is achieved. The extracted proteins can be removed and subjected to partial digestion by trypsin or the like, followed by two-dimensional electrophoresis, resulting in a gel slab having a pattern of peptide gel spots which can be cored out and subjected to electrophoretic extraction to extract individual peptides.

  2. 27 CFR 21.107 - Ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ethyl acetate. 21.107 Section 21.107 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.107 Ethyl acetate. (a) 85 percent ester:...

  3. Manufacturing Ethyl Acetate From Fermentation Ethanol

    NASA Technical Reports Server (NTRS)

    Rohatgi, Naresh K.; Ingham, John D.

    1991-01-01

    Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

  4. 21 CFR 522.533 - Deslorelin acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Deslorelin acetate. 522.533 Section 522.533 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.533 Deslorelin acetate. (a) Specifications....

  5. Detection of glycoproteins in the Acanthamoeba plasma membrane

    SciTech Connect

    Paatero, G.I.L. ); Gahmberg, C.G. )

    1988-11-01

    In the present study the authors have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by {sup 125}I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB{sup 3}H{sub 4} and galactose oxidase/NaB{sup 3}H{sub 4} labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with M{sub r} of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic labeling with ({sup 35}S)methionine followed by lectin-Sepharose affinity chromatography and polyacrylamide gel electrophoresis.

  6. Detection of glycoproteins in the Acanthamoeba plasma membrane.

    PubMed

    Paatero, G I; Gahmberg, C G

    1988-11-01

    In the present study we have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by 125I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB3H4 and galactose oxidase/NaB3H4 labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with Mr of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic labeling with [35S]methionine followed by lectin-Sepharose affinity chromatography and polyacrylamide gel electrophoresis. PMID:3169144

  7. Degeneration and regeneration of chloroplasts in Euglena gracilis grown in the presence of acetate: ultrastructural evidence.

    PubMed

    Vannini, G L

    1983-05-01

    When green cells of Euglena gracilis, strain Z, were light-grown for several months on a solid medium containing an excess of sodium acetate (1.0% instead of the normal 0.1%), some 30% of the cells were colourless. The 'acetate-bleached' organisms, isolated by plating methods and subsequently incubated in the light in a liquid medium, regained the capacity to form chlorophyll in a few days in the absence of any organic carbon source, and within 1-2 weeks in the presence of 0.1% acetate. A number of bleached colonies, however, gave rise to populations in which the delay in pigment synthesis initiation was at least 2 months. Besides numerous paramylum granules and lipid inclusions, the acetate-bleached cells exhibited variably shaped and sized plastids, apparently lacking in ribosomes and showing a deeply disorganized membrane system. In the alga greened in the presence of 0.1% acetate, the pattern of plastidome reorganization was altered; the thylakoids were often unpaired and vesiculated in different degrees, owing primarily to the swelling of the lumen. A complete recovery of normal chloroplast structure occurred only after several weeks of exponential growth. The entire population greened in the absence of acetate constantly showed normal chloroplasts with perfectly reassociated thylakoids and clear partitions. PMID:6411750

  8. The fluid mechanics of continuous flow electrophoresis

    NASA Technical Reports Server (NTRS)

    Saville, D. A.

    1990-01-01

    The overall objective is to establish theoretically and confirm experimentally the ultimate capabilities of continuous flow electrophoresis chambers operating in an environment essentially free of particle sedimentation and buoyancy. The efforts are devoted to: (1) studying the effects of particle concentration on sample conductivity and dielectric constant. The dielectric constant and conductivity were identified as playing crucial roles in the behavior of the sample and on the resolving power and throughput of continuous flow devices; and (2) improving the extant mathematical models to predict flow fields and particle trajectories in continuous flow electrophoresis. A dielectric spectrometer was designed and built to measure the complex dielectric constant of a colloidal dispersion as a function of frequency between 500 Hz and 200 kHz. The real part of the signal can be related to the sample's conductivity and the imaginary part to its dielectric constant. Measurements of the dielectric constants of several different dispersions disclosed that the dielectric constants of dilute systems of the sort encountered in particle electrophoresis are much larger than would be expected based on the extant theory. Experiments were carried out to show that, in many cases, this behavior is due to the presence of a filamentary structure of small hairs on the particle surface. A technique for producing electrokinetically ideal synthetic latex particles by heat treating was developed. Given the ubiquitous nature of hairy surfaces with both cells and synthetic particles, it was deemed necessary to develop a theory to explain their behavior. A theory for electrophoretic mobility of hairy particles was developed. Finally, the extant computer programs for predicting the structure of electro-osmotically driven flows were extended to encompass flow channels with variable wall mobilities.

  9. Ulipristal acetate in emergency contraception.

    PubMed

    Goldstajn, Marina Sprem; Baldani, Dinka Pavici?; Skrgati?, Lana; Radakovi?, Branko; Vrbi?, Hrvoje; Cani?, Tomislav

    2014-03-01

    Despite the widespread availability of highly effective methods of contraception, unintended pregnancy is common. Unplanned pregnancies have been linked to a range of health, social and economic consequences. Emergency contraception reduces risk of pregnancy after unprotected intercourse, and represents an opportunity to decrease number of unplanned pregnancies and abortions. Emergency contraception pills (ECP) prevent pregnancy by delaying or inhibiting ovulation, without interfering with post fertilization events. If pregnancy has already occurred, ECPs will not be effective, therefore ECPs are not abortificants. Ulipristal acetate (17alpha-acetoxy-11beta-(4N-N,N-dymethilaminophenyl)-19-norpregna--4,9-diene-3,20-dione) is the first drug that was specifically developed and licensed for use as an emergency contraceptive. It is an orally active, synthetic, selective progesterone modulator that acts by binding with high affinity to the human progesterone receptor where it has both antagonist and partial agonist effects. It is a new molecular entity and the first compound in a new pharmacological class defined by the pristal stem. Up on the superior clinical efficacy evidence, UPA has been quickly recognized as the most effective emergency contraceptive pill, and recently recommended as the first prescription choice for all women regardless of the age and timing after intercourse. This article provides literature review of UPA and its role in emergency contraception. PMID:24851646

  10. Capillary zone electrophoresis in pharmaceutical analysis.

    PubMed

    Fanali, S; Cristalli, M; Nardi, A; Ossicini, L; Shukla, S K

    1990-06-01

    The paper presents a brief characterization of capillary zone electrophoresis, a modern analytical separation method with high expediency for practical applications, especially in pharmaceutical analysis. Basic theoretical considerations are presented and discussed to explain the effects of the operational parameters upon the separation efficiency and resolution of species. Descriptions of simple instrumentation and of the analytical procedure itself are given. Experimental examples are given of the separation of mixtures of pharmaceutically important compounds and of the effects of operational parameters, especially pH of BGE and voltage applied. Lastly, the practical application of CZE for analysis of isoxsuprine in commercial preparations is shown. PMID:2205222

  11. Flat Gel Polyacrylamide Electrophoresis of Porcine Mycoplasmas

    PubMed Central

    Wreghitt, T. G.; Windsor, G. D.; Butler, M.

    1974-01-01

    The flat gel acrylamide electrophoresis technique was standardized and applied to the comparison of four species of porcine mycoplasmas. Clear differences were observed between these species, and differences were seen among the strains of Mycoplasma hyosynoviae. The clarity of the patterns and the number of bands developed was influenced by the amount of protein in the extract and the age of the culture. The technique allows the comparison of several protein extracts in parallel without the problems associated with the rearrangement of separate gel columns. Images PMID:4472455

  12. Flat gel polyacrylamide electrophoresis of porcine mycoplasmas.

    PubMed

    Wreghitt, T G; Windsor, G D; Butler, M

    1974-10-01

    The flat gel acrylamide electrophoresis technique was standardized and applied to the comparison of four species of porcine mycoplasmas. Clear differences were observed between these species, and differences were seen among the strains of Mycoplasma hyosynoviae. The clarity of the patterns and the number of bands developed was influenced by the amount of protein in the extract and the age of the culture. The technique allows the comparison of several protein extracts in parallel without the problems associated with the rearrangement of separate gel columns. PMID:4472455

  13. Determination of aristolochic acids by capillary electrophoresis.

    PubMed

    Priestap, Horacio A; Iglesias, Silvia L; Desimone, Martín F; Diaz, Luis E

    2003-01-01

    A method for the separation and quantification of aristolochic acids by capillary electrophoresis is described. Buffer solutions composed of sodium dihydrogen phosphate, sodium borate, and sodium dodecyl sulfate at pH 6.5-7 were found to be suitable for the separation of aristolochic acids, which can be well resolved in a few minutes. The separation and identification of six aristolochic acids contained in a commercial tincture called charrua, a traditional herbal medicine consisting of a hydroalcoholic extract of Aristolochia argentina, corroborate the usefulness of the method. The eventual toxic properties of the aristolochic acid containing charrua tincture are discussed. PMID:14596334

  14. A new approach to scaling up electrophoresis

    SciTech Connect

    Tarnopolsky, Y.; Roman, M.; Brown, P.R.

    1993-01-01

    Free Flow Electrophoresis (FFE) has been utilized for the separation of proteins and cells for many years, and has evolved into the most promising method of continuous separation. One of the major drawbacks inherent with FFE, however, is the thermal convection due to Joule heating which occurs whenever current is passed through a conducting solution. To provide efficient heat dissipation, the size of FFE units is restricted, which limits sample throughput. A new type of FFE design, which internally cools the separation unit by passing water through capillary tubes, has been developed and tested. Results of separations of dyes are presented, using a bed {1/4} inch thick which maintains efficient cooling.

  15. Microfabricated capillary array electrophoresis device and method

    DOEpatents

    Simpson, Peter C.; Mathies, Richard A.; Woolley, Adam T.

    2004-06-15

    A capillary array electrophoresis (CAE) micro-plate with an array of separation channels connected to an array of sample reservoirs on the plate. The sample reservoirs are organized into one or more sample injectors. One or more waste reservoirs are provided to collect wastes from reservoirs in each of the sample injectors. Additionally, a cathode reservoir is also multiplexed with one or more separation channels. To complete the electrical path, an anode reservoir which is common to some or all separation channels is also provided on the micro-plate. Moreover, the channel layout keeps the distance from the anode to each of the cathodes approximately constant.

  16. Microfabricated capillary array electrophoresis device and method

    DOEpatents

    Simpson, Peter C. (Oakland, CA); Mathies, Richard A. (Moraga, CA); Woolley, Adam T. (Belmont, MA)

    2000-01-01

    A capillary array electrophoresis (CAE) micro-plate with an array of separation channels connected to an array of sample reservoirs on the plate. The sample reservoirs are organized into one or more sample injectors. One or more waste reservoirs are provided to collect wastes from reservoirs in each of the sample injectors. Additionally, a cathode reservoir is also multiplexed with one or more separation channels. To complete the electrical path, an anode reservoir which is common to some or all separation channels is also provided on the micro-plate. Moreover, the channel layout keeps the distance from the anode to each of the cathodes approximately constant.

  17. Hybrid slab-microchannel gel electrophoresis system

    SciTech Connect

    Balch, Joseph W.; Carrano, Anthony V.; Davidson, James C.; Koo, Jackson C.

    1998-01-01

    A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.

  18. Electrophoretic extraction of proteins from two-dimensional electrophoresis gel spots

    DOEpatents

    Zhang, Jian-Shi; Giometti, C.S.; Tollaksen, S.L.

    1987-09-04

    After two-dimensional electrophoresis of proteins or the like, resulting in a polyacrylamide gel slab having a pattern of protein gel spots thereon, an individual protein gel spot is cored out from the slab, to form a gel spot core which is placed in an extraction tube, with a dialysis membrane across the lower end of the tube. Replicate gel spots can be cored out from replicate gel slabs and placed in the extraction tube. Molten agarose gel is poured into the extraction tube where the agarose gel hardens to form an immobilizing gel, covering the gel spot cores. The upper end portion of the extraction tube is filled with a volume of buffer solution, and the upper end is closed by another dialysis membrane. Upper and lower bodies of a buffer solution are brought into contact with the upper and lower membranes and are provided with electrodes connected to the positive and negative terminals of a dc power supply, thereby producing an electrical current which flows through the upper membrane, the volume of buffer solution, the agarose, the gel spot cores and the lower membrane. The current causes the proteins to be extracted electrophoretically from the gel spot cores, so that the extracted proteins accumulate and are contained in the space between the agarose gel and the upper membrane. 8 figs.

  19. Membrane stabilizer

    DOEpatents

    Mingenbach, W.A.

    1988-02-09

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material. 10 figs.

  20. Immobilized Metal Affinity Electrophoresis: A Novel Method of Capturing Phosphoproteins by Electrophoresis

    PubMed Central

    Lee, Bao-Shiang; Lasanthi, G.D.; Jayathilaka, P.; Huang, Jin-Sheng; Gupta, Shalini

    2008-01-01

    An immobilized metal affinity electrophoresis (IMAEP) method is described here. In this method, metal ions are immobilized in a native polyacrylamide gel to capture phosphoproteins. The capture of phosphoproteins by IMAEP is demonstrated with immobilized metals like iron, aluminum, manganese, or titanium. In the case studies, phosphoproteins ?-casein, ?-casein, and phosvitin are successfully extracted from a protein mixture by IMAEP. PMID:19137092

  1. Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.

    PubMed

    Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

    2013-01-01

    When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2, MIPC 9.1, M(IP)2C 2.2) and Z. bailii (IPC 4.9, MIPC 2.7, M(IP)2C 2.7), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile. PMID:24023914

  2. Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress

    PubMed Central

    Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

    2013-01-01

    When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L?1, while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L?1 acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2, MIPC 9.1, M(IP)2C 2.2) and Z. bailii (IPC 4.9, MIPC 2.7, M(IP)2C 2.7), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile. PMID:24023914

  3. Monitoring of arrays of amino acids in clinical samples using capillary electrophoresis with contactless conductivity detection.

    PubMed

    T?ma, Petr; Stulk, Karel

    2013-01-01

    Capillary electrophoresis (CE) with contactless conductivity detection (C(4)D) is readily applicable to determinations of amino acids in clinical samples. Most of these analyses employ long separation pathways. This chapter describes CE/C(4)D determinations of 28 biogenic amino acids in a short capillary with an effective length of 18 cm. All the test amino acids can be mutually separated in electrolytes of 0.5-10 mol/L acetic acid. The time of analysis does not exceed 6 min; the limits of detection vary from 0.1 to 1.7 ?mol/L for all the analytes. The pretreatment of the biological material is very simple, consisting of the removal of proteins by an addition of acetonitrile and subsequent filtration. The procedure has been successfully applied to determinations of the whole amino acid spectra in blood plasma, urine, saliva, cerebrospinal, and amniotic fluid samples. PMID:22976086

  4. Separation and determination of strychnine and brucine in Strychnos nux-vomica L. and its preparation by nonaqueous capillary electrophoresis.

    PubMed

    Li, Yuqin; He, Xiaojun; Qi, Shengda; Gao, Wenhua; Chen, Xingguo; Hu, Zhide

    2006-05-01

    An easy, rapid method for simultaneous determination of strychnine and brucine in Strychnos nux-vomica L. and its preparation was developed by nonaqueous capillary electrophoresis (NACE) without pretreatment for the first time. Optimum separation was achieved with a fused-silica capillary column (50 cmx75 microm i.d.) and a running buffer containing 30 mM ammonium acetate, 1.0% acetic acid and 15% acetonitrile (ACN) in methanol medium. The applied voltage was 30.0 kV. The analytes were detected by UV at 214 nm. The effects of concentration of ammonium acetate, acetic acid and organic modifier on electrophoretic behavior of the analytes were studied. The established method with sophoridine as internal standard was linear in the range of 5-1000 mg/mL for both strychnine and brucine. The extracts of Strychnos nux-vomica and its preparation could be directly injected for determination with recoveries ranging from 94.5 to 104%. PMID:16406713

  5. Separation and determination of homologues of linear alkylbenzenesulfonates by nonaqueous capillary zone electrophoresis using alkylammonium salts in ethanol.

    PubMed

    Herrero-Martínez, J M; Simó-Alfonso, E F; Ramis-Ramos, G

    2001-06-01

    The separation of linear alkylbenzene sulfonates (LAS) by nonaqueous capillary electrophoresis (NACE) using negative polarity, and a buffer containing acetic acid and an alkylamine in nonaqueous ethanol, has been investigated. Several primary, secondary, and tertiary alkylamines with alkyl chains of different length were compared. The solutes travelled against the electroosmotic flow (EOF), and at the same time were braked by association with the alkylamine molecules or with the alkylammonium ions. The best resolution between adjacent LAS homologues (R approximately 2.1), partial isomer resolution in two peaks, and at the same time an excellent repeatability, was obtained with a small dipentylamine excess over the acetic acid. When the buffer concentration increased, resolution between the homologues increased slightly (R approximately 2.4), and a different isomer group was partially separated. A background electrolyte (BGE) containing 10 mM acetic acid and 20 mM dipentylamine to separate and quantify the homologues within 25 min is recommended. The isomer peak profile with up to three peaks can be estimated using this buffer and another one with 80 mM acetic acid and 90 mM dipentylamine. The former BGE was used to determine LAS in liquid and powder laundry detergents. The detection limit for the determination of total LAS in these products was 2.5 microg mL(-1), and the peak area and migration time interday repeatabilities were below 4.3 and 2.8%, respectively. PMID:11465501

  6. Micro-injector for capillary electrophoresis.

    PubMed

    Siz, Jorge; Koenka, Israel Joel; Garca-Ruiz, Carmen; Mller, Beat; Chwalek, Thomas; Hauser, Peter C

    2015-08-01

    A novel micro-injector for capillary electrophoresis for the handling of samples with volumes down to as little as 300 nL was designed and built in our laboratory for analyses in which the available volume is a limitation. The sample is placed into a small cavity located directly in front of the separation capillary, and the injection is then carried out automatically by controlled pressurization of the chamber with compressed air. The system also allows automated flushing of the injection chamber as well as of the capillary. In a trial with a capillary electrophoresis system with contactless conductivity detector, employing a capillary of 25 ?m diameter, the results showed good stability of migration times and peak areas. To illustrate the technique, the fast separation of five inorganic cations (Na(+) , K(+) , NH4 (+) , Ca(2+) , and Mg(2+) ) was set up. This could be achieved in less than 3 min, with good limits of detection (10 ?M) and linear ranges (between about 10 and 1000 ?M). The system was demonstrated for the determination of the inorganic cations in porewater samples of a lake sediment core. PMID:25752271

  7. Fractionation of mineral species by electrophoresis

    NASA Technical Reports Server (NTRS)

    Dunning, J. D.; Herren, B. J.; Tipps, R. W.; Snyder, R. S.

    1982-01-01

    The fractionation of fine-grained aggregates into their major components is a problem in many scientific areas including earth and planetary science. Electrophoresis, the transport of electrically charged particles, immersed in a suspension medium, by a direct current field (Bier, 1959), was employed in this study as a means of separating simulated lunar soil into its constituent minerals. In these tests, conducted in a static analytical cylindrical microelectrophoresis apparatus, samples of simulated lunar soil and samples of pure mineral constituents were placed in the chamber; the electrophoretic mobilities of the lunar soil and the individual mineral constituents were measured. In most of the suspension buffers employed separability was indicated, on the basis of differences in mobility, for all the constituent mineral species except ilmenite and pyroxene, which were not efficiently separable in any of the buffers. Although only a few suspension media were employed, the success of this initial study suggests that electrophoresis may be an important mineral fractionation option in fine-grained aggregate processing.

  8. Capillary Electrophoresis coupled with Automated Fraction Collection

    PubMed Central

    Huge, Bonnie Jaskowski; Flaherty, Ryan; Dada, Oluwatosin O.; Dovichi, Norman J.

    2014-01-01

    A fraction collector based on a drop-on-demand ink-jet printer was developed to interface capillary zone electrophoresis with a 96 well microtiter plate. We first evaluated the performance of the collector by using capillary zone electrophoresis to analyze a 1 mM solution of tetramethylrhodamine; a fluorescent microtiter plate reader was then used to detect the analyte and characterize fraction carryover between wells. Relative standard deviation in peak height was 20% and the relative standard deviation in migration time was 1%. The mean and standard deviation of the tetramethylrhodamine peak width was 5 1 s and likely limited by the 4-s period between droplet deposition. We next injected a complex mixture of DNA fragments and used real-time PCR to quantify the product in a CE-SELEX experiment. The reconstructed electrophoretic peak was 27 s in duration. Finally, we repeated the experiment in the presence of a 30-?M thrombin solution under CE-SELEX conditions; fractions were collected and next-generation sequencing was used to characterize the DNA binders. Over 25,000 sequences were identified with close matches to known thrombin binding aptamers. PMID:25159411

  9. Capillary electrophoresis coupled with automated fraction collection.

    PubMed

    Huge, Bonnie Jaskowski; Flaherty, Ryan J; Dada, Oluwatosin O; Dovichi, Norman J

    2014-12-01

    A fraction collector based on a drop-on-demand ink-jet printer was developed to interface capillary zone electrophoresis with a 96 well microtiter plate. We first evaluated the performance of the collector by using capillary zone electrophoresis to analyze a 1mM solution of tetramethylrhodamine; a fluorescent microtiter plate reader was then used to detect the analyte and characterize fraction carryover between wells. Relative standard deviation in peak height was 20% and the relative standard deviation in migration time was 1%. The mean and standard deviation of the tetramethylrhodamine peak width was 5 ± 1 s and likely limited by the 4-s period between droplet deposition. We next injected a complex mixture of DNA fragments and used real-time PCR to quantify the product in a CE-SELEX experiment. The reconstructed electrophoretic peak was 27 s in duration. Finally, we repeated the experiment in the presence of a 30-µM thrombin solution under CE-SELEX conditions; fractions were collected and next-generation sequencing was used to characterize the DNA binders. Over 25,000 sequences were identified with close matches to known thrombin binding aptamers. PMID:25159411

  10. Gel Electrophoresis of Gold-DNA Nanoconjugates

    DOE PAGESBeta

    Pellegrino, T.; Sperling, R. A.; Alivisatos, A. P.; Parak, W. J.

    2007-01-01

    Gold-DNA conjugates were investigated in detail by a comprehensive gel electrophoresis study based on 1200 gels. A controlled number of single-stranded DNA of different length was attached specifically via thiol-Au bonds to phosphine-stabilized colloidal gold nanoparticles. Alternatively, the surface of the gold particles was saturated with single stranded DNA of different length either specifically via thiol-Au bonds or by nonspecific adsorption. From the experimentally determined electrophoretic mobilities, estimates for the effective diameters of the gold-DNA conjugates were derived by applying two different data treatment approaches. The first method is based on making a calibration curve for the relation between effectivemore » diameters and mobilities with gold nanoparticles of known diameter. The second method is based on Ferguson analysis which uses gold nanoparticles of known diameter as reference database. Our study shows that effective diameters derived from gel electrophoresis measurements are affected with a high error bar as the determined values strongly depend on the method of evaluation, though relative changes in size upon binding of molecules can be detected with high precision. Furthermore, in this study, the specific attachment of DNA via gold-thiol bonds to Au nanoparticles is compared to nonspecific adsorption of DNA. Also, the maximum number of DNA molecules that can be bound per particle was determined.« less

  11. Quantitative determination of short single-stranded oligonucleotides from blood plasma using capillary electrophoresis with laser-induced fluorescence.

    PubMed

    Reyderman, L; Stavchansky, S

    1997-08-15

    The quantitative determination of short (< 20 bases) single-standed (ss-) oligonucleotides (oligos) from blood plasma using capillary gel electrophoresis with laser-induced fluorescence is reported. Oligos were derivatized on column after equilibration of the column with a 1:150 dilution of OliGreen dye. The resulting fluorescent complex was detected and measured with an argon ion laser detector using excitation/emission wavelengths of 488/520 nm, respectively. The method involves precipitation of plasma proteins with phenol-chloroform followed by dilution and drop analysis in nanopure water for 30 min on a 0.025 microns cellulose acetate membrane. This treatment lowers the ionic strength of the plasma sample resulting in a significant improvement of the electrokinetic loading (5 kV, 10 s) of the analyte. Optimal electrophoretic separation was achieved at 13 kV using 4 M urea in a 10% polyacrylamide gel filled capillary, 100 mM Tris borate as the running buffer, and a temperature of 30 degrees C. Oligos were determined in the presence of p(dT)20/40 as internal standard. The observed migration times were 6.35 and 6.60 min for the oligo and internal standard, respectively. The migration times and fluorescent yield of the complex were temperature dependent. Increasing the separation temperature (20 to 60 degrees C) resulted in a decrease in the migration time and fluorescent yield of the oligonucleotide-dye complex. A linear response over a broad concentration range (0.02-1.5 micrograms/mL, R2 = 0.997) was obtained. The limit of quantitation was set at 20 ng/mL (CV% = 11.3%). The intraday variability was 9.44, 5.28, and 9.2% for 190, 760, and 1520 ng/mL plasma samples, respectively. Data are presented to illustrate the practicality of the method for the pharmacokinetic evaluation of GS522 and potential metabolites in plasma after intravenous administration to rats. PMID:9271066

  12. Acetate metabolism and aging: An emerging connection.

    PubMed

    Shimazu, Tadahiro; Hirschey, Matthew D; Huang, Jing-Yi; Ho, Linh T Y; Verdin, Eric

    2010-01-01

    Sirtuins are NAD(+)-dependent protein deacetylases that regulate gene silencing, energy metabolism and aging from bacteria to mammals. SIRT3, a mammalian mitochondrial sirtuin, deacetylates acetyl-CoA synthetase (AceCS2) in the mitochondria. AceCS2 is conserved from bacteria to humans, catalyzes the conversion of acetate to acetyl-CoA and enables peripheral tissues to utilize acetate during fasting conditions. Here, we review the regulation of acetate metabolism by sirtuins, the remarkable conservation of this metabolic regulatory pathway and its emerging role in the regulation of aging and longevity. PMID:20478325

  13. Viscosity of Mixtures of ?-Tocopherol Acetate + Mesitylene

    NASA Astrophysics Data System (ADS)

    Szwajczaka, El?bieta; Stagraczy?ski, Ryszard; Herba, Henryk; ?wiergielb, Jolanta; Jad?yn, Jan

    2009-08-01

    The paper presents results of the share viscosity measurements performed as a function of temperature and concentration for mixtures of ?-tocopherol acetate (vitamine E acetate) and mesitylene, two liquids of essentially different viscosity (four order of magnitude difference at 280 K). The viscosity/ temperature dependence for pure ?-tocopherol acetate as well as for the mixtures studied can be well described with the Vogel-Fulcher-Tammann equation. The viscosities of the mixtures exhibit a strong negative deviation from the rule of additive dependence on concentration and for increasing temperature the maximum value of the deviation shows an exponential decreasing.

  14. Recent advances in microchip electrophoresis for amino acid analysis.

    PubMed

    Ou, Gaozhi; Feng, Xiaojun; Du, Wei; Liu, Xin; Liu, Bi-Feng

    2013-10-01

    With the maturation of microfluidic technologies, microchip electrophoresis has been widely employed for amino acid analysis owing to its advantages of low sample consumption, reduced analysis time, high throughput, and potential for integration and automation. In this article, we review the recent progress in amino acid analysis using microchip electrophoresis during the period from 2007 to 2012. Innovations in microchip materials, surface modification, sample introduction, microchip electrophoresis, and detection methods are documented, as well as nascent applications of amino acid analysis in single-cell analysis, microdialysis sampling, food analysis, and extraterrestrial exploration. Without doubt, more applications of microchip electrophoresis in amino acid analysis may be expected soon. PMID:23436170

  15. Determination of herbicides paraquat, glyphosate, and aminomethylphosphonic acid in marijuana samples by capillary electrophoresis.

    PubMed

    Lanaro, Rafael; Costa, Jos L; Cazenave, Silvia O S; Zanolli-Filho, Luiz A; Tavares, Marina F M; Chasin, Alice A M

    2015-01-01

    In this work, two methods were developed to determine herbicides paraquat, glyphosate, and aminomethylphosphonic acid (AMPA) in marijuana samples by capillary electrophoresis. For paraquat analysis, sample was extracted with aqueous acetic acid solution and analyzed by capillary zone electrophoresis with direct UV detection. The running electrolyte was 50 mmol/L phosphate buffer (pH 2.50). For glyphosate and AMPA, indirect UV/VIS detection was used, as these substances do not present chromophoric groups. Samples were extracted with 5 mmol/L hydrochloric acid. The running electrolyte was 10 mmol/L gallic acid, 6 mmol/L TRIS, and 0.1 mmol/L CTAB (pH = 4.7). The methods presented good linearity, precision, accuracy, and recovery. Paraquat was detected in 12 samples (n = 130), ranging from 0.01 to 25.1 mg/g. Three samples were positive for glyphosate (0.15-0.75 mg/g), and one sample presented AMPA as well. Experimental studies are suggested to evaluate the risks of these concentrations to marijuana user. PMID:25413634

  16. Fragrance material review on 3-phenylpropyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 3-phenylpropyl acetate when used as a fragrance ingredient is presented. 3-Phenylpropyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 3-phenylpropyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, skin sensitization, and toxicokinetics data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al., 2012 for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414651

  17. Fragrance material review on anisyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of anisyl acetate when used as a fragrance ingredient is presented. Anisyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for anisyl acetate were evaluated, then summarized, and includes: physical properties, skin irritation, skin sensitization, elicitation, and phototoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al., 2012 for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414654

  18. A microchannel electrophoresis DNA sequencing system

    SciTech Connect

    Madabhushi, R S; Warth, T; Balch, J W; Bass, M; Brewer, L R; Copeland, A C; Davidson, J C; Fitch, J P; Kegelmeyer, L M; Kimbrough, J R; McCready, P; Nelson, D; Pastrone, R L; Richardson, P M; Swierkowski, S P; Tarte, L A; Vainer, M

    1999-01-01

    In order to increase the DNA sequencing throughput of the Joint Genome Institute, we have developed a microchannel electrophoresis system. The critical new and unique elements of this system include 1) a process for the production of arrays of 96 and 384 microchannels on bonded glass substrates up to 14 x 58 cm and 2) new sieving media for high resolution and high speed separations. With custom fabrication apparatus, microchannels are etched in a borosilicate substrate, and then fusion bonded to a top substrate 1.1 mm thick that has access holes formed in it. SEM examination shows a typical microchannel to be 40 micrometers deep x 180 micrometers wide by 46 cm long. This technology offers significant advantages over discrete capillaries or conventional slab-gel approaches. High throughput DNA sequencing with over 550 base pairs resolution has been achieved in roughly half the time of conventional sequencers. In February 1999, we begin a pre-production evaluation protocol for the microchannel and for three glass capillary electrophoresis systems (two from industry and one developed by Lawrence Berkeley National Laboratory for the Joint Genome Institute). In order to utilize these instruments for DNA production sequencing, we have been evaluating and implementing software to convert raw electropherograms into called DNA bases with an associated probability of error. Our original intent was to utilize the DNA base calling software known as Plan and Phred developed by the University of Washington. This software has been outstanding for our slab gel electrophoresis systems currently in the production facility. In our tests and evaluations of this software applied to microchannel data, we observed that the electropherograms are of a different statistical and underlying signal structure compared to slab gels. Even with substantial modifications to the software, base calling performance was not satisfactory for the microchannel data. In this paper, we will present o The microchannel DNA sequencing system and show the advantages compared to current slab gel and capillary systems. o The signal processing modules needed including correction of multiple wavelength channels, signal averaging, non-uniform sampling, variable DNA mobility, and peak shape and spreading effects. o A comparison of the DNA base signatures in the raw data of microchannels vs. slab gels including some simple modeling results. This will be propagated through the base calling software to show the impact on DNA sequencing.

  19. [Metabolism of C(14)-acetate by cestodes

    PubMed

    Rim, Han Jong; Park, Chung Jai; Min, Yong Ok; On, Byong Jong; Lee, Hyun Kyo; Yun, Myong Soon

    1965-12-01

    The adult worm and plerocercoid larva(sparganum) of Diphyllobothrium mansoni and Moniezia expansa employed in this experiment. The adult worms were divided into three portions, i.e. immature, mature and gravid proglottids, and each proglottids were incubated in 50 cc or 250 cc volume of special incubation flasks with incubation medium consisting of 10 cc of 25 cc of Krebs-Ringer phosphate buffer (pH 7.4). The incubation medium was added C(14)-acetate and non-radioactive carrier Na-acetate so as to contain acetate concentration of 50 mg per cent. The worms were allowed to incubate for 5 hours in the Dubnoff metabolic shaking incubator at 38 degrees C. After incubation period, the lactate and pyruvate appearance rate, total CO2 production tate, the turnover rates were employed as pervious report(Seo et al., 1965). The quantitative analysis of C(14)-acetate utilized by the adult worm and plerocercoid larva of D. mansoni and M. expansa were compared and discussed in this report. According to these data of the experiment, it is impressed that the fatty acid such as acetate may play a role of major part of their metabolism in the adult worm and plerocercoid larva of D. mansoni, whereas minor part of acetate participated in the metabolism by M. expansa. PMID:12913584

  20. Activation of methyl acetate on Pd(111)

    NASA Astrophysics Data System (ADS)

    Xu, Lijun; Xu, Ye

    2010-06-01

    The adsorption and activation of methyl acetate (CH 3COOCH 3), one of the simplest carboxylic esters, on Pd(111) have been studied using self-consistent periodic density functional theory calculations. Methyl acetate adsorbs weakly through the carbonyl oxygen. Its activation occurs via dehydrogenation, instead of direct C-O bond dissociation, on clean Pd(111): It is much more difficult to dissociate the C-O bonds ( Ea ? 2.0 eV for the carbonyl and acetate-methyl bonds; Ea = 1.0 eV for the acetyl-methoxy bond) than to dissociate the C-H bonds to produce enolate (CH 2COOCH 3; Ea = 0.74 eV) or methylene acetate (CH 3COOCH 2; Ea = 0.82 eV). The barriers for C-H and C-O bond dissociation are directly calculated for enolate and methylene acetate, and estimated for further dehydrogenated derivatives (CH 3COOCH, CH 2COOCH 2, and CHCOOCH 3) based on the Brnsted-Evans-Polanyi linear energy relations formed by the calculated steps. The enolate pathway leads to successive dehydrogenation to CCOOCH 3, whereas methylene acetate readily dissociates to yield acetyl. The selectivity for dissociating the acyl-alkoxy C-O bond, which is desired for alcohol formation, is therefore fundamentally limited by the facility of dehydrogenation under vacuum/low-pressure conditions on Pd(111).

  1. DNA sequencing using capillary array electrophoresis

    SciTech Connect

    Huang, X.C.; Quesada, M.A.; Mathies, R.A.

    1992-09-15

    A DNA sequencing method is presented that utilizes capillary array electrophoresis, two-color fluorescence detection, and a two-dye labeling protocol. Sanger DNA sequencing fragments are separated on an array of capillaries and detected on-column using a two-color, laser-excited, confocal-fluorescence scanner. The four set of DNA sequencing fragments are separated in a single capillary and then distinguished by using a binary coding scheme where each fragment set is labeled with a characteristic ratio of two dye-labeled primers. Since only two dye-labeled primers are required, it is possible to select dyes that have identical mobility shifts. It is also shown that the ratio of the signal in the two detection channels provides a reliable identification of the sequencing fragment. DNA sequencing results on a 25-capillary array are presented. 30 refs., 6 figs, 1 tab.

  2. Electrophoresis in nanochannels: brief review and speculation

    PubMed Central

    Baldessari, Fabio; Santiago, Juan G

    2006-01-01

    The relevant physical phenomena that dominate electrophoretic transport of ions and macromolecules within long, thin nanochannels are reviewed, and a few papers relevant to the discussion are cited. Sample ion transport through nanochannels is largely a function of their interaction with electric double layer. For small ions, this coupling includes the net effect of the external applied field, the internal field of the double layer, and the non-uniform velocity of the liquid. Adsorption/desorption kinetics and the effects of surface roughness may also be important in nanochannel electrophoresis. For macromolecules, the resulting motion is more complex as there is further coupling via steric interactions and perhaps polarization effects. These complex interactions and coupled physics represent a valuable opportunity for novel electrophoretic and chromatographic separations. PMID:17116262

  3. Combined electrophoresis-electrospray interface and method

    DOEpatents

    Smith, R.P.; Udseth, H.R.; Olivares, J.A.

    1989-12-05

    A system and method for analyzing molecular constituents of a composition sample includes: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5--100 kVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g., [+-]2--8 kVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit. 21 figs.

  4. Novel absorption detection techniques for capillary electrophoresis

    SciTech Connect

    Xue, Y.

    1994-07-27

    Capillary electrophoresis (CE) has emerged as one of the most versatile separation methods. However, efficient separation is not sufficient unless coupled to adequate detection. The narrow inner diameter (I.D.) of the capillary column raises a big challenge to detection methods. For UV-vis absorption detection, the concentration sensitivity is only at the {mu}M level. Most commercial CE instruments are equipped with incoherent UV-vis lamps. Low-brightness, instability and inefficient coupling of the light source with the capillary limit the further improvement of UV-vis absorption detection in CE. The goals of this research have been to show the utility of laser-based absorption detection. The approaches involve: on-column double-beam laser absorption detection and its application to the detection of small ions and proteins, and absorption detection with the bubble-shaped flow cell.

  5. Combined electrophoresis-electrospray interface and method

    DOEpatents

    Smith, Richard D.; Udseth, Harold R.; Olivares, Jose A.

    1994-10-18

    A system and method for analyzing molecular constituents of a composition sample includes: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5-100 KVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g., .+-.2-8 KVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit.

  6. Combined electrophoresis-electrospray interface and method

    DOEpatents

    Smith, R.D.; Udseth, H.R.; Olivares, J.A.

    1994-10-18

    A system and method for analyzing molecular constituents of a composition sample include: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5--100 kVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g.,{+-}2--8 kVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit. 21 figs.

  7. Combined electrophoresis-electrospray interface and method

    DOEpatents

    Smith, Richard P. (Richland, WA); Udseth, Harold R. (Richland, WA); Olivares, Jose A. (North Augusta, SC)

    1989-01-01

    A system and method for analyzing molecular constituents of a composition sample includes: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5-100 KVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g., .+-.2-8 KVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit.

  8. Diode array detection in capillary electrophoresis.

    PubMed

    Heiger, D N; Kaltenbach, P; Sievert, H J

    1994-10-01

    Diode array detection (DAD) in capillary electrophoresis (CE) offers similar advantages over single-wavelength detection as it does in high performance liquid chromatography (HPLC). Thus, confirmation of compound identity and establishment of peak purity are critical issues in CE, necessitating sensitive and specific detection. With an optimized optical system, DAD yields sensitivity comparable to that of single or variable wavelength detectors. Sensitivity can be further improved three to five times by use of expanded pathlength capillaries employing the so-called bubble cell. Optimization of optical design, as well as maintenance of spectral fidelity, will be discussed in this work. A variety of applications of CE, and specifically of micellar electrokinetic capillary chromatography (MEKC), with emphasis on quantitative analysis, sensitivity, linearity, spectral identification, and peak purity verification will be presented. The use of spectral information for peak tracking in MEKC method development and for the assessment of purity of electrodistorted peaks will also be illustrated. PMID:7895713

  9. Nanoinjector for capillary electrophoresis and capillary electrochromatography.

    PubMed

    Iizuka, Eiji; Tsuda, Takao; Munesue, Motonori; Samizo, Shinichi

    2003-08-01

    A rotary valve nanoinjector was devised for use in capillary electrophoresis (CE) and capillary electrochromatography (CEC). A fused-silica capillary tip was inserted in a small through-hole in the rotor. The narrow and short capillary tip, with an inner volume of 6-24 nL, was embedded in the hole using epoxy resin. The injection volume was confirmed chromatographically by comparing the peak areas obtained with the nanoinjector to those of a conventional injector. In addition, both the rotor and stator of the injector were made of a nonconducting material, polyimide resin, to be utilized for CE and CEC. The application of the nanoinjector for CE was demonstrated. PMID:14572065

  10. Hybrid slab-microchannel gel electrophoresis system

    SciTech Connect

    Balch, J.W.; Carrano, A.V.; Davidson, J.C.; Koo, J.C.

    1998-05-05

    A hybrid slab-microchannel gel electrophoresis system is described. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate. 4 figs.

  11. A biologically inspired hydrophobic membrane for application in pervaporation.

    PubMed

    Jullok, Nora; Martnez, Rodrigo; Wouters, Christine; Luis, Patricia; Sanz, Mara Teresa; Van der Bruggen, Bart

    2013-02-01

    An artificial polydimethylsiloxane/polyphenylsulfone (PDMS/PPSU) membrane, which emulates the hydrophobic behavior of natural membranes, was synthesized. Hydrophobicity was achieved by coating the membrane surface sublayer using conventional silicon material, which imitates the character of epicuticular wax (EW) of Prunus laurocerasus L. leaves. It was then applied as a separation medium in pervaporation (PV) of diluted mixtures of ethyl acetate and aroma compounds. The membrane's biomimetic characteristics were evaluated using surface morphology analyses, that is, Fourier transform infrared (FTIR), water contact angle measurements, and SEM imaging. A comparison of properties of the membranes synthesized in this work against selected hydrophobic plant leaves indicated a good agreement. PV using these biologically inspired artificial membranes demonstrated preference for the permeation of ethyl acetate. Besides intrinsic characteristics, it was also observed that the chemical potential is highly influential in activating sorption, diffusion, and desorption of a specific compound. PMID:23323794

  12. Two-dimensional Gel Electrophoresis (2DE)

    NASA Astrophysics Data System (ADS)

    K?odzi?ska, Ewa; Buszewski, Bogus?aw

    The chemical compounds, which are present in the environment, increasingly cause bad effects on health. The most serious effects are tumors and various mutations at the cellular level. Such compounds, from the analytical point of view, can serve the function of biomarkers, constituting measurable changes in the organism's cells and biochemical processes occurring therein. The challenge of the twenty-first century is therefore searching for effective and reliable methods of identification of biomarkers as well as understanding bodily functions, which occur in living organisms at the molecular level. The irreplaceable tool for these examinations is proteomics, which includes both quality and quantity analysis of proteins composition, and also makes it possible to learn their functions and expressions. The success of proteomics examinations lies in the usage of innovative analytical techniques, such as electromigration technique, two-dimensional electrophoresis in polyacrylamide gel (2D PAGE), liquid chromatography, together with high resolution mass spectrometry and bio-informatical data analysis. Proteomics joins together a number of techniques used for analysis of hundreds or thousands of proteins. Its main task is not the examination of proteins inside the particular tissue but searching for the differences in the proteins' profile between bad and healthy tissues. These differences can tell us a lot regarding the cause of the sickness as well as its consequences. For instance, using the proteomics analysis it is possible to find relatively fast new biomarkers of tumor diseases, which in the future will be used for both screening and foreseeing the course of illness. In this chapter we focus on two-dimensional electrophoresis because as it seems, it may be of enormous importance when searching for biomarkers of cancer diseases.

  13. Indium acetate toxicity in male reproductive system in rats.

    PubMed

    Lee, Kuo-Hsin; Chen, Hsiu-Ling; Leung, Chung-Man; Chen, Hsin-Pao; Hsu, Ping-Chi

    2016-01-01

    Indium, a rare earth metal characterized by high plasticity, corrosion resistance, and a low melting point, is widely used in the electronics industry, but has been reported to be an environmental pollutant and a health hazard. We designed a study to investigate the effects of subacute exposure of indium compounds on male reproductive function. Twelve-week old male Sprague-Dawley rats were randomly divided into test and control groups, and received weekly intraperitoneal injections of indium acetate (1.5 mg/kg body weight) and normal saline, respectively, for 8 weeks. Serum indium levels, cauda epididymal sperm count, motility, morphology, chromatin DNA structure, mitochondrial membrane potential, oxidative stress, and testis DNA content were investigated. The indium acetate-treated group showed significant reproductive toxicity, as well as an increased percentage of sperm morphology abnormality, chromatin integrity damage, and superoxide anion generation. Furthermore, positive correlations among sperm morphology abnormalities, chromatin DNA damage, and superoxide anion generation were also noted. The results of this study demonstrated the toxic effect of subacute low-dose indium exposure during the period of sexual maturation on male reproductive function in adulthood, through an increase in oxidative stress and sperm chromatin DNA damage during spermiogenesis, in a rodent model. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 68-76, 2016. PMID:25044390

  14. Inexpensive and Safe DNA Gel Electrophoresis Using Household Materials

    ERIC Educational Resources Information Center

    Ens, S.; Olson, A. B.; Dudley, C.; Ross, N. D., III; Siddiqi, A. A.; Umoh, K. M.; Schneegurt, M. A.

    2012-01-01

    Gel electrophoresis is the single most important molecular biology technique and it is central to life sciences research, but it is often too expensive for the secondary science classroom or homeschoolers. A simple safe low-cost procedure is described here that uses household materials to construct and run DNA gel electrophoresis. Plastic

  15. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Instruments 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including plasma... media. This device is used in conjunction with certain materials to measure a variety of analytes as...

  16. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Instruments 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including plasma... media. This device is used in conjunction with certain materials to measure a variety of analytes as...

  17. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Instruments 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including plasma... media. This device is used in conjunction with certain materials to measure a variety of analytes as...

  18. Gel Electrophoresis on a Budget to Dye for

    ERIC Educational Resources Information Center

    Yu, Julie H.

    2010-01-01

    Gel electrophoresis is one of the most important tools used in molecular biology and has facilitated the entire field of genetic engineering by enabling the separation of nucleic acids and proteins. However, commercial electrophoresis kits can cost up to $800 for each setup, which is cost prohibitive for most classroom budgets. This article

  19. Gel Electrophoresis on a Budget to Dye for

    ERIC Educational Resources Information Center

    Yu, Julie H.

    2010-01-01

    Gel electrophoresis is one of the most important tools used in molecular biology and has facilitated the entire field of genetic engineering by enabling the separation of nucleic acids and proteins. However, commercial electrophoresis kits can cost up to $800 for each setup, which is cost prohibitive for most classroom budgets. This article…

  20. Inexpensive and Safe DNA Gel Electrophoresis Using Household Materials

    ERIC Educational Resources Information Center

    Ens, S.; Olson, A. B.; Dudley, C.; Ross, N. D., III; Siddiqi, A. A.; Umoh, K. M.; Schneegurt, M. A.

    2012-01-01

    Gel electrophoresis is the single most important molecular biology technique and it is central to life sciences research, but it is often too expensive for the secondary science classroom or homeschoolers. A simple safe low-cost procedure is described here that uses household materials to construct and run DNA gel electrophoresis. Plastic…

  1. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrophoresis apparatus for clinical use. 862... SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An...

  2. Distinct Effects of Sorbic Acid and Acetic Acid on the Electrophysiology and Metabolism of Bacillus subtilis

    PubMed Central

    van Beilen, J. W. A.; Teixeira de Mattos, M. J.; Hellingwerf, K. J.

    2014-01-01

    Sorbic acid and acetic acid are among the weak organic acid preservatives most commonly used to improve the microbiological stability of foods. They have similar pKa values, but sorbic acid is a far more potent preservative. Weak organic acids are most effective at low pH. Under these circumstances, they are assumed to diffuse across the membrane as neutral undissociated acids. We show here that the level of initial intracellular acidification depends on the concentration of undissociated acid and less on the nature of the acid. Recovery of the internal pH depends on the presence of an energy source, but acidification of the cytosol causes a decrease in glucose flux. Furthermore, sorbic acid is a more potent uncoupler of the membrane potential than acetic acid. Together these effects may also slow the rate of ATP synthesis significantly and may thus (partially) explain sorbic acid's effectiveness. PMID:25038097

  3. Analysis of Central European Corydalis species by nonaqueous capillary electrophoresis-electrospray ion trap mass spectrometry.

    PubMed

    Sturm, Sonja; Seger, Christoph; Stuppner, Hermann

    2007-08-01

    In the presented study, Central European Corydalis species, namely C. cava, C. intermedia, C. pumila, and C. solida were investigated by nonaqueous capillary electrophoresis-electrospray ion trap mass spectrometry (NACE-ESI-MS) utilizing an electrolyte consisting of 50 mM ammonium acetate, 1 M acetic acid and 10% methanol in acetonitrile, applying a separation voltage of 30 and 20 kV for 1 s for injection. Isopropanol-water (1:1) was used as sheath liquid at a flow-rate of 3 microl/min. Peak assignment was assisted by multistage-ESI-mass spectrometry (ESI-MSn). The optimized method was fully validated (RSD inter- and intraday < 5%, LOD < 2.3 microg/ml, LOQ < 27.6 microg/ml, recovery rates > 98.8%) and subsequently applied for the qualitative and quantitative determination of isoquinoline alkaloids in single plant tubers (sample size < 0.5 g) of the four Central European Corydalis species, each of them showing a characteristic and unique alkaloid pattern. Application of a principal component analysis (PCA) to the complete dataset of 39 analytes and 79 samples allowed the identification of 8 analytes responsible for lot discrimination. Hierarchical cluster analysis and descriptive statistical methods were used to confirm the findings of the explorative PCA. PMID:17395190

  4. Separation and analysis of triazine herbcide residues by capillary electrophoresis.

    PubMed

    Elbashir, Abdalla A; Aboul-Enein, Hassan Y

    2015-06-01

    Triazines are widely used in agriculture around the world as selective pre- and post-emergence herbicides for the control of broad leaf and grassy weeds. With high toxicity and persistence, triazines can contaminate the environment and crops, so the development of rapid and sensitive methods for the determination of different triazines is necessary. Capillary electrophoresis comprises a group of techniques used to separate chemical mixtures. Analytical separation is based on different electrophoretic mobilities. This review focuses on the analysis of triazine herbicides with different modes of capillary electrophoresis, including capillary zone electrophoresis, micellar electrokinetic capillary electrophoresis, capillary electrochromatography and nonaqueous capillary electrophoresis. Determinations of triazines in various matrices such as surface water, groundwater, vegetables, soil and grains are emphasized. PMID:25515940

  5. A centrifugal method for the evaluation of polymer membranes for reverse osmosis

    NASA Technical Reports Server (NTRS)

    Hollahan, J. R.; Wydeven, T.; Mccullough, R. P.

    1973-01-01

    A rapid and simple method employing the laboratory centrifuge shows promise for evaluation of membrane performance during reverse osmosis. Results are presented for cellulose acetate membranes for rejection of salt and urea dissolved solids. Implications of the study are to rapid screening of membrane performance, use in laboratories with limited facilities, and possible space waste water purification.

  6. Golgi Enrichment and Proteomic Analysis of Developing Pinus radiata Xylem by Free-Flow Electrophoresis

    PubMed Central

    Macdonald, Lucy J.; Adams, Paul D.; Petzold, Christopher J.; Strabala, Timothy J.; Wagner, Armin; Heazlewood, Joshua L.

    2013-01-01

    Our understanding of the contribution of Golgi proteins to cell wall and wood formation in any woody plant species is limited. Currently, little Golgi proteomics data exists for wood-forming tissues. In this study, we attempted to address this issue by generating and analyzing Golgi-enriched membrane preparations from developing xylem of compression wood from the conifer Pinus radiata. Developing xylem samples from 3-year-old pine trees were harvested for this purpose at a time of active growth and subjected to a combination of density centrifugation followed by free flow electrophoresis, a surface charge separation technique used in the enrichment of Golgi membranes. This combination of techniques was successful in achieving an approximately 200-fold increase in the activity of the Golgi marker galactan synthase and represents a significant improvement for proteomic analyses of the Golgi from conifers. A total of thirty known Golgi proteins were identified by mass spectrometry including glycosyltransferases from gene families involved in glucomannan and glucuronoxylan biosynthesis. The free flow electrophoresis fractions of enriched Golgi were highly abundant in structural proteins (actin and tubulin) indicating a role for the cytoskeleton during compression wood formation. The mass spectrometry proteomics data associated with this study have been deposited to the ProteomeXchange with identifier PXD000557. PMID:24416096

  7. Further development of an electroosmotic medium pump system for preparative disk gel electrophoresis.

    PubMed

    Hayakawa, Mitsuo; Hosogi, Yumiko; Takiguchi, Hisashi; Shiroza, Teruaki; Shibata, Yasuko; Hiratsuka, Koichi; Kiyama-Kishikawa, Michiko; Hamajima, Susumu; Abiko, Yoshimitsu

    2003-02-01

    A simple and practical 6.8-cm-diameter (36.30-cm(2) cross-sectional-area) preparative disk gel electrophoresis device, based on the design of M. Hayakawa et al. (Anal. Biochem. 288 (2001) 168), in which the elution buffer is driven by an electroosmotic buffer flow through the membrane into the elution chamber from the anode chamber was constructed. We have found that the dialysis membranes employed provide suitable flow rates for the elution buffer, similar to those of an earlier 3.6-cm-diameter device, resulting in the prevention of excess eluate dilution. The efficiency of this device was demonstrated by the fractionation of a bovine serum albumin (BSA) Cohn V fraction into monomer, dimer, and oligomer components using nondenaturing polyacrylamide gel electrophoresis (native-PAGE). The maximum protein concentration of the eluate achieved was 133 mg/ml of BSA monomer, which required a dilution of the eluate for subsequent analytical PAGE performance. As a practical example, the two-dimensional fractionation of soluble dipeptidyl peptidase IV (sDPP IV) from 50 ml fetal bovine serum (3.20 g protein) per gel is presented. The sDPP IV enzyme protein was recovered in a relatively short time, utilizing a 6.5% T native-PAGE and subsequential sodium dodecyl sulfate-PAGE system. This device enhances the possibility of continuous electrophoretic fractionation of complex protein mixtures on a preparative scale. PMID:12576059

  8. Androgen dynamics in vitro in the human prostate gland. Effect of cyproterone and cyproterone acetate

    PubMed Central

    Giorgi, Eleonora P.; Shirley, I. M.; Grant, J. K.; Stewart, Joan C.

    1973-01-01

    Hyperplastic and adenocarcinomatous human prostatic tissue was superfused in vitro with radioactively labelled androst-4-ene-3,17-dione, testosterone and 5?-dihydrotestosterone (17?-hydroxy-5?-androstan-3-one), with and without addition of the anti-androgens cyproterone and cyproterone acetate. Cyproterone competitively inhibited the entry of the androgens into the majority of the tissues, whereas cyproterone acetate increased this entry. These findings indicated that transport of androstenedione, testosterone and 5?-dihydrotestosterone into prostatic tissue is performed by a specific mechanism, possibly involving a carrier situated in the cell membrane. The extent of metabolism of the three androgens was also modified: formation of 5?-dihydrotestosterone from testosterone, and of the latter from androstenedione, was decreased by cyproterone and increased by the acetate. Acetate was more effective than cyproterone in decreasing the `uptake' of the perfused androgens by the tissue; at the same time, it increased the androgen clearance from the tissue. As cyproterone acetate is the more potent of the two anti-androgens, the possibility that these findings in vitro are related to the different anti-androgenic potency exhibited by the two compounds in vivo is discussed. `Uptake' of the two anti-androgens and the response to their action on androgen dynamics were similar in adenocarcinomatous and hyperplastic glands. PMID:4125095

  9. Modification of gel architecture and TBE/TAE buffer composition to minimize heating during agarose gel electrophoresis

    PubMed Central

    Sanderson, Brian A.; Araki, Naoko; Lilley, Jennifer L.; Guerrero, Gilberto; Lewis, L. Kevin

    2014-01-01

    Agarose gel electrophoresis of DNA and RNA is routinely performed using buffers containing either Tris, acetate and EDTA (TAE) or Tris, borate and EDTA (TBE). Gels are run at a low, constant voltage (~ 10 V/cm) to minimize current and asymmetric heating effects, which can induce band artifacts and poor resolution. In this study, alterations of gel structure and conductive media composition were analyzed to identify factors causing higher electrical currents during horizontal slab gel electrophoresis. Current was reduced when thinner gels and smaller chamber buffer volumes were used, but was not influenced by agarose concentration or the presence of ethidium bromide. Current was strongly dependent upon the amount and type of EDTA used and on the concentrations of the major acid-base components of each buffer. Interestingly, resolution and the mobilities of circular versus linear plasmid DNAs were also affected by the chemical form and amount of EDTA. With appropriate modifications to gel structure and buffer constituents, electrophoresis could be performed at high voltages (20–25 V/cm), reducing run times by up to 3-fold. The most striking improvements were observed with small DNAs and RNAs (10 – 100 bp): high voltages and short run times produced sharper bands and higher resolution. PMID:24637158

  10. Direct detection of the acetate-forming activity of the enzyme acetate kinase.

    PubMed

    Fowler, Matthew L; Ingram-Smith, Cheryl J; Smith, Kerry S

    2011-01-01

    Acetate kinase, a member of the acetate and sugar kinase-Hsp70-actin (ASKHA) enzyme superfamily, is responsible for the reversible phosphorylation of acetate to acetyl phosphate utilizing ATP as a substrate. Acetate kinases are ubiquitous in the Bacteria, found in one genus of Archaea, and are also present in microbes of the Eukarya. The most well characterized acetate kinase is that from the methane-producing archaeon Methanosarcina thermophila. An acetate kinase which can only utilize PP(i) but not ATP in the acetyl phosphate-forming direction has been isolated from Entamoeba histolytica, the causative agent of amoebic dysentery, and has thus far only been found in this genus. In the direction of acetyl phosphate formation, acetate kinase activity is typically measured using the hydroxamate assay, first described by Lipmann, a coupled assay in which conversion of ATP to ADP is coupled to oxidation of NADH to NAD(+) by the enzymes pyruvate kinase and lactate dehydrogenase, or an assay measuring release of inorganic phosphate after reaction of the acetyl phosphate product with hydroxylamine. Activity in the opposite, acetate-forming direction is measured by coupling ATP formation from ADP to the reduction of NADP(+) to NADPH by the enzymes hexokinase and glucose 6-phosphate dehydrogenase. Here we describe a method for the detection of acetate kinase activity in the direction of acetate formation that does not require coupling enzymes, but is instead based on direct determination of acetyl phosphate consumption. After the enzymatic reaction, remaining acetyl phosphate is converted to a ferric hydroxamate complex that can be measured spectrophotometrically, as for the hydroxamate assay. Thus, unlike the standard coupled assay for this direction that is dependent on the production of ATP from ADP, this direct assay can be used for acetate kinases that produce ATP or PP(i). PMID:22214984

  11. Membrane Extraction for Detoxification of Biomass Hydrolysates

    SciTech Connect

    Grzenia, D. L.; Schell, D. J.; Wickramasinghe, S. R.

    2012-05-01

    Membrane extraction was used for the removal of sulfuric acid, acetic acid, 5-hydroxymethyl furfural and furfural from corn stover hydrolyzed with dilute sulfuric acid. Microporous polypropylene hollow fiber membranes were used. The organic extractant consisted of 15% Alamine 336 in: octanol, a 50:50 mixture of oleyl alcohol:octanol or oleyl alcohol. Rapid removal of sulfuric acid, 5-hydroxymethyl and furfural was observed. The rate of acetic acid removal decreased as the pH of the hydrolysate increased. Regeneration of the organic extractant was achieved by back extraction into an aqueous phase containing NaOH and ethanol. A cleaning protocol consisting of flushing the hydrolysate compartment with NaOH and the organic phase compartment with pure organic phase enabled regeneration and reuse of the module. Ethanol yields from hydrolysates detoxified by membrane extraction using 15% Alamine 336 in oleyl alcohol were about 10% higher than those from hydrolysates detoxified using ammonium hydroxide treatment.

  12. Purification of fibrinogen and virus removal using preparative electrophoresis.

    PubMed

    Gilbert, A; Evtushenko, M; Nair, H

    2001-01-01

    The Gradiflow is a novel, scalable preparative electrophoresis technique that uses the dual characteristics of size and charge to isolate target macro- and micromolecules from complex biological solutions. It does this with high resolution and in rapid time. The mild buffers are used to assist in retaining biological activity of the isolated protein. Gradiflow technology employs a sandwich of three polyacrylamide membranes configured to allow passage of macromolecules ranging in size from 10 kDa to 1,500 kDa. Fibrinogen was isolated from cryoprecipitate 1 using a single phase process. This separation was achieved within three hours with yields of 85%. Purified fibrinogen was then characterized using biophysical characterization of fibrin clot structure and compared with clots derived from a commercially available product and human plasma. Significantly, clots developed from Gradiflow fibrinogen had characteristics closer to human plasma. Viral removal characteristics of the Gradiflow were investigated by spiking the source material (cryoprecipitate 1) with canine parvovirus and testing for its presence in the isolated fibrinogen using PCR. Parvo removal was found to be greater than 4 logs and was achieved during the purification process. The Gradiflow offers the advantage of large-scale separation of macromolecules and provides a new approach to fibrinogen separation that is quite distinct from other present-day technologies. The technology is capable of isolating protein with high purity, recovery, and functionality in combination with the removal of viruses during the purification. Furthermore, it is capable of integrating into present production systems, significantly improving yield and functionality of target molecules. PMID:11460522

  13. Removal of bisphenol A (BPA) from water by various nanofiltration (NF) and reverse osmosis (RO) membranes.

    PubMed

    Yüksel, Suna; Kabay, Nalan; Yüksel, Mithat

    2013-12-15

    The removal of an endocrine disrupting compound, bisphenol A (BPA), from model solutions by selected nanofiltration (NF) and reverse osmosis (RO) membranes was studied. The commercially available membranes NF 90, NF 270, XLE BWRO, BW 30 (Dow FilmTech), CE BWRO and AD SWRO (GE Osmonics) were used to compare their performances for BPA removal. The water permeability coefficients, rejection of BPA and permeate flux values were calculated for all membranes used. No significant changes in their BPA removal were observed for all tight polyamide based NF and RO membranes tested except for loose NF 270 membrane. The polyamide based membranes exhibited much better performance than cellulose acetate membrane for BPA removal. Almost a complete rejection (≥ 98%) for BPA was obtained with three polyamide based RO membranes (BW 30, XLE BWRO and AD SWRO). But cellulose acetate based CE BWRO membrane offered a low and variable (10-40%) rejection for BPA. PMID:23731784

  14. Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.

    ERIC Educational Resources Information Center

    Donahue, Craig J.; Panek, Mary G.

    1985-01-01

    Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)

  15. Predicting total soil lead from an acetic acid-sodium acetate buffered solution

    SciTech Connect

    Nicklow, C.W.; Norvell, W.A.; Spittler, T.

    1981-01-01

    Total soil lead was predicted satisfactorily from the lead extracted by the Standard Morgan soil testing solution (sodium acetate with acetic acid, pH 4.8). A modified Morgan solution, utilizing EDTA as a chelating agent, extracted greater than 3 times as much lead as the regular Morgan's solution, but was no better in predicting total lead.

  16. Acetylation of Starch with Vinyl Acetate in Imidazolium Ionic Liquids and Characterization of Acetate Distribution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch was acetylated with vinyl acetate in different 1-butyl-3-methylimidazolium (BMIM) salts as solvent in effort to produce starches with different acetylation patterns. Overall degree of substitution was much higher for basic anions such as acetate and dicyanimide (dca) than for neutral anions ...

  17. Acetic acid production from food wastes using yeast and acetic acid bacteria micro-aerobic fermentation.

    PubMed

    Li, Yang; He, Dongwei; Niu, Dongjie; Zhao, Youcai

    2015-05-01

    In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22g/L, and improve acetic acid production to 25.88g/L, with food wastes as substrate. In contrast, only 12.81g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid. PMID:25416587

  18. A mammalian acetate switch regulates stress erythropoiesis

    PubMed Central

    Xu, Min; Nagati, Jason S.; Xie, Jian; Li, Jiwen; Walters, Holly; Moon, Young-Ah; Gerard, Robert D.; Huang, Chou-Long; Comerford, Sarah A.; Hammer, Robert E.; Horton, Jay D.; Chen, Rui; Garcia, Joseph A.

    2014-01-01

    Endocrine erythropoietin (Epo), which is synthesized in the kidney or liver of adult mammals, controls erythrocyte production and is regulated by the stress-responsive transcription factor Hypoxia Inducible Factor 2 (HIF-2). We previously reported that the lysine acetyltransferase Cbp is required for HIF-2? acetylation and efficient HIF-2 dependent Epo induction during hypoxia. We now show these processes require acetate-dependent acetyl CoA synthetase 2 (Acss2). In Hep3B hepatoma cells and in Epo-generating organs of hypoxic or acutely anemic mice, acetate levels increase and Acss2 is required for HIF-2? acetylation, Cbp/HIF-2? complex formation and recruitment to the Epo enhancer, and efficient Epo induction. In acutely anemic mice, acetate supplementation augments stress erythropoiesis in an Acss2-dependent manner. In acquired and genetic chronic anemia mouse models, acetate supplementation also increases Epo expression and resting hematocrits. Thus, a mammalian stress-responsive acetate switch controls HIF-2 signaling and Epo induction during pathophysiological states marked by tissue hypoxia. PMID:25108527

  19. Dynamic Protonation Equilibrium of Solvated Acetic Acid

    SciTech Connect

    Gu, Wei; Frigato, Tomaso; Straatsma, TP; Helms, Volkhard H.

    2007-04-13

    For the first time, the dynamic protonation equilibrium between an amino acid side chain analogue and bulk water as well as the diffusion properties of the excess proton were successfully reproduced through unbiased computer simulations. During a 50 ns Q-HOP MD simulation, two different regimes of proton transfer were observed. Extended phases of frequent proton swapping between acetic acid and nearby water were separated by phases where the proton freely diffuses in the simulation box until it is captured again by acetic acid. The pKa of acetic acid was calculated around 3.0 based on the relative population of protonated and deprotonated states and the diffusion coefficient of excess proton was computed from the average mean squared displacement in the simulation. Both calculated values agree well with the experimental measurements.

  20. Sulfidogenic fluidized-bed treatment of metal-containing wastewater at 8 and 65 degrees C temperatures is limited by acetate oxidation.

    PubMed

    Sahinkaya, Erkan; Ozkaya, Bestamin; Kaksonen, Anna H; Puhakka, Jaakko A

    2007-06-01

    Acetate utilization in sulfidogenic fluidized-bed reactors (FBRs) was investigated for the treatment of iron containing wastewater at low (8 degrees C) and high (65 degrees C) temperatures. The FBRs operated at low and high temperatures were inoculated with cultures of sulfate-reducing bacteria (SRB) originally enriched from arctic and hot mining environments, respectively. Acetate was not utilized as a carbon and electron source for SRB at 8 degrees C. With ethanol, hydrogen sulfide was produced from ethanol to acetate oxidation, which precipitated the iron. Then, several attempts were made to obtain acetate oxidation at 8 degrees C. Inoculation of two different low temperature enrichments and operating the FBR for a long period of time (321 days) did not result in enrichment of acetate oxidizing SRB. Due to the absence of acetate oxidation at 8 degrees C, external alkalinity addition was required to keep the pH neutral. At 65 degrees C, average acetate and sulfate removals were 52+/-12% and 24+/-8% at 670 mg/Ld acetate and 1500 mg/Ld sulfate loadings, respectively. The produced alkalinity from acetate oxidation increased the pH from 6.4 to around 7.5 and electron flow to sulfate reduction averaged 65%. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes showed quite stable SRB community at 8 degrees C, whereas, at 65 degrees C SRB community was dynamic. In the FBRs, Desulfomicrobium apsheronum and Desulfosporosinus sp. at 8 degrees C and Desulfotomaculum sp. at 65 degrees C were detected. PMID:17418880

  1. Activation of methyl acetate on Pd(111)

    SciTech Connect

    Xu, Lijun; Xu, Ye

    2010-01-01

    The absorption and activation of methyl acetate (CH{sub 3}COOCH{sub 3}), one of the simplest carboxylic esters, on Pd(111) have been studied using self-consistent periodic density functional theory calculations. Methyl acetate adsorbs weakly through the carbonyl oxygen. Its activation occurs via dehydrogenation, instead of direct C-O bond dissociation, on clean Pd(111): It is much more difficult to dissociate the C--O bonds ({epsilon}{sub a} ? 2.0 eV for the carbonyl and acetate-methyl bonds; {epsilon}{sub a} = 1.0 eV for the acetyl-methoxy bond) than to dissociate the C-H bonds to produce enolate (CH{sub 2}COOCH{sub 3}; {epsilon}{sub a} = 0.74 eV) or methylene acetate (CH{sub 3}COOCH{sub 2}; {epsilon}{sub a} = 0.82 eV). The barriers for C-H and C-O bond dissociation are directly calculated for enolate and methylene acetate, and estimated for further dehydrogenated derivatives (CH{sub 3}COOCH, CH{sub 2}COOCH{sub 2}, and CHCOOCH{sub 3}) based on the Bronsted-Evans-Polanyi linear energy relations formed by the calculated steps. The enolate pathway leads to successive dehydrogenation to CCOOCH{sub 3}, whereas methylene acetate readily dissociates to yield acetyl. The selectivity for dissociating the acyl-alkoxy C-O bond, which is desired for alcohol formation, is therefore fundamentally limited by the facility of dehydrogenation under vacuum/low-pressure conditions on Pd(111).

  2. Membrane Processes.

    PubMed

    Pellegrin, Marie-Laure; Sadler, Mary E; Greiner, Anthony D; Aguinaldo, Jorge; Min, Kyungnan; Zhang, Kai; Arabi, Sara; Burbano, Marie S; Kent, Fraser; Shoaf, Robert

    2015-10-01

    This review, for literature published in 2014, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, fixed film and anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:26420079

  3. Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.

    PubMed

    Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao

    2014-03-01

    This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L. PMID:24434701

  4. Induced-charge electrophoresis near a wall.

    PubMed

    Kilic, Mustafa Sabri; Bazant, Martin Z

    2011-02-01

    Induced-charge electrophoresis (ICEP) has mostly been analyzed for asymmetric particles in an infinite fluid, but channel walls in real systems further break symmetry andlead to dielectrophoresis (DEP) in local ?eld gradients. Zhao and Bau (Langmuir 2007, 23,4053) predicted that a metal (ideally polarizable) cylinder is repelled from an insulating wall in a DC field. We revisit this problem with an AC field and show that attraction to the wall sets in at high frequency and leads to an equilibrium distance, where DEP balances ICEP, although, in three dimensions, a metal sphere is repelled from the wall at all frequencies. This conclusion, however, does not apply to asymmetric particles. Consistent with the experiments of Gangwal et al. (Phys. Rev. Lett. 2008, 100, 058302), we show that a metal/insulator Janus particle is always attracted to the wall in an AC field. The Janus particle tends to move toward its insulating end, perpendicular to the field, but ICEP torque rotates this end toward the wall. Under some conditions, the theory predicts steady translation along the wall, perpendicular to the field, at an equilibrium tilt angle around 451, consistent with the experiments, although improved models are needed for a complete understanding of this phenomenon. PMID:21341288

  5. Analysis of venlafaxine by capillary zone electrophoresis.

    PubMed

    Fanali, S; Cotichini, V; Porr, R

    1997-01-01

    Capillary electrophoresis has been used for the separation of venlafaxine and two of its impurities deriving from the synthesis process. The electrophoretic experiments were performed using background electrolytes at different pHs in the 2.5-9.2 range in order to study the effective mobilities and resolution of the three examined compounds. The optimum experimental conditions for the baseline resolution of the three analytes was found at pH 6.5. Very good repeatability for both migration time and corrected peak areas was achieved. The calibration curve was studied for venlafaxine (concentration range 26-224 micrograms/mL), and the plot of the peak area ratio (sample/internal standard [IS]) versus venlafaxine concentration was linear with a correlation coefficient of 0.9991. The effect of different cyclodextrins (CDs), namely, gamma-cyclodextrin (gamma-CD), hydroxypropyl-beta-CD (HP-beta-CD), and alpha-cyclodextrin (alpha-CD), on effective mobility and enantiomeric resolution (R) of venlafaxine (Wy45030) and its impurities (imp1 and imp2) was studied at different pHs, and the best results were obtained at pH 9.2. Venlafaxine was baseline resolved in its enantiomers using gamma-CD or HP-beta-CD, while imp1 (Wy45494) was baseline resolved using alpha-CD. PMID:9384716

  6. Strongly nonlinear waves in capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Chen, Zhen; Ghosal, Sandip

    2012-05-01

    In capillary electrophoresis, sample ions migrate along a microcapillary filled with a background electrolyte under the influence of an applied electric field. If the sample concentration is sufficiently high, the electrical conductivity in the sample zone could differ significantly from the background. Under such conditions, the local migration velocity of sample ions becomes concentration-dependent, resulting in a nonlinear wave that exhibits shocklike features. If the nonlinearity is weak, the sample concentration profile, under certain simplifying assumptions, can be shown to obey Burgers’ equation [Ghosal and Chen, Bull. Math. Biol.BMTBAP0092-824010.1007/s11538-010-9527-2 72, 2047 (2010)], which has an exact analytical solution for arbitrary initial condition. In this paper, we use a numerical method to study the problem in the more general case where the sample concentration is not small in comparison to the concentration of background ions. In the case of low concentrations, the numerical results agree with the weakly nonlinear theory presented earlier, but at high concentrations, the wave evolves in a way that is qualitatively different.

  7. Microfab-less Microfluidic Capillary Electrophoresis Devices.

    PubMed

    Segato, Thiago P; Bhakta, Samir A; Gordon, Matthew; Carrilho, Emanuel; Willis, Peter A; Jiao, Hong; Garcia, Carlos D

    2013-04-01

    Compared to conventional bench-top instruments, microfluidic devices possess advantageous characteristics including great portability potential, reduced analysis time (minutes), and relatively inexpensive production, putting them on the forefront of modern analytical chemistry. Fabrication of these devices, however, often involves polymeric materials with less-than-ideal surface properties, specific instrumentation, and cumbersome fabrication procedures. In order to overcome such drawbacks, a new hybrid platform is proposed. The platform is centered on the use of 5 interconnecting microfluidic components that serve as the injector or reservoirs. These plastic units are interconnected using standard capillary tubing, enabling in-channel detection by a wide variety of standard techniques, including capacitively-coupled contactless conductivity detection (C(4)D). Due to the minimum impact on the separation efficiency, the plastic microfluidic components used for the experiments discussed herein were fabricated using an inexpensive engraving tool and standard Plexiglas. The presented approach (named 5(2)-platform) offers a previously unseen versatility: enabling the assembly of the platform within minutes using capillary tubing that differs in length, diameter, or material. The advantages of the proposed design are demonstrated by performing the analysis of inorganic cations by capillary electrophoresis on soil samples from the Atacama Desert. PMID:23585815

  8. Microfab-less Microfluidic Capillary Electrophoresis Devices

    PubMed Central

    Segato, Thiago P.; Bhakta, Samir A.; Gordon, Matthew; Carrilho, Emanuel; Willis, Peter A.; Jiao, Hong; Garcia, Carlos D.

    2013-01-01

    Compared to conventional bench-top instruments, microfluidic devices possess advantageous characteristics including great portability potential, reduced analysis time (minutes), and relatively inexpensive production, putting them on the forefront of modern analytical chemistry. Fabrication of these devices, however, often involves polymeric materials with less-than-ideal surface properties, specific instrumentation, and cumbersome fabrication procedures. In order to overcome such drawbacks, a new hybrid platform is proposed. The platform is centered on the use of 5 interconnecting microfluidic components that serve as the injector or reservoirs. These plastic units are interconnected using standard capillary tubing, enabling in-channel detection by a wide variety of standard techniques, including capacitively-coupled contactless conductivity detection (C4D). Due to the minimum impact on the separation efficiency, the plastic microfluidic components used for the experiments discussed herein were fabricated using an inexpensive engraving tool and standard Plexiglas. The presented approach (named 52-platform) offers a previously unseen versatility: enabling the assembly of the platform within minutes using capillary tubing that differs in length, diameter, or material. The advantages of the proposed design are demonstrated by performing the analysis of inorganic cations by capillary electrophoresis on soil samples from the Atacama Desert. PMID:23585815

  9. Active airborne contamination control using electrophoresis

    SciTech Connect

    Veatch, B.D.

    1994-06-01

    In spite of our best efforts, radioactive airborne contamination continues to be a formidable problem at many of the Department of Energy (DOE) weapons complex sites. For workers that must enter areas with high levels of airborne contamination, personnel protective equipment (PPE) can become highly restrictive, greatly diminishing productivity. Rather than require even more restrictive PPE for personnel in some situations, the Rocky Flats Plant (RFP) is actively researching and developing methods to aggressively combat airborne contamination hazards using electrophoretic technology. With appropriate equipment, airborne particulates can be effectively removed and collected for disposal in one simple process. The equipment needed to implement electrophoresis is relatively inexpensive, highly reliable, and very compact. Once airborne contamination levels are reduced, less PPE is required and a significant cost savings may be realized through decreased waste and maximized productivity. Preliminary ``cold,`` or non-radioactive, testing results at the RFP have shown the technology to be effective on a reasonable scale, with several potential benefits and an abundance of applications.

  10. Integrated polymerase chain reaction/electrophoresis instrument

    DOEpatents

    Andresen, Brian D. (Livermore, CA)

    2000-01-01

    A new approach and instrument for field identification of micro-organisms and DNA fragments using a small and disposable device containing integrated polymerase chain reaction (PCR) enzymatic reaction wells, attached capillary electrophoresis (CE) channels, detectors, and read-out all on/in a small hand-held package. The analysis instrument may be made inexpensively, for example, of plastic, and thus is disposable, which minimizes cross contamination and the potential for false positive identification between samples. In addition, it is designed for multiple users with individual applications. The integrated PCR/CE is manufactured by the PCR well and CE channels are "stamped" into plastic depressions where conductive coatings are made in the wells and ends of the CE microchannels to carry voltage and current to heat the PCR reaction mixtures and simultaneously draw DNA bands up the CE channels. Light is transmitted through the instrument at appropriate points and detects PCR bands and identifies DNA fragments by size (retention time) and quantifies each by the amount of light generated as each phototransistor positioned below each CE channel detects a passing band. The instrument is so compact that at least 100 PCR/CE reactions/analyses can be performed easily on one detection device.

  11. Contactless conductivity detector array for capillary electrophoresis.

    PubMed

    Stojkovic, Marko; Koenka, Israel Joel; Thormann, Wolfgang; Hauser, Peter C

    2014-02-01

    A CE system featuring an array of 16 contactless conductivity detectors was constructed. The detectors were arranged along 70 cm length of a capillary with 100 cm total length and allow the monitoring of separation processes. As the detectors cannot be accommodated on a conventional commercial instrument, a purpose built set-up employing a sequential injection manifold had to be employed for automation of the fluid handling. Conductivity measurements can be considered universal for electrophoresis and thus any changes in ionic composition can be monitored. The progress of the separation of Na(+) and K(+) is demonstrated. The potential of the system to the study of processes in CZE is shown in two examples. The first demonstrates the differences in the developments of peaks originating from a sample plug with a purely aqueous background to that of a plug containing the analyte ions in the buffer. The second example visualizes the opposite migration of cations and anions from a sample plug that had been placed in the middle of the capillary. PMID:24285496

  12. Improving the sensitivity in chiral capillary electrophoresis.

    PubMed

    Snchez-Lpez, Elena; Marina, Mara Luisa; Crego, Antonio L

    2016-01-01

    CE is known for being one of the most powerful analytical techniques when performing enantioseparations due to its numerous advantages such as excellent separation efficiency and extremely low solvents and reagents consumption, all of them derived from the capillary small dimensions. Moreover, it is worth highlighting that unlike in chromatographic techniques, in CE the chiral selector is generally within the separation medium instead of being attached to the separation column which makes the method optimization a more versatile task. Despite its numerous advantages, when using UV-Vis detection, CE lacks of sensitivity detection due to its short optical path length derived from the narrow separation capillary. This issue can be overcome by means of different approaches, either by sample treatment procedures or by in-capillary preconcentration techniques or even by employing detection systems more sensitive than UV-Vis, such as LIF or MS. The present review assembles the latest contributions regarding improvements of sensitivity in chiral CE published from June 2013 until May 2015, which follows the works included in a previous review reported by Snchez-Hernndez etal. [Electrophoresis 2014, 35, 12-27]. PMID:26434566

  13. Strongly nonlinear waves in capillary electrophoresis

    PubMed Central

    Chen, Zhen; Ghosal, Sandip

    2012-01-01

    In capillary electrophoresis, sample ions migrate along a micro-capillary filled with a background electrolyte under the influence of an applied electric field. If the sample concentration is sufficiently high, the electrical conductivity in the sample zone could differ significantly from the background. Under such conditions, the local migration velocity of sample ions becomes concentration dependent resulting in a nonlinear wave that exhibits shock like features. If the nonlinearity is weak, the sample concentration profile, under certain simplifying assumptions, can be shown to obey Burgers equation (S. Ghosal and Z. Chen Bull. Math. Biol. 2010 72(8), pg. 2047) which has an exact analytical solution for arbitrary initial condition. In this paper, we use a numerical method to study the problem in the more general case where the sample concentration is not small in comparison to the concentration of background ions. In the case of low concentrations, the numerical results agree with the weakly nonlinear theory presented earlier, but at high concentrations, the wave evolves in a way that is qualitatively different. PMID:23004798

  14. Determination of acarbose by capillary zone electrophoresis.

    PubMed

    Lachmann, B; Noe, C R

    2013-07-01

    Acarbose (Glucobay, Bayer AG) acts as a potent alpha-glucosidase-inhibitor, which delays the intestinal starch digestion resulting in a reduction of postprandial blood glucose and insulin levels. Acarbose is a pseudo-tetrasaccharide, with two D-glucose units linked via an alpha 1-->4 glycosidic bond to acarviosin, which is a N-glycoside composed of an unsaturated cyclitol and 4-amino-4,6-dideoxy-alpha-D-glucopyranose. Several methods for the determination of acarbose by capillary electrophoresis can be found in literature. They are based either on the derivatisation with 7-aminonaphthalene-1,3-disulfonic acid (ANDS) or on the detection of the unsaturated cyclitol at wavelengths below 200 nm. The aim of our work was the determination of acarbose making use of a previously developed method based on reductive amination with S-phenylethylamine. The aminoalditols generated in the reaction formed differently charged borate-complexes depending on the configuration of the sugar. After successful method optimisation we were able to separate two potential impurities of acarbose, D-maltose und D-glucose. For the quantitation of acarbose in Glucobay tablets an additional borate-buffer system was established, reducing the total time of analysis to less than 10 min. PMID:23923633

  15. Amperometric detector designs for capillary electrophoresis microchips.

    PubMed

    Castao-Alvarez, Mario; Fernndez-Abedul, M Teresa; Costa-Garca, Agustn

    2006-03-24

    Electrochemical (EC) detection is a sensitive and miniaturisable detection mode for capillary electrophoresis (CE) microchips. Detection cell design is very important in order to ensure electrical isolation from the high separation voltage. Amperometric detectors with different designs have been developed for coupling EC detection to CE-microchips. Different working electrode alignment: in-channel or end-channel has been tested in conjunction with several materials: gold, platinum or carbon. The end-channel detector was based on a platinum or gold wire manually aligned at the exit of the separation channel. Thick- (screen-printed carbon electrode) and thin-film (sputtered gold film) electrodes have also been employed with this configuration, but with a different design that allowed the rapid replacement of the electrode. The in-channel detector was based on a gold film within the separation channel. A gold-based dual electrode detector, which combined for the first time in- and end-channel detection, has been also tested. These amperometric detectors have been evaluated in combination to poly(methylmethacrylate) (PMMA) and Topas (thermoplastic olefin polymer of amorphous structure) CE-microchips. Topas is a new and promising cyclic olefin copolymer with high chemical resistance. Relevant parameters of the polymer microchip separation such as precision, efficiency or resolution and amperometric detection were studied with the different detector designs using p-aminophenol and L-ascorbic acid as model analytes in Tris-based buffer pH 9.0. PMID:16472530

  16. Redox options in two-dimensional electrophoresis.

    PubMed

    Wait, R; Begum, S; Brambilla, D; Carabelli, A M; Conserva, F; Rocco Guerini, A; Eberini, I; Ballerio, R; Gemeiner, M; Miller, I; Gianazza, E

    2005-05-01

    Two-dimensional electrophoresis is usually run on fully reduced samples. Under these conditions even covalently bound oligomers are dissociated and individual polypeptide chains may be fully unfolded by both, urea and SDS, which maximizes the number of resolved components and allows their pI and M(r) to be most accurately evaluated. However, various electrophoretic protocols for protein structure investigation require a combination of steps under varying redox conditions. We review here some of the applications of these procedures. We also present some original data about a few related samples -- serum from four species: Homo sapiens, Mus musculus, Rattus norvegicus, Bos taurus -- which we run under fully unreduced and fully reduced conditions as well as with reduction between first and second dimension. We demonstrate that in many cases the unreduced proteins migrate with a better resolution than reduced proteins, mostly in the crowded 'alpha-globulin' area of pI 4.5-6 and M(r) 50-70 kDa. PMID:15744479

  17. Micro-size polyacrylamide gel electrophoresis system

    NASA Astrophysics Data System (ADS)

    Hinson, W. G.; Pipkin, J. L.; Anson, J. F.; Casciano, D. A.; Burns, E. R.

    1987-09-01

    The development and characterization of a micro-size two-dimensional polyacrylamide gel electrophoresis system is described. Some of the techniques which have evolved with use of the system are also discussed. This apparatus has unique features which provide advantages over other small scale units. Up to ten first- and second-dimension gels can be processed simultaneously with excellent resolution of protein regions. Consistent reproducibility is possible from protein samples as small as 400 ng and individual protein regions as small as 1 pg can be visualized by silver staining of the two-dimensional gels. Similar sensitivities are achieved in autoradiographs of 3H-labeled proteins extracted from the nuclei of cultured cells. The application of this system in conjunction with flow cytometric examination of nuclear DNA and electrostatic cell sorting of specific cell nuclei to provide homogeneous sample populations, allows subtle variations in isotope incorporation in proteins to be detected; whereas many times in generalized tissue samples these changes are masked. Also, these techniques elucidate the effects of external stimuli (chemicals, drugs, or environment) on protein synthesis and phosphorylation for analyses and comparison. Fabrication drawings are available upon request.

  18. Investigations of the inhibitory effects of tocopherol (vitamin E) on free radical deterioration of cellular membranes

    NASA Technical Reports Server (NTRS)

    Richardson, D.

    1975-01-01

    The inhibitory effects are investigated of d,1-alpha-tocopherol and d,1-alpha-tocopheryl acetate on the free radical deterioration of cellular membranes. The level of toxicity of d,1-alpha-tocopherol and d,1-alpha-tocopheryl acetate in mice is determined.

  19. Extended length microchannels for high density high throughput electrophoresis systems

    DOEpatents

    Davidson, James C. (Livermore, CA); Balch, Joseph W. (Livermore, CA)

    2000-01-01

    High throughput electrophoresis systems which provide extended well-to-read distances on smaller substrates, thus compacting the overall systems. The electrophoresis systems utilize a high density array of microchannels for electrophoresis analysis with extended read lengths. The microchannel geometry can be used individually or in conjunction to increase the effective length of a separation channel while minimally impacting the packing density of channels. One embodiment uses sinusoidal microchannels, while another embodiment uses plural microchannels interconnected by a via. The extended channel systems can be applied to virtually any type of channel confined chromatography.

  20. Multicomponent membranes

    DOEpatents

    Kulprathipanja, Santi (Hoffman Estates, IL); Kulkarni, Sudhir S. (Hoffman Estates, IL); Funk, Edward W. (Highland Park, IL)

    1988-01-01

    A multicomponent membrane which may be used for separating various components which are present in a fluid feed mixture comprises a mixture of a plasticizer such as a glycol and an organic polymer cast upon a porous organic polymer support. The membrane may be prepared by casting an emulsion or a solution of the plasticizer and polymer on the porous support, evaporating the solvent and recovering the membrane after curing.

  1. Analysis of the Microbial Community in an Acidic Hollow-Fiber Membrane Biofilm Reactor (Hf-MBfR) Used for the Biological Conversion of Carbon Dioxide to Methane.

    PubMed

    Shin, Hyun Chul; Ju, Dong-Hun; Jeon, Byoung Seung; Choi, Okkyoung; Kim, Hyun Wook; Um, Youngsoon; Lee, Dong-Hoon; Sang, Byoung-In

    2015-01-01

    Hydrogenotrophic methanogens can use gaseous substrates, such as H2 and CO2, in CH4 production. H2 gas is used to reduce CO2. We have successfully operated a hollow-fiber membrane biofilm reactor (Hf-MBfR) for stable and continuous CH4 production from CO2 and H2. CO2 and H2 were diffused into the culture medium through the membrane without bubble formation in the Hf-MBfR, which was operated at pH 4.5-5.5 over 70 days. Focusing on the presence of hydrogenotrophic methanogens, we analyzed the structure of the microbial community in the reactor. Denaturing gradient gel electrophoresis (DGGE) was conducted with bacterial and archaeal 16S rDNA primers. Real-time qPCR was used to track changes in the community composition of methanogens over the course of operation. Finally, the microbial community and its diversity at the time of maximum CH4 production were analyzed by pyrosequencing methods. Genus Methanobacterium, related to hydrogenotrophic methanogens, dominated the microbial community, but acetate consumption by bacteria, such as unclassified Clostridium sp., restricted the development of acetoclastic methanogens in the acidic CH4 production process. The results show that acidic operation of a CH4 production reactor without any pH adjustment inhibited acetogenic growth and enriched the hydrogenotrophic methanogens, decreasing the growth of acetoclastic methanogens. PMID:26694756

  2. Analysis of the Microbial Community in an Acidic Hollow-Fiber Membrane Biofilm Reactor (Hf-MBfR) Used for the Biological Conversion of Carbon Dioxide to Methane

    PubMed Central

    Jeon, Byoung Seung; Choi, Okkyoung; Kim, Hyun Wook; Um, Youngsoon; Lee, Dong-Hoon; Sang, Byoung-In

    2015-01-01

    Hydrogenotrophic methanogens can use gaseous substrates, such as H2 and CO2, in CH4 production. H2 gas is used to reduce CO2. We have successfully operated a hollow-fiber membrane biofilm reactor (Hf-MBfR) for stable and continuous CH4 production from CO2 and H2. CO2 and H2 were diffused into the culture medium through the membrane without bubble formation in the Hf-MBfR, which was operated at pH 4.5–5.5 over 70 days. Focusing on the presence of hydrogenotrophic methanogens, we analyzed the structure of the microbial community in the reactor. Denaturing gradient gel electrophoresis (DGGE) was conducted with bacterial and archaeal 16S rDNA primers. Real-time qPCR was used to track changes in the community composition of methanogens over the course of operation. Finally, the microbial community and its diversity at the time of maximum CH4 production were analyzed by pyrosequencing methods. Genus Methanobacterium, related to hydrogenotrophic methanogens, dominated the microbial community, but acetate consumption by bacteria, such as unclassified Clostridium sp., restricted the development of acetoclastic methanogens in the acidic CH4 production process. The results show that acidic operation of a CH4 production reactor without any pH adjustment inhibited acetogenic growth and enriched the hydrogenotrophic methanogens, decreasing the growth of acetoclastic methanogens. PMID:26694756

  3. Evaluation of different protein extraction methods for banana (Musa spp.) root proteome analysis by two-dimensional electrophoresis.

    PubMed

    Vaganan, M Mayil; Sarumathi, S; Nandakumar, A; Ravi, I; Mustaffa, M M

    2015-02-01

    Four protocols viz., the trichloroacetic acid-acetone (TCA), phenol-ammonium acetate (PAA), phenol/SDS-ammonium acetate (PSA) and trisbase-acetone (TBA) were evaluated with modifications for protein extraction from banana (Grand Naine) roots, considered as recalcitrant tissues for proteomic analysis. The two-dimensional electrophoresis (2-DE) separated proteins were compared based on protein yield, number of resolved proteins, sum of spot quantity, average spot intensity and proteins resolved in 4-7 pI range. The PAA protocol yielded more proteins (0.89 mg/g of tissues) and protein spots (584) in 2-DE gel than TCA and other protocols. Also, the PAA protocol was superior in terms of sum of total spot quantity and average spot intensity than TCA and other protocols, suggesting phenol as extractant and ammonium acetate as precipitant of proteins were the most suitable for banana rooteomics analysis by 2-DE. In addition, 1:3 ratios of root tissue to extraction buffer and overnight protein precipitation were most efficient to obtain maximum protein yield. PMID:26040117

  4. Free zone electrophoresis simulation of static column electrophoresis in microgravity on shuttle flight STS-3

    NASA Technical Reports Server (NTRS)

    Todd, P. W.; Hjerten, S.

    1985-01-01

    Experiments were designed to replicate, as closely as possible in 1-G, the conditions of the STS-3 red blood cell (RBC) experiments. Free zone electrophoresis was the method of choice, since it minimizes the role of gravity in cell migration. The physical conditions of the STS-3 experiments were used, and human and rabbit RBC's fixed by the same method were the test particles. The effects of cell concentration, electroosmotic mobility, and sample composition were tested in order to seek explanations for the STS-3 results and to provide data on cell concentration effects for future zero-G separation on the continuous-flow zero-G electrophoretics separator.

  5. An improved scheme for the identification of antigens recognized by specific antibodies in two-dimensional gel electrophoresis and immunoblotting.

    PubMed

    Shen, H D; Choo, K B; Lin, W L; Lin, R Y; Han, S H

    1990-10-01

    This paper describes an improved scheme for the identification of antigens in crude extracts recognized by specific antibodies when analyzed by a combination of two-dimensional gel electrophoresis and immunoblotting. First, protein components in gels are electrophoretically transferred to a polyvinylidene difluoride membrane which does not shrink or change dimensions in organic solvents. The efficiency of transfer and the localization of sample proteins on the membrane are checked and recorded by staining the blotting membrane with Fast Green FCF and recording the profile on a transparency. After blocking and the immunoassay, the results are recorded by photography. The sites of immune reaction are marked and the same membrane is restained briefly with Coomassie Brilliant Blue R-250 for the protein profile. Thus antigens in complex mixtures, recognized by antibodies of interest, can easily be identified from the restained membrane. If the whole protein profile is not well demonstrated, when used in combination with the profile recorded on the transparency, spots appearing on the restained membrane can still be used as useful landmarks in the final unequivocal antigenic identification. This improved scheme circumvents problems arising from membrane shrinkage and difficulties in accurately matching immunoreactive spots by conventional procedures and thus provides an accurate, simple and fast approach in the identification of antigens after immunoblotting. PMID:2079030

  6. CAPILLARY ELECTROPHORESIS FOR THE CHARACTERIZATION OF HUMIC SUBSTANCES

    EPA Science Inventory

    The potential of high performance capillary electrophoresis (HPCE), especially in the free solution mode (FSCE), is demonstrated for the analysis/characterization of environmental humic substances (HUS). he very high efficiency of HPCE separations allows the production of electro...

  7. Microchannel DNA Sequencing by End-Labelled Free Solution Electrophoresis

    SciTech Connect

    Barron, A.

    2005-09-29

    The further development of End-Labeled Free-Solution Electrophoresis will greatly simplify DNA separation and sequencing on microfluidic devices. The development and optimization of drag-tags is critical to the success of this research.

  8. TECHNIQUES WITH POTENTIAL FOR HANDLING ENVIRONMENTAL SAMPLES IN CAPILLARY ELECTROPHORESIS

    EPA Science Inventory

    An assessment of the methods for handling environmental samples prior to capillary electrophoresis (CE) is presented for both aqueous and solid matrices. Sample handling in environmental analyses is the subject of ongoing research at the Environmental Protection Agency's National...

  9. Capillary electrophoresis based on continuous-wave multiphoton excitation fluorescence

    NASA Astrophysics Data System (ADS)

    Chen, Sheng; Luo, Qingming; Zeng, Shaoqun; Chen, Tongsheng; Gong, Hui; Fu, Ling

    2003-12-01

    High performance capillary electrophoresis(HPCE) has been widely applied to the field of chemistry and life science for its advantages of high separation efficiency, short analysis times and low sample volume requirements. But how to improve the detection capability of capillary electrophoresis was ever a key problem. Multi-photon excitation (MPE) fluorescence detection could solve this problem, however this method needed expensive femtosecond mod-locked laser, which restricted the improvement of capillary electrophoresis. In this paper, we implemented a set of MPE-CE system based on a continuous wave (CW), successfully exploited the CW multi-photon excitation to achieve detection of capillary electrophoresis. In our current MPE-CE system we used Ti:sapphire laser to prove MPE-CE could work in CW mode. From this point, we would substitute the laser with laser diode (LD) in future. This is really a new but also practical idea in MPE-CE system based on CW.

  10. A New Electrophoresis Technique to Seperate Microsatellite Alleles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional agarose and polyacrylamide gel electrophoresis have been used commonly for microsatellite (simple sequence repeats, SSRs) analysis, but they are labor- intensive and not always able to provide accurate sizes for different alleles. Capillary sequencers provide automated analysis and accur...

  11. Characterization of microporous membranes using confocal scanning laser microscopy in fluorescence mode

    NASA Astrophysics Data System (ADS)

    Charcosset, C.; Bernengo, J.-C.

    2000-12-01

    Confocal Scanning Laser Microscopy (CSLM) in fluorescence mode was used to characterize microporous membranes. Two microfiltration membranes were investigated: a mixed ester (cellulose nitrate/cellulose acetate) 1.2 ?m-rated membrane and a polycarbonate track-etched membrane with cylindrical pores of 2 ?m diameter. Optical sections of the membranes stained with rhodamine and mounted in glycerol were performed at 1 ?m intervals, from 0 to 10 ?m. CSLM was found useful for microporous membrane characterization, as it gives some insight into bulk membrane morphology.

  12. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl acetate. 173.228 Section 173.228 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... with current good manufacturing practice as a solvent in the decaffeination of coffee and tea....

  13. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD...

  14. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD...

  15. Heat Bonding of Irradiated Ethylene Vinyl Acetate

    NASA Technical Reports Server (NTRS)

    Slack, D. H.

    1986-01-01

    Reliable method now available for joining parts of this difficult-tobond material. Heating fixture encircles ethylene vinyl acetate multiplesocket part, providing heat to it and to tubes inserted in it. Fixtures specially designed to match parts to be bonded. Tube-and-socket bonds made with this technique subjected to tensile tests. Bond strengths of 50 percent that of base material obtained consistently.

  16. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

    1998-02-17

    This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85 and 200 C and removing the reaction products from the contact zone.

  17. Corrosion of stainless steel during acetate production

    SciTech Connect

    Qi, J.S.; Lester, G.C.

    1996-07-01

    Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CH{sub 3}COOH under the process conditions commonly practiced in industry. The corrosive action of the catalyst occurred only in the presence of water. Thus, for the batch processes, corrosion occurred mostly during the initial stage of esterification, where water produced by the reaction created an aqueous environment. After water was distilled off, the corrosion rate declined to a negligible value. The corrosion inhibitor copper sulfate, often used in industrial acetate processes, was found to work well for a low-temperature process (< 95 C) such as in production of butyl acetate, but it accelerated corrosion in the glycol ether acetate processes where temperatures were > 108 C. Process conditions that imparted low corrosion rates were determined.

  18. Synthesis of Cellulose Acetate from Cotton Byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton burr and cottonseed hull are relatively inexpensive cotton byproducts. In an effort to derive greater value out of these natural renewable materials, we have succeeded in converting part of them into cellulose acetate without prior chemical breakdown or physical separation of cellulose, ligni...

  19. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles (Kingsport, TN); Zoeller, Joseph Robert (Kingsport, TN); Depew, Leslie Sharon (Kingsport, TN)

    1998-01-01

    This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85.degree. and 200.degree. C. and removing the reaction products from the contact zone.

  20. Advanced Colloids Experiment (ACE-T1)

    NASA Technical Reports Server (NTRS)

    Meyer, William V.; Sicker, Ron; Brown, Dan; Eustace, John

    2015-01-01

    Increment 45 - 46 Science Symposium presentation of Advanced Colloids Experiment (ACE-T1) to RPO. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators.

  1. A novel approach to pseudopodia proteomics: excimer laser etching, two-dimensional difference gel electrophoresis, and confocal imaging

    PubMed Central

    Mimae, Takahiro; Ito, Akihiko; Hagiyama, Man; Nakanishi, Jun; Hosokawa, Yoichiroh; Okada, Morihito; Murakami, Yoshinori; Kondo, Tadashi

    2014-01-01

    Pseudopodia are actin-rich ventral cellular protrusions shown to facilitate the migration and metastasis of tumor cells. Here, we present a novel approach to perform pseudopodia proteomics. Tumor cells growing on porous membranes extend pseudopodia into the membrane pores. In our method, cell bodies are removed by horizontal ablation at the basal cell surface with the excimer laser while pseudopodia are left in the membrane pores. For protein expression profiling, whole cell and pseudopodia proteins are extracted with a lysis buffer, labeled with highly sensitive fluorescent dyes, and separated by two-dimensional gel electrophoresis. Proteins with unique expression patterns in pseudopodia are identified by mass spectrometry. The effects of the identified proteins on pseudopodia formation are evaluated by measuring the pseudopodia length in cancer cells with genetically modified expression of target proteins using confocal imaging. This protocol allows global identification of pseudopodia proteins and evaluation of their functional significance in pseudopodia formation within one month. PMID:25309719

  2. Field-portable Capillary Electrophoresis Instrument with Conductivity Detection

    NASA Astrophysics Data System (ADS)

    Zhang, H. F.; Liu, X. W.; Wang, W.; Wang, X. L.; Tian, L.

    2006-10-01

    In this paper a novel capillary electrophoresis chip (CEC) is presented with integrated platinum electrodes and simplified conductivity detector. CEC is fabricated by the method of mechanical modification with probe on organic glass. Capillary electrophoresis chip can rapidly completed ion separation by simulation of concentration distribution and zone-broadening. Detection circuit is simple which can detect pA order current. This system has those advantages such as small volume, low power consumption and linearity, and well suit for field analysis.

  3. Nicked-sleeve interface for two-dimensional capillary electrophoresis

    PubMed Central

    Flaherty, Ryan J.; Huge, Bonnie J.; Bruce, Spencer M.; Dada, Oluwatosin O.; Dovichi, Norman J.

    2013-01-01

    We report an improved interface for two-dimensional capillary electrophoresis. This interface is based on capillary tubing and a Plexiglas chip, both of which were milled using a micro-dicing saw. The interface was evaluated and compared to a traditional interface design for both pseudo one-dimensional and two-dimensional capillary electrophoresis. We observe less than 70% transfer efficiency for the traditional design and greater than 90% transfer efficiency with this new interface. PMID:23702824

  4. The comparison of rat liver rough endoplasmic reticulum membrane proteins before and after in vitro removal of its bound ribosomes.

    PubMed

    Czosnek, H H; de Groot, N; Hochberg, A A

    1975-07-01

    The comparison of the proteins of rat liver rough membrane after stripping with EDTA or KCl-puromycin by two dimensional gel electrophoresis is described. By stripping the membrane with EDTA, most of the basic ribosomal proteins are still attached to the membrane; in contrast to the EDTA stripping method, treatment with KCl-puromycin removes most of the ribosomal proteins and does not remove any of the membranal proteins. PMID:808702

  5. Linear drug release from laminated hydroxypropyl cellulose-polyvinyl acetate films.

    PubMed

    Borodkin, S; Tucker, F E

    1975-08-01

    Release of drug from a single-layer film containing dispersed drug follows a diffusion-controlled matrix model, where the quantity released per unit area is proportional to the square root of time. The kinetics may be made linear with time (zero order) by laminating a second film without drug to the releasing side of the film with dispersed drug. In this manner, the drug layer serves as a reservoir and controls the duration of drug release, while the nondrug layer functions as a rate-controlling membrane. Zero-order drug release was demonstrated in such laminated films using 18-45 percent pentobarbital, methapyrilene, or salicylic acid contained in hydroxypropyl cellulose as the reservoir layer and mixtures of hydroxypropyl cellulose and polyvinyl acetate as the membrane layer. Inverse relationships between the release rate and membrane thickness and between the logarithm of the rate and the percentage of polyvinyl acetate in the membrane layer were observed. Of the three drugs tested, salicylic acid gave the fastest release rates while pentobarbital gave the slowest. PMID:1151700

  6. DNA sequencing using fluorescence background electroblotting membrane

    DOEpatents

    Caldwell, K.D.; Chu, T.J.; Pitt, W.G.

    1992-05-12

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through amino groups contained on the surface. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to the target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membranes may be reprobed numerous times. No Drawings

  7. Novel separation and detection methods of DNA fragments in electrophoresis

    SciTech Connect

    Chan, King Cheung

    1993-01-27

    A charge-coupled device (CCD) based electrophoresis system was developed. The system allowed non-destructive, sensitive, and on-line detection of native DNA in slab-gel electrophoresis via ultraviolet absorption measurement. The detection limit of double-stranded DNA fragment was 5 ng per band. Since the amount of DNA used in this experiment was typical, the CCD-based system could be readily implemented in molecular biology. Gel-filled and non-gel sieving capillary electrophoresis was developed for rapid and efficient separation of double-stranded DNA fragments. For the gel-filled CE separation a new gel matrix, the HydroLink gel (HL), was used. The HL capillary gel was easier to cast than the polyacrylamide capillary gel. For the non-gel separation, a GC capillary was used as the separation chamber, and cellulose additive was included in the electrophoresis as the sieving medium. Indirect fluorometry was applied in non-gel and gel electrophoresis for the detection of DNA fragments. This method allowed non-destructive and on-line detection of DNA during electrophoresis. The amount of DNA used with this method was comparable to those obtained with absorption measurement.

  8. Novel separation and detection methods of DNA fragments in electrophoresis

    SciTech Connect

    Chan, K.C.

    1992-01-01

    A charge-coupled device (CCD) based electrophoresis system was developed. The system allowed non-destructive, sensitive, and on-line detection of native DNA in slab-gel electrophoresis via ultraviolet absorption measurement. The detection limit of double-stranded DNA fragment was 5 ng per band. Since the amount of DNA used in this experiment was typical, the CCD-based system could be readily implemented in molecular biology. Gel-filled and non-gel sieving capillary electrophoresis (CE) was developed for rapid and efficient separation of double-stranded DNA fragments. For the gel-filled CE separation a new gel matrix, the HydroLink gel (HL), was used. The HL capillary gel was easier to cast than the polyacrylamide capillary gel. For the non-gel separation, a GC capillary was used as the separation chamber, and cellulose additive was included in the electrophoresis as the sieving medium. Indirect fluorometry was applied in non-gel and gel electrophoresis for the detection of DNA fragments. This method allowed nondestructive and on-line detection of DNA during electrophoresis. The amount of DNA used with this method was comparable to those obtained with absorption measurement.

  9. Phenyl Acetate Preparation from Phenol and Acetic Acid: Reassessment of a Common Textbook Misconception.

    ERIC Educational Resources Information Center

    Hocking, M. B.

    1980-01-01

    Reassesses a common textbook misconception that "...phenols cannot be esterified directly." Results of experiments are discussed and data tables provided of an effective method for the direct preparation of phenyl acetate. (CS)

  10. Basement membranes.

    PubMed Central

    Kramer, James M

    2005-01-01

    Basement membranes are thin, specialized extracellular matrices surrounding most tissues in all metazoans. The compositions and functions of basement membranes have generally been well conserved throughout the subkingdom. Genetic analyses of basement membrane components in C. elegans have provided insights into their assembly and functions during development. Immuno- or GFP-tagged localization studies have shown that basement membranes on different tissues, or even sub-regions of tissues, contain different sets of proteins or alternatively spliced isoforms of them. Several components, including laminin, perlecan, type IV collagen and possibly osteonectin/SPARC, are essential for completion of embryogenesis, being necessary for tissue organization and structural integrity. In contrast, type XVIII collagen and nidogen are not required for viability but primarily influence organization of the nervous system. All of these proteins, with the exception of nidogen and the addition of fibulin, have roles of varying degree in morphogenesis of the gonad. A major family of cellular receptors for basement membrane proteins, the integrins, have also been characterized in C. elegans. As one might expect, integrins have been shown to function in many of the same processes as their potential ligands, the basement membrane components. While much remains to be explored, studies of basement membranes in C. elegans have been highly informative and hold great promise for improving our understanding of how these structures are assembled and how they function in development. PMID:18050423

  11. Polyethylene-supported polyvinylidene fluoride-cellulose acetate butyrate blended polymer electrolyte for lithium ion battery

    NASA Astrophysics Data System (ADS)

    Liu, Jiansheng; Li, Weishan; Zuo, Xiaoxi; Liu, Shengqi; Li, Zhao

    2013-03-01

    The polyethylene (PE)-supported polymer membranes based on the blended polyvinylidene fluoride (PVDF) and cellulose acetate butyrate (CAB) are prepared for gel polymer electrolyte (GPE) of lithium ion battery. The performances of the prepared membranes and the resulting GPEs are investigated by scanning electron microscopy, electrochemical impedance spectroscopy, linear potential sweep, and charge-discharge test. The effect of the ratio of PVDF to CAB on the performance of the prepared membranes is considered. It is found that the GPE based on the blended polymer with PVDF:CAB = 2:1 (in weight) has the largest ionic conductivity (2.48 10-3 S cm-1) and shows good compatibility with anode and cathode of lithium ion battery. The LiCoO2/graphite battery using this GPE exhibits superior cyclic stability at room temperature, storage performance at elevated temperature, and rate performance.

  12. Fragrance material review on 1,1-dimethyl-2-phenylethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 1,1-dimethyl-2-phenylethyl acetate when used as a fragrance ingredient is presented. 1,1-Dimethyl-2-phenylethyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an Aryl Alkyl Alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to 1,1-dimethyl-2-phenylethyl acetate and is not intended as a stand-alone document. Available data were evaluated, then summarized, and includes: physical properties; acute toxicity; skin irritation; mucous membrane (eye) irritation; skin sensitization; elicitation; and toxicokinetics data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22445843

  13. Viscometric study of chitosan solutions in acetic acid/sodium acetate and acetic acid/sodium chloride.

    PubMed

    Costa, Cristiane N; Teixeira, Viviane G; Delpech, Marcia C; Souza, Josefa Virginia S; Costa, Marcos A S

    2015-11-20

    A viscometric study was carried out at 25C to assess the physical-chemical behavior in solution and the mean viscometric molar mass (Mv) of chitosan solutions with different deacetylation degrees, in two solvent mixtures: medium 1-acetic acid 0.3mol/L and sodium acetate 0.2mol/L; and medium 2-acetic acid 0.1mol/L and sodium chloride 0.2mol/L. Different equations were employed, by graphical extrapolation, to calculate the intrinsic viscosities [?] and the viscometric constants, to reveal the solvent's quality: Huggins (H), Kraemer (K) and Schulz-Blaschke (SB). For single-point determination, the equations used were SB, Solomon-Ciuta (SC) and Deb-Chanterjee (DC), resulting in a faster form of analysis. The values of ?Mv were calculated by applying the equation of Mark-Houwink-Sakurada. The SB and SC equations were most suitable for single-point determination of [?] and ?Mv and the Schulz-Blachke constant (kSB), equal to 0.28, already utilized for various systems, can also be employed to analyze chitosan solutions under the conditions studied. PMID:26344278

  14. Crystalline Membranes

    NASA Technical Reports Server (NTRS)

    Tsapatsis, Michael (Inventor); Lai, Zhiping (Inventor)

    2008-01-01

    In certain aspects, the invention features methods for forming crystalline membranes (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals. The rate of growth of the seed crystals in the plane of the substrate is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains of uniform crystallographic orientation that extend through the depth of the layer.

  15. Characterization of copolymer latexes by capillary electrophoresis.

    PubMed

    Anik, Nadia; Airiau, Marc; Labeau, Marie-Pierre; Bzducha, Wojciech; Cottet, Hervé

    2010-02-01

    Latexes are widely used for industrial applications, including decorative paints, binders for the papermaking industry, and drilling fluids for oil-field applications. In this work, the interest of capillary zone electrophoresis (CE) for the characterization of hydrophobic block copolymer latexes obtained by the conventional emulsion polymerization technique consisting of a core of polystyrene (PS) surrounded by a layer of poly(ethyl acrylate) (PEA) has been investigated. The PEA part of the copolymer can be partially hydrolyzed in poly(acrylic acid) (PAA) leading to PS-PEA-AA water-soluble amphiphilic copolymer having high viscosifying properties. The main purpose of this work was to evaluate the potential of CE for the characterization of the latexes at the different stages of the synthesis (PS core, PS-PEA diblock latex, and hydrolyzed PS-PEA-AA gel). The main analytical issues were to state (i) if there was free PS or PEA homopolymer latexes in the PS-PEA latex sample and (ii) if there was free PS, PEA, PS-PEA latexes, or free PAA chains in the PS-PEA-AA gel. Within this scope, this work describes the optimization of the selectivity of the separation between the different species (PS, PEA particles in the not hydrolyzed diblock latex and PS, PEA, PS-PEA particles as well as the polymer PAA chains in the PS-PEA-AA diblock gel sample obtained by latter latex hydrolysis). For that purpose, several experimental parameters were investigated such as pH and ionic strength of the background electrolyte (BGE) or the concentration of neutral surfactant added in the BGE. A challenging issue was to overcome the high viscosity of the PS-PEA-AA gel. This was resolved by the addition of 10 mM neutral surfactant in the gel sample and in the BGE. Finally, it is demonstrated that, within the detection limits, CE is a suitable analytical tool for controlling and monitoring the syntheses of these latexes and for intrinsically characterizing the distribution in charge density of the final PS-PEA-AA gel at different hydrolysis rates. PMID:19873976

  16. System zones in capillary zone electrophoresis.

    PubMed

    Beckers, J L; Gebauer, P; Bocek, P

    2001-10-01

    This paper brings an overview of system zones (SZs) in capillary zone electrophoresis (CZE) and their effects upon the migration of zones of analytes. It is shown that the formation and migration of SZs is an inherent feature of CZE, and that it depends predominantly on the composition of an actual background electrolyte (BGE). One can distinguish between stationary SZs and migrating SZs. Stationary SZs, which move due to the electroosmotic flow only, are induced in any BGE by sample injection. Migrating SZs may be induced by a sample injection in BGEs which show at least one of the following features: (i) BGE contains two or more co-ions, (ii) BGE has low or high pH whereby H+ or OH- act as the second co-ion, and (iii) BGE contains multivalent weak acids or bases. SZs do not contain any analyte and show always BGE-like composition. They contain components of the BGE only and the concentrations of these components are different from their values in the original BGE. Providing that some of the ionic components of the BGE are visible by the detector, the migrating SZs can be detected and they are present as system peaks/dips in the electropherogram. It is shown that a migrating SZ may be characterized by its mobility, and examples are given how this mobility can depend on the composition of the BGE. Further, the effects of the migrating SZs (either visible or not visible by the detector) upon the zones of analytes are presented and the typical disturbances of the peaks (extra broadening, zig-zag form, schizophrenic behavior) are exemplified and discussed. Finally, some conclusions are presented how to cope with the SZs in practice. The proposed procedure is based on the theoretical predictions and/or measurements of the mobilities of SZs and on the so-called unsafe region. Then, such operational conditions should be selected where the unsafe region is outside of the required analytical window. PMID:11699902

  17. Novel cationic polyelectrolyte coatings for capillary electrophoresis.

    PubMed

    Dua, Filip; Witos, Joanna; Karjalainen, Erno; Viitala, Tapani; Tenhu, Heikki; Wiedmer, Susanne K

    2016-01-01

    The use of bare fused silica capillary in CE can sometimes be inconvenient due to undesirable effects including adsorption of sample or instability of the EOF. This can often be avoided by coating the inner surface of the capillary. In this work, we present and characterize two novel polyelectrolyte coatings (PECs) poly(2-(methacryloyloxy)ethyl trimethylammonium iodide) (PMOTAI) and poly(3-methyl-1-(4-vinylbenzyl)-imidazolium chloride) (PIL-1) for CE. The coated capillaries were studied using a series of aqueous buffers of varying pH, ionic strength, and composition. Our results show that the investigated polyelectrolytes are usable as semi-permanent (physically adsorbed) coatings with at least five runs stability before a short coating regeneration is necessary. Both PECs showed a considerably decreased stability at pH 11.0. The EOF was higher using Good's buffers than with sodium phosphate buffer at the same pH and ionic strength. The thickness of the PEC layers studied by quartz crystal microbalance was 0.83 and 0.52 nm for PMOTAI and PIL-1, respectively. The hydrophobicity of the PEC layers was determined by analysis of a homologous series of alkyl benzoates and expressed as the distribution constants. Our result demonstrates that both PECs had comparable hydrophobicity, which enabled separation of compounds with log Po/w > 2. The ability to separate cationic drugs was shown with ?-blockers, compounds often misused in doping. Both coatings were also able to separate hydrolysis products of the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene acetate at highly acidic conditions, where bare fused silica capillaries failed to accomplish the separation. PMID:26464098

  18. Cathepsin D protects colorectal cancer cells from acetate-induced apoptosis through autophagy-independent degradation of damaged mitochondria

    PubMed Central

    Oliveira, C S F; Pereira, H; Alves, S; Castro, L; Baltazar, F; Chaves, S R; Preto, A; Côrte-Real, M

    2015-01-01

    Acetate is a short-chain fatty acid secreted by Propionibacteria from the human intestine, known to induce mitochondrial apoptotic death in colorectal cancer (CRC) cells. We previously established that acetate also induces lysosome membrane permeabilization in CRC cells, associated with release of the lysosomal protease cathepsin D (CatD), which has a well-established role in the mitochondrial apoptotic cascade. Unexpectedly, we showed that CatD has an antiapoptotic role in this process, as pepstatin A (a CatD inhibitor) increased acetate-induced apoptosis. These results mimicked our previous data in the yeast system showing that acetic acid activates a mitochondria-dependent apoptosis process associated with vacuolar membrane permeabilization and release of the vacuolar protease Pep4p, ortholog of mammalian CatD. Indeed, this protease was required for cell survival in a manner dependent on its catalytic activity and for efficient mitochondrial degradation independently of autophagy. In this study, we therefore assessed the role of CatD in acetate-induced mitochondrial alterations. We found that, similar to acetic acid in yeast, acetate-induced apoptosis is not associated with autophagy induction in CRC cells. Moreover, inhibition of CatD with small interfering RNA or pepstatin A enhanced apoptosis associated with higher mitochondrial dysfunction and increased mitochondrial mass. This effect seems to be specific, as inhibition of CatB and CatL with E-64d had no effect, nor were these proteases significantly released to the cytosol during acetate-induced apoptosis. Using yeast cells, we further show that the role of Pep4p in mitochondrial degradation depends on its protease activity and is complemented by CatD, indicating that this mechanism is conserved. In summary, the clues provided by the yeast model unveiled a novel CatD function in the degradation of damaged mitochondria when autophagy is impaired, which protects CRC cells from acetate-induced apoptosis. CatD inhibitors could therefore enhance acetate-mediated cancer cell death, presenting a novel strategy for prevention or therapy of CRC. PMID:26086961

  19. 21 CFR 582.5892 - a-Tocopherol acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 582.5892 a-Tocopherol acetate. (a) Product. a-Tocopherol acetate. (b) Conditions of use....

  20. [Control of nanoparticles in food and biological objects. Report 2. Filtration, centrifugation, spectral methods and electrophoresis].

    PubMed

    Raspopov, R V; Gmoshinskiĭ, I V; Popov, K I; Rykhtik, O V; Khotimchenko, S A

    2012-01-01

    The large number of the analysis methods of engineered nanoparticles and nanoobjects as a part of disperse systems on the basis of principles of a membrane filtration (micro, ultra- and a nanofiltration) ultracentrifugation, spectral methods, including dynamic and static laser light scattering, Raman light scattering, low-angle X-ray scattering, x-ray techniques, laser decomposition spectroscopy, and other methods are developed. Mass spectrometry with inductively coupled plasma can be successfully used in studying of nanomaterials chemical composition in conditions when there is additional independent information on presence of analyzed substance in a nanoscale form. Methods of electrophoresis in a supportive environment and capillary electrophoresis are beginning to be successfully applied in the study of artificial nanomaterials. However, in terms of the identification of engineered nanoparticles and nanoobjects in complex, multicomponent, heterophase systems, that the objects of the environment and, in particular, food products are, all these methods currently can't compete transmission electron microscopy and atomic force microscopy, specified for purpose of certain particular applications, features of which been described in a previous eport in detail. PMID:22888665

  1. Use of pulsed-field gel electrophoresis to measure DNA damage and repair

    SciTech Connect

    Scicchitano, D.A. New York Univ., New York )

    1991-03-11

    A method is described here for the analysis of single-strand break formation and repair in genomic DNA. The procedure involves exposing cells to a DNA-damaging agent, allowing time for recovery, and embedding the cells in agarose. After lysis and digestion with a protease, the DNA, which remains in the agarose plug, is denatured with glyoxal and separated by pulsed-field gel electrophoresis. The DNA in the gel is then transferred to a support membrane and quantitated with a radioanalytic imaging system to determine the average size of the DNA at each time point of recovery. The results indicate that the repair of methyl-induced breaks in total genomic DNA is approximately 80% complete in 48 hr in CHO B11 and ARL 14 cells exposed to dimethyl sulfate. These results are in agreement with those obtained by using other techniques like alkaline sucrose sedimentation. The method developed and described here has several advantages over existing techniques for repair measurements: It can be used to monitor genotoxic agents that nick DNA, to study the removal of breaks from genomic DNA, and to test for repair of damage in specific domains of chromatin that would be too large to examine by conventional electrophoresis.

  2. Expression of Acetate Permease-like (apl) Genes in Subsurface Communities of Geobacter Species Under Fluctuating Acetate Concentrations

    SciTech Connect

    Elifantz, H.; N'Guessan, A. L.; Mouser, Paula; Williams, Kenneth H.; Wilkins, Michael J.; Risso, Carla; Holmes, Dawn; Long, Philip E.; Lovley, Derek R.

    2010-09-01

    The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that suf?cient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Ri?e, CO) in two continuous amendments separated by 5 days of groundwater ?ush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater ?ush, the transcript levels of aplII were the highest. The expression of aplII decreased 210-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under ?eld conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.

  3. Expression of acetate permease-like (apl) genes in subsurface communities of Geobacter species under fluctuating acetate concentrations

    SciTech Connect

    Elifantz, H.; N'Guessan, L.A.; Mouser, P.J.; Williams, K H.; Wilkins, M J.; Risso, C.; Holmes, D.E.; Long, P.E.; Lovley, D.R.

    2010-03-01

    The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that sufficient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Rifle, CO) in two continuous amendments separated by 5 days of groundwater flush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater flush, the transcript levels of aplII were the highest. The expression of aplII decreased 2-10-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under field conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.

  4. Biological membranes

    PubMed Central

    Watson, Helen

    2015-01-01

    Biological membranes allow life as we know it to exist. They form cells and enable separation between the inside and outside of an organism, controlling by means of their selective permeability which substances enter and leave. By allowing gradients of ions to be created across them, membranes also enable living organisms to generate energy. In addition, they control the flow of messages between cells by sending, receiving and processing information in the form of chemical and electrical signals. This essay summarizes the structure and function of membranes and the proteins within them, and describes their role in trafficking and transport, and their involvement in health and disease. Techniques for studying membranes are also discussed. PMID:26504250

  5. Recent Developments in Instrumentation for Capillary Electrophoresis and Microchip-Capillary Electrophoresis

    PubMed Central

    Felhofer, Jessica L.; Blanes, Lucas; Garcia, Carlos D.

    2010-01-01

    Over the last years there has been an explosion in the number of developments and applications of capillary electrophoresis (CE) and microchip-CE. In part, this growth has been the direct consequence of recent developments in instrumentation associated with CE. This review, which is focused on contributions published in the last five years, is intended to complement the papers presented in this special issue dedicated to Instrumentation and to provide an overview on the general trend and some of the most remarkable developments published in the areas of high voltage power supplies, detectors, auxiliary components, and compact systems. It also includes few examples of alternative uses of and modifications to traditional CE instruments. PMID:20665910

  6. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl alcohol containing ethyl acetate....

  7. 21 CFR 522.2477 - Trenbolone acetate and estradiol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 522.2477, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... milligrams (mg) trenbolone acetate and 24 mg estradiol (one implant consisting of 6 pellets, each pellet containing 20 mg trenbolone acetate and 4 mg estradiol) per implant dose. (B) 120 mg trenbolone acetate...

  8. 21 CFR 522.2477 - Trenbolone acetate and estradiol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 522.2477, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... milligrams (mg) trenbolone acetate and 24 mg estradiol (one implant consisting of 6 pellets, each pellet containing 20 mg trenbolone acetate and 4 mg estradiol) per implant dose. (B) 120 mg trenbolone acetate...

  9. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  10. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  11. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  12. 40 CFR 721.532 - Substituted hydroxyalkane acetate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted hydroxyalkane acetate... Specific Chemical Substances 721.532 Substituted hydroxyalkane acetate (generic). (a) Chemical substance... substituted hydroxyalkane acetate (PMN P-00-0618) is subject to reporting under this section for...

  13. 40 CFR 721.303 - Substituted acetate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted acetate (generic). 721.303... Substances 721.303 Substituted acetate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted acetate (PMN...

  14. 40 CFR 721.532 - Substituted hydroxyalkane acetate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted hydroxyalkane acetate... Specific Chemical Substances 721.532 Substituted hydroxyalkane acetate (generic). (a) Chemical substance... substituted hydroxyalkane acetate (PMN P-00-0618) is subject to reporting under this section for...

  15. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Trenbolone acetate and estradiol benzoate. 522... ANIMAL DRUGS 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose consists of: (1) 8 pellets, each pellet containing 25 milligrams (mg) trenbolone acetate and 3.5...

  16. 40 CFR 721.303 - Substituted acetate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted acetate (generic). 721.303... Substances 721.303 Substituted acetate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted acetate (PMN...

  17. 21 CFR 582.5892 - a-Tocopherol acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false a-Tocopherol acetate. 582.5892 Section 582.5892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 582.5892 a-Tocopherol acetate. (a) Product. a-Tocopherol acetate. (b) Conditions of use....

  18. 40 CFR 721.532 - Substituted hydroxyalkane acetate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted hydroxyalkane acetate... Specific Chemical Substances 721.532 Substituted hydroxyalkane acetate (generic). (a) Chemical substance... substituted hydroxyalkane acetate (PMN P-00-0618) is subject to reporting under this section for...

  19. 21 CFR 582.5892 - a-Tocopherol acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false a-Tocopherol acetate. 582.5892 Section 582.5892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 582.5892 a-Tocopherol acetate. (a) Product. a-Tocopherol acetate. (b) Conditions of use....

  20. 40 CFR 721.303 - Substituted acetate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted acetate (generic). 721.303... Substances 721.303 Substituted acetate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted acetate (PMN...

  1. 40 CFR 721.532 - Substituted hydroxyalkane acetate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted hydroxyalkane acetate... Specific Chemical Substances 721.532 Substituted hydroxyalkane acetate (generic). (a) Chemical substance... substituted hydroxyalkane acetate (PMN P-00-0618) is subject to reporting under this section for...

  2. 40 CFR 721.303 - Substituted acetate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted acetate (generic). 721.303... Substances 721.303 Substituted acetate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted acetate (PMN...

  3. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Trenbolone acetate and estradiol benzoate. 522... ANIMAL DRUGS 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose consists of: (1) 8 pellets, each pellet containing 25 milligrams (mg) trenbolone acetate and 3.5...

  4. 40 CFR 721.532 - Substituted hydroxyalkane acetate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted hydroxyalkane acetate... Specific Chemical Substances 721.532 Substituted hydroxyalkane acetate (generic). (a) Chemical substance... substituted hydroxyalkane acetate (PMN P-00-0618) is subject to reporting under this section for...

  5. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Trenbolone acetate and estradiol benzoate. 522... ANIMAL DRUGS 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose consists of: (1) 8 pellets, each pellet containing 25 milligrams (mg) trenbolone acetate and 3.5...

  6. 21 CFR 582.5892 - a-Tocopherol acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false a-Tocopherol acetate. 582.5892 Section 582.5892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 582.5892 a-Tocopherol acetate. (a) Product. a-Tocopherol acetate. (b) Conditions of use....

  7. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    ERIC Educational Resources Information Center

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  8. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  9. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  10. 21 CFR 522.1881 - Sterile prednisolone acetate aqueous suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sterile prednisolone acetate aqueous suspension... ANIMAL DRUGS 522.1881 Sterile prednisolone acetate aqueous suspension. (a) Specifications. Each milliliter of sterile aqueous suspension contains 25 milligrams of prednisolone acetate. (b) Sponsor. See...

  11. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ethyl alcohol containing ethyl acetate....

  12. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    ERIC Educational Resources Information Center

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The

  13. Acetate concentrations and oxidation in salt marsh sediments

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Acetate concentrations and rates of acetate oxidation and sulfate reduction were measured in S. alterniflora sediments in New Hampshire and Massachusetts. Pore water extracted from cores by squeezing or centrifugation contained in greater than 0.1 mM acetate and, in some instances, greater than 1.0 mM. Pore water sampled nondestructively contained much less acetate, often less than 0.01 mM. Acetate was associated with roots, and concentrations varied with changes in plant physiology. Acetate turnover was very low whether whole core or slurry incubations were used. Radiotracers injected directly into soils yielded rates of sulfate reduction and acetate oxidation not significantly different from core incubation techniques. Regardless of incubation method, acetate oxidation did not account for a substantial percentage of sulfate reduction. These results differ markedly from data for unvegetated coastal sediments where acetate levels are low, oxidation rate constants are high, and acetate oxication rates greatly exceed rates of sulfate reduction. The discrepancy between rates of acetate oxidation and sulfate reduction in these marsh soils may be due either to the utilization of substrates other than acetate by sulfate reducers or artifacts associated with measurements of organic utilization by rhizosphere bacteria. Care must be taken when interpreting data from salt marsh sediments since the release of material from roots during coring may affect the concentrations of certain compounds as well as influencing results obtained when sediment incubations are employed.

  14. Thermochemical characteristics of cellulose acetates with different degrees of acetylation

    NASA Astrophysics Data System (ADS)

    Larina, V. N.; Ur'yash, V. F.; Kushch, D. S.

    2012-12-01

    The standard enthalpies of combustion and formation of cellulose acetates with different degrees of acetylation are determined. It is established that there is a proportional dependence of these thermochemical characteristics vs. the degree of acetylation, weight fraction of bonded acetic acid, and molar mass of the repeating unit of cellulose acetates.

  15. Hydrogel plug for independent sample and buffer handling in continuous microchip capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Puchberger-Enengl, Dietmar; Bipoun, Mireille; Smolka, Martin; Krutzler, Christian; Keplinger, Franz; Vellekoop, Michael J.

    2013-05-01

    In microchip capillary electrophoresis most frequently electrokinetic sample injection is utilized, which does not allow pressure driven sample handling and is sensitive for pressure drops due to different reservoir levels. For efficient field tests a multitude of samples have to be processed with the least amount of external equipment. We present the use of a hydrogel plug to separate the sample from clean buffer to enable independent sample change and buffer refreshment. In-situ polymerization of the gel does away with complex membrane fabrication techniques. The sample is electrokinetically injected through the gel and subsequently separated by a voltage between the second gel inlet and the buffer outlet. By blocking of disturbing flows by the gel barrier a well-defined ion plug is obtained. After each experiment, the sample and the separation channel can be flushed independently, allowing for a continuous operation mode in order to process multiple samples.

  16. Quantitative determination of surface concentration of human apolipoprotein H with capillary electrophoresis.

    PubMed

    Wang, S; Sun, Y; Ru, Q; Luo, G; Sui, S

    2000-05-01

    The phospholipid monolayer at an air/water interface is widely used to mimic the biological membrane. The dynamic process of the protein or peptide interacting with lipid molecules can be reflected in the change in surface pressure of the monolayer. But the conventional method used to measure the surface pressure change gives results that cannot easily be correlated with the contribution of a single protein molecule. Previously, measuring the surface concentration of the protein molecules at the air/water interface has required the protein to be labeled with radioactivity or fluorescence. Here, a new method using capillary electrophoresis is introduced to measure the surface concentration of the protein. The results show at least two advantages of the new method: The numerical results of protein concentration can be obtained in a more precise and rapid way; and there is no need to label the protein sample or to build a special monolayer setup. PMID:10902576

  17. Characterization of the microdialysis junction interface for capillary electrophoresis/microelectrospray ionization mass spectrometry

    SciTech Connect

    Severs, J.C.; Smith, R.D.

    1997-06-01

    A capillary electrophoresis/electrospray ionization mass spectrometry (CE/ESI-MS) interface, based on an electric circuit across a microdialysis membrane surrounding a short capillary segment closely connected to the separation capillary terminus, is demonstrated to be sensitive, efficient, and rugged. A microspray type ionization emitter produces a stable electrospray at the low flow rates provided by CE and thus avoids both the need for a makeup liquid flow provided by liquid junction or sheath flow interfaces and the subsequent dilution and reduction in sensitivity. Reproducibility studies and comparisons with CE/UV and the CE/sheath flow interface with ESI-MS are presented. Additionally, postrun acidification via the microdialysis junction interface is demonstrated and shown to be capable of denaturing the holomyoglobin protein noncovalent complex while maintaining separation efficiency. 21 refs., 7 figs., 1 tab.

  18. Biochemistry of Vibrio cholerae virulence: purification of cholera enterotoxin by preparative disc electrophoresis.

    PubMed Central

    Lewis, A C; Richardson, S H; Sheridan, B

    1976-01-01

    Procedures for cholera enterotoxin purification previously developed in this labarotory were not applicable to large-scale purification, and these methods resulted in low yields of pure toxin. An efficient scheme has been developed whereby pure cholera enterotoxin can be obtained from 6 to 8 liters of culture supernatant fluid. This method consists of concentration by membrane ultrafiltration followed by gel filtration and cation-exchange chromatography. Pure cholera enterotoxin of high biological potency was obtained after a final step of preparative acrylamide gel electrophoresis. The degree of purity of the toxin-antigen as well as its biological activity were determined at various setps of purification. This alternate technique for purification is offered because of the widespread interest in cholera enterotoxin as a specific stimulator of adenyl cyclase. Images PMID:987751

  19. Analysis of Mitochondrial Respiratory Chain Supercomplexes Using Blue Native Polyacrylamide Gel Electrophoresis (BN-PAGE).

    PubMed

    Jha, Pooja; Wang, Xu; Auwerx, Johan

    2016-01-01

    Mitochondria are cellular organelles that harvest energy in the form of ATP through a process termed oxidative phosphorylation (OXPHOS), which occurs via the protein complexes of the electron transport chain (ETC). In recent years it has become unequivocally clear that mitochondrial complexes of the ETC are not static entities in the inner mitochondrial membrane. These complexes are dynamic and in mammals they aggregate in different stoichiometric combinations to form supercomplexes (SCs) or respirasomes. It has been proposed that the net respiration is more efficient via SCs than via isolated complexes. However, it still needs to be determined whether the activity of a particular SC is associated with a disease etiology. Here we describe a simplified method to visualize and assess in-gel activity of SCs and the individual complexes with good resolution using blue native polyacrylamide gel electrophoresis (BN-PAGE). © 2016 by John Wiley & Sons, Inc. PMID:26928661

  20. Evaluation of cytogenetic and DNA damage caused by thallium(I) acetate in human blood cells.

    PubMed

    Rodrguez-Mercado, Juan J; Hernndez-de la Cruz, Heriberto; Felipe-Reyes, Miriam; Jaramillo-Cruz, Eduardo; Altamirano-Lozano, Mario A

    2015-05-01

    Although thallium is detrimental to all living organisms, information regarding the mutagenic and genotoxic effects of this element and its compounds remains scarce. Therefore, we tested the genotoxic and cytotoxic effects of thallium(I) acetate on human peripheral blood cells in vitro using structural chromosomal aberrations (SCAs), sister chromatid exchanges (SCEs), and single-cell gel electrophoresis (at pH >13 or 12.1) analysis. Whole blood samples were incubated with 0.5, 1, 5, 10, 50, or 100 g/mL thallium salt. Exposure to this metal compound resulted in a clear dose-dependent reduction in the mitotic and replicative indices. An increase in SCAs was evident in the treated group compared with the control group, and significant differences were observed in the percentage of cells with SCAs when metaphase cells were treated with 0.5-10 g/mL of thallium(I). The SCE test did not reveal any significant differences. We observed that a 1-h treatment with thallium(I) at pH?>?13 significantly increased the comet length for all the concentrations tested; however, at pH 12.1, only the two highest concentrations affected the comet length. These results suggested that thallium(I) acetate induces cytotoxic, cytostatic, and clastogenic effects, as well as DNA damage. PMID:24318865

  1. Access to aldehydo acetals of sugars via palladium-catalyzed oxidation of alpha,beta-unsaturated cyclic acetals.

    PubMed

    Fayet, Catherine; Gelas, Jacques; Danková, Katerina; Yokaris, Alexandre

    2002-11-19

    The palladium(II)-catalyzed oxidation of alpha,beta-unsaturated cyclic acetals derived from mono- and disaccharides leads in appreciable yields to new aldehydo acetals which, overall, results in an anti-Markovnikov addition. PMID:12433496

  2. Co-fermentation of acetate and sugars facilitating microbial lipid production on acetate-rich biomass hydrolysates.

    PubMed

    Gong, Zhiwei; Zhou, Wenting; Shen, Hongwei; Yang, Zhonghua; Wang, Guanghui; Zuo, Zhenyu; Hou, Yali; Zhao, Zongbao K

    2016-05-01

    The process of lignocellulosic biomass routinely produces a stream that contains sugars plus various amounts of acetic acid. As acetate is known to inhibit the culture of microorganisms including oleaginous yeasts, little attention has been paid to explore lipid production on mixtures of acetate and sugars. Here we demonstrated that the yeast Cryptococcus curvatus can effectively co-ferment acetate and sugars for lipid production. When mixtures of acetate and glucose were applied, C. curvatus consumed both substrates simultaneously. Similar phenomena were also observed for acetate and xylose mixtures, as well as acetate-rich corn stover hydrolysates. More interestingly, the replacement of sugar with equal amount of acetate as carbon source afforded higher lipid titre and lipid content. The lipid products had fatty acid compositional profiles similar to those of cocoa butter, suggesting their potential for high value-added fats and biodiesel production. This co-fermentation strategy should facilitate lipid production technology from lignocelluloses. PMID:26874438

  3. DNA sequencing using fluorescence background electroblotting membrane

    DOEpatents

    Caldwell, Karin D.; Chu, Tun-Jen; Pitt, William G.

    1992-01-01

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through said smino groups contained on the surface thereof. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to said target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membrances may be reprobed numerous times.

  4. Targeting acetate kinase: inhibitors as potential bacteriostatics.

    PubMed

    Asgari, Saeme; Shariati, Parvin; Ebrahim-Habibi, Azadeh

    2013-11-28

    Despite the importance of acetate kinase in the metabolism of bacteria, limited structural studies have been carried out on this enzyme. In this study, a three-dimensional structure of the Escherichia coli acetate kinase was constructed by use of molecular modeling methods. In the next stage, by considering the structure of the catalytic intermediate, trifluoroethanol (TFE) and trifluoroethyl butyrate were proposed as potential inhibitors of the enzyme. The putative binding mode of these compounds was studied with the use of a docking program, which revealed that they can fit well into the enzyme. To study the role of these potential enzyme inhibitors in the metabolic pathway of E. coli, their effects on the growth of this bacterium were studied. The results showed that growth was considerably reduced in the presence of these inhibitors. Changes in the profile of the metabolic products were studied by proton nuclear magnetic resonance spectroscopy. Remarkable changes were observed in the quantity of acetate, but other products were less altered. In this study, inhibition of growth by the two inhibitors as reflected by a change in the metabolism of E. coli suggests the potential use of these compounds (particularly TFE) as bacteriostatic agents. PMID:23928841

  5. Multiple-anion nonvolatile acetal (MANA) resists

    NASA Astrophysics Data System (ADS)

    Guevremont, Jeffrey M.; Brainard, Robert L.; Reeves, Scott D.; Zhou, Xin; Nguyen, Thinh B.; Mackevich, Joseph F.; Anderson, Erik H.; Taylor, Gary N.

    2001-08-01

    New acetal or ketal blocking reagents were investigated for use in e-beam lithography and compared with the performance of ethyl vinyl either (EVE). Three blocking groups, (alpha) -Angelicalactone (AL), 6-methylene-5,6-benzo-1,4- dioxane (MBD), and MANA50 (an undisclosed blocking group used to show the potential of this chemistry) were reacted with poly(p-hydroxystyrene) (PHS) under acid catalyzed conditions to form AL-PHS, MBD-PHS, MANA50-PHS. The performance objectives pursued in the design of these new materials was to use acetal (ketal) chemistry to deliver wide process latitudes (e.g. good PED performance and minimal PEB sensitivity), use high molecular weight blocking groups to eliminate outgassing, and use the novel concept of multiple anions to deliver lithographic performance. These new materials are called Multiple Anion Nonvolatile Acetal (MANA) resists. Resists films were exposed with 50kV electrons, post exposure baked (PEB), and developed with 0.26 N TMAH. Resists prepared with the third blocking group, MANA50, gave contrast and imaging performance independent of PEB humidity and were relatively insensitive to PEB temperature and post exposure delay (PED). These resists gave the best resolution (90 nm) and profiles of all the materials tested, as well as showing no outgassing (as measured by film thickness loss).

  6. Letter: Medroxyprogesterone acetate and diabetes mellitus.

    PubMed

    Bottino, J C; Tashima, C K

    1976-03-01

    This letter briefly reports a case linking the appearance of overt diabetes mellitus to progestational therapy, and is intended as an addition to the literature associating insulin-dependent diabetes with progestational therapy. A 51-year-old white woman, who had undergone masectomy and prophylactic oophorectomy, had no history of glucose intolerance and was given Prednisolone (15 mg daily) postoophorectomy. Interval clinical evaluations of glucose levels were between 184 and 223 mg/dl during estrogen therapy. Tumor recurrence 12 years later forced withdrawal of estrogen therapy, and the patient was placed on trial therapy with megestrol acetate (40 mg, 4 times daily). 6 weeks after initiation of progestational therapy, the patient was admitted with a glucose level of 400 mg/dl and a 4+ acetone reading in her urine. Insulin therapy was instituted; megestrol acetate was withdrawn; but the diabetes was not reversed and insulin treatment continues. The author compares this case with others previously reported where medroxyprogesterone acetate was the progestational agent apparently causing irreversible diabetes mellitus. PMID:1259275

  7. Optimization of in-line fritless solid-phase extraction for capillary electrophoresis-mass spectrometry.

    PubMed

    Tak, Yvonne H; Torao, Javier Sastre; Somsen, Govert W; de Jong, Gerhardus J

    2012-12-01

    In this study, in-line frit-free solid-phase extraction (SPE) has been studied for the preconcentration of analytes prior to analysis by capillary electrophoresis-mass spectrometry (CE-MS). The mixed-mode sorbent Oasis HLB was selected for the trapping of compounds of different polarity. Using 2-ethylidene-1,5-dimethyl-3,3-diphenylpirrolidine (EDDP), dihydrocodeine and codeine as test compounds, SPE parameters such as the pH of the sample and composition of the washing and elution solvent were optimized. Trapping of the analytes was optimal at pH 8.0 or higher. For efficient elution of the SPE micro column, 85% of methanol in water with 2% (v/v) acetic acid was used, which also prevented current break down in subsequent CE analysis. CE resolution of the test compounds was highest for background electrolytes (BGEs) with a pH above 8. For optimal analysis, samples were 1:1 diluted with carbonate buffer (1M, pH 8.0) prior to analysis, BGE was 60mM ammonium acetate buffer (pH 10.0), and the injected sample volume was 60 ?l (i.e., 30 capillary volumes). Good recoveries were found: 101% for EDDP, 88% for codeine and 90% for dihydrocodeine. Intraday RSDs for migration time and peak areas were below 0.56% and 15%, respectively. Peak widths at half height obtained with SPE-CE-MS were 12s for EDDP, 3.7s for dihydrocodeine and 7.4s for codeine, and were comparable to those for CE-MS. LODs were 0.22 pg/ml for EDDP, 2.1 pg/ml for dihydrocodeine and 24 pg/ml for codeine. It is concluded that the applied fritless in-line preconcentration construct proved to be highly useful for improving the sensitivity of CE while maintaining separation. PMID:22959866

  8. Analysis of diterpenoic compounds in natural resins applied as binders in museum objects by capillary electrophoresis.

    PubMed

    Findeisen, Anna; Kolivoska, Viliam; Kaml, Isabella; Baatz, Wolfgang; Kenndler, Ernst

    2007-07-20

    The exudates of conifers consist mainly of diterpenoic acids of the abietane and pimarane type (abietic, neoabietic, dehydroabietic, palustric, pimaric, isopimaric, levopimaric and sandaracopimaric acid) and larixol acetate. These natural resins were used as adhesives, coatings, varnishes or plasticizers in artistic and historic works since ancient times. For the purpose of conservation and restoration and for art historic examination of such museum objects the identification of the binding media used is undoubtedly of paramount importance. In the present paper, the characterization of these resins based on the pattern of their diterpenoid constituents is carried out by capillary electrophoresis. For separation a background electrolyte which has been initially introduced for the analysis of chlorinated and natural resin acids in waste water was modified and the experimental conditions were adjusted in terms of resolution and analysis time. Separation was carried out in borate buffer at pH 9.25 (ionic strength 20 mmol L(-1)) with methyl-beta-cyclodextrin and sulfobutylether-beta-cyclodextrin as additives to increase selectivity and enhance the solubility of the analytes. With this electrophoretic system the resin acids of interest and larixol acetate--all as anionic cyclodextrin complexes--were separated within 5 min and detected at 200, 250 and 270 nm with a diode array detector. The electrophoretic patterns served for the characterisation of the relevant diterpenoic resins, balsams and copals. Sample pre-treatment was limited to sonication in methanol at 55 degrees C for 30 min. This enables the identification of the resins in mixtures with other binders like plant gums, animal glues or drying oils, even when these media are present in excess. Colophony was identified as resinous constituent of a modelling mass for gilded frames originating from the 19th century. PMID:17521659

  9. Relation Between the Dielectric Constant of Hydrophobic Cation Exchange Membrane and Membrane Permeability to Counterions

    PubMed Central

    Shohami, Esther; Ilani, Asher

    1973-01-01

    Filters made of cellulose acetate-nitrate when saturated with organic solvents and interposed between aqueous solutions form membranes which behave like cation exchangers. The diffusion coefficients of counterions in such membranes are strongly dependent upon the dielectric constant of the saturating solvent. The results obtained suggest that a linear relationship between the log of the cation's diffusion coefficient (or membrane conductance) and the reciprocal value of the dielectric constant of the saturating solvent exists. There is also a good correlation between the relative membrane permeability to organic cations and the solubility of the cations in the pure solvent phase. These studies indicate that there are two routes for cation movement through the membrane: (a) the bulk hydrophobic phase and (b) continuous narrow aqueous channels. PMID:4754201

  10. Electrophoresis: the march of pennies, the march of dimes.

    PubMed

    Righetti, Pier Giorgio

    2005-06-24

    The present review encompasses ca. 65 years of history of developments in electrokinetic separations, taking as a starting point the year 1937, i.e. the official launching of Tiselius' moving boundary electrophoresis (MBE). The 1950s have been particularly rich in introducing novel methodologies in zone electrophoresis (ZE), thus bringing about the decline of MBE. Among them of extraordinary importance was the development of electrophoresis on agar gels coupled to immuno-diffusion at right angles, which brought a big revolution not only in biochemistry but also in clinical chemistry. Also the by now forgotten paper electrophoresis was a landmark in separation science, in that it implemented, in its "fingerprinting" version, the first genuine two-dimensional (2D) map, coupling orthogonally a charge to a hydrophobic scale separation, while permitting for the first time the detection of spot mutations, i.e. single amino acid replacements in a polypeptide chain, that paved the way to modern genetic analysis. Equally important was the introduction of starch-block electrophoresis, that brought about the notion of sieving and the first discontinuous buffers, refined, in the 1960s, by Ornstein and Davies with their classical papers combining multiphasic buffer systems to polyacrylamide gels, that went down to history as disc-electrophoresis. The 1960s also contributed with two fundamental techniques, isoelectric focusing (IEF) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) that permitted to discriminate proteins solely on the basis of surface charge and molecular mass, respectively. The 1970s gave other fundamental contributions, such as isotachophoresis, the first example of a fully instrumental approach to electrophoresis, both in its analytical and preparative version (Tachophor and Tachofrac), 2D maps combining IEF to SDS-PAGE at right angles and silver staining techniques, that incremented sensitivity by 3 orders of magnitude. The 1980s generated immobilized pH gradients and capillary zone electrophoresis (CZE), two big players that dominated the electrokinetic horizon for all the 1990s and still in vigorous use in present days. The review terminates with a glimpse, in the third millennium, onto microchip technology and hyphenated techniques, notably direct interfacing of various electrophoretic separation methods with mass spectrometry (MS). PMID:16038288

  11. Metalless electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips.

    PubMed

    Duarte Junior, Gerson F; Fracassi da Silva, Jos Alberto; Mendona Francisco, Kelliton Jos; do Lago, Claudimir Lucio; Carrilho, Emanuel; Coltro, Wendell K T

    2015-08-01

    This paper describes the use of ionic solutions as sensing electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips. Initially, two channels were engraved in a PMMA holder by using a CO2 laser system and sealed with a thin adhesive membrane. PDMS electrophoresis chips were fabricated by soft lithography and reversibly sealed against the polymer membrane. Different ionic solutions were investigated as metalless electrodes. The electrode channels were filled with KCl solutions prepared in conductivity values from approximately 10 to 40 S/m. The best analytical response was achieved using the KCl solution with 21.9 S/m conductivity (2 mol/L). Besides KCl, we also tested NaCl and LiCl solutions for actuating as detection electrodes. Taking into account the same electrolyte concentration (2 mol/L), the best response was recorded with KCl solution due to its higher ionic conductivity. The optimum operating frequency (400 kHz) and the best sensing electrode (2 mol/L KCl) were used to monitor electrophoretic separations of a mixture containing K(+) , Na(+) , and Li(+) . The use of liquid solutions as sensing electrodes for capacitively coupled contactless conductivity detection measurements has revealed great performance to monitor separations on chip-based devices, avoiding complicated fabrication schemes to include metal deposition and encapsulation of electrodes. The LOD values were estimated to be 28, 40, and 58 ?mol/L for K(+) , Na(+) , and Li(+) , respectively, what is comparable to that of conventional metal electrodes. When compared to the use metal electrodes, the proposed approach offers advantages regarding the easiness of fabrication, simplicity, and lower cost per device. PMID:25809443

  12. Resistance of Streptococcus bovis to acetic acid at low pH: Relationship between intracellular pH and anion accumulation

    SciTech Connect

    Russell, J.B. )

    1991-01-01

    Streptococcus bovis JB1, an acid-tolerant ruminal bacterium, was able to grown at pHs from 6.7 to 4.5, and 100 mM acetate had little effect on growth rate or proton motive force across the cell membrane. When S. bovis was grown in glucose-limited chemostats at pH 5.2, the addition of sodium acetate (as much as 100 mM) had little effect on the production of bacterial protein. At higher concentrations of sodium acetate (100 to 360 mM), production of bacterial protein declined, but this decrease could largely be explained by a shift in fermentation products (acetate, formate, and ethanol production to lactate production) and a decline in ATP production (3 ATP per glucose versus 2 ATP per glucose). Y{sub ATP} (grams of cells per mole at ATP) was not decreased significantly even by high concentrations of acetate. Cultures supplemented with 100 mM sodium acetate took up ({sup 14}C)acetate and ({sup 14}C)benzoate in accordance with the Henderson-Hasselbalch equation and gave similar estimates of intracellular pH. As the extracellular pH declined, S. bovis allowed its intracellular pH to decrease and maintained a relatively constant pH gradient across the cell membrane (0.9 unit). The decrease in intracellular pH prevented S. bovis from accumulating large amounts of acetate anion. On the basis of these results it did not appear that acetate was acting as an uncoupler. The sensitivity of other bacteria to volatile fatty acids at low pH is explained most easily by a high transmembrane pH gradient and anion accumulation.

  13. Direct chiral resolution of tiaprofenic acid in pharmaceutical formulations by capillary zone electrophoresis using cyclodextrins as chiral selector.

    PubMed

    Aturki, Z; Camera, E; La Torre, F; Fanali, S

    1995-01-01

    Capillary zone electrophoresis (CZE) was used for the enantiomeric separation of (R,S)-tiaprofenic acid ([R,S]-Tia) in a pharmaceutical formulation employing an acetate buffer at pH 4.5 and 2,3,6-tri-O-methyl-beta-cyclodextrin (tri-OMe-beta-CD) as the chiral selector. The effect of the concentration of trimethylated-beta-cyclodextrin in the presence of carboxymethylated-beta-cyclodextrin (CM-beta-CD) on enantiomeric resolution of (R,S)-Tia and (R,S)-5-benzoyl-alpha-methyl-3-thiopheneacetic acid (3-isomer of tiaprofenic acid, 3-Tia) was investigated at pH 4, 4.5, and 5. PMID:9384778

  14. Absorbance detector for capillary electrophoresis based on light-emitting diodes and photodiodes for the deep-ultraviolet range.

    PubMed

    Bui, Duy Anh; Hauser, Peter C

    2015-11-20

    A new absorbance detector for capillary electrophoresis featuring relatively high intensity light-emitting diodes as radiation sources and photodiodes for the deep-UV range was developed. The direct relationship of absorbance values and concentrations was obtained by emulating Lambert-Beer's law with the application of a beam splitter to obtain a reference signal and a log-ratio amplifier circuitry. The performance of the cell was investigated at 255nm with the detection of sulfanilic, 4-nitrobenzoic, 4-hydroxybenzoic and 4-aminobenzoic acid and the indirect detection of acetate, propionate, butyrate and caproate using benzoate as the displacement dye molecule. Vanillic acid, L-tyrosine and DL-tryptophan as well as the sulfonamides sulfamerazine, sulfathiazole and sulfamethazine were determined at 280nm. Good linearities over 3 orders of magnitude were obtained. The noise level recorded was as low as 50?AU and the drift typically <200?AU/5min. PMID:26091783

  15. Two-dimensional electrophoresis with cationic detergents, a powerful tool for the proteomic analysis of myelin proteins. Part 1: technical aspects of electrophoresis.

    PubMed

    Yamaguchi, Yoshihide; Miyagi, Yudai; Baba, Hiroko

    2008-03-01

    The analysis of proteins in damaged myelin is crucial to clarify the mechanisms of dysmyelination and demyelination. In the present study, proteomic analysis of myelin using a modified two-dimensional electrophoresis (2-DE) method was carried out to obtain a better understanding of myelin biology. Although standard 2-DE (immobilized pH gradient isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis; IPG/SDS-PAGE) methods of analysis provide high resolutions of soluble proteins with isoelectric focusing points in the pH range of 4-8, major myelin components include highly basic proteins are compacted at the basic edge of the 2-DE gels and are not sufficiently separated for satisfactory analysis. In an attempt to improve the separation of these proteins, an alternative 2-DE method using the cationic detergents was applied. In part 1 of this study, we describe technical aspects of conditioning 2-DE using cationic detergent. In the accompanying paper (part 2), practical 2-DE analysis using cationic detergents is described to identify proteins in the purified CNS myelin fraction. We carried out benzyldimethyl-n-hexadecylammonium chloride (16-BAC)/SDS-PAGE 2-DE and tested 2-DE with four other cationic detergents. We found that 16-BAC was the most effective agent for separation of myelin proteins and that hexadecyltrimethylammonium bromide (cetyltrimethylammonium bromide; CTAB) was the most effective agent for solubilization of myelin proteins. The combination of 16-BAC/SDS-PAGE and CTAB/SDS-PAGE is a powerful tool for the analysis of myelin proteins, including highly basic, high-MW (MW > 100K), and integral membrane proteins. PMID:17960830

  16. Control of isocitrate lyase synthesis in Chlorella fusca var. vacuolata. Rate of enzyme synthesis in the presence and absence of acetate measured by [35S]methionine labelling and immunoprecipitation.

    PubMed Central

    Dunham, S M; Thurston, C F

    1978-01-01

    The rate of increase of isocitrate lyase activity was measured in darkened Chlorella fusca var. vaculoata cultures in the presence and absence of acetate and compared with the rate of incorporation of [35S]methionine into isocitrate lyase enzyme protein under the same conditions. Isocitrate lyase enzyme protein was isolated for this purpose by specific immunoprecipitation and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. After 4h in the dark, in the presence of acetate the rate of increase of isocitrate lyase activity was 75 times that in the absence of acetate. Incorporation of [35S]methionine into isocitrate lyase was 140 times greater in the presence of acetate. Incorporation of [35S]methionine into the trichloroacetic acid-insoluble fraction overall was about five times as fast in the presence of acetate. These data are not consistent with an increased turnover of isocitrate lyase enzyme molecules, sufficient to account for the low rate of increase of isocitrate lyase activity in the absence of acetate. The greater rate of enzyme synthesis in the presence of acetate must therefore be due to some effect of this metabolite on the processing or translation of isocitrate lyase mRNA. PMID:728107

  17. Joule heating effects on peak broadening in capillary zone electrophoresis

    NASA Astrophysics Data System (ADS)

    Xuan, Xiangchun; Li, Dongqing

    2004-08-01

    Based on Taylor-Aris dispersion theory, a general analytical formula was derived for the theoretical plate height in capillary zone electrophoresis with the consideration of Joule heating effects. During the electrophoresis, the Joule heating causes a temperature rise and temperature gradients in the buffer solution. The temperature variations can affect the molecular diffusion, electroosmotic flow and electrophoretic flow via the temperature-dependent diffusion coefficient, dynamic viscosity and electrical conductivity. All these factors contribute to the peak broadening and are considered simultaneously in the present general model. The general formula derived in this paper is employed to discuss quantitatively the peak broadening in the presence of Joule heating effects. This formula can be easily extended to capillary zone electrophoresis with higher zeta potentials, if an approximate solution to Poisson-Boltzmann equation is employed.

  18. Preparative cell electrophoresis at 1 and 0 gravity

    NASA Technical Reports Server (NTRS)

    Van Oss, C. J.; Bronson, P. M.

    1979-01-01

    It is attempted to show that the use of heavy water (D2O) as starting cushion for the cells combines the advantages of the required density difference, with no lasting biochemical or physiochemical influence on the cells. Phosphate buffers of low ionic strength were prepared in distilled water or heavy water. A vertical starch gel electrophoresis was used to support a cylindrical polystyrene electrophoresis tube used for lymphocyte separations, 25 cm in length and 0.75 cm I.D., prepared from a 10 ml disposable pipet. Erythrocyte separations were carried out in a jacketed rectangular plexiglas chamber. It is pointed out that the described preparative D2O gradient electrophoresis method cannot be readily used for the measurement of electrophoretic mobilities for analytical purposes. However, for the preparative separation of cells with only slightly different electrokinetic properties the method appears promising, simple, and entirely inocuous to the cells.

  19. Synchrotron radiation for direct analysis of metalloproteins on electrophoresis gels.

    PubMed

    Ortega, Richard

    2009-03-01

    Metalloproteomics requires analytical techniques able to assess and quantify the inorganic species in metalloproteins. The most widely used methods are hyphenated techniques, based on the coupling of a high resolution chromatographic method with a high sensitivity method for metal analysis in solution. An alternative approach is the use of methods for solid sample analysis, combining metalloprotein separation by gel electrophoresis and direct analysis of the gels. Direct methods are based on beam analysis, such as lasers, ion beams or synchrotron radiation beams. The aim of this review article is to present the main features of synchrotron radiation based methods and their applications for metalloprotein analysis directly on electrophoresis gels. Synchrotron radiation X-ray fluorescence has been successfully employed for sensitive metal identification, and X-ray absorption spectroscopy for metal local structure speciation in proteins. Synchrotron based methods will be compared to ion beam and mass spectrometry for direct analysis of metalloproteins in electrophoresis gels. PMID:21305106

  20. Micro free-flow electrophoresis: theory and applications

    PubMed Central

    Turgeon, Ryan T.

    2009-01-01

    Free-flow electrophoresis (FFE) is a technique that performs an electrophoretic separation on a continuous stream of analyte as it flows through a planar flow channel. The electric field is applied perpendicularly to the flow to deflect analytes laterally according to their mobility as they flow through the separation channel. Miniaturization of FFE (?FFE) over the past 15 years has allowed analytical and preparative separation of small volume samples. Advances in chip design have improved separations by reducing interference from bubbles generated by electrolysis. Mechanisms of band broadening have been examined theoretically and experimentally to improve resolution in ?FFE. Separations using various modes such as zone electrophoresis, isoelectric focusing, isotachophoresis, and field-step electrophoresis have been demonstrated. PMID:19290514