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Sample records for acetate membrane electrophoresis

  1. 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).

  2. Uranyl complexation with acetate studied by means of affinity capillary electrophoresis.

    PubMed

    Sladkov, Vladimir

    2013-05-10

    The interaction of uranyl with acetate is studied by affinity capillary electrophoresis in aqueous acid solutions at the pH values 2.0 and 2.5. The use of data on metal ion mobilities at different pHs allows to establish the ligand species interacting with metal ion and complex species formed. The formation of two complex species UO2CH3COO(+) and UO2(CH3COO)2 is observed (acetic acid concentration is up to 0.8M). In the case of uranyl-acetic acid system, the viscosity of solution is significantly changed with an increase of acid concentration. For calculation of ion mobilities the viscosity changes are taken into account. The stability constants are calculated at the ionic strengths 0.02 and 0.05 mol L(-1). The logarithms of the thermodynamic stability constants (β°) calculated with Davies equation for the activity coefficients of the ions are log β1(°)=2.94±0.08 and log β2(°)=5.50±0.15 at 25 °C. Obtained values are compared with literature data. PMID:23570853

  3. 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.

  4. 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 Umeå strain, S. feltiae L1C strain, Steinernema carpocapsae All strain, and Steinernema riobravis TX strain. Based on comparisons of the relative electrophoretic mobilities (μ) of the isozymes, one of the eight enzymes (arginine kinase) yielded zymograms that were distinctive for each of the isolates, except for the Umeå 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

  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 Umeå 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 Umeå 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. Enzymatic membranes for the selective transport of neutral molecules by electrophoresis.

    PubMed

    Perrin, Bernard; Couturier, Roger; Fiaty, Koffi; Charcosset, Catherine; Maïsterrena, Bernard

    2008-06-01

    The active and selective transport of glucose and glycerol was carried out using electrophoresis and artificial enzymatic membranes. These positively charged composite membranes carry, on the face adjacent to the donor compartment of an electrophoresis module, a specific kinase (hexokinase or glycerokinase) and, on the opposite face, an alkaline phosphatase (ALP). Phosphorylation of the neutral substrate (glucose or glycerol) on the donor side by the kinase generates a negatively charged phosphorylated substrate, whose transmembrane migration is promoted by an electric field and by the membrane's positive charge. Dephosphorylation of the phosphorylated substrate by ALP on the opposite face regenerates the neutral substrate, which accumulates in the receiver compartment of the electrophoresis module. Using an electrophoresis module specifically designed for this study, our experiments were carried out enabling glucose and glycerol to be concentrated approximately eight- and twelve-fold, respectively, in 8 h. PMID:18435500

  7. 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 454 days 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

  8. Dynamic determination of anaerobic acetate kinetics using membrane mass spectrometry

    PubMed

    Meyer; Heinzle

    1998-01-20

    A small, stirred, 14.4-mL tank reactor was designed to serve as a measurement cell for short-term investigation of microbial kinetics. A mass spectrometer membrane probe allowed the measurement of the dissolved gases of hydrogen, methane, oxygen, and carbon dioxide. pH was measured by an electrode and controlled by addition of acid or alkali. The highly sensitive measurement of gases with low solubility allowed rapid measurements at very low conversion. In kinetic experiments, a stepwise increase of substrate concentration (method A) and continuous feed of substrate (method B) were used, allowing quick estimation of substrate kinetics. Acetate conversion in mixed culture biofilms from a fluidized bed reactor was investigated. Substrate inhibition was found to be negligible in the concentration range studied. Experiments at various pH values showed that the undissociated acid form was the kinetic determinant. Kinetic parameters for Haldane kinetics of protons were KSH = 1.3 x 10(-5) mol m-3 and KIH = 8.1 x 10(-3) mol m-3. With free acid (HAc) as the rate determining species, the kinetic parameters for method A were KSHAc = 0.005 mol m-3 and KIHAc = 100 mol m-3 and for method B were KSHAc = 0.2 mol m-3 and KIHAc = 50 mol m-3. The maximum biomass activity occurred at around pH 6.5. Acetate was exclusively converted to methane and CO2 at pH > 6. Copyright 1998 John Wiley & Sons, Inc. PMID:10099187

  9. Uranyl acetate induces gel phase formation in model lipid and biological membranes.

    PubMed Central

    Caffrey, M; Morris, S J; Feigenson, G W

    1987-01-01

    The effect of uranyl acetate on the mesomorphic phase state of lipids in model membranes as well as in isolated biological membranes has been examined. As little as 0.8 mM (0.03% [wt/vol]) uranyl acetate induces a liquid crystal-to-gel phase transformation in egg phosphatidic acid, bovine brain phosphatidylserine, and in lysed chromaffin granule membranes. These results along with others in the literature indicate that the uranyl acetate used in samples for electron microscopy could alter membrane morphology. Images FIGURE 1 FIGURE 1 FIGURE 1 PMID:3651563

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

    SciTech Connect

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

    2015-12-29

    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.

  11. 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.

  12. 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

  13. Synthesis and characterization of polyurethane-cellulose acetate blend membrane for chromium (VI) removal.

    PubMed

    Riaz, Tabinda; Ahmad, Adnan; Saleemi, Sidra; Adrees, Muhammad; Jamshed, Fahad; Hai, Abdul Moqeet; Jamil, Tahir

    2016-11-20

    Blended membranes of polyurethane and cellulose acetate were prepared, characterized and investigated for their performance. Various ratios of cellulose acetate were employed to prepare four different blend membranes. The characteristics of both pure and blend membranes were investigated and results were compared to distinguish their properties. Functional group analysis was carried out by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) of pure and blend samples. Contact angle measurement and water content were evaluated to determine the membrane hydrophilicity. Moreover, the membrane morphology was studied by scanning electron microscopy (SEM). The membrane permeation properties and ability to reject chromium (VI) ions were tested at various pH and pressure by utilizing different salt concentrations. PMID:27561531

  14. Investigation of the pore structure and morphology of cellulose acetate membranes using small-angle neutron scattering. 1: Cellulose acetate active layer membranes

    SciTech Connect

    Kulkarni, S.; Krause, S. ); Wignall, G.D. . Solid State Div.); Hammouda, B. . Center for High Resolution Neutron Scattering)

    1994-11-07

    The structure of ultrathin cellulose acetate membranes, known as active layer membranes, has been investigated using small-angle neutron scattering. These membranes are known to have structural and functional similarity to the surface or skin layer in commercial reverse-osmosis (RO) membranes and hence are useful model systems for understanding the structure of the RO membrane skin layer. Active layer membranes were studied after swelling them with either D[sub 2]O or CD[sub 3]OD. The results in both cases clearly indicated the presence of very small (10--20 [angstrom]) porous structures in the membrane. The presence of such pores has been a subject of long-standing controversy in this area. The data were analyzed using a modified Debye-Bueche analysis and the resultant membrane structure was seen to agree well with structural information from electron microscopic studies. Finally, a possible explanation for the differences in scattering observed between the D[sub 2]O swollen membranes and the CD[sub 3]OD swollen membranes has been presented.

  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. Self-sterilized composite membranes of cellulose acetate/polyethylene glycol for water desalination.

    PubMed

    Ahmad, Adnan; Jamshed, Fahad; Riaz, Tabinda; Gul, Sabad-E-; Waheed, Sidra; Sabir, Aneela; AlAnezi, Adnan Alhathal; Adrees, Muhammad; Jamil, Tahir

    2016-09-20

    Cellulose acetate/Polyethylene glycol-600 composite membranes were fabricated by two step phase inversion procedure and modified by in-situ reduction of silver nitrate. FTIR spectra demonstrated the existence of functional groups for bonding of silver with oxygen at 370cm(-1), 535cm(-1). The XRD diffractogram indicates characteristic peaks at 2θ values of 38.10°, 44.30°, 64.40°, and 77.30° which confirm the successful incorporation of silver within matrix of composite membranes. The morphology of composite membranes with appearances of spongy voids was exemplified from the scanning electron microscope. The atomic force microscopy was used to determine the increase in the surface roughness of the membranes. The increase in hydrophilicity, measured through contact angle, is rendered to the embedment of silver. The modification of membranes increased the flux from 0.80 to 0.95L/hr.m(2). The resulting membranes have outstanding ability to fight against gram negative Escherichia Coli and Bacillus Sabtilus. The novel cellulose acetate/polyethylene glycol membranes customized with silver have paved the path for evolution of axenic membranes. PMID:27261744

  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. Enzymatic activation of cellulose acetate membrane for reducing of protein fouling.

    PubMed

    Koseoglu-Imer, Derya Y; Dizge, Nadir; Koyuncu, Ismail

    2012-04-01

    In this study, the surface of cellulose acetate (CA) ultrafiltration membrane was activated with serine protease (Savinase) enzyme to reduce protein fouling. Enzyme molecules were covalently immobilized with glutaraldehyde (cross-linking agent) onto the surface of CA membranes. The membrane activation was verified using filtration experiments and morphological analysis. Scanning electron microscopy (SEM) images and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy of the activated membrane when compared with raw membrane were confirmed that the enzyme was immobilized onto the membrane surface. The immobilization efficiencies changed from 13.2 to 41.2% according to the enzyme ratios from 2.5 to 10.0 mg/mL. However, the permeability values decreased from 232±6 to 121±4 L/m(2) h bar with increasing enzyme concentration from 2.5 to 10.0 mg/mL. In fouling experiments, bovine serum albumin (BSA) was used as the protein model solution and activated sludge was used as the model biological sludge. Enzyme-activated membranes exhibited good filtration performances and protein rejection efficiencies were compared with raw CA membrane. Also the relative flux reduction (RFR) ratios of membranes were calculated as 97% and 88% for raw CA and enzyme-activated membranes (5 mg/mL savinase), respectively. The membrane activated with Savinase enzyme could be proposed as a surface treatment method before filtration to mitigate protein fouling. PMID:22218336

  1. 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.

  2. Effect of coagulant bath on the gas permeation properties of cellulose acetate asymmetric membrane

    NASA Astrophysics Data System (ADS)

    Mohamed, F.; Hasbullah, H.; Jami'an, W. N. R.; Salleh, W. N. H. W.; Ibrahim, N.; Ali, R. R.

    2016-06-01

    Membrane based gas separation process technology has been recognized as one of the most efficient and advanced unit operation for gas separation. One of the problems in membrane gas separation is membrane performance. This paper explores the application of cellulose acetate (CA) membrane for natural gas purification and separation by improving its permeability and selectivity. The main interest in this research is to study the effect of quench medium on the gas separation performance towards its physical characteristics and gas separation performance of CA membrane. Cellulose acetate polymer was dissolved in n- methyl-2-pyrrolidone solvent and casted onto a glass plate using a pneumatically controlled casting system with fixed shear rate and solvent evaporation times. The parameter varied was the non-solvent used as quench medium during membrane post treatment that were methanol and n-hexane. The different quench media as post treatment affected the O2 and N2 gas permeation and O2/N2 selectivity as well as the tensile strength of the flat sheet asymmetric membrane. Combination of methanol and n-hexane as quench media gave the best result than the other steps. This solvent exchange step influenced the morphology by producing thin skin layer and thus gives better gas separation performance than other steps

  3. Fabrication and performance of PET mesh enhanced cellulose acetate membranes for forward osmosis.

    PubMed

    Li, Guoliang; Wang, Jun; Hou, Deyin; Bai, Yu; Liu, Huijuan

    2016-07-01

    Polyethylene terephthalate mesh (PET) enhanced cellulose acetate membranes were fabricated via a phase inversion process. The membrane fabrication parameters that may affect the membrane performance were systematically evaluated including the concentration and temperature of the casting polymer solution and the temperature and time of the evaporation, coagulation and annealing processes. The water permeability and reverse salt flux were measured in forward osmosis (FO) mode for determination of the optimal membrane fabrication conditions. The optimal FO membrane shows a typical asymmetric sandwich structure with a mean thickness of about 148.2μm. The performance of the optimal FO membrane was tested using 0.2mol/L NaCl as the feed solution and 1.5mol/L glucose as the draw solution. The membrane displayed a water flux of 3.47L/(m(2)·hr) and salt rejection of 95.48% in FO mode. While in pressure retarded osmosis (PRO) mode, the water flux was 4.74L/(m(2)·hr) and salt rejection 96.03%. The high ratio of water flux in FO mode to that in PRO mode indicates that the fabricated membrane has a lower degree of internal concentration polarization than comparable membranes. PMID:27372114

  4. Separation of macromolecular proteins and removal of humic acid by cellulose acetate modified UF membranes.

    PubMed

    Kanagaraj, P; Nagendran, A; Rana, D; Matsuura, T

    2016-08-01

    Surface modifying macromolecules (SMMs) were synthesized with various polyurethane pre polymers end-capped with different groups and blended into the casting solution of cellulose acetate (CA) to prepare surface modified ultra-filtration (UF) membranes for water filtration applications. The surface modification of the CA membranes was confirmed by the FTIR and static contact angle (SCA) measurements. The membranes so prepared had the typical characteristics of UF membranes as confirmed by scanning electron microscopy (SEM). Membrane properties were studied in terms of membrane compaction, percentage water content (%WC), pure water flux (PWF), membrane hydraulic resistance (Rm), molecular weight cut-off (MWCO), average pore size and porosity. The result showed that PWF, %WC, MWCO and pore size increased whereas the Rm decreased by the addition of SMMs. The significant effect of SMMs on the fouling by humic acid (HA) was also observed. It was found that the cSMM-3 membrane, in which SMM was synthesized with diethylene glycol (DEG) and hydroxyl benzene sulfonate (HBS) was blended, had the highest flux recovery ratio FRR (84.6%), as well as the lowest irreversible fouling (15.4%), confirming their improved antifouling properties. Thus, the SMM modified CA membranes had proven, to play an important role in the water treatment by UF. PMID:27118046

  5. Effect of evaporation time on cellulose acetate membrane for gas separation

    NASA Astrophysics Data System (ADS)

    Jami'an, W. N. R.; Hasbullah, H.; Mohamed, F.; Yusof, N.; Ibrahim, N.; Ali, R. R.

    2016-06-01

    Throughout this decades, membrane technology has been the desirable option among the others gas separation technologies. However, few issues have been raised regarding the membrane gas separation application including the trade-off between its permeability and selectivity and also its effects towards environment. Therefore, for this research, a biopolymer membrane for gas separation application will be developed with reasonably high on both permeability and selectivity. The main objective of this research is to study the effect of solvent evaporation time on the flat sheet asymmetric membrane morphology and gas separation performance. The membranes were produced by a simple dry/wet phase inversion technique using a pneumatically controlled casting system. The dope solution for the membrane casting was prepared by dissolving the cellulose acetate (CA) polymer in N-Methyl-2-pyrrolidone (NMP) and the solvent evaporation time was varied. Permeability and selectivity of the membrane was performed by using pure gases of carbon dioxide, CO2 and methane, CH4. The increase in solvent evaporation time had improved the membrane morphologies as the porosity of the membrane surface decrease and formation of a more mature skin layer. The gas permeation tests determined that increasing in solvent evaporation time had increased the selectivity of CO2/CH4 but reduce the permeability of both gases

  6. 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

  7. Microemulsion liquid membranes. I. Application to acetic acid removal from water

    SciTech Connect

    Wiencek, J.M.; Qutubuddin, S. )

    1992-08-01

    A separation technique utilizing nonionic microemulsions as emulsion liquid membranes has been successfully applied to the removal of acetic acid from an aqueous feed phase. The surfactant systems were carefully characterized in order to assure that they were truly microemulsions. The effects of mixing intensity, feed concentration, treat ratio, and microemulsion viscosity on the separation kinetics were investigated. The microemulsions did not typically display leakage and had negligible swell over 5-minute duration. The reversible phase behavior of the microemulsion was utilized to demulsify the liquid membrane phase and recover the acetate ion via a temperature change of approximately 40 C. Material balances closed to within 10% and rates of separation were faster than the sampling rates when the microemulsion was fully dispersed in the aqueous feed phase.

  8. Oligosaccharide mapping of heparan sulphate by polyacrylamide-gradient-gel electrophoresis and electrotransfer to nylon membrane.

    PubMed Central

    Turnbull, J E; Gallagher, J T

    1988-01-01

    A new method that we have called 'oligosaccharide mapping' is described for the analysis of radiolabelled heparan sulphate and other glycosaminoglycans. The method involves specific enzymic or chemical scission of polysaccharide chains followed by high-resolution separation of the degradation products by polyacrylamide-gradient-gel electrophoresis. The separated oligosaccharides are immobilized on charged nylon membranes by electrotransfer and detected by fluorography. A complex pattern of discrete bands is observed covering an oligosaccharide size range from degree of polymerization (d.p.) 2 (disaccharide) to approximately d.p. 40. Separation is due principally to differences in Mr, though the method also seems to detect variations in conformation of oligosaccharide isomers. Resolution of oligosaccharides is superior to that obtained with isocratic polyacrylamide-gel-electrophoresis systems or gel chromatography, and reveals structural details that are not accessible by other methods. For example, in this paper we demonstrate a distinctive repeating doublet pattern of iduronate-rich oligosaccharides in heparitinase digests of mouse fibroblast heparan sulphate. This pattern may be a general feature of mammalian heparan sulphates. Oligosaccharide mapping should be a valuable method for the analysis of fine structure and sequence of heparan sulphate and other complex polysaccharides, and for making rapid assessments of the molecular distinctions between heparan sulphates from different sources. Images Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. PMID:2969727

  9. Comparison of diffusion by anionic surfactants through cellulose acetate and collagen membranes.

    PubMed

    García Ramón, M T; Ribosa, I; Leal, J S; Parra, J L

    1989-06-01

    Synopsis From a dermatological point of view, it is important to know what is the irritation potential of surfactants on human skin. Recent research trends have been oriented towards the establishment of new 'in vitro' techniques that will avoid animal experimentation. In this paper, some results on the rate of diffusion of different anionic surfactants through both cellulose acetate and collagen membranes are described. A correlation between results of diffusion through the protein membrane and results published on the same surfactants and their irritation potential during 'in vivo' experiments appears possible. PMID:19456944

  10. Automated SDS Depletion for Mass Spectrometry of Intact Membrane Proteins though Transmembrane Electrophoresis.

    PubMed

    Kachuk, Carolyn; Faulkner, Melissa; Liu, Fang; Doucette, Alan A

    2016-08-01

    Membrane proteins are underrepresented in proteome analysis platforms because of their hydrophobic character, contributing to decreased solubility. Sodium dodecyl sulfate is a favored denaturant in proteomic workflows, facilitating cell lysis and protein dissolution; however, SDS impedes MS detection and therefore must be removed prior to analysis. Although strategies exist for SDS removal, they provide low recovery, purity, or reproducibility. Here we present a simple automated device, termed transmembrane electrophoresis (TME), incorporating the principles of membrane filtration, but with an applied electric current to ensure near-complete (99.9%) removal of the surfactant, including protein-bound SDS. Intact proteins are recovered in solution phase in high yield (90-100%) within 1 h of operation. The strategy is applied to protein standards and proteome mixtures, including an enriched membrane fraction from E. coli, resulting in quality MS spectra free of SDS adducts. The TME platform is applicable to both bottom-up MS/MS as well as LC-ESI-MS analysis of intact proteins. SDS-depleted fractions reveal a similar number of protein identifications (285) compared wit a non-SDS control (280), being highly correlated in terms of protein spectral counts. This fully automated approach to SDS removal presents a viable tool for proteome sample processing ahead of MS analysis. Data are available via ProteomeXchange, identifier PXD003941. PMID:27376408

  11. Quantitative analysis of plasma membrane proteome using two-dimensional difference gel electrophoresis.

    PubMed

    Tang, Wenqiang

    2012-01-01

    The plasma membrane (PM) controls cell's exchange of both material and information with the outside environment, and PM-associated proteins play key roles in cellular regulation. Numerous cell surface receptors allow cells to perceive and respond to various signals from neighbor cells, pathogens, or the environment; large numbers of transporter and channel proteins control material uptake or release. Quantitative proteomic analysis of PM-associated proteins can identify key proteins involved in signal transduction and cellular regulation. Here, we describe a protocol for quantitative proteomic analysis of PM proteins using two-dimensional difference gel electrophoresis. The protocol has been successfully employed to identify new components of the brassinosteroid signaling pathway, and should also be applicable to the studies of other plant signal transduction pathways and regulatory mechanisms. PMID:22576086

  12. Morphological analysis of Polyethersulfone/polyvinyl Acetate blend membrane synthesized at various polymer concentrations

    NASA Astrophysics Data System (ADS)

    Hadi, S. H. A. A.; Mannan, H. A.; Mukhtar, H.; Shaharun, M. S.; Murugesan, T.

    2016-06-01

    This paper reports the effect of varying polymer concentration i.e. solvent/polymer ratio on the morphology and gas transport behaviour of polyethersulfone/polyvinyl acetate blend membrane. The solvent used was dimethylformamide, while the manipulated variable was polymer concentration. The concentrations were varied from 75-90 weight % solvent. A homogeneous surface with dense cross-section structure membranes were successfully developed as deduced from FESEM images. The permeability of CO2 and CH4 gases increased with increasing polymer concentration and an improved CO2/CH4 selectivity was observed. These observation made from the characterization justified the applicability of the blend to be synthesized as membrane for gas separation.

  13. Electrospun cellulose acetate composites containing supported metal nanoparticles for antifungal membranes.

    PubMed

    Quirós, Jennifer; Gonzalo, Soledad; Jalvo, Blanca; Boltes, Karina; Perdigón-Melón, José Antonio; Rosal, Roberto

    2016-09-01

    Electrospun cellulose acetate composites containing silver and copper nanoparticles supported in sepiolite and mesoporous silica were prepared and tested as fungistatic membranes against the fungus Aspergillus niger. The nanoparticles were in the 3-50nm range for sepiolite supported materials and limited by the size of mesopores (5-8nm) in the case of mesoporous silica. Sepiolite and silica were well dispersed within the fibers, with larger aggregates in the micrometer range, and allowed a controlled release of metals to create a fungistatic environment. The effect was assessed using digital image analysis to evaluate fungal growth rate and fluorescence readings using a viability stain. The results showed that silver and copper nanomaterials significantly impaired the growth of fungi when the spores were incubated either in direct contact with particles or included in cellulose acetate composite membranes. The fungistatic effect took place on germinating spores before hyphae growth conidiophore formation. After 24h the cultures were separated from fungistatic materials and showed growth impairment only due to the prior exposure. Growth reduction was important for all the particles and membranes with respect to non-exposed controls. The effect of copper and silver loaded materials was not significantly different from each other with average reductions around 70% for bare particles and 50% for membranes. Copper on sepiolite was particularly efficient with a decrease of metabolic activity of up to 80% with respect to controls. Copper materials induced rapid maturation and conidiation with fungi splitting in sets of subcolonies. Metal-loaded nanomaterials acted as reservoirs for the controlled release of metals. The amount of silver or copper released daily by composite membranes represented roughly 1% of their total load of metals. Supported nanomaterials encapsulated in nanofibers allow formulating active membranes with high antifungal performance at the same time

  14. Hydrophilicity and antifouling property of membrane materials from cellulose acetate/polyethersulfone in DMAc.

    PubMed

    Sun, Zhonghua; Chen, Fushan

    2016-10-01

    In this study, cellulose acetate (CA) was blended with polyethersulfone (PES) to endow the ultrafiltration membrane with the improved hydrophilicity and antifouling property by using N,N-dimethylacetamide (DMAc) as the solvent. The effects of blend composition and evaporation time on the mechanical strength and pure water flux were investigated. It was found that the optimal composition of the casting solution was: 18wt% (PES), 4wt% (Polyvinylpyrrolidone K30), 3wt% (CA) and 20s (Evaporation time). The characteristics of CA-PES blend membranes were investigated through the methods of contact angle goniometer, antifouling property, compatibility, thermo gravimetric analysis and SEM. The results showed that the hydrophilicity and antifouling property of CA-PES ultrafiltration membranes were enhanced in comparison with the pure PES membranes. The CA-PES membranes exhibited semi-compatibility and good thermal stability below 270°C. This study provided a potential industrial application prospect of CA-PES membranes prepared in DMAc. PMID:27211301

  15. Tunable membranes for free-flow zone electrophoresis in PDMS microchip using guided self-assembly of silica microbeads.

    PubMed

    Song, Yong-Ak; Wu, Lidan; Tannenbaum, Steven R; Wishnok, John S; Han, Jongyoon

    2013-12-17

    In this paper, we evaluate the strategy of using self-assembled microbeads to build a robust and tunable membrane for free-flow zone electrophoresis in a PDMS microfluidic chip. To fabricate a porous membrane as a salt bridge for free-flow zone electrophoresis, we used silica or polystyrene microbeads between 3-6 μm in diameter and packed them inside a microchannel. After complete evaporation, we infiltrated the porous microbead structure with a positively or negatively charged hydrogel to modify its surface charge polarity. Using this device, we demonstrated binary sorting (separation of positive and negative species at a given pH) of peptides and dyes in standard buffer systems without using sheath flows. The sample loss during sorting could be minimized by using ion selectivity of hydrogel-infiltrated microbead membranes. Our fabrication method enables building a robust membrane for pressure-driven free-flow zone electrophoresis with tunable pore size as well as surface charge polarity. PMID:24251795

  16. 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.

  17. 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.

  18. Synthesis of polymer electrolyte membranes from cellulose acetate/poly(ethylene oxide)/LiClO{sub 4} for lithium ion battery application

    SciTech Connect

    Nurhadini, Arcana, I Made

    2015-09-30

    This study was conducted to determine the effect of cellulose acetate on poly(ethylene oxide)-LiClO{sub 4} 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{sup −4} S/cm was observed in SA/PEO/LiClO{sub 4} 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.

  19. Application of denaturing gradient gel electrophoresis (DGGE) analysis to evaluate acetic acid bacteria in traditional balsamic vinegar.

    PubMed

    De Vero, Luciana; Gala, Elisabetta; Gullo, Maria; Solieri, Lisa; Landi, Sara; Giudici, Paolo

    2006-12-01

    Acetic acid bacteria (AAB) are fastidious micro-organisms to isolate and cultivate despite of the great number of growth media available. Moreover, conventional techniques used to study AAB populations are time consuming and not completely reliable. In this study, we tested the usefulness of the polymerase chain reaction-denaturing gradient gel electophoresis (PCR-DGGE) as a rapid and cost effective method for the screening of AAB in traditional balsamic vinegar (TBV). DGGE analysis was applied to 19 AAB strains isolated by agar plating from three different samples of TBV. DGGE was also used for the analysis of PCR products obtained from DNA extracted directly from the TBV samples. A tentative species identification was achieved comparing the PCR-DGGE patterns of the isolated strains and the TBV samples to those of 15 AAB reference strains. The results support that DGGE is functional to monitor vinegar's AAB population. PMID:16943087

  20. 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

  1. 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.

  2. 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

  3. Net Increase of platelet membrane tyrosine specific-protein kinase activity by phorbol myristate acetate

    SciTech Connect

    Ishihara, Noriko; Sakamoto, Hikaru; Iwama, Minako; Kobayashi, Bonro )

    1990-01-01

    Tyrosine protein kinase (TPK) activity in rabbit platelets after stimulation by phorbol myristate acetate (PMA) or thrombin was directly estimated by {sup 32}P incorporation from ({gamma}-{sup 32})ATP into synthetic peptide angiotensin II. By PMA-treatment a net increase of TPK activity was obtained, while thrombin acted on the TPK quickly but stimulation was limited within the range attained by the control after lengthy incubation. The responsive TPK to these stimulators was localized mainly in membrane but much less in cytosol. The specific activity of the particulate TPK was low in the sonicate of control ice cold platelets but increased about 6-fold when the platelets were incubated at 37{degree}C. On a brief contact of platelets with PMA at 37{degrees}C the TPK was fully activated and reached a maximum value about 130% of the control. Determination of phosphotyrosine phosphatase in the stimulated platelet sonicate revealed that its participation in the above described increase of {sup 32}P-incorporation was meagre. The quick response suggested a possible role of TPK in the signal transduction through the platelet cell membrane.

  4. 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

  5. Analysis of steric partition behavior of molecules in membranes using statistical physics. Application to gel chromatography and electrophoresis.

    PubMed Central

    Schnitzer, J E

    1988-01-01

    The principles of statistical physics are used to formulate general expressions for the steric partition behavior of molecules in both random and ordered membrane structures that may be applied to any shape of the solute and/or the volume-excluding element of the membrane. These expressions fully define partitioning in terms of the volume excluded to point molecules and to finite-sized molecules. The mean effective exclusion volume for a molecule is calculated as a function of a global interaction energy, which varies with position, conformation, and orientation of the molecule. It allows consideration of electrostatic and other nonsteric factors. To test the model, specific partition functions are derived for several simple geometries describing the membrane and solute. Frequently, the derived expressions agree with past analyses; however, a new expression describing partitioning within an random network of fibers is derived. It agrees with past results only in the limit of low exclusion volumes. With greater volume exclusions, past results greatly overestimate the partition function. It is applied to gel electrophoresis and chromatography and survives testing with available experimental data. Unlike past analyses, it predicts nonlinear Ferguson plots for agarose gel electrophoresis. In addition, an analytical expression predicting the minimum radius of a sphere excluded from a random fiber matrix is derived, tested, and found to agree with experimental data. PMID:3148335

  6. 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

  7. 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.

  8. Preparation and evaluation of water-in-soybean oil-in-water emulsions by repeated premix membrane emulsification method using cellulose acetate membrane.

    PubMed

    Muhamad, Ida Idayu; Quin, Chang Hui; Selvakumaran, Suguna

    2016-04-01

    The purpose of this study was to investigate the preparation of formulated water- in-soybean oil-in-water emulsions by repeated premix membrane emulsification method using a cellulose acetate membrane. The effect of selective membrane emulsification process parameters (concentration of the emulsifiers, number of passes of the emulsions through the membrane and storage temperature) on the properties and stability of the developed emulsions were also investigated. 1, 3, 6, 8-pyrenetetrasulfonic acid tetrasodium salt (PTSA) was used as a hydrophilic model ingredient for the encapsulation of bioactive substances. W/O emulsions with 7 wt% (weight percentage) PGPR displays homogeneous and very fine dispersions, with the median diameter at 0.640 μm. Meanwhile, emulsions prepared by membrane emulsification (fine W/O/W) showed the highest stability at Tween 80 concentrations of 0.5 wt.% (weight percentage). It concluded that at 7 wt.% (weight percentage) PGPR concentration and 0.5 wt.% (weight percentage) Tween 80 concentrations, the most uniform particles with minimum mean size of oil drops (9.926 μm) were obtained after four passes through the membrane. Thus, cellulose acetate membrane can be used for preparing a stable W/O/W emulsions by repeated premix ME due to low cost and relatively easy to handle. PMID:27413211

  9. Simultaneous analysis of serum immunoglobulins in patients with M protein using cellulose acetate membrane isoelectric focusing.

    PubMed

    Iijima, S; Shiba, K; Kurihara, Y; Kamei, S; Kimura, S; Kimura, M; Fukumura, Y; Kobayashi, I

    1999-01-01

    We developed a method for the simultaneous analysis of microheterogeneity of human serum IgG, IgA, IgM, IgD, and IgE, and serum protein pattern using cellulose acetate membrane isoelectric focusing, and analyzed in 11 healthy subjects and 67 patients with M protein (17 cases of multiple myeloma [MM] and 50 cases of monoclonal gammopathy of undetermined significance [MGUS]). Using this method, bands indicating the microheterogeneity of each immunoglobulin could clearly be detected.Among healthy subjects, the detected IgG, IgA, and IgM bands did not vary, but the detected IgE and IgD bands did vary. Therefore, IgA, IgM, and IgG were selected for comparison of serum immunoglobulins in MM and in MGUS. In the IgA-type M protein group, normal IgM and IgG bands were decreased in MM patients compared to MGUS patients, while the M band and other bands were increased in MM patients compared to MGUS patients, but the differences between the two groups were not significant. In the IgG-type M protein group, normal IgM, IgA, and IgG were significantly decreased in MM patients compared to MGUS patients. We examined the changes in electrophoretic pattern in six MM patients and eight MGUS patients with IgA-type M protein after neuraminidase treatment. The width of the M band in MM patients with IgA-type M protein decreased with neuraminidase treatment. On the other hand, the width of the M band in MGUS patients with IgA-type M protein increased with neuraminidase treatment. We concluded that the decrease of the normal immunoglobulins in MM patients with IgG type M protein could be detected by this method, and IgA type of M protein binding sugar chain were different between MM and MGUS patients. PMID:10414593

  10. Quantifying contribution of synthrophic acetate oxidation to methane production in thermophilic anaerobic reactors by membrane inlet mass spectrometry.

    PubMed

    Mulat, Daniel Girma; Ward, Alastair James; Adamsen, Anders Peter S; Voigt, Niels Vinther; Nielsen, Jeppe Lund; Feilberg, Anders

    2014-02-18

    A unique method was developed and applied for monitoring methanogenesis pathways based on isotope labeled substrates combined with online membrane inlet quadrupole mass spectrometry (MIMS). In our study, a fermentation sample from a full-scale biogas plant fed with pig and cattle manure, maize silage, and deep litter was incubated with 100 mM of [2-(13)C] sodium acetate under thermophilic anaerobic conditions. MIMS was used to measure the isotopic distribution of dissolved CO2 and CH4 during the degradation of acetate, while excluding interference from water by applying a cold trap. After 6 days of incubation, the proportion of methane derived from reduction of CO2 had increased significantly and reached up to 87% of total methane, suggesting that synthrophic acetate oxidation coupled to hydrogenotrophic methanogenesis (SAO-HM) played an important role in the degradation of acetate. This study provided a new approach for online quantification of the relative contribution of methanogenesis pathways to methane production with a time resolution shorter than one minute. The observed contribution of SAO-HM to methane production under the tested conditions challenges the current widely accepted anaerobic digestion model (ADM1), which strongly emphasizes the importance of the acetoclastic methanogenesis. PMID:24437339

  11. 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.

  12. 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.

  13. 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

  14. Dynamic supported liquid membrane tip extraction of glyphosate and aminomethylphosphonic acid followed by capillary electrophoresis with contactless conductivity detection.

    PubMed

    See, Hong Heng; Hauser, Peter C; Sanagi, M Marsin; Ibrahim, Wan Aini Wan

    2010-09-10

    A dynamic supported liquid membrane tip extraction (SLMTE) procedure for the effective extraction and preconcentration of glyphosate (GLYP) and its metabolite aminomethylphosphonic acid (AMPA) in water has been investigated. The SLMTE procedure was performed in a semi-automated dynamic mode and demonstrated a greater performance against a static extraction. Several important extraction parameters such as donor phase pH, cationic carrier concentration, type of membrane solvent, type of acceptor stripping phase, agitation and extraction time were comprehensively optimized. A solution of Aliquat-336, a cationic carrier, in dihexyl ether was selected as the supported liquid incorporated into the membrane phase. Quantification of GLYP and AMPA was carried out using capillary electrophoresis with contactless conductivity detection. An electrolyte solution consisting of 12 mM histidine (His), 8 mM 2-(N-morpholino)ethanesulfonic acid (MES), 75 microM cetyltrimethylammonium bromide (CTAB), 3% methanol, pH 6.3, was used as running buffer. Under the optimum extraction conditions, the method showed good linearity in the range of 0.01-200 microg/L (GLYP) and 0.1-400 microg/L (AMPA), acceptable reproducibility (RSD 5-7%, n=5), low limits of detection of 0.005 microg/L for GLYP and 0.06 microg/L for AMPA, and satisfactory relative recoveries (90-94%). Due to the low cost, the SLMTE device was disposed after each run which additionally eliminated the possibility of carry-over between runs. The validated method was tested for the analysis of both analytes in spiked tap water and river water with good success. PMID:20696433

  15. 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. .

  16. 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; González Fernández-Niño, 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

  17. 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)...

  18. Grafting of cellulose acetate with ionic liquids for biofuel purification by a membrane process: Influence of the cation.

    PubMed

    Hassan Hassan Abdellatif, Faten; Babin, Jérôme; Arnal-Herault, Carole; David, Laurent; Jonquieres, Anne

    2016-08-20

    A new strategy was developed for grafting ionic liquids (ILs) onto cellulose acetate in order to avoid IL extraction and improve its performance for ethyl tert-butyl ether (ETBE) biofuel purification by the pervaporation membrane process. This work extended the scope of IL-containing membranes to the challenging separation of organic liquid mixtures, in which these ILs were soluble. The ILs contained the same bromide anion and different cations with increasing polar feature. The membrane properties were strongly improved by IL grafting. Their analysis in terms of structure-property relationships revealed the influence of the IL content, chemical structure and chemical physical parameters α, β, π* in the Kamlet-Taft polarity scale. The ammonium IL led to the best normalized flux of 0.182kg/m(2)h for a reference thickness of 5μm, a permeate ethanol content of 100% and an outstanding infinite separation factor for the azeotropic mixture EtOH/ETBE at 50°C. PMID:27178937

  19. Serum sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of patients with membranous nephropathy and focal and segmental glomerulosclerosis.

    PubMed

    Pant, Pragya; Singh, R G; Singh, Santosh K; Singh, Vijay P; Doley, Prodip K; Sivasankar, M

    2016-01-01

    Diagnosis of membranous nephropathy (MN) and focal and segmental glomerulo- sclerosis (FSGS) needs a renal biopsy, which is an invasive procedure with potentially serious complications. Proteomics may be applied for the development of a biomarker for these diseases which will obviate the need of biopsy. Serum sodium dodecyl sulfate-polyacrylamide gel electro-phoresis (SDS-PAGE) analysis gives an idea of the various proteins with different molecular weights (MWs) in a given sample. This study was conducted to analyze proteins with different MWs in patients with MN and FSGS and to compare the two groups with regard to their protein profile. This was a comparative, experimental study performed from June 2013 to July 2014 in the Department of Nephrology, Sir Sunderlal Hospital, Banaras Hindu University, Varanasi. Twenty-three histologically diagnosed cases of primary MN and 25 cases of FSGS were included in the study. Patients were categorized as having mild, moderate, and severe proteinuria with 24 h urinary protein levels of <4, 4- 8 and ≥8 g/24 h, respectively. SDS-PAGE analysis was performed by the method of Laemmli and revealed a significantly higher number of patients with FSGS (80%) having a protein corresponding to 29 kDa MW, than those with MN (39.1%) (P = 0.004). Protein of 5 kDa MW was present in a significantly higher number of patients with moderate (80%) and severe (100%) proteinuria than those with mild proteinuria (25%) (P <0.001). Thus, protein of MW 29 kDa may be a marker for FSGS and needs further characterization. Similarly, 5 kDa protein, present in patients with moderate and severe proteinuria, might be either contributing to or be a marker of severe illness. PMID:27215247

  20. Kinetics of radiation-induced graft copolymerization of vinyl acetate onto ethylene-co-propylene rubber membranes

    NASA Astrophysics Data System (ADS)

    Yue-E, Fang; Lu Xiao Bing; Wang Shan Zhi; Xia, Zhao; Wang, Fang

    1997-02-01

    The kinetics of radiation-induced graft copolymerization of vinyl acetate onto ethylene-co-propylene rubber (EPR) membrane has been studied in methanol with a radiation source of cobalt-60. The effect of monomer concentration, dose rate, Cu 2+ concentration and temperature on the grafting rate were investigated. The results show that the functional relationship is dg 0/ dt = k[M] 01.95Ḋ[ Cu2+] 0.5. The apparent activation energy and collision frequency factor of the grafting polymerization are 49 kJ mol -1 and 8.9 × 10 8G% kGy -1h -1mol -2.45L 2.45, respectively. The work established the relationship of the initial grafting rate (d g0/d t) with various effect factors: ln(d g0/d t) = 20.61 - 5894(1/ T) + 1.95 ln[ M] 0 + ln D + 0.5 ln[Cu 2+].

  1. Fluorescence Detection In Electrophoresis

    NASA Astrophysics Data System (ADS)

    Swarner, Susan

    1988-04-01

    Fluorescence detection is in common usage in forensic science laboratories for the visualization of three enzyme markers. The fluorogenic substrates, 4-methylumbelliferyl phosphate, 4-methylutbel-liveryl acetate, and fluorecein diacetate, are acted upon by the enzymes Erythrocyte Acid Phospha, tase, Esterase-D, and Carbonic Anhydrase-III, respectively, to produce compounds visible to the analyst when viewed with transmitted UV light at 365 nm. Additionally, the choice of fluorogenic corn, pounds may help detect a specific enzyme from a related enzyme. One of the responsibilities of a forensic science laboratory may be the analysis of blood for genetically controlled polymorphic enzymes and protein markers. The genetic markers are said to be polymorphic because each exhibits types which can be differentiated and allows for the inclusion or exclusion of possible-donors of the blood. Each genetic marker can be separated into these recognizable types by electrophoresis, a technique which separates compounds based on electrical charges. Electrophoresis is conducted by placing a portion or extract of each bloodstain into a support medium which will conduct electricity. This is known as a plate or membrane. By controlling the pH of the buffer and the potential that is applied to the plate, the analyst can achieve separation of the types within an enzyme marker. The types appear as differing patterns of bands. Once the bloodstain has been subjected to electrophoresis, the enzymes must be visualized. This is generally best accomplished by using the specific activity of the enzyme. For the enzymes described in the present work, the visualization is performed by over-layering the plate with a piece of filter paper that 'has been saturated with the appropriate non-fluorescent substrate and buffer. The bands of enzyme, which is now in discrete patterns, will act upon the non-fluorescent substrate to create a fluorescent compound. The plate is then viewed with transmitted UV

  2. Capillary electrophoresis

    SciTech Connect

    Warner, M.

    1988-10-15

    Rapid instrumental methods for performing electrophoretic separations in capillary tubes have recently been developed, making capillary electrophoresis one of the most exciting new techniques available to analytical chemists. This article discusses detection methods, applications, and the future of capillary electrophoresis.

  3. Direct determination of chlorophenols present in liquid samples by using a supported liquid membrane coupled in-line with capillary electrophoresis equipment.

    PubMed

    Almeda, S; Nozal, L; Arce, L; Valcárcel, M

    2007-03-21

    Actually there is a great trend on the development of effective analytical methods for monitoring trace levels of various phenols which can indicate, among others compounds, the water quality. A simple, inexpensive supported liquid membrane (SLM) device was used in combination with commercially available capillary electrophoresis (CE) equipment for the direct determination of chlorophenols in surface water samples. The manifold was used simultaneously to extract and preconcentrate the analytes from liquid samples. In the extraction set-up, the donor phase (4 mL) was placed in the CE vial, where a micro-membrane extraction unit (MMEU) accommodating the acceptor phase (100 microL) in its lumen was immersed. The supported liquid membrane was constructed by impregnating a porous Fluoropore Teflon (PTFE) membrane with a water-immiscible organic solvent (dihexyl ether). The extraction process was optimized with regard to the pH of the donor and acceptor phases, membrane liquid, extraction time and voltage applied to the inlet or outlet vial during extraction. The chlorinated phenols pentachlorophenol (PCP), 2,3,6 trichlorophenol (TCP) and 2,6 dichlorophenol (DCP) were thus efficiently separated by CE, using tris(hydroxymethyl)aminomethane (Tris) and an NaH(2)PO(4) solution containing 1% (v/v) methanol at pH 10.5 as running buffer. PMID:17386759

  4. 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).

  5. 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

  6. Comparison of sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles and antigenic relatedness among outer membrane proteins of 49 Brucella abortus strains.

    PubMed Central

    Verstreate, D R; Winter, A J

    1984-01-01

    Outer membrane proteins were solubilized from 49 strains of Brucella abortus by sequential extraction of physically disrupted cells with N-lauroylsarcosinate and a dipolar ionic detergent (Verstreate et al., Infect. Immun. 35:979-989, 1982). The strains tested included standard agglutination test strain 1119, virulent strain 2308, and eight reference strains representing each of the biotypes; the remainder were isolates from cattle in North America with natural infections and included biotypes 1, 2, and 4. Three principal protein groups with apparent molecular weights of 88,000 to 94,000 (group 1), 35,000 to 40,000 (group 2, now established as porins [Douglas et al., Infect. Immun. 44:16-21, 1984]), and 25,000 to 30,000 (group 3) were observed in every strain. Some variability in banding patterns occurred among strains, but intrastrain variation was sufficient to preclude the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of outer membrane proteins for differentiating among strains of B. abortus. One antigen ([b]) was shared among the porin proteins, and three others ([c], ([d], and ([ e]) were shared among the group 3 proteins of all of the strains tested, indicating that these relationships are probably species wide. These results suggest that it may be possible to use outer membrane proteins from a representative strain of B. abortus in a vaccine for species-wide immunization. Images PMID:6434426

  7. 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)

  8. 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

  9. Preparation and application of functionalized cellulose acetate/silica composite nanofibrous membrane via electrospinning for Cr(VI) ion removal from aqueous solution.

    PubMed

    Taha, Ahmed A; Wu, Yi-na; Wang, Hongtao; Li, Fengting

    2012-12-15

    Novel NH(2)-functionalized cellulose acetate (CA)/silica composite nanofibrous membranes were successfully prepared by sol-gel combined with electrospinning technology. Tetraethoxysilane (TEOS) as a silica source, CA as precursor and 3-ureidopropyltriethoxysilane as a coupling agent were used in membrane preparation. The membrane's chemical and morphological structures were investigated by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) images, X-ray diffraction (XRD), element analyzer, Fourier-transform infrared spectroscopy (FTIR) and N(2) adsorption-desorption isotherms. The composite nanofibrous membranes exhibited high surface area and porosity. The membranes were used for Cr(VI) ion removal from aqueous solution through static and dynamic experiments. The adsorption behavior of Cr(VI) can be well described by the Langmuir adsorption model, and the maximum adsorption capacity for Cr(VI) is estimated to be 19.46 mg/g. The membrane can be conveniently regenerated by alkalization. Thus the composite membrane prepared from biodegradable raw material has potential applications in the field of water treatment. PMID:22858801

  10. 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

  11. 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...

  12. Gypsum (CaSO4·2H2O) 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 (CaSO4·2H2O) 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

  13. 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.

  14. Miniaturized supported liquid membrane device for selective on-line enrichment of basic drugs in plasma combined with capillary zone electrophoresis.

    PubMed

    Pálmarsdóttir, S; Thordarson, E; Edholm, L E; Jönsson, J A; Mathiasson, L

    1997-05-01

    A hollow fiber miniaturized supported liquid membrane (SLM) device for sample preparation is connected on-line with capillary electrophoresis and used for determination of a basic drug, bambuterol, in human plasma. The analyte is extracted from the outside of the hollow fiber (donor) through the liquid membrane (pores of the fiber impregnated with organic solvent) into the acceptor solution in the fiber lumen. The process is driven by differences in pH between the donor and acceptor solution. The whole volume of the acceptor solution can then be injected into the CZE capillary by using the double-stacking procedure for large volume-injection. Very clean extracts of low ionic strength are obtained from the SLM treatment, making this sample pretreatment method compatible with the CZE double-stacking procedure, which in turn makes it possible to inject large volumes of sample onto the separation capillary. Good performance of the whole procedure is demonstrated, and detection limits in the low nanomolar range were obtained in spite of the relatively weak UV absorbance of bambuterol. Extractions through the miniaturized SLM unit can be performed for 5-6 h without regenerating the fiber. The regeneration procedure was tested, and no relevant changes in the performance of the extraction could be found after seven regenerations, allowing the same fiber to be used for a week. PMID:9145027

  15. 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

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

    PubMed

    Casado-Coterillo, Clara; Del Mar López-Guerrero, María; Irabien, Angel

    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

  17. Quantitative structure-activity relationship (QSAR) analysis of surfactants influencing attachment of a Mycobacterium sp. to cellulose acetate and aromatic polyamide reverse osmosis membranes.

    PubMed

    Campbell, P; Srinivasan, R; Knoell, T; Phipps, D; Ishida, K; Safarik, J; Cormack, T; Ridgway, H

    1999-09-01

    A series of 23 neutral, anionic, and zwitterionic surfactants were tested at a concentration of 0.1% wt/vol for their influence on attachment of a Mycobacterium sp. to cellulose acetate (CA) and polyamide (PA) reverse osmosis (RO) membranes. Four cell attachment bioassays were used: (1) semiconcurrent addition of surfactant and bacteria to RO coupons (standard assay); (2) surfactant pretreatment of RO membranes (membrane pretreatment assay); (3) surfactant treatment of adsorbed cells (detachment assay); and (4) surfactant pretreatment of mycobacteria (cell pretreatment assay). Seventeen surfactants inhibited attachment to PA membranes, whereas 15 inhibited attachment to CA in standard assays and, in 13 cases, the same surfactant inhibited attachment to both PA and CA. Despite greater cell attachment to PA than CA, surfactants were typically more effective in the former membrane system. More surfactants were effective in impairing cell attachment than in promoting detachment and a number enhanced attachment in membrane pretreatment assays, suggesting surface modification of RO membranes. Cell pretreatment inhibited attachment to CA membranes, suggesting the bacterial surface was also a target for detergent activity. Multivariate regression and cluster analyses indicated that critical micellar concentration (CMC) was positively correlated with Mycobacterium attachment in CA and PA standard assays. Surfactant dipole moment and octanol/water partitioning (LogP) also contributed to detergent activity in the PA system, whereas dipole moment, molecular topology (i.e., connectivity indices), and charge properties influenced activity in the CA system. Influential variables in membrane pretreatment assays included the LogP, topology indices, and charge properties, whereas CMC played a diminished role. Surfactant dipole moment was most influential in CA membrane detachment assays. Increasing system ionic strength by LiBr addition strengthened inhibition of cell attachment to

  18. 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.

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

    PubMed Central

    Tözeren, 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

  20. Membrane filtration of Sudan orange G on a cellulose acetate membrane filter for separation-preconcentration and spectrophotometric determination in water, chili powder, chili sauce and tomato sauce samples.

    PubMed

    ALOthman, Zeid A; Unsal, Yunus E; Habila, Mohamed; Shabaka, Azza; Tuzen, Mustafa; Soylak, Mustafa

    2012-08-01

    A simple membrane filtration procedure for separation-enrichment of Sudan orange G is presented. The method is based on the adsorption of Sudan orange G on a cellulose acetate filter and its elution from the membrane with 10 mL of ethanol. Sudan orange G in the eluent was determined by UV-visible spectrophotometry at 388 nm. The effect of analytical conditions, including pH, flow rates and eluent, sample volume, type of membrane for quantitative preconcentration and separation of Sudan orange G were examined. The influences of matrix components on Sudan orange G recoveries were studied. The preconcentration factor was 125. The detection limit was 4.9 μg L(-1). The relative standard deviation was 4.3%. The presented procedure was applied to chili powder, chili sauce, tomato sauce, powdered beverage and water samples. PMID:22617351

  1. 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.

  2. 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

  3. 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

  4. Supported liquid membrane extraction coupled in-line to commercial capillary electrophoresis for rapid determination of formate in undiluted blood samples.

    PubMed

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2013-07-19

    A cheap, disposable sample pretreatment device with planar supported liquid membrane (SLM) was proposed, assembled and placed into an autosampler carousel of a commercial capillary electrophoresis (CE) instrument for automated pretreatment and analysis of formate in undiluted whole blood and serum samples. All analytical procedures except for filling the pretreatment device with donor and acceptor solutions, i.e., extraction across SLM, injection of the extracted sample and CE-UV determination of formate, were performed fully automatically. The pretreatment device required only μL volumes of blood sample and organic solvent per extraction and was disposed off after each extraction. Good repeatability of peak areas (≤7.7%) and migration times (≤1.5%), linear relationship (r(2)=0.998-0.999) and limits of detection (≤35μM) were achieved. The overall analytical process including blood withdrawal, filling the SLM device with respective solutions, extraction of blood sample, injection into separation capillary and CE separation of formate from other anions took less than 4min. The method was proved useful by direct determination of elevated formate concentrations in undiluted serum samples of a methanol intoxicated patient. Due to its compatibility with currently commercially available CE instrumentation, disposability of extraction devices, minimum sample handling/consumption, and short extraction/analysis times, the developed method might be attractive for rapid diagnosis of methanol poisoning in clinical and toxicological laboratories. PMID:23777836

  5. Parallel Characterization of Anaerobic Toluene- and Ethylbenzene-Degrading Microbial Consortia by PCR-Denaturing Gradient Gel Electrophoresis, RNA-DNA Membrane Hybridization, and DNA Microarray Technology

    PubMed Central

    Koizumi, Yoshikazu; Kelly, John J.; Nakagawa, Tatsunori; Urakawa, Hidetoshi; El-Fantroussi, Saïd; 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. PMID:12088997

  6. 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.

  7. A difference gel electrophoresis study on thylakoids isolated from poplar leaves reveals a negative impact of ozone exposure on membrane proteins.

    PubMed

    Bohler, Sacha; Sergeant, Kjell; Hoffmann, Lucien; Dizengremel, Pierre; Hausman, Jean-Francois; Renaut, Jenny; Jolivet, Yves

    2011-07-01

    Populus tremula L. x P. alba L. (Populus x canescens (Aiton) Smith), clone INRA 717-1-B4, saplings were subjected to 120 ppb ozone exposure for 28 days. Chloroplasts were isolated, and the membrane proteins, solubilized using the detergent 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC), were analyzed in a difference gel electrophoresis (DiGE) experiment comparing control versus ozone-exposed plants. Extrinsic photosystem (PS) proteins and adenosine triphosphatase (ATPase) subunits were detected to vary in abundance. The general trend was a decrease in abundance, except for ferredoxin-NADP(+) oxidoreductase (FNR), which increased after the first 7 days of exposure. The up-regulation of FNR would increase NAPDH production for reducing power and detoxification inside and outside of the chloroplast. Later on, FNR and a number of PS and ATPase subunits decrease in abundance. This could be the result of oxidative processes on chloroplast proteins but could also be a way to down-regulate photochemical reactions in response to an inhibition in Calvin cycle activity. PMID:21520910

  8. 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)

  9. 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...

  10. Immobilization of Aspergillus oryzae  β-Galactosidase on Cellulose Acetate-Polymethylmethacrylate Membrane and Its Application in Hydrolysis of Lactose from Milk and Whey

    PubMed Central

    Ansari, Shakeel Ahmed; Satar, Rukhsana; Kashif Zaidi, Syed; Ahmad, Abrar

    2014-01-01

    The present study demonstrates the immobilization of Aspergillus oryzae β-galactosidase on cellulose acetate-polymethylmethacrylate (CA-PMMA) membrane and its application in hydrolyzing lactose in dairy industries. The effect of physical and chemical denaturants like pH, temperature, product inhibition by galactose, storage stability, and reuse number of the enzyme immobilized on CA-PMMA membrane has been investigated. Lactose was hydrolyzed from milk and whey in batch reactors at 50°C by free and immobilized β-galactosidase (IβG). Optimum pH for the free and immobilized enzyme was found to be the same, that is, 4.5. However, IβG retained greater fractions of catalytic activity at lower and higher pH ranges. The temperature optimum for the immobilized enzyme was increased by 10°C. Moreover, Michaelis-Menten constant was increased for IβG as compared to the native one while maximum reaction rate was reduced for the immobilized enzyme. The preserved activity of free and immobilized enzyme was found to be 45% and 83%, respectively, after five weeks of storage at 4°C. Reusability of IβG was observed to be 86% even after fifth repeated use, thereby signifying its application in lactose hydrolysis (as shown in lab-scale batch reactors) in various dairy products including milk and whey. PMID:27350979

  11. 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

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

    PubMed

    Siemieniuk, Agnieszka; Karcz, Waldemar

    2015-01-01

    The role of potassium (K(+)) and calcium (Ca(2+)) 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 Ca(2+) 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 Ca(2+), 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 Ca(2+), respectively, while in the presence of 1 mM K(+) they were inhibited only by 1 mM Ca(2+). At 10 mM K(+), endogenous growth and growth induced by either IAA or FC did not depend on Ca(2+) 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 Ca(2+) 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 Ca(2+). However, lack of Ca(2+) 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

  13. 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.

  14. 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.

  15. Electrophoresis device

    NASA Technical Reports Server (NTRS)

    Rhodes, P. H.; Snyder, R. S. (Inventor)

    1982-01-01

    A device for separating cellular particles of a sample substance into fractionated streams of different cellular species includes a casing having a distribution chamber, a separation chamber, and a collection chamber. The electrode chambers are separated from the separation chamber interior by means of passages such that flow variations and membrane variations around the slotted portion of the electrode chamber do not enduce flow perturbations into the laminar buffer curtain flowing in the separation chamber. The cellular particles of the sample are separated under the influence of the electrical field and the separation chamber into streams of different cellular species. The streams of separated cells enter a partition array in the collection chamber where they are fractionated and collected.

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Metal ion dependence of a heat-modifiable protein from the outer membrane of Escherichia coli upon sodium dodecyl sulfate-gel electrophoresis.

    PubMed Central

    McMichael, J C; Ou, J T

    1977-01-01

    One heat-modifiable protein of Escherichia coli outer membrane does not completely change to the high-temperature form in the presence of magnesium ion in sodium dodecyl sulfate solution. When the metal ion complexing reagents ethylenediaminetetraacetic acid, phosphate ion, hydroxyl ion, or the competitive cations Zn2+ or Ca2+ are added to the sodium dodecyl sulfate-solubilized sample of outer membrane, and then the sample is heated to 100 degrees C and recooled to room temperature, the protein is almost completely converted to the high-temperature form. In control samples, or if sodium chloride, magnesium chloride, or manganous chloride are added to these samples and treated the same way, a large amount of the low-temperature form of the protein is preserved. beta-Mercaptoethanol additions gave the same results as the metal ion complexing reagents and may owe its activity in these solutions to metal-binding activity and not to its role as a reducing reagent. We concluded that magnesium ion may be involved with stabilization of the low-temperature form of the protein either by directly binding the magnesium or by mediating interaction with other components of the membrane. Images PMID:410782

  5. 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.

  6. Electrophoresis for biological production

    NASA Technical Reports Server (NTRS)

    Mccreight, L. R.

    1977-01-01

    Preparative electrophoresis may provide a unique method for meeting ever more stringent purity requirements. Prolonged near zero gravity in space may permit the operation of preparative electrophoresis equipment with 100 times greater throughput than is currently available. Some experiments with influenza Virus Antigen, Erythropoietin and Antihemophaliac Factor, along with process and economic projections, are briefly reviewed.

  7. 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.

  8. Automatic multiple applicator electrophoresis

    NASA Technical Reports Server (NTRS)

    Grunbaum, B. W.

    1977-01-01

    Easy-to-use, economical device permits electrophoresis on all known supporting media. System includes automatic multiple-sample applicator, sample holder, and electrophoresis apparatus. System has potential applicability to fields of taxonomy, immunology, and genetics. Apparatus is also used for electrofocusing.

  9. Formation of 4-keto-D-aldopentoses and 4-pentulosonates (4-keto-D-pentonates) with unidentified membrane-bound enzymes from acetic acid bacteria.

    PubMed

    Adachi, Osao; Hours, Roque A; Shinagawa, Emiko; Akakabe, Yoshihiko; Yakushi, Toshiharu; Matsushita, Kazunobu

    2011-01-01

    In our previous study, a new microbial reaction yielding 4-keto-D-arabonate from 2,5-diketo-D-gluconate was identified with Gluconacetobacter liquefaciens RCTMR 10. It appeared that decarboxylation and dehydrogenation took place together in the reaction. To analyze the nature of the reaction, investigations were done with the membrane fraction of the organism, and 4-keto-D-arabinose was confirmed as the direct precursor of 4-keto-D-arabonate. Two novel membrane-bound enzymes, 2,5-diketo-D-gluconate decarboxylase and 4-keto-D-aldopentose 1-dehydrogenase, were involved in the reaction. Alternatively, D-arabonate was oxidized to 4-keto-D-arabonate by another membrane-bound enzyme, D-arabonate 4-dehydrogenase. More directly, D-arabinose oxidation was examined with growing cells and with the membrane fraction of G. suboxydans IFO 12528. 4-Keto-D-arabinose, the same intermediate as that from 2,5-diketo-D-gluconate, was detected, and it was oxidized to 4-keto-D-arabonate. Likewise, D-ribose was oxidized to 4-keto-D-ribose and then it was oxidized to 4-keto-D-ribonate. In addition to 4-keto-D-aldopentose 1-dehydrogenase, the presence of a novel membrane-bound enzyme, D-aldopentose 4-dehydrogenase, was confirmed in the membrane fraction. The formation of 4-keto-D-aldopentoses and 4-keto-D-pentonates (4-pentulosonates) was finally confirmed as reaction products of four different novel membrane-bound enzymes. PMID:21897028

  10. 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.

  11. 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. PMID:26416641

  12. Effect of phorbol myristate acetate on secretion of parathyroid hormone

    SciTech Connect

    Morrissey, J.J. )

    1988-01-01

    The influence of phorbol myristate acetate (PMA), an activator of protein kinase c, on the secretion of parathyroid hormone from collagenase-dispersed bovine parathyroid cells was tested. The cells were incubated at low or high concentrations of calcium in the medium, and the hormone secreted into the medium was measured by a radioimmunoassay that recognizes both intact and C-terminal fragments of hormone. A stimulatory effect of PMA at high calcium, seen at PMA concentrations as low as 1.6 nM, did not occur with a biologically inactive 4{alpha}-isomer of phorbol ester, and was independent of changes in cellular adenosine 3{prime},5{prime}-cyclic monophosphate levels. Examination of {sup 32}P-labeled phosphoproteins by two-dimensional gel electrophoresis revealed acidic proteins of {approximately}20,000 and 100,000 Da that were phosphorylated at low and high calcium + 1.6 {mu}M PMA but not at high calcium alone. The protein kinase c activity associated with the membrane fraction of parathyroid cells significantly decreased 40% when the cells were incubated at high vs. low calcium. The data suggest that calcium may regulate parathyroid hormone secretion through changes in protein kinase c activity of the membrane fraction of the cell and protein phosphorylation.

  13. Serum globulin electrophoresis

    MedlinePlus

    ... may indicate: Acute infection Bone marrow cancer called multiple myeloma Chronic inflammatory disease (for example, rheumatoid arthritis and ... test Hemoglobin Hyperimmunization Immunoelectrophoresis - ... electrophoresis - serum Rheumatoid arthritis Systemic lupus erythematosus ...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Segmented field OFFGEL® electrophoresis.

    PubMed

    Tobolkina, Elena; Cortés-Salazar, Fernando; Momotenko, Dmitry; Maillard, Julien; Girault, Hubert H

    2012-11-01

    A multielectrode setup for protein OFFGEL electrophoresis that significantly improves protein separation efficiency has been developed. Here, the electric field is applied by segments between seven electrodes connected in series to six independent power supplies. The aim of this strategy is to distribute evenly the electric field along the multiwell system, and as a consequence to enhance electrophoresis in terms of separation time, resolution, and protein collection efficiency, while minimizing the overall potential difference and therefore the Joule heating. The performances were compared to a standard two-electrode setup for OFFGEL fractionation of a protein mixture, using UV-Vis spectroscopy for quantification and MALDI-MS for identification. The electrophoretic separation process was simulated, and optimized by solving the time-dependent Nernst-Planck differential equation. PMID:23086720

  19. 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

  20. 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.

  1. 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.

  2. Multiplexed Western Blotting Using Microchip Electrophoresis.

    PubMed

    Jin, Shi; Furtaw, Michael D; Chen, Huaxian; Lamb, Don T; Ferguson, Stephen A; Arvin, Natalie E; Dawod, Mohamed; Kennedy, Robert T

    2016-07-01

    Western blotting is a commonly used protein assay that combines the selectivity of electrophoretic separation and immunoassay. The technique is limited by long time, manual operation with mediocre reproducibility, and large sample consumption, typically 10-20 μg per assay. Western blots are also usually used to measure only one protein per assay with an additional housekeeping protein for normalization. Measurement of multiple proteins is possible; however, it requires stripping membranes of antibody and then reprobing with a second antibody. Miniaturized alternatives to Western blot based on microfluidic or capillary electrophoresis have been developed that enable higher-throughput, automation, and greater mass sensitivity. In one approach, proteins are separated by electrophoresis on a microchip that is dragged along a polyvinylidene fluoride membrane so that as proteins exit the chip they are captured on the membrane for immunoassay. In this work, we improve this method to allow multiplexed protein detection. Multiple injections made from the same sample can be deposited in separate tracks so that each is probed with a different antibody. To further enhance multiplexing capability, the electrophoresis channel dimensions were optimized for resolution while keeping separation and blotting times to less than 8 min. Using a 15 μm deep × 50 μm wide × 8.6 cm long channel, it is possible to achieve baseline resolution of proteins that differ by 5% in molecular weight, e.g., ERK1 (44 kDa) from ERK2 (42 kDa). This resolution allows similar proteins detected by cross-reactive antibodies in a single track. We demonstrate detection of 11 proteins from 9 injections from a single Jurkat cell lysate sample consisting of 400 ng of total protein using this procedure. Thus, multiplexed Western blots are possible without cumbersome stripping and reprobing steps. PMID:27270033

  3. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, Edward S.; Li, Qingbo; Lu, Xiandan

    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.

  4. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, Edward S.; Chang, Huan-Tsang; Fung, Eliza N.; Li, Qingbo; Lu, Xiandan

    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.

  5. 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.

  6. 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.

  7. Preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles; Zoeller, Joseph Robert; Depew, Leslie Sharon

    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.

  8. 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.

  9. Apparatus for electrophoresis separation

    DOEpatents

    Anderson, Norman L.

    1978-01-01

    An apparatus is disclosed for simultaneously performing electrophoresis separations on a plurality of slab gels containing samples of protein, protein subunits or nucleic acids. A reservoir of buffer solution is divided into three compartments by two parallel partitions having vertical slots spaced along their length. A sheet of flexible, electrically insulative material is attached to each partition and is provided with vertical slits aligned with the slots. Slab-gel holders are received within the slots with the flexible material folded outwardly as flaps from the slits to overlay portions of the holder surfaces and thereby act as electrical and liquid seals. An elongated, spaghetti-like gel containing a sample of specimen that was previously separated by isoelectric focusing techniques is vertically positioned along a marginal edge portion of the slab gel. On application of an electrical potential between the two outer chambers of buffer solution, a second dimensional electrophoresis separation in accordance with molecular weight occurs as the specimen molecules migrate across the slab gel.

  10. 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.

  11. Analysis of Protein Oligomerization by Electrophoresis.

    PubMed

    Cubillos-Rojas, Monica; Schneider, Taiane; Sánchez-Tena, Susana; Bartrons, Ramon; Ventura, Francesc; Rosa, Jose Luis

    2016-01-01

    A polypeptide chain can interact with other polypeptide chains and form stable and functional complexes called "oligomers." Frequently, biochemical analysis of these complexes is made difficult by their great size. Traditionally, size exclusion chromatography, immunoaffinity chromatography, or immunoprecipitation techniques have been used to isolate oligomers. Components of these oligomers are then further separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and identified by immunoblotting with specific antibodies. Although they are sensitive, these techniques are not easy to perform and reproduce. The use of Tris-acetate polyacrylamide gradient gel electrophoresis allows the simultaneous analysis of proteins in the mass range of 10-500 kDa. We have used this characteristic together with cross-linking reagents to analyze the oligomerization of endogenous proteins with a single electrophoretic gel. We demonstrate how the oligomerization of p53, the pyruvate kinase isoform M2, or the heat shock protein 27 can be studied with this system. We also show how this system is useful for studying the oligomerization of large proteins such as clathrin heavy chain or the tuberous sclerosis complex. Oligomerization analysis is dependent on the cross-linker used and its concentration. All of these features make this system a very helpful tool for the analysis of protein oligomerization. PMID:27613048

  12. Protein content and enzyme activities in methanol- and acetate-grown Methanosarcina thermophila.

    PubMed Central

    Jablonski, P E; DiMarco, A A; Bobik, T A; Cabell, M C; Ferry, J G

    1990-01-01

    The cell extract protein content of acetate- and methanol-grown Methanosarcina thermophila TM-1 was examined by two-dimensional polyacrylamide gel electrophoresis. More than 100 mutually exclusive spots were present in acetate- and methanol-grown cells. Spots corresponding to acetate kinase, phosphotransacetylase, and the five subunits of the carbon monoxide dehydrogenase complex were identified in acetate-grown cells. Activities of formylmethanofuran dehydrogenase, formylmethanofuran:tetrahydromethanopterin formyltransferase, 5,10-methenyltetrahydromethanopterin cyclohydrolase, methylene tetrahydromethanopterin:coenzyme F420 oxidoreductase, formate dehydrogenase, and carbonic anhydrase were examined in acetate- and methanol-grown Methanosarcina thermophila. Levels of formyltransferase in either acetate- or methanol-grown Methanosarcina thermophila were approximately half the levels detected in H2-CO2-grown Methanobacterium thermoautotrophicum. All other enzyme activities were significantly lower in acetate- and methanol-grown Methanosarcina thermophila. Images FIG. 1 FIG. 2 PMID:2307649

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Polyacrylamide gel electrophoresis.

    PubMed

    Chrambach, A; Rodbard, D

    1971-04-30

    Polyacrylamide gel electrophoresis (PAGE) provides a versatile, gentle, high resolution method for fractionation and physical-chemical characterization of molecules on the basis of size, conformation, and net charge. The polymerization reaction can be rigorously controlled to provide uniform gels of reproducible, measurable pore size over a wide range. This makes it possible to obtain reproducible relative mobility (Rf) values as physical-chemical constants. Application and extension of Ogston's (random fiber) model for a gel allows for calculation of molecular volume, surface area, or radius, free mobility, and valence from RJ measurements at several gel concentrations, to calculate gel concentration for optimal resolution, and to predict behavior of macromolecules on gel gradients by computerized methods. Extension of classical moving boundary theory has been used to generate multiphasic buffer systems (providing selective stacking, unstacking, restacking, and preparative steady-state-stacking) with known operating characteristics for any pH at 0 degrees and 25 degrees C. A general strategy for isolation of macromolecules and for macromolecular mapping has been developed. Preparative scale PAGE is operational for milligram loads and feasible for gram quantities. PMID:4927678

  19. Copolymers For Capillary Gel Electrophoresis

    DOEpatents

    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.

  20. 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.

  1. 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.

  2. Comparison of the phosphorylation events in membranes prepared from proliferating versus quiescent endothelial cells

    SciTech Connect

    Kazlauskas, A.; DiColeto, P.E.

    1986-05-01

    Little is known of the intracellular events which regulate the proliferation of endothelial cells (EC). Triton-solubilized membranes from proliferating (sparse) and quiescent (confluent) EC were incubated at pH 6.5 in the presence of divalent cations and (/sup 32/P)ATP. Membrane proteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. The overall kinase activity per mg protein was slightly greater in membranes prepared from proliferating versus quiescent cells. They found four proteins labeled in sparse cells to a dramatically greater extent having the following approximate molecular masses: 180, 100, 97 and 55 kilodalton (kd). The first two phosphoproteins were phosphorylated on serine residues exclusively; the 97 kd phosphoprotein contained 39% phosphoserine (p-ser) and 61% phosphothreonine (p-thr); and the 55 kd phosphoprotein contained 62% p-ser, 16% p-thr, and 22% phosphotyrosine (p-tyr). The kinases acting on all four phosphoproteins were independent of Ca/sup 2 +/, cAMP, cGMP, or phorbol 12-myristate 13-acetate. The observed differences in phosphorylation events between sparse and confluent membranes occurred in membranes from two EC lines - pig aortic and bovine aortic - but were not apparent in membranes prepared from human foreskin fibroblasts or 3T3 cells. Sparse endothelial cells made quiescent by serum deprivation were found to resemble confluent cells in the kinase activity; therefore, the enhanced kinase activity in sparse membranes may be growth dependent.

  3. 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.

  4. 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

  5. Preparative electrophoresis of living lymphocytes

    NASA Technical Reports Server (NTRS)

    Vanoss, C. J.; Bigazzi, P. E.; Gillman, C. F.; Allen, R. E.

    1974-01-01

    Vertical liquid columns containing low molecular weight dextran density gradients can be used for preparative lymphocyte electrophoresis on earth, in simulation of 0 gravity conditions. Another method that has been tested at 1 G, is the electrophoresis of lymphocytes in a upward direction in vertical columns. By both methods up to 10 to the 7th power lymphocytes can be separated at one time in a 30 cm glass column of 8 mm inside diameter, at 12 v/cm, in 2 hours. Due to convection and sedimentation problems, the separation at 1 G is less than ideal, but it is expected that at 0 gravity electrophoresis will prove to be a uniquely powerful cell separation tool. The technical feasibility of electrophoresing inert particles at 0 G has been proven earlier, during the flight of Apollo 16.

  6. 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.

  7. 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.

  8. [Mechanisms of organic drug electrophoresis].

    PubMed

    Nuritdinov, V A

    1990-01-01

    Riboflavin, riboflavin mononucleotide, and fluorescein penetration from the ocular bath without electric current (control), from the anode, from the cathode, and without current after preliminary galvanization was studied in rabbit eyes. Penetration of organic drugs into intraocular fluid in electrophoresis was found to be increased not only from the adequate pole of the active electrode, but from the contrary pole as well. Galvanic current sharply abated the barrier function of the cornea. Therapeutic electrophoresis of the eyeball permits the use of many-component solutions with drug ions of different charge. PMID:2238327

  9. 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

  10. 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

  11. [Does bilirubin interfere with capillary electrophoresis of serum proteins?].

    PubMed

    Hellara, Ilhem; Fekih, Ons; Triki, Sonia; Elmay, Ahlem; Neffati, Fadoua; Najjar, Mohamed Fadhel

    2014-01-01

    Capillary electrophoresis of serum proteins is a fast, reliable and simple technique, but many interference exist. The objective of our work is to study the interference of bilirubin on this technique; 70 icteric sera were analysed on Capillarys ™ (Sebia). A second electrophoresis was performed on 40 samples after bilirubin photodegradation. The bilirubin and serum proteins were determinated respectively by Jendrassik and Grof and biuret methods on Konélab 20i ™ (Thermo Electron Corporation). We found abnormal spreading of the albumin fraction of the anode side wich constitute sometimes an isolated fraction in the traditional area of pre-albumin migration. This fraction varies from 2.0 ± 2.0% (0.0 to 7.3%) or 0.98 ± 1.53 g/L (0 to 5.3 g/L) and it seems to be related to the direct bilirubin since, following overloading sera with a solution of bilirubin, no further fraction was recovered. An average decrease of bilirubin after photodegradation of 58 ± 17% (26-89%) is followed by a decrease in the same order 64 ± 38% (10-100%) of the additional fraction. Acetate cellulose electrophoresis of the same samples showed no variation. The high bilirubin levels seem modify slightly the electrophoretic profile. However the impact of the interference on the interpretation of electrophoretic trace is negligible. PMID:24492101

  12. Bioprocessing: Prospects for space electrophoresis

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1977-01-01

    The basic principles of electrophoresis are reviewed in light of its past contributions to biology and medicine. The near-zero gravity environment of orbiting spacecraft may present some unique advantages for a variety of processes, by abolishing the major source of convection in fluids. As the ground-based development of electrophoresis was heavily influenced by the need to circumvent the effects of gravity, this process should be a prime candidate for space operation. Nevertheless, while a space facility for electrophoresis may overcome the limitations imposed by gravity, it will not necessarily overcome all problems inherent in electrophoresis. These are, mainly, electroosmosis and the dissipation of the heat generated by the electric field. The NASA program has already led to excellent coatings to prevent electroosmosis, while the need for heat dissipation will continue to impose limits on the actual size of equipment. It is also not excluded that, once the dominant force of gravity is eliminated, disturbances in fluid stability may originate from weaker forces, such as surface tension.

  13. 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.

  14. Cell morphology variations of Klebsiella pneumoniae induced by acetate stress using biomimetic vesicle assay.

    PubMed

    Lu, Shengguo; Han, Yuwang; Duan, Xujia; Luo, Fang; Zhu, Lingyan; Li, Shuang; Huang, He

    2013-10-01

    Supplementation with acetate under low levels was used as a novel approach to control the morphological development of Klebsiella pneumoniae aimed to improve 1,3-propanediol (1,3-PD) production. A full range of morphological types formed from rod shape to oval shape even round shape in response to different concentrations of acetate. The cell growth and 1,3-PD productions in the shake flasks with 0.5 g/L acetate addition were improved by 9.4 and 28.37%, respectively, as compared to the control, while the cell became shorter and began to lose its original shape. The cell membrane penetration by acetate was investigated by the biomimetic vesicles, while higher concentration of acetate led to more moderate colorimetric transitions. Moreover, the percentage composition of unsaturated fatty acid (UFA) was increased as well as the increased concentrations of acetate, whereas higher UFA percentage, higher fluidity of bacterial cell membrane. PMID:23892619

  15. Characterization of the formyl peptide chemotactic receptor appearing at the phagocytic cell surface after exposure to phorbol myristate acetate

    SciTech Connect

    Gardner, J.P.; Melnick, D.A.; Malech, H.L.

    1986-02-15

    The biochemistry and subcellular source of new formyl peptide chemotactic receptor appearing at the human neutrophil and differentiated HL-60 (d-HL-60) cell surface after stimulation with phorbol myristate acetate (PMA) were examined. Formyl peptide receptor was analyzed by affinity labeling with formyl-norleu-leu-phe-norleu- (/sup 125/I)iodotyr-lys and ethylene glycol bis(succinimidyl succinate) followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and densitometric analysis of autoradiographs. PMA, a specific granule secretagogue, increases affinity labeling of formyl peptide receptors on the neutrophil surface by 100%, and on d-HL-60, which lack specific granule markers, by 20%. Papain treatment markedly reduces surface labeling of formyl peptide receptor in both neutrophils and d-HL-60, and results in the appearance of a lower m.w. membrane-bound receptor fragment. PMA stimulation of papain-treated cells increases uncleaved surface receptor on neutrophils by 400%, and on D-HL-60 by only 45%. This newly appearing receptor is the same apparent m.w. (55,000 to 75,000 for neutrophils; 62,000 to 80,000 for d-HL-60) and yields the same papain cleavage product as receptor on the surface of unstimulated cells. These observations suggest that specific granule membranes contain large amounts of formyl peptide receptor, which is biochemically identical to that found on the cell surface and can be mobilized to the cell surface with appropriate stimulation.

  16. The clinical use of PET with 11C-acetate

    PubMed Central

    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 11C-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. 11C-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 11C-acetate focused on its use in prostate cancer. Subsequently, 11C-acetate was studied in other urological malignancies, as well as renal cell carcinoma and bladder cancer. Well differentiated hepatocellular carcinoma represents an 18F-fluoro-deoxyglucose (18F-FDG) PET pitfall, so many authors have proposed to use 11C-acetate in addition to 18F-FDG in studying this tumor. 11C-acetate PET has also been used in other malignancies, such as brain tumors and lung carcinoma. Some authors reported a few cases in which 11C-acetate PET incidentally found multiple myeloma or rare tumors, such as thymoma, multicentric angiomyolipoma of the kidney and cerebellopontine angle schwannoma. Lastly, 11C-acetate PET was also employed in a differential diagnosis case between glioma and encephalitis. The numerous studies on 11C-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 18F-FDG-avid neoplasm, such as differentiated lung cancer or hepatocellular carcinoma. PMID:23133801

  17. 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.

  18. 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.

  19. 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.

  20. Ratcheted electrophoresis of Brownian particles

    NASA Astrophysics Data System (ADS)

    Kowalik, Mikołaj; Bishop, Kyle J. M.

    2016-05-01

    The realization of nanoscale machines requires efficient methods by which to rectify unbiased perturbations to perform useful functions in the presence of significant thermal noise. The performance of such Brownian motors often depends sensitively on their operating conditions—in particular, on the relative rates of diffusive and deterministic motions. In this letter, we present a type of Brownian motor that uses contact charge electrophoresis of a colloidal particle within a ratcheted channel to achieve directed transport or perform useful work against an applied load. We analyze the stochastic dynamics of this model ratchet to show that it functions under any operating condition—even in the limit of strong thermal noise and in contrast to existing ratchets. The theoretical results presented here suggest that ratcheted electrophoresis could provide a basis for electrochemically powered, nanoscale machines capable of transport and actuation of nanoscale components.

  1. Electrophoresis in strong electric fields.

    PubMed

    Barany, Sandor

    2009-01-01

    Two kinds of non-linear electrophoresis (ef) that can be detected in strong electric fields (several hundred V/cm) are considered. The first ("classical" non-linear ef) is due to the interaction of the outer field with field-induced ionic charges in the electric double layer (EDL) under conditions, when field-induced variations of electrolyte concentration remain to be small comparatively to its equilibrium value. According to the Shilov theory, the non-linear component of the electrophoretic velocity for dielectric particles is proportional to the cubic power of the applied field strength (cubic electrophoresis) and to the second power of the particles radius; it is independent of the zeta-potential but is determined by the surface conductivity of particles. The second one, the so-called "superfast electrophoresis" is connected with the interaction of a strong outer field with a secondary diffuse layer of counterions (space charge) that is induced outside the primary (classical) diffuse EDL by the external field itself because of concentration polarization. The Dukhin-Mishchuk theory of "superfast electrophoresis" predicts quadratic dependence of the electrophoretic velocity of unipolar (ionically or electronically) conducting particles on the external field gradient and linear dependence on the particle's size in strong electric fields. These are in sharp contrast to the laws of classical electrophoresis (no dependence of V(ef) on the particle's size and linear dependence on the electric field gradient). A new method to measure the ef velocity of particles in strong electric fields is developed that is based on separation of the effects of sedimentation and electrophoresis using videoimaging and a new flowcell and use of short electric pulses. To test the "classical" non-linear electrophoresis, we have measured the ef velocity of non-conducting polystyrene, aluminium-oxide and (semiconductor) graphite particles as well as Saccharomice cerevisiae yeast cells as a

  2. Capillary electrophoresis systems and methods

    DOEpatents

    Dorairaj, Rathissh; Keynton, Robert S.; Roussel, Thomas J.; Crain, Mark M.; Jackson, Douglas J.; Walsh, Kevin M.; Naber, John F.; Baldwin, Richard P.; Franco, Danielle B.

    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.

  3. Enhancing Centrifugal Separation With Electrophoresis

    NASA Technical Reports Server (NTRS)

    Herrmann, F. T.

    1986-01-01

    Separation of biological cells by coil-planet centrifuge enhanced by electrophoresis. By itself, coil-planet centrifuge offers relatively gentle method of separating cells under low centrifugal force in physiological medium that keeps cells alive. With addition of voltage gradient to separation column of centrifuge, separation still gentle but faster and more complete. Since separation apparatus contains no rotary seal, probability of leakage, contamination, corrosion, and short circuits reduced.

  4. DNA Electrophoresis on Nanopatterned surfaces

    NASA Astrophysics Data System (ADS)

    Luo, Haobin; Gersappe, Dilip

    2002-03-01

    Conventional electrophoretic methods for DNA separation use topological restriction such as the network point in a gel to separate DNA. Here, we present a new approach to DNA electrophoresis using a nanopatterned surface. We exploit the conformational differences that arise when chains of different length are adsorbed onto a flat nanopatterned surface. We use a MD simulation to determine conditions that will optimize separation and present guidelines for the design of nanopatterned surfaces that can separate DNA in a broad size range.

  5. Capillary Electrophoresis - Optical Detection Systems

    SciTech Connect

    Sepaniak, M. J.

    2001-08-06

    Molecular recognition systems are developed via molecular modeling and synthesis to enhance separation performance in capillary electrophoresis and optical detection methods for capillary electrophoresis. The underpinning theme of our work is the rational design and development of molecular recognition systems in chemical separations and analysis. There have been, however, some subtle and exciting shifts in our research paradigm during this period. Specifically, we have moved from mostly separations research to a good balance between separations and spectroscopic detection for separations. This shift is based on our perception that the pressing research challenges and needs in capillary electrophoresis and electrokinetic chromatography relate to the persistent detection and flow rate reproducibility limitations of these techniques (see page 1 of the accompanying Renewal Application for further discussion). In most of our work molecular recognition reagents are employed to provide selectivity and enhance performance. Also, an emerging trend is the use of these reagents with specially-prepared nano-scale materials. Although not part of our DOE BES-supported work, the modeling and synthesis of new receptors has indirectly supported the development of novel microcantilevers-based MEMS for the sensing of vapor and liquid phase analytes. This fortuitous overlap is briefly covered in this report. Several of the more significant publications that have resulted from our work are appended. To facilitate brevity we refer to these publications liberally in this progress report. Reference is also made to very recent work in the Background and Preliminary Studies Section of the Renewal Application.

  6. DNA Sequencing by Capillary Electrophoresis

    PubMed Central

    Karger, Barry L.; Guttman, Andras

    2009-01-01

    Sequencing of human and other genomes has been at the center of interest in the biomedical field over the past several decades and is now leading toward an era of personalized medicine. During this time, DNA sequencing methods have evolved from the labor intensive slab gel electrophoresis, through automated multicapillary electrophoresis systems using fluorophore labeling with multispectral imaging, to the “next generation” technologies of cyclic array, hybridization based, nanopore and single molecule sequencing. Deciphering the genetic blueprint and follow-up confirmatory sequencing of Homo sapiens and other genomes was only possible by the advent of modern sequencing technologies that was a result of step by step advances with a contribution of academics, medical personnel and instrument companies. While next generation sequencing is moving ahead at break-neck speed, the multicapillary electrophoretic systems played an essential role in the sequencing of the Human Genome, the foundation of the field of genomics. In this prospective, we wish to overview the role of capillary electrophoresis in DNA sequencing based in part of several of our articles in this journal. PMID:19517496

  7. [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

  8. 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)

  9. 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.

  10. 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.

  11. Supported bilayer electrophoresis under controlled buffer conditions.

    PubMed

    Monson, Christopher F; Pace, Hudson P; Liu, Chunming; Cremer, Paul S

    2011-03-15

    A pH controlled flow cell device was constructed to allow electrophoretic movement of charged lipids and membrane associated proteins in supported phospholipid bilayers. The device isolated electrolysis products near the electrodes from the electrophoresis process within the bilayer. This allowed the pH over the bilayer region to remain within ±0.2 pH units or better over many hours at salt concentrations up to 10 mM. Using this setup, it was found that the electrophoretic mobility of a dye conjugated lipid (Texas Red 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (TR-DHPE)) was essentially constant between pH 3.3 and 9.3. In contrast, streptavidin, which was bound to biotinylated lipids, shifted from migrating cathodically at acidic pH values to migrating anodically under basic conditions. This shift was due to the modulation of the net charge on the protein, which changed the electrophoretic forces experienced by the macromolecule. The addition of a polyethylene glycol (PEG) cushion beneath the bilayer or the increase in the ionic strength of the buffer solution resulted in a decrease of the electroosmotic force experienced by the streptavidin with little effect on the Texas Red-DHPE. As such, it was possible in part to control the electrophoretic and electroosmotic contributions to streptavidin independently of one another. PMID:21319743

  12. Microbeam-coupled capillary electrophoresis.

    PubMed

    Garty, G; Ehsan, M U; Buonanno, M; Yang, Z; Sweedler, J V; Brenner, D J

    2015-09-01

    Within the first few microseconds following a charged particle traversal of a cell, numerous oxygen and nitrogen radicals are formed along the track. Presented here is a method, using capillary electrophoresis, for simultaneous measurement, within an individual cell, of specific reactive oxygen species, such as the superoxide radical ([Formula: see text]) as well as the native and oxidised forms of glutathione, an ubiquitous anti-oxidant that assists the cell in coping with these species. Preliminary data are presented as well as plans for integrating this system into the charged particle microbeam at Columbia University. PMID:25870435

  13. Integrated multiplexed capillary electrophoresis system

    SciTech Connect

    Yeung, Edward S.; Tan, Hongdong

    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.

  14. Capillary electrophoresis in metallodrug development.

    PubMed

    Holtkamp, Hannah; Hartinger, Christian G

    2015-09-01

    Capillary electrophoresis (CE) is a separation method based on differential migration of analytes in electric fields. The compatibility with purely aqueous separation media makes it a versatile tool in metallodrug research. Many metallodrugs undergo ligand exchange reactions that can easily be followed with this method and the information gained can even be improved by coupling the CE to advanced detectors, such as mass spectrometers. This gives the method high potential to facilitate the development of metallodrugs, especially when combined with innovative method development and experimental design. PMID:26547417

  15. 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.

  16. Conducting Polymer Electrodes for Gel Electrophoresis

    PubMed Central

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D.

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation. PMID:24586761

  17. 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

  18. 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...

  19. Chip-based capillary electrophoresis with an electrodeless nanospray interface.

    PubMed

    Vrouwe, E X; Gysler, J; Tjaden, U R; van der Greef, J

    2000-01-01

    A sheathless and electrodeless nanospray interface has been used to interface a polycarbonate capillary electrophoresis (CE) chip to a mass spectrometer (MS). The chip was made of two flat polycarbonate plates which were bolted together. Channels were imprinted in one of the plates with metal wires, using a hydraulic press. A short tapered capillary connected to the chip was used as the nanospray emitter. The advantage of this electrodeless interface is that it was not necessary to apply a electrospray voltage to the chip or the nanospray emitter. Instead, the CE voltage already applied to the buffer compartment on the chip, to drive the electrophoresis, was used to generate the spray also. A low conductivity buffer of 1.25 mmol/L ammonium acetate in 80% methanol was used to obtain a large electric field across the buffer channel. The performance of the device was evaluated by analyzing a mixture of three beta-agonists Relative standard deviation (RSD) values obtained were between 4.8 and 5.0%. A sample concentration of 40 nmol/L resulted in a signal-to-noise ratio of 2 to 5 for the different components. Compared to a conventional CE analysis in a fused silica capillary with UV detection, only a minor loss of resolution was observed, which can be attributed to the design of the chip. PMID:10962491

  20. Separation of radiolabelled glycosaminoglycan oligosaccharides by polyacrylamide-gel electrophoresis.

    PubMed Central

    Hampson, I N; Gallagher, J T

    1984-01-01

    Glycosaminoglycan oligosaccharides generated by treatment of biosynthetically radiolabelled dermatan sulphate and hyaluronic acid with chondroitin AC lyase or testicular hyaluronidase may be resolved into a series of discrete bands by polyacrylamide-gel electrophoresis. Bands were identified by fixation in glacial acetic acid containing 20% (w/v) 2,5-diphenyloxazole followed by fluorography. The bands represented glycans which differed in size by one disaccharide unit. For the larger oligosaccharides (decasaccharides and above) of similar charge: mass ratio, there was a linear relationship between electrophoretic mobility and log Mr. However, the smaller species showed anomalous migration patterns. Consideration of the structures of the fragments produced by the different enzyme treatments suggests that copolymeric and homopolymeric oligosaccharides may be separated by polyacrylamide-gel electrophoresis. There are many potential applications of this technique, foremost amongst them being studies on the molecular size heterogeneity and patterns of enzyme-mediated depolymerization of native glycosaminoglycan chains and investigations into rates of polymer chain elongation and post-polymerization modification reactions so essential to glycosaminoglycan function. Images Fig. 1. Fig. 2. Fig. 5. Fig. 6. PMID:6477495

  1. 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.

  2. 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

  3. 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.

  4. Electrophoresis-mass spectrometry probe

    DOEpatents

    Andresen, Brian D.; Fought, Eric R.

    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.

  5. 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.

  6. Analytical biotechnology: Capillary electrophoresis and chromatography

    SciTech Connect

    Horvath, C.; Nikelly, J.G.

    1990-01-01

    The papers describe the separation, characterization, and equipment required for the electrophoresis or chromatography of cyclic nucleotides, pharmaceuticals, therapeutic proteins, recombinant DNA products, pheromones, peptides, and other biological materials. One paper, On-column radioisotope detection for capillary electrophoresis, has been indexed separately for inclusion on the data base.

  7. 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.

  8. 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…

  9. 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.

  10. 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)

  11. 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

  12. 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

  13. 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...

  14. Rapid and simple pretreatment of human body fluids using electromembrane extraction across supported liquid membrane for capillary electrophoretic determination of lithium.

    PubMed

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-05-01

    Electromembrane extraction was used for simultaneous sample cleanup and preconcentration of lithium from untreated human body fluids. The sample of a body fluid was diluted 100 times with 0.5 mM Tris solution and lithium was extracted by electromigration through a supported liquid membrane composed of 1-octanol into 100 mM acetic acid acceptor solution. Matrix compounds, such as proteins, red blood cells, and other high-molecular-weight compounds were efficiently retained on the supported liquid membrane. The liquid membrane was anchored in pores of a short segment of a polypropylene hollow fiber, which represented a low cost, single use, disposable extraction unit and was discarded after each use. Acceptor solutions were analyzed using capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4) D) and baseline separation of lithium was achieved in a background electrolyte solution consisting of 18 mM L-histidine and 40 mM acetic acid at pH 4.6. Repeatability of the electromembrane extraction-CE-C(4) D method was evaluated for the determination of lithium in standard solutions and real samples and was better than 0.6 and 8.2% for migration times and peak areas, respectively. The concentration limit of detection of 9 nM was achieved. The developed method was applied to the determination of lithium in urine, blood serum, blood plasma, and whole blood at both endogenous and therapeutic concentration levels. PMID:21500213

  15. 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

  16. Phenomenology of colloidal crystal electrophoresis

    NASA Astrophysics Data System (ADS)

    Medebach, Martin; Palberg, Thomas

    2003-08-01

    We studied the motion of polycrystalline solids comprising of charged sub-micron latex spheres suspended in deionized water. These were subjected to a low frequency alternating square wave electric field in an optical cell of rectangular cross section. Velocity profiles in X and Y direction were determined by Laser Doppler Velocimetry. The observed complex flow profiles are time dependent due to the combined effects of electro-osmosis, electrophoresis, crystal elasticity, and friction of the crystals at the cell wall. On small time scales elastic deformation occurs. On long time scales channel formation is observed. At intermediate times steady state profiles are dominated by a solid plug of polycrystalline material moving in the cell center. At large field strengths the plug shear melts. Mobilities in the shear molten state are on the order of (6.5±0.5) 10-8 m2 V-1 s-1 and connect continuously with those of the equilibrium fluid. The apparent mobility of the plug is much larger than of the fluid and like the mobility of the fluid decreases with increasing particle number density. We qualitatively attribute the accelerated motion of the plug to an incomplete exposure to the electro-osmotic flow profile.

  17. Atomic Force Controlled Capillary Electrophoresis

    NASA Astrophysics Data System (ADS)

    Lewis, Aaron; Yeshua, Talia; Palchan, Mila; Lovsky, Yulia; Taha, Hesham

    2010-03-01

    Lithography based on scanning probe microscopic techniques has considerable potential for accurate & localized deposition of material on the nanometer scale. Controlled deposition of metallic features with high purity and spatial accuracy is of great interest for circuit edit applications in the semiconductor industry, for plasmonics & nanophotonics and for basic research in surface enhanced Raman scattering & nanobiophysics. Within the context of metal deposition we will review the development of fountain pen nanochemistry and its most recent emulation Atomic Force Controlled Capillary Electrophoresis (ACCE). Using this latter development we will demonstrate achievement of unprecedented control of nanoparticle deposition using a three-electrode geometry. Three electrodes are attached: one on the outside of a metal coated glass probe, one on the inside of a hollow probe in a solution containing Au nanoparticles in the capillary, and a third on the surface where the writing takes place. The three electrodes provide electrical pulses for accurate control of deposition and retraction of the liquid from the surface overcoming the lack of control seen in both dip pen lithography & fountain pen nanochemistry when the tip contacts the surface. With this development, we demonstrate depositing a single 1.3 nm Au nanoparticle onto surfaces such as semiconductors.

  18. [Characterization of Acholeplasma Strains by Horizontal Polyacrylamide Flat Gel Electrophoresis (author's transl)].

    PubMed

    Boden, K; Kirchhoff, H

    1977-01-01

    Proteins extracted with phenol-acetic acid-water (2:1:0.5, w/v/v) from Acholeplasma laidlawii (PG 8), A. granularum (BTS-39), A. oculi (19L), A. modicum (PG 49), A. axanthum (S743) and the Acholeplasma strains C1 and C112 (which were isolated from aborted horse foetuses) were compared by electrophoresis in horizontal acidic polyacylamide flat gel using the electrophoresis equipment LKB Multiphor 2117. In this system the gels are not prepared in the electrophoresis chamber but between glas plates. For electrophoresis they are applied onto a special cooling plate. This makes it possible to produce a number of identical gels (from the same gel mixture and polymerized under the same conditions) what can be important for comparing investigations. The gels can be stored for more than 4 weeks in the refrigerator at +4 degrees C. Marked differences were observed between the electrophoretic patterns of each of the established species and the horse strains C1 and C112. The results are in agreement with those obtained in serological investigations in which the strains C1 and C112 were different from the established Acholeplasma species. PMID:848216

  19. 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; 100°C, 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.

  20. 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

  1. 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.

  2. Capillary electrophoresis electrospray ionization mass spectrometry interface

    SciTech Connect

    Smith, R.D.; Severs, J.C.

    1999-11-30

    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 analyte 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.

  3. Capillary electrophoresis electrospray ionization mass spectrometry interface

    DOEpatents

    Smith, Richard D.; Severs, Joanne C.

    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.

  4. Microfluidic Breadboard Approach to Capillary Electrophoresis.

    PubMed

    Koenka, Israel Joel; Sáiz, Jorge; Rempel, Paul; Hauser, Peter C

    2016-04-01

    A breadboard approach for electrophoretic separations with contactless conductivity detection is presented. This is based on miniature off-the-shelf components such as syringe pumps, valves, and pressure controllers which could be set up in a very compact overall arrangement. It has a high flexibility for different tasks at hand, and the common operations of hydrodynamic injection and capillary flushing are automated. For demonstration of the versatility of the proposition, several very diverse configurations and modes of electrophoresis were successfully implemented, namely, standard capillary zone electrophoresis, pressure assisted zone electrophoresis, the simultaneous separation of cations and anions by dual-capillary zone electrophoresis, the separation of cationic amino acids by isotachophoresis, as well as the separation of small carboxylic acids by gradient elution moving boundary electrophoresis. The system also allows fast separations, as demonstrated by the analysis of six inorganic cations within 35 s. The approach addresses respective limitations of either conventional capillary electrophoresis instruments as well as electrophoretic lab-on-chip devices, while maintaining a performance in terms of detection limits and reproducibility comparable to standard instrumentation. PMID:26926522

  5. Desmopressin Acetate in Intracranial Haemorrhage

    PubMed Central

    Kapapa, Thomas; Röhrer, Stefan; Struve, Sabine; Petscher, Matthias; König, Ralph; Wirtz, Christian Rainer; Woischneck, Dieter

    2014-01-01

    Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N = 4) or multiple (N = 6) doses of acetylsalicylic acid and 3 patients (control group) who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P ≤ 0.05. Results. (1) Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2) The platelet function worsened again after three hours. (3) There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients. PMID:25610644

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

    PubMed

    Chéry, Florence; Cabianca, Elena; Tatibouët, 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 ω-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. Proteins causing membrane fouling in membrane bioreactors.

    PubMed

    Miyoshi, Taro; Nagai, Yuhei; Aizawa, Tomoyasu; Kimura, Katsuki; Watanabe, Yoshimasa

    2015-01-01

    In this study, the details of proteins causing membrane fouling in membrane bioreactors (MBRs) treating real municipal wastewater were investigated. Two separate pilot-scale MBRs were continuously operated under significantly different operating conditions; one MBR was a submerged type whereas the other was a side-stream type. The submerged and side-stream MBRs were operated for 20 and 10 days, respectively. At the end of continuous operation, the foulants were extracted from the fouled membranes. The proteins contained in the extracted foulants were enriched by using the combination of crude concentration with an ultrafiltration membrane and trichloroacetic acid precipitation, and then separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). The N-terminal amino acid sequencing analysis of the proteins which formed intensive spots on the 2D-PAGE gels allowed us to partially identify one protein (OmpA family protein originated from genus Brevundimonas or Riemerella anatipestifer) from the foulant obtained from the submerged MBR, and two proteins (OprD and OprF originated from genus Pseudomonas) from that obtained from the side-stream MBR. Despite the significant difference in operating conditions of the two MBRs, all proteins identified in this study belong to β-barrel protein. These findings strongly suggest the importance of β-barrel proteins in developing membrane fouling in MBRs. PMID:26360742

  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. 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

  10. Acetate enhances the specific consumption rate of toluene under denitrifying conditions.

    PubMed

    Martínez-Hernández, Sergio; Olguín, Eugenia J; Gómez, Jorge; Cuervo-López, Flor de María

    2009-11-01

    Toluene is usually present in the environment as a contaminant along with other carbon sources which may influence its removal. In this work we studied the effect of a readily consumable carbon source such as acetate on toluene mineralization under denitrifying conditions. Continuous and batch cultures with stabilized denitrifying sludge were carried out. An upflow anaerobic sludge blanket reactor (UASB) was fed with several ratios of acetate-C/toluene-C loading rates (mg C/L-day: 100/0, 75/25, 50/50, and 0/100). Batch assays with different acetate-C/toluene-C ratios (10/70, 30/50, 50/30, and 65/20 mg C/L) were also done. As the acetate loading rate decreased in the culture, the carbon and nitrate consumption efficiency decreased by 40% and 34%, respectively. HCO(3) (-) and N(2) yields also decreased by 43%. Analysis of the denitrifying community using the denaturing gradient gel electrophoresis technique indicated that there was no clear relationship between its population profile and the metabolic pattern. In batch assays, when the acetate concentration was higher than that of toluene (65 mg acetate-C/L vs 20 mg toluene-C/L), the specific consumption rate of toluene (q(T)) was two times higher than in assays with 20 mg toluene-C/L as the sole electron source (0.006 mg C/mg volatile suspended solids-day). It is proposed that acetate can act by enhancing the growth of microbial populations and as a biochemical enhancer. The results show that acetate addition can be useful to improve the consumption rate of toluene in contaminated water. PMID:19387525

  11. 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

  12. 21 CFR 522.533 - Deslorelin acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Deslorelin acetate. (a) Specifications. Each implant contains 2.1 milligrams deslorelin acetate. (b) Sponsor.... One implant per mare. (ii) Indications for use. For inducing ovulation within 48 hours in...

  13. 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.

  14. 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.

  15. 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.

  16. Recent advances in affinity capillary electrophoresis for binding studies.

    PubMed

    Albishri, Hassan M; El Deeb, Sami; AlGarabli, Noura; AlAstal, Raghda; Alhazmi, Hassan A; Nachbar, Markus; El-Hady, Deia Abd; Wätzig, Hermann

    2014-01-01

    The present review covers recent advances and important applications of affinity capillary electrophoresis (ACE). It provides an overview about various ACE types, including ACE-MS, the multiple injection mode, the use of microchips and field-amplified sample injection-ACE. The most common scenarios of the studied affinity interactions are protein-drug, protein-metal ion, protein-protein, protein-DNA, protein-carbohydrate, carbohydrate-drug, peptide-peptide, DNA-drug and antigen-antibody. Approaches for the improvements of ACE in term of precision, rinsing protocols and sensitivity are discussed. The combined use of computer simulation programs to support data evaluation is presented. In conclusion, the performance of ACE is compared with other techniques such as equilibrium dialysis, parallel artificial membrane permeability assay, high-performance affinity chromatography as well as surface plasmon resonance, ultraviolet, circular dichroism, nuclear magnetic resonance, Fourier transform infrared, fluorescence, MS and isothermal titration calorimetry. PMID:25534793

  17. 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....

  18. Kinetics of the Methanogenic Fermentation of Acetate

    PubMed Central

    Fukuzaki, Satoshi; Nishio, Naomichi; Nagai, Shiro

    1990-01-01

    Inhibition of the fermentation of acetate to methane and carbon dioxide by acetate was analyzed with an acetate-acclimatized sludge and with Methanosarcina barkeri Fusaro under mesophilic conditions. A second-order substrate inhibition model, qch4 = qmS/[Ks + S + (S2/Ki)], where S was the concentration of undissociated acetic acid, not ionized acetic acid, could be applicable in both cases. The analysis resulted in substrate saturation constants, Ks, of 4.0 μM for the acclimatized sludge and 104 μM for M. barkeri. The threshold concentrations of undissociated acetic acid when no further acetate utilization was observed were 0.078 μM (pH 7.50) for the acclimatized sludge and 4.43 μM (pH 7.45) for M. barkeri. These kinetic results suggested that the concentration of undissociated acetic acid became a key factor governing the actual threshold acetate concentration for acetate utilization and that the acclimatized sludge in which Methanothrix spp. appeared dominant could utilize acetate better and survive at a lower concentration of undissociated acetic acid than could M. barkeri. Images PMID:16348323

  19. 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...

  20. 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...

  1. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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....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. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. Acet-oxy-γ-valerolactone.

    PubMed

    Tristram, Cameron; Gainsford, Graeme J; Hinkley, Simon

    2013-06-01

    Levulinyl cellulose esters have been produced as an effective renewable binder for architectural coatings. The title compound, C7H10O4 (systematic name: 2-methyl-5-oxo-tetra-hydro-furan-2-yl acetate), assigned as the esterifying species, was isolated and crystallized to confirm the structure. In the crystal, the mol-ecules pack in layers parallel to (102) utilizing weak C-H⋯O inter-actions. PMID:23795112

  16. All natural cellulose acetate-Lemongrass essential oil antimicrobial nanocapsules.

    PubMed

    Liakos, Ioannis L; D'autilia, Francesca; Garzoni, Alice; Bonferoni, Cristina; Scarpellini, Alice; Brunetti, Virgilio; Carzino, Riccardo; Bianchini, Paolo; Pompa, Pier Paolo; Athanassiou, Athanassia

    2016-08-30

    Nanocapsules and nanoparticles play an essential role in the delivery of pharmaceutical agents in modern era, since they can be delivered in specific tissues and cells. Natural polymers, such as cellulose acetate, are becoming very important due to their availability, biocompatibility, absence of toxicity and biodegradability. In parallel, essential oils are having continuous growth in biomedical applications due to the inherent active compounds that they contain. A characteristic example is lemongrass oil that has exceptional antimicrobial properties. In this work, nanocapsules of cellulose acetate with lemongrass oil were developed with the solvent/anti-solvent method with resulting diameter tailored between 95 and 185nm. Various physico-chemical and surface analysis techniques were employed to investigate the formation of the nanocapsules. These all-natural nanocapsules found to well bioadhere to mucous membranes and to have very good antimicrobial properties at little concentrations against Escherichia coli and Staphylococcus aureus. PMID:26827919

  17. 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.

  18. DNA electrophoresis in Pluronic F127

    NASA Astrophysics Data System (ADS)

    You, Seungyong; van Winkle, David

    2006-03-01

    Electrophoresis involves the separation of bio-molecules in a sieving medium by applying an electric field. DNA molecule fragments are separated in conventional gels and a several models have been successfully applied for understanding the separations. Recently, a pluronic gel was found to be an effective sieving medium for electrophoresis. However, the mobility of DNA in this gel cannot be described by the conventional theories. One reason is that Pluronic F127 is not a crosslinked gel, but a lattice of polymer micelles. The migration of single DNA molecules stained with various dye molecules was studied in slab gel electrophoresis by real-time fluorescence microscopy. Results for a variety of sizes will be presented.

  19. 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.

  20. Determination of dissociation constants of cytokinins by capillary zone electrophoresis.

    PubMed

    Barták, P; Bednár, P; Stránský, Z; Bocek, P; Vespalec, R

    2000-05-12

    A method for the pKa determination, based on mobility data measured by capillary zone electrophoresis, was applied to cytokinins and their analogs. The combination of charged mobility standards with an uncharged electroosmosis marker, injected in the uncoated capillary simultaneously with the measured substances, allows one to minimize the number of runs, reduce their duration and, in addition, to inform on the run-to-run stability of electroosmosis and on contingent side-effects. pKa values of investigated cytokinins and their analogs ranged from 2.8 to 4.0 at 25 degrees C in the phosphate and acetate buffers of ionic strength 0.015 M. Standard deviations of the constants, obtained by the non-linear fitting of equations for the pKa calculation, were 3-5-times lower than standard deviations from the linear fitting or from the point-to-point calculation utilizing the Hendersson-Haselbalch equation. The equation of Boltzman sigmoid offers two checks on reliability of effective mobilities that serve as the raw data in the pKa calculation. PMID:10866070

  1. 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.

  2. 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.

  3. 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.

  4. Synthesis of cellulose acetate and carboxymethylcellulose from sugarcane straw.

    PubMed

    Candido, R G; Gonçalves, A R

    2016-11-01

    Sugarcane straw (SCS) is a raw material with high potential for production of cellulose derivatives due to its morphology and structure. The proposal of this work was to synthesize cellulose acetate (CA) and carboxymethylcellulose (CMC) from sugarcane straw cellulose, and applied the CA in the preparation of a membrane. The cellulose extraction was carried out in four steps. Firstly, SCS was treated with H2SO4 (10% v/v) followed by NaOH (5% w/v) treatment. Subsequently, a chelating process was performed before ending the extraction process with chemical bleaching using H2O2 (5% v/v). The extracted cellulose was employed in the obtainment of CA and CMC. The CA presented a degree of substitution (DS) of 2.72. Its FTIR spectrum showed that practically all hydroxyl groups were replaced by acetate groups. The membrane synthesized from CA was dense and homogeneous. The presence of small particles on the top and bottom surfaces decreased the mechanical resistance of the membrane. The CMC presented a low DS (0.4) demonstrating the carboxymethylation reaction was not very effective due to the presence of lignin. These results proved that SCS can be utilized in the synthesis of CA and CMC. PMID:27516319

  5. 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.

  6. DNA ADDUCT RESEARCH WITH CAPILLARY ELECTROPHORESIS

    EPA Science Inventory

    DNA's central importance in all biological systems dictates a wide variety of DNA-related research. or much of this research, the utilization of capillary electrophoresis (CE) can be of significant advantage. pen-tube CE yields excellent separations of DNA components, which can b...

  7. 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…

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. [Advances in the progress of anti-bacterial biofilms properties of acetic acid].

    PubMed

    Gao, Xinxin; Jin, Zhenghua; Chen, Xinxin; Yu, Jia'ao

    2016-06-01

    Bacterial biofilms are considered to be the hindrance in the treatment of chronic wound, because of their tolerance toward antibiotics and other antimicrobial agents. They also have strong ability to escape from the host immune attack. Acetic acid, as a kind of organic weak acid, can disturb the biofilms by freely diffusing through the bacterial biofilms and bacterial cell membrane structure. Then the acid dissociates to release the hydrogen ions, leading to the disorder of the acid-base imbalance, change of protein conformation, and the degradation of the DNA within the membranes. This paper reviews the literature on the characteristics and treatment strategies of the bacterial biofilms and the acetic acid intervention on them, so as to demonstrate the roles acetic acid may play in the treatment of chronic wound, and thus provide a convincing treatment strategy for this kind of disease. PMID:27321493

  13. Study on Dicarboxylic Acids in Aerosol Samples with Capillary Electrophoresis

    PubMed Central

    Adler, Heidi; Sirén, Heli

    2014-01-01

    The research was performed to study the simultaneous detection of a homologous series of α, ω-dicarboxylic acids (C2–C10), oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, and sebacic acids, with capillary electrophoresis using indirect UV detection. Good separation efficiency in 2,6-pyridinedicarboxylic acid as background electrolyte modified with myristyl trimethyl ammonium bromide was obtained. The dicarboxylic acids were ionised and separated within five minutes. For the study, authentic samples were collected onto dry cellulose membrane filters of a cascade impactor (12 stages) from outdoor spring aerosols in an urban area. Hot water and ultrasonication extraction methods were used to isolate the acids from membrane filters. Due to the low concentrations of acids in the aerosols, the extracts were concentrated with solid-phase extraction (SPE) before determination. The enrichment of the carboxylic acids was between 86 and 134% with sample pretreatment followed by 100-time increase by preparation of the sample to 50 μL. Inaccuracy was optimised for all the sample processing steps. The aerosols contained dicarboxylic acids C2–C10. Then, mostly they contained C2, C5, and C10. Only one sample contained succinic acid. In the study, the concentrations of the acids in aerosols were lower than 10 ng/m3. PMID:24729915

  14. 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

  15. 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)

  16. 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.

  17. Two methods that facilitate autoradiography of small /sup 32/P-labeled DNA fragments following electrophoresis in agarose gels

    SciTech Connect

    Cockerill, P.N.

    1988-02-01

    Two methods which permit detection by autoradiography of small /sup 32/P-labeled DNA fragments resolved by agarose gel electrophoresis are described. Agarose gel electrophoresis poses problems for autoradiography as (i) the gels are normally too thick to allow autoradiography without being dried first, and (ii) fragments of DNA of 1000 bp or less in length are readily lost during drying. In this study DNA fragments as small as 121 bp have been retained in agarose gels upon drying. This has been achieved by either (i) first fixing the DNA with the cationic detergent cetyltrimethylammonium bromide, or (ii) drying the agarose gels onto Zeta-Probe charge-modified membranes.

  18. Degradation of basement membrane laminin by human neutrophil elastase and cathepsin G.

    PubMed Central

    Heck, L. W.; Blackburn, W. D.; Irwin, M. H.; Abrahamson, D. R.

    1990-01-01

    To determine the susceptibility of laminin to proteolytic degradation by inflammatory cells, soluble laminin was incubated with supernatants from phorbol 12-myristate 13-acetate (PMA)-stimulated human neutrophils. The appearance of laminin cleavage fragments was then detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Treatment of supernatants with diisopropylfluorophosphate (DFP), anti-human neutrophil elastase (HNE), and anti-human neutrophil cathepsin G (HNCG) IgGs effectively blocked the degradation of laminin. In contrast, treatment of supernatants with EDTA failed to inhibit laminin digestion, indicating that neutrophil metalloproteinases had little laminin-degrading activity. In additional experiments, laminin was incubated with purified HNE and HNCG. Both enzymes extensively cleaved laminin in a dose- and time-dependent manner yielding similar products, but HNE was generally more potent. Immunofluorescence microscopy of cryostat sections of mouse kidney treated with HNE or HNCG also showed widespread loss of laminin epitopes from basement membranes. The proteolytic degradation of laminin by neutrophil elastase and cathepsin G indicates an important role for these enzymes in basement membrane damage during inflammation. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:2356859

  19. Proteomic analysis of thylakoid membranes.

    PubMed

    Yadavalli, Venkateswarlu; Nellaepalli, Sreedhar; Subramanyam, Rajagopal

    2011-01-01

    Chlamydomonas is a model organism to study photosynthesis. Thylakoid membranes comprise several proteins belonging to photosystems I and II. In this chapter, we show the accurate proteomic measurements in thylakoid membranes. The chlorophyll-containing membrane protein complexes were precipitated using chloroform/methanol solution. These complexes were separated using two-dimensional gel electrophoresis, and the resolved spots were exercised from the gel matrix and digested with trypsin. These peptide fragments were separated by MALDI-TOF, and the isotopic masses were blasted to a MASCOT server to obtain the protein sequence. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF). The method discussed here would be a useful method for the separation and identification of thylakoid membrane proteins. PMID:20960129

  20. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrophoresis apparatus for clinical use....

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrophoresis apparatus for clinical use....

  2. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrophoresis apparatus for clinical use....

  3. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  4. 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...

  5. Understanding Palladium Acetate from a User Perspective.

    PubMed

    Carole, William A; Colacot, Thomas J

    2016-06-01

    The behavior of palladium acetate is reviewed with respect to its synthesis, characterization, structure (in both solution and solid state), and activation pathways. In addition, comparisons of catalytic activities between pure palladium acetate and two common byproducts, Pd3 (OAc)5 (NO2 ) and polymeric [Pd(OAc)2 ]n , typically present in commercially available material are reviewed. Hence, this minireview serves as a concise guide for the users of palladium acetate from both academia and industry. PMID:27125630

  6. 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...

  7. 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...

  8. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 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...

  9. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 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...

  10. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 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...

  11. Positron scattering from vinyl acetate

    NASA Astrophysics Data System (ADS)

    Chiari, L.; Zecca, A.; Blanco, F.; García, G.; Brunger, M. J.

    2014-09-01

    Using a Beer-Lambert attenuation approach, we report measured total cross sections (TCSs) for positron scattering from vinyl acetate (C4H6O2) in the incident positron energy range 0.15-50 eV. In addition, we also report an independent atom model with screening corrected additivity rule computation results for the TCSs, differential and integral elastic cross sections, the positronium formation cross section and inelastic integral cross sections. The energy range of these calculations is 1-1000 eV. While there is a reasonable qualitative correspondence between measurement and calculation for the TCSs, in terms of the energy dependence of those cross sections, the theory was found to be a factor of ˜2 larger in magnitude at the lower energies, even after the measured data were corrected for the forward angle scattering effect.

  12. Use of acetate for enrichment of electrochemically active microorganisms and their 16S rDNA analyses.

    PubMed

    Lee, Jiyoung; Phung, Nguyet Thu; Chang, In Seop; Kim, Byung Hong; Sung, Ha Chin

    2003-06-27

    A fuel cell-type electrochemical device has been used to enrich microbes oxidizing acetate with concomitant electricity generation without using an electron mediator from activated sludge. The device generated a stable current of around 5 mA with complete oxidation of 5 mM acetate at the hydraulic retention time of 2.5 h after 4 weeks of enrichment. Over 70% of electrons available from acetate oxidation was recovered as current. Carbon monoxide or hydrogen did not influence acetate oxidation or current generation from the microbial fuel cell (MFC). Denaturing gradient gel electrophoresis showed that DNA extracted from the acetate-enriched MFC had different 16S rDNA patterns from those of sludge or glucose+glutamate-enriched MFCs. Nearly complete 16S rDNA sequence analyses showed that diverse bacteria were enriched in the MFC fed with acetate. Electron microscopic observations showed biofilm developed on the electrode, but not microbial clumps observed in MFCs fed with complex fuel such as glucose and wastewater from a corn-processing factory. PMID:12829284

  13. 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

  14. 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.

  15. Electrophoresis for genotyping: microtiter array diagonal gel electrophoresis on horizontal polyacrylamide gels, hydrolink, or agarose.

    PubMed

    Day, I N; Humphries, S E

    1994-11-01

    Electrophoresis of DNA has been performed traditionally in either an agarose or acrylamide gel matrix. Considerable effort has been directed to improved quality agaroses capable of high resolution, but for small fragments, such as those from polymerase chain reaction (PCR) and post-PCR digests, acrylamide still offers the highest resolution. Although agarose gels can easily be prepared in an open-faced format to gain the conveniences of horizontal electrophoresis, acrylamide does not polymerize in the presence of air and the usual configurations for gel preparation lead to electrophoresis in the vertical dimension. We describe here a very simple device and method to prepare and manipulate horizontal polyacrylamide gels (H-PAGE). In addition, the open-faced horizontal arrangement enables loading of arrays of wells. Since many procedures are undertaken in standard 96-well microtiter plates, we have also designed a device which preserves the exact configuration of the 8 x 12 array and enables electrophoresis in tracks following a 71.6 degrees diagonal between wells (MADGE, microtiter array diagonal gel electrophoresis), using either acrylamide or agarose. This eliminates almost all of the staff time taken in setup, loading, and recordkeeping and offers high resolution for genotyping pattern recognition. The nature and size of the gels allow direct stacking of gels in one tank, so that a tank used typically to analyze 30-60 samples can readily be used to analyze 1000-2000 samples. The gels would also enable robotic loading. Electrophoresis allows analysis of size and charge, parameters inaccessible to liquid-phase methods: thus, genotyping size patterns, variable length repeats, and haplotypes is possible, as well as adaptability to typing of point variations using protocols which create a difference detectable by electrophoresis. PMID:7864363

  16. Mathematical Models of Continuous Flow Electrophoresis

    NASA Technical Reports Server (NTRS)

    Saville, D. A.; Snyder, R. S.

    1985-01-01

    Development of high resolution continuous flow electrophoresis devices ultimately requires comprehensive understanding of the ways various phenomena and processes facilitate or hinder separation. A comprehensive model of the actual three dimensional flow, temperature and electric fields was developed to provide guidance in the design of electrophoresis chambers for specific tasks and means of interpreting test data on a given chamber. Part of the process of model development includes experimental and theoretical studies of hydrodynamic stability. This is necessary to understand the origin of mixing flows observed with wide gap gravitational effects. To insure that the model accurately reflects the flow field and particle motion requires extensive experimental work. Another part of the investigation is concerned with the behavior of concentrated sample suspensions with regard to sample stream stability particle-particle interactions which might affect separation in an electric field, especially at high field strengths. Mathematical models will be developed and tested to establish the roles of the various interactions.

  17. 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

  18. 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.

  19. 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.

  20. Comparative proteomics and difference gel electrophoresis.

    PubMed

    Minden, Jonathan

    2007-12-01

    The goal of comparative proteomics is to analyze proteome changes in response to development, disease, or environment. This is a two-step process in which proteins within cellular extracts are first fractionated to reduce sample complexity, and then the proteins are identified by mass spectrometry. Two-dimensional electrophoresis (2DE) is the long-time standard for protein separation, but it has suffered from poor reproducibility and limited sensitivity. Difference gel electrophoresis (DIGE), in which two protein samples are separately labeled with different fluorescent dyes and then co-electrophoresed on the same 2DE gel, was developed to overcome the reproducibility and sensitivity limitations. In this essay, I discuss the principles of comparative proteomics and the development of DIGE. PMID:18251249

  1. Study of an alternate glyoxylate cycle for acetate assimilation by Rhodobacter sphaeroides.

    PubMed

    Alber, Birgit E; Spanheimer, Regina; Ebenau-Jehle, Christa; Fuchs, Georg

    2006-07-01

    Organisms, which grow on organic substrates that are metabolized via acetyl-CoA, are faced with the problem to form all cell constituents from this C(2)-unit. The problem was solved by the seminal work of Kornberg and is known as the glyoxylate cycle. However, many bacteria are known to not contain isocitrate lyase, the key enzyme of this pathway. This problem was addressed in acetate-grown Rhodobacter sphaeroides. An acetate-minus mutant identified by transposon mutagenesis was affected in the gene for beta-ketothiolase forming acetoacetyl-CoA from two molecules of acetyl-CoA. This enzyme activity was missing in this mutant, which grew on acetoacetate and on acetate plus glyoxylate. A second acetate/acetoacetate-minus mutant was affected in the gene for a putative mesaconyl-CoA hydratase, an enzyme which catalyses the hydration of mesaconyl-CoA to beta-methylmalyl-CoA. Beta-methylmalyl-CoA is further cleaved into glyoxylate and propionyl-CoA. These results as well as identification of acetate-upregulated proteins by two-dimensional gel electrophoresis lead to the proposal of a new pathway for acetate assimilation. In a first part, affected by the mutations, two molecules of acetyl-CoA and one molecule CO(2) are converted via acetoacetyl-CoA and mesaconyl-CoA to glyoxylate and propionyl-CoA. In a second part glyoxylate and propionyl-CoA are converted with another molecule of acetyl-CoA and CO(2) to l-malyl-CoA and succinyl-CoA. PMID:16856937

  2. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, Edward S.; Taylor, John 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.

  3. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, Edward S.; Taylor, John 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Method and apparatus for continuous electrophoresis

    DOEpatents

    Watson, Jack S.

    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.

  9. 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.

  10. 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 (0–100 μM) 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

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

    PubMed

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

    2015-05-01

    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 (0-100 μM) 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

  12. SOLID-PHASE ASSAY FOR THE PHOSPHORYLATION OF PROTEINS BLOTTED ON NITROCELLULOSE MEMBRANE FILTERS

    EPA Science Inventory

    A new procedure for the phosphorylation and assay of phosphoproteins is described. Proteins are solubilized from tissue samples, separated by polyacrylamide gel electrophoresis, transferred onto nitrocellulose membrane filters and the blotted polypeptides are phosphorylated with ...

  13. Membrane stabilizer

    DOEpatents

    Mingenbach, William A.

    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.

  14. Highly multiplexed DNA sequencing by capillary electrophoresis

    SciTech Connect

    Yeung, E.S.; Ueno, K.; Chang, H.T.

    1994-12-31

    It is obvious that irrespective of whichever basic technology is eventually selected to sequence the entire human genome there are substantial gains to be made if a high degree of multiplexing of parallel runs can be implemented. Such multiplexing should not involve expensive instrumentation and should not require additional personnel, or else the main objective of cost reduction will not be satisfied even though the total time for sequencing is reduced. In the last two years, several research groups have shown that capillary electrophoresis (CE) is an attractive alternative for DNA sequencing. Part of the improvement in sequencing speed in CE is counteracted by the inherent ability of slab gels for accommodating multiple lanes in a single run. Recently, the authors have developed several excitation schemes for highly multiplexed capillary electrophoresis. Detection at the pM level was demonstrated. The authors report here the use of a novel excitation geometry to simultaneously monitor 100 capillary tubes during electrophoresis. This represents a truly parallel multiplexing scheme for high-speed DNA sequencing.

  15. 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 and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts...

  16. 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 and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts...

  17. 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 and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts...

  18. 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... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts...

  19. 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.

  20. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which are... 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...

  1. Electrophoresis: The Basics (by D. M. Hawcroft)

    NASA Astrophysics Data System (ADS)

    Voige, William H.

    1999-01-01

    D. M. Hawcroft. Oxford University Press: Oxford, 1997. 142 + xii pp. Index. ISBN 0-19-963563-3. $100.00. This concise monograph is one of a series on techniques in widespread use in biochemistry and cell and molecular biology. It seeks to present, in compact and readable form, the fundamentals of electrophoresis and does so very well. Both theory and practice are included, but emphasis is on the latter. Although the preface makes it clear that this book is intended for biologists, it also deserves a place in a truly complete chemistry library. The book is logically organized. Each of the nine chapters corresponds to either a step in an electrophoresis experiment (e.g., Chapter 7: Visualization of Separated Materials) or a major application (Chapter 4: The Electrophoresis of Native and Denatured Proteins). It is written as though the reader is getting ready to begin doing electrophoresis for the first time and needs a survey of the technique and its applications. A question that occurred to me repeatedly as I read through the book is: Exactly how did the author intend it to be used? One can view the book as either a text or a laboratory manual. As a resource that might be used as a supplementary text in a graduate or upper-division undergraduate course, it does an admirable job of presenting a thorough overview of modern electrophoresis. The figures and diagrams are exceptionally clear and present useful comparisons of results that can be obtained under a variety of conditions (e.g., the resolution of DNA fragments obtained with otherwise identical wedge and normal gels). Not all its explanations, however, are as cogent. It defines how the two portions of a discontinuous gel differ but fails to explain clearly how the porosity and pH differences result in the stacking effect, which is such a gel's primary advantage. Having it on hand as a laboratory manual would be much like having colleagues who are experts in all phases of electrophoresis to consult or to go to

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

    DOEpatents

    Zhang, Jian-Shi; Giometti, Carol S.; Tollaksen, Sandra L.

    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.

  3. Elucidating acetate tolerance in E. coli using a genome-wide approach.

    PubMed

    Sandoval, Nicholas R; Mills, Tirzah Y; Zhang, Min; Gill, Ryan T

    2011-03-01

    Engineering organisms for improved performance using lignocellulose feedstocks is an important step towards a sustainable fuel and chemical industry. Cellulosic feedstocks contain carbon and energy in the form of cellulosic and hemicellulosic sugars that are not metabolized by most industrial microorganisms. Pretreatment processes that hydrolyze these polysaccharides often also result in the accumulation of growth inhibitory compounds, such as acetate and furfural among others. Here, we have applied a recently reported strategy for engineering tolerance towards the goal of increasing Escherichia coli growth in the presence of elevated acetate concentrations (Lynch et al., 2007). We performed growth selections upon an E. coli genome library developed using a moderate selection pressure to identify genomic regions implicated in acetate toxicity and tolerance. These studies identified a range of high-fitness genes that are normally involved in membrane and extracellular processes, are key regulated steps in pathways, and are involved in pathways that yield specific amino acids and nucleotides. Supplementation of the products and metabolically related metabolites of these pathways significantly increased growth rate (a 130% increase in specific growth) at inhibitory acetate concentrations. Our results suggest that acetate tolerance will not involve engineering of a single pathway; rather we observe a range of potential mechanisms for overcoming acetate based inhibition. PMID:21163359

  4. Identification of hemoglobin AC heterozygote status in a Malay family: a decision between hemoglobin electrophoresis and high performance liquid chromotography.

    PubMed

    Rosline, H; Roshan, T M; Ahmed, S A; Ilunihayati, I

    2007-05-01

    Thalassemia is a common public health problem among Malays. Hemoglobin C (Hb C) is a hemoglobin beta variant resulting from a single base mutation at the 6th position of the beta-globin gene leading to the substitution of glycine for glutamic acid. Hb C is commonly detected in West Africans and in African American but has not been reported in Malaysia. It can be falsely diagnosed as HbE trait in the Malaysian Thalassemia Screening Program which utilizes cellulose acetate hemoglobin electrophoresis. This is the first reported case of Hb AC heterozygote status in a Malay family, with unusual splenomegaly in one of the family members. PMID:17877232

  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. 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

  7. 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.

  8. Two-dimensional polyacylamide gel electrophoresis of envelope proteins of Escherichia coli.

    PubMed

    Johnson, W C; Silhavy, T J; Boos, W

    1975-03-01

    A method of separating envelope proteins by two-dimensional polyacrylamide gel electrophoresis is described. Escherichia coli envelopes (inner and outer membranes) were prepared by French pressing and washed by repeated centrifugation. Membrane proteins were solubilized with guanidine thiocyanate and were dialyzed against urea prior to two-dimensional electrophoretic analysis. The slab gel apparatus and conditions were similar to the technique developed by Metz and Bogorad (1974) for the separation of ribosomal proteins. This separation occurs in 8 M urea for the first dimension and in 0.2% sodium dodecyl sulfate for the second dimension. The technique separates about 70 different membrane proteins in a highly reproducible fashion according to both intrinsic charge and molecular weight. Some examples of alterations in the membrane protein pattern are demonstrated. These alterations are caused by a mutation affecting a sugar transport system and by growth in the presence of D-fucose, inducer of the transport system. A further example of membrane protein changes introduced by growth at the nonpermissive temperature of a temperature-sensitive cell division mutant is shown. Finally, it is demonstrated that the major outer membrane component of Escherichia coli K-12 contains more than four proteins of similar molecular weight. PMID:803821

  9. 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.

  10. Serum protein electrophoresis in spontaneous canine hyperadrenocorticalism.

    PubMed

    van den Broek, A H; Lida, J

    1989-01-01

    The serum protein concentrations of dogs with confirmed spontaneous hyperadrenocorticalism were determined by agarose gel electrophoresis before and during treatment with mitotane. In untreated animals a significant increase was detected in the mean concentration of total protein and the mean concentration and percentage of alpha-2 globulin. The mean concentration and percentage of albumin and gamma-globulin were significantly decreased. In animals on treatment the mean concentration of total proteins and the mean concentration and percentage of beta-2 globulin were significantly reduced. PMID:2466309

  11. Pulsed field gel electrophoresis for dairy propionibacteria.

    PubMed

    Chuat, Victoria; de Freitas, Rosangela; Dalmasso, Marion

    2015-01-01

    Pulsed field gel electrophoresis (PFGE) is a technique using alternating electric fields to migrate high molecular weight DNA fragments with a high resolution. This method consists of the digestion of bacterial chromosomal DNA with rare-cutting restriction enzymes and in applying an alternating electrical current between spatially distinct pairs of electrodes. DNA molecules migrate at different speeds according to the size of the fragments. Among other things, this technique is considered as the "gold standard" for genotyping, genetic fingerprinting, epidemiological studies, genome size estimation, and studying radiation-induced DNA damage and repair. This chapter describes a PFGE method that can be used to differentiate dairy propionibacteria. PMID:25862063

  12. 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.

  13. Microfabricated capillary array electrophoresis device and method

    DOEpatents

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

    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.

  14. Cytokine Analysis by Immunoaffinity Capillary Electrophoresis

    PubMed Central

    Mendonca, Mark; Kalish, Heather

    2014-01-01

    Immunoaffinity capillary electrophoresis (ICE) is a powerful tool used to detect and quantify target proteins of interest in complex biological fluids. The target analyte is captured and bound to antibodies immobilized onto the wall of a capillary, labeled in situ with a fluorescent dye, eluted and detected online using laser-induced fluorescence following electrophoretic separation. Here, we illustrate how to construct an immunoaffinity capillary and utilize it to run ICE in order to capture and quantify target cytokines and chemokines from a clinical sample. PMID:22976107

  15. Hybrid slab-microchannel gel electrophoresis system

    DOEpatents

    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.

  16. Analysis of Stevia glycosides by capillary electrophoresis.

    PubMed

    Mauri, P; Catalano, G; Gardana, C; Pietta, P

    1996-02-01

    The determination of diterpene glycosides from Stevia rebaudiana leaves using capillary electrophoresis is described. Analyses were performed on fused silica capillaries with 20 mM sodium tetraborate buffer, pH 8.3, and 30 mM sodium dodecyl sulfate. The effect of the organic solvent injected with the sample solution on the electrophoretic solution has been confirmed, and an absolute amount of 1.6 nL per injected sample was optimal. Rebaudioside A and steviolbioside were isolated by semipreparative high performance liquid chromatography (HPLC), and their structure was assessed by mass spectrometry. PMID:8900944

  17. The pharmacology of nomegestrol acetate.

    PubMed

    Ruan, Xiangyan; Seeger, Harald; Mueck, Alfred O

    2012-04-01

    Nomegestrol acetate (NOMAC) is a 19-norprogesterone derivative with high biological activity at the progesterone receptor, a weak anti-androgenic effect, but with no binding to estrogen, glucocorticoid or mineralocorticoid receptors. At dosages of 1.5mg/day or more, NOMAC effectively suppresses gonadotropic activity and ovulation in women of reproductive age. Hemostasis, lipids and carbohydrate metabolism remain largely unchanged. In normal and cancerous human breast cells, NOMAC has shown favorable effects on estrogen metabolism. Like natural progesterone (but in contrast to some other synthetic progestogens), it does not appear stimulate the proliferation of cancerous breast cells. While there has been some experience of the use of NOMAC in combination with estrogens as a hormone replacement therapy, most of the data on the compound are reported in the context of its inclusion as a component of a new contraceptive pill comprising 2.5mg NOMAC combined with 1.5mg estradiol. Because of its strong endometrial efficacy, and due to its high antigonadotropic activity and long elimination half-life (about 50h), the contraceptive efficacy of the new pill is maintained even when dosages are missed. Furthermore, for the first time with a monophasic 24/4 regimen containing estradiol, cyclical stability can be achieved comparable with that obtained using pills containing ethinyl estradiol and progestogens like levonorgestrel or drospirenone. The addition of NOMAC to estradiol means that the beneficial effects of estrogen are not lost, which is of especial importance in relation to the cardiovascular system. On the basis both of its pharmacology and of studies performed during the development of the NOMAC/estradiol pill, involving some 4000 women in total, good long-term tolerability can be expected for NOMAC, although its safety profile is still to be fully ascertained, as the clinical endpoint studies are yet to be completed. PMID:22364709

  18. Conversion to eslicarbazepine acetate monotherapy

    PubMed Central

    French, Jacqueline; Jacobson, Mercedes P.; Pazdera, Ladislav; Gough, Mallory; Cheng, Hailong; Grinnell, Todd; Blum, David

    2016-01-01

    Objective: To assess the efficacy and safety of eslicarbazepine acetate (ESL) monotherapy. Methods: This post hoc pooled analysis of 2 randomized double-blind studies (093-045 and -046) included adults with partial-onset seizures medically uncontrolled by 1 or 2 antiepileptic drugs (AEDs). Following the baseline period (8 weeks), eligible patients were randomized 2:1 to receive ESL 1,600 mg or 1,200 mg once daily for 18 weeks; the primary endpoint was study exit by meeting predefined exit criteria (signifying worsening seizure control). In each study, treatment was considered effective if the upper 95% confidence limit for exit rate was lower than the historical control threshold (65.3%). Results: Pooled exit rates were as follows: ESL 1,600 mg = 20.6% (95% confidence interval: 15.6%–26.8%); ESL 1,200 mg = 30.8% (23.0%–40.5%). Use of 2 baseline AEDs or rescue medication, US location, epilepsy duration ≥20 years, and higher maximum baseline seizure frequency were associated with higher exit risks. Median percent reductions in standardized seizure frequency between baseline and the 18-week double-blind period were as follows: ESL 1,600 mg = 43.2%; ESL 1,200 mg = 35.7%; baseline carbamazepine use was associated with smaller reductions. Safety profiles were similar between ESL doses. Conclusions: Exit rates for ESL monotherapy (1,600 mg and 1,200 mg once daily) were lower than the historical control threshold, irrespective of baseline AED use and region, with no additional safety concerns identified. Clinical factors and location clearly influence treatment responses in conversion-to-monotherapy trials. Classification of evidence: This pooled analysis provides Class IV evidence that for adults with medically uncontrolled partial-onset seizures, ESL monotherapy is well tolerated and effective. PMID:26911639

  19. Detection of Connexins in Liver Cells Using Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis and Immunoblot Analysis.

    PubMed

    Willebrords, Joost; Maes, Michaël; Yanguas, Sara Crespo; Cogliati, Bruno; Vinken, Mathieu

    2016-01-01

    Since connexin expression is partly regulated at the protein level, immunoblot analysis represents a frequently addressed technique in the connexin research field. The present chapter describes the setup of an immunoblot procedure, including protein extraction and quantification from biological samples, gel electrophoresis, protein transfer, and immunoblotting, which is optimized for analysis of connexins in liver tissue. In essence, proteins are separated on a polyacrylamide gel using sodium dodecyl sulfate followed by transfer of proteins on a nitrocellulose membrane. The latter allows specific detection of connexins with antibodies combined with revelation through enhanced chemiluminescence. PMID:27207285

  20. Detection of connexins in liver cells using sodiumdodecylsulfate polyacrylamide gel electrophoresis and immunoblot analysis

    PubMed Central

    Willebrords, Joost; Maes, Michaël; Yanguas, Sara Crespo; Cogliati, Bruno; Vinken, Mathieu

    2016-01-01

    Summary Since connexin expression is partly regulated at the protein level, immunoblot analysis represents a frequently addressed technique in the connexin research field. The present chapter describes the set-up of an immunoblot procedure, including protein extraction and quantification from biological samples, gel electrophoresis, protein transfer and immunoblotting, which is optimized for analysis of connexins in liver tissue. In essence, proteins are separated on a polyacrylamide gel using sodiumdodecylsulfate followed by transfer of proteins on a nitrocellulose membrane. The latter allows specific detection of connexins with antibodies combined with revelation through enhanced chemiluminescence. PMID:27207285

  1. 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.

  2. Capillary electrophoresis of DNA for molecular diagnostics.

    PubMed

    Righetti, P G; Gelfi, C

    1997-09-01

    A number of applications of capillary zone electrophoresis (CZE) in sieving liquid polymers (notably linear polyacrylamides and cellulose) for the analysis of polymerase chain reaction (PCR) products of clinically relevant, diagnostic DNA, are reviewed. The fields covered are: human genetics, quantitative gene dosage, microbiology and virology, forensic medicine and therapeutic DNA (notably, antisense nucleotides). Some unique, novel developments are highlighted, such as: (i) nonisocratic CZE, i.e., temperature-programmed CZE for detection of DNA point mutations; (ii) the synthesis of novel N-substituted acrylamides, offering extreme resistance to alkaline hydrolysis coupled to high hydrophilicity. In the field of denaturing gradient gel electrophoresis (DGGE), as routinely performed in gel slabs, a novel methodology is described in CZE: double-gradient DGGE. In this technique, two gradients are simultaneously applied along the migration direction: a chemical (or thermal) denaturing gradient, for partially unwinding homo- and hetero-duplexes of DNA, and a porosity gradient, for recompacting diffuse bands melting over a broader range of denaturing conditions. It is thus demonstrated that chemical gradients, in addition to temperature gradients, can be easily implemented even in a capillary format. PMID:9372261

  3. 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

  4. Capillary zone electrophoresis of large DNA.

    PubMed

    Guszczynski, T; Pulyaeva, H; Tietz, D; Garner, M M; Chrambach, A

    1993-01-01

    Capillary zone electrophoresis (CZE) of DNA 23.1 to 48.5 kb in length in polyacrylamide solutions of several concentrations provides evidence for polymer concentration and DNA length-dependent stretching and orientation of these species and suggests an effective separation at a polymer concentration of about 0.6%. Applying a 0.1% polyacrylamide concentration to the lambda-phage DNA ladder, at least 5 components are separated; separation improves with lowering of the field strength to 2 V/cm and, correspondingly, extended duration of CZE. Saccharomyces pombe chromosomal DNA separates into 3 major components on CZE at high field strength (270 V/cm) in 0.9% polyacrylamide solution, confirming a previous finding made on electrophoresis in a 1.1 mm ID tube at low field strength. However, the finding is limited to one source of the DNA plug, and the chromosomal identity of the components remains unknown. Methodological problems in the CZE of large DNA relate to the need for extended duration of pressure injection if absorbance detection is applied, the need to define the starting zone after extended pressure injection, the need to melt and digest agarose plugs prior to loading, and related needs for thermostating of the sample chamber and for software compatible with low voltage operation. PMID:8354238

  5. Determination of surfactants by capillary electrophoresis.

    PubMed

    Heinig, K; Vogt, C

    1999-10-01

    Capillary electrophoresis has been increasingly used during the past few years for the separation and determination of surfactants. These substances are applied in many household and industrial products such as laundry detergents, cosmetics and pharmaceuticals, often as homologous and isomeric mixtures. Product development and control as well as toxicological and environmental analyses require selective and sensitive analytical methods. This review presents capillary electrophoretic techniques to determine important representatives of cationic, anionic, and neutral surfactants. The application of different buffer additives such as organic solvents, cyclodextrins or micelles to enhance the resolution of complex mixtures is discussed. Besides direct and indirect UV and fluorescence detection, examples for conductivity and mass spectrometric detection are also given. Derivatization procedures to improve the detectability and implement charge in neutral analytes are described. The successful use of capillary electrophoresis for surfactant determinations has proven that it can serve as a routine technique in many real-world applications. Robust, validated methods for the quantitation of single compounds, such as alkylbenzene sulfonates, sodium dodecyl sulfate and benzalkonium salts, are now available. Characteristic peak patterns (fingerprint analysis) can be used for the identification of surfactants in multicomponent formulations (e.g. ethoxylates and phosphonates). PMID:10596832

  6. 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

  7. Using capillary electrophoresis to characterize polymeric particles.

    PubMed

    Riley, Kathryn R; Liu, Sophia; Yu, Guo; Libby, Kara; Cubicciotti, Roger; Colyer, Christa L

    2016-09-01

    Capillary electrophoresis (CE) was used for the characterization of a variety of polymeric micron and sub-micron particles based on size, surface functionality, and binding properties. First, a robust capillary zone electrophoresis (CZE) method was developed for the baseline separation and quantitation of commercially available polystyrene particles with various surface modifications (including amino, carboxylate, and sulfate functional groups) and various sizes (0.2, 0.5, 1.0, and 3.0μm). The separation of DNA-templated polyacrylamide particles from untemplated particles (as used for the Ion Torrent Personal Genome Machine) was demonstrated. Finally, using the 29-base thrombin aptamer and thrombin protein as a model system, a study was undertaken to determine dissociation constants for the aptamer and protein in free solution and when the aptamer was conjugated to a particle, with the goal of better understanding how the use of solid substrates, like particles, affects selection and binding processes. Dissociation constants were determined and were found to be approximately 5-fold higher for the aptamer conjugated to a particle relative to that in free solution. PMID:27543386

  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-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

  9. 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.

  10. Clostridium thermosaccharolyticum strain deficient in acetate production

    SciTech Connect

    Rothstein, D.M.

    1986-01-01

    A mutant of Clostridium thermosaccharolyticum that is blocked in acetate production was isolated after treatment with nitrosoguanidine and selection for fluoroacetate resistance. The mutant produced more ethanol than the parent strain did.

  11. Acetate Causes Alcohol Hangover Headache in Rats

    PubMed Central

    Maxwell, Christina R.; Spangenberg, Rebecca Jay; Hoek, Jan B.; Silberstein, Stephen D.; Oshinsky, Michael L.

    2010-01-01

    Background The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache. Methods We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats. Results Ethanol initially decreased sensitivity to mechanical stimuli on the face (analgesia), followed 4 to 6 hours later by inflammatory pain. Inhibiting alcohol dehydrogenase extended the analgesia whereas inhibiting aldehyde dehydrogenase decreased analgesia. Neither treatment had nociceptive effects. Direct administration of acetate increased nociceptive behaviors suggesting that acetate, not acetaldehyde, accumulation results in hangover-like hypersensitivity in our model. Since adenosine accumulation is a result of acetate formation, we administered an adenosine antagonist that blocked hypersensitivity. Discussion Our study shows that acetate contributes to hangover headache. These findings provide insight into the mechanism of hangover headache and the mechanism of headache induction. PMID:21209842

  12. Mafenide acetate allergy presenting as recurrent chondritis.

    PubMed

    Pickus, Evan J; Lionelli, Gerald T; Charles, E Woodall; Korentager, Richard A

    2002-02-01

    Acute chondritis has a strong predilection for recurrence. Mafenide acetate has been implicated in causing reactions that mimic this condition; however, these hypersensitivity reactions lack fever, fluctuance, and pain. The authors report a case of mafenide acetate allergy presenting as recurrent chondritis in a patient who had previously been treated successfully for this condition. In this patient, the allergic response resolved within 3 days after cessation of mafenide acetate. If unappreciated, it may have led to unnecessary operative intervention. Therefore, auricular edema and erythema, without fever, fluctuance, and pain, must be recognized by surgeons as a possible mafenide acetate allergy and must be considered in the differential diagnosis for patients who present with recurrent acute suppurative chondritis. PMID:11910229

  13. Cultivation of MDCK epithelial cells on chitosan membranes.

    PubMed

    Popowicz, P; Kurzyca, J; Dolińska, B; Popowicz, J

    1985-01-01

    Deacetylated chitin upon evaporation from aqueous acetic acid solutions forms a thin, permeable and transparent porous membrane which can be successfully used as support of cell culture. An established MDCK cell line grown as monolayer on both chitosan membrane and millipore filter generates comparable bioelectrical properties when studied in a typical transporting chamber. PMID:4084278

  14. Nomegestrol acetate/estradiol: in oral contraception.

    PubMed

    Yang, Lily P H; Plosker, Greg L

    2012-10-01

    Nomegestrol acetate/estradiol is a combined oral contraceptive with approval in many countries. This fixed-dose combination tablet contains nomegestrol acetate, a highly selective progestogen, and estradiol, a natural estrogen. It is the first monophasic combined oral contraceptive to contain estradiol, and is taken in 28-day cycles, consisting of 24 active therapy days with 4 placebo days (i.e. 24/4-day cycles). In two large, 1-year, randomized, open-label, multicentre, phase III trials in healthy adult women (aged 18-50 years), nomegestrol acetate/estradiol was at least as effective as drospirenone/ethinylestradiol as contraceptive therapy, as the pregnancy rates in women aged 18-35 years (primary efficacy population) in terms of the Pearl Index (primary endpoint) were numerically lower with nomegestrol acetate/estradiol, although the between-group difference was not statistically significant. In both trials, nomegestrol acetate/estradiol was given in a 24/4-day cycle, and drospirenone/ethinylestradiol was given in a 21/7-day cycle. The criteria for using condoms in case of forgotten doses were less stringent in the nomegestrol acetate/estradiol group than in the drospirenone/ethinylestradiol group. Nomegestrol acetate/estradiol therapy for up to 1 year was generally well tolerated in healthy adult women, with an acceptable tolerability profile in line with that expected for a combined oral contraceptive. The most commonly reported adverse events were acne and abnormal withdrawal bleeding (most often shorter, lighter or absent periods). Overall, compared with drospirenone/ethinylestradiol, nomegestrol acetate/estradiol appeared to be associated with less favourable acne-related outcomes, and shorter, lighter or absent periods. PMID:22950535

  15. Methanogenesis from acetate: a nonmethanogenic bacterium from an anaerobic acetate enrichment.

    PubMed

    Ward, D M; Mah, R A; Kaplan, I R

    1978-06-01

    A methanogenic acetate enrichment was initiated by inoculation of an acetate-mineral salts medium with domestic anaerobic digestor sludge and maintained by weekly transfer for 2 years. The enrichment culture contained a Methanosarcina and several obligately anaerobic nonmethanogenic bacteria. These latter organisms formed varying degrees of association with the Methanosarcina, ranging from the nutritionally fastidious gram-negative rod called the satellite bacterium to the nutritionally nonfastidious Eubacterium limosum. The satellite bacterium had growth requirements for amino acids, a peptide, a purine base, vitamin B12, and other B vitamins. Glucose, mannitol, starch, pyruvate, cysteine, lysine, leucine, isoleucine, arginine, and asparagine stimulated growth and hydrogen production. Acetate was neither incorporated nor metabolized by the satellite organism. Since acetate was the sole organic carbon source in the enrichment culture, organism(s) which metabolize acetate (such as the Methanosarcina) must produce substrates and growth factors for associated organisms which do not metabolize acetate. PMID:677881

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

    PubMed

    Lanaro, Rafael; Costa, José 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

  17. Toxic Membrane Fractions from Mycoplasma fermentans1

    PubMed Central

    Gabridge, Michael G.; Murphy, William H.

    1971-01-01

    A recent isolate of Mycoplasma fermentans (strain K10, from human leukemic bone marrow) induced a lethal toxicity syndrome in mice. High doses of both viable and inactivated cells were toxic when injected intraperitoneally. Whole lysates and membranes from osmotically shocked cells killed mice, but cytoplasm did not. When membranes were dissolved in detergents and reaggregated by dialysis in the presence of Mg2+, the lipid-protein complex thus formed was toxic. Lipids extracted from membranes with chloroform-methanol did not kill mice. Protein-rich fractions (obtained by reaggregation plus acetone washes or ammonium sulfate precipitation of dissolved membranes) were also not toxic. No qualitative differences in proteins from three toxic isolates and three nontoxic laboratory strains of M. fermentans were detectable by polyacrylamide gel electrophoresis. The toxic factor contained in reaggregated membranes was heat-stable but sensitive to Pronase, trypsin, and lipase. Images PMID:5154902

  18. 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. PMID:25044390

  19. Membrane characteristics for biological blast overpressure testing using blast simulators.

    PubMed

    Alphonse, Vanessa D; Siva Sai Sujith Sajja, Venkata; Kemper, Andrew R; Rizel, Dave V; Duma, Stefan M; VandeVord, Pamela J

    2014-01-01

    Blast simulators often use passive-rupture membranes to generate shock waves similar to free-field blasts. The purpose of this study was to compare rupture patterns and pressure traces of three distinct membrane materials for biological and biomechanical blast studies. An Advanced Blast Simulator (ABS) located at the Center for Injury Biomechanics at Virginia Tech was used to test membrane characteristics. Acetate, Mylar, and aluminum sheets with different thicknesses were used to obtain pressures between 70–210 kPa. Static pressure was measured inside the tube at the test section using piezoelectric pressure sensors. Peak overpressure, positive duration, and positive impulse were calculated for each test. Rupture patterns and characteristic pressure traces were unique to each membrane type and thickness. Shock wave speed ranged between 1.2-1.8 Mach for static overpressures of 70–210 kPa. Acetate membranes fragmented sending pieces down the tube, but produced ideal (Friedlander) pressure traces. Mylar membranes bulged without fragmenting, but produced less-than-ideal pressure traces. Aluminum membranes did not fragment and produced ideal pressure traces. However, the cost of manufacturing and characterizing aluminum membranes should be considered during membrane selection. This study illustrates the advantages and disadvantages of using Mylar, acetate, and aluminum for passive rupture membranes for blast simulators. PMID:25405432

  20. 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

  1. 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

  2. Use of metal complexation in non-aqueous capillary electrophoresis systems for the separation and improved detection of tetracyclines.

    PubMed

    Tjørnelund, J; Hansen, S H

    1997-08-29

    Metal complexation in non-aqueous capillary electrophoresis systems was evaluated for the separation and improved detection of tetracycline antibiotics using laser-induced fluorescence detection. It was found that three factors were important for the choice of complexing agent: (i) it should be soluble in the organic solvent used for the separation, (ii) it should have a sufficient fast complexing rate so as not to invalidate the electrophoretic separation and, (iii) it should give a large increase in the fluorescence intensity. Mg2+ ions were found to be the most suitable ions for the separation of the tetracyclines as the acetate salt of magnesium is very soluble in organic solvents and only a relatively low current was generated during electrophoresis making it possible to use high concentrations of the complexing metal ion. Metal complexation strongly intensified the fluorescence of tetracyclines and all organic solvents investigated further intensified the fluorescence, e.g. dimethylformamide improved the fluorescence of the oxytetracycline metal complex by a factor of 34 compared to water. However, magnesium acetate was not sufficiently soluble in dimethylformamide and therefore N-methylformamide, improving the fluorescence intensity by only a factor of 9, was used. It was demonstrated that the method can be used for the detection of tetracyclines at the ppb level in milk and plasma. PMID:9335125

  3. Membrane tension and membrane fusion.

    PubMed

    Kozlov, Michael M; Chernomordik, Leonid V

    2015-08-01

    Diverse cell biological processes that involve shaping and remodeling of cell membranes are regulated by membrane lateral tension. Here we focus on the role of tension in driving membrane fusion. We discuss the physics of membrane tension, forces that can generate the tension in plasma membrane of a cell, and the hypothesis that tension powers expansion of membrane fusion pores in late stages of cell-to-cell and exocytotic fusion. We propose that fusion pore expansion can require unusually large membrane tensions or, alternatively, low line tensions of the pore resulting from accumulation in the pore rim of membrane-bending proteins. Increase of the inter-membrane distance facilitates the reaction. PMID:26282924

  4. Automated DNA electrophoresis, hybridization and detection

    SciTech Connect

    Zapolski, E.J.; Gersten, D.M.; Golab, T.J.; Ledley, R.S.

    1986-05-01

    A fully automated, computer controlled system for nucleic acid hybridization analysis has been devised and constructed. In practice, DNA is digested with restriction endonuclease enzyme(s) and loaded into the system by pipette; /sup 32/P-labelled nucleic acid probe(s) is loaded into the nine hybridization chambers. Instructions for all the steps in the automated process are specified by answering questions that appear on the computer screen at the start of the experiment. Subsequent steps are performed automatically. The system performs horizontal electrophoresis in agarose gel, fixed the fragments to a solid phase matrix, denatures, neutralizes, prehybridizes, hybridizes, washes, dries and detects the radioactivity according to the specifications given by the operator. The results, printed out at the end, give the positions on the matrix to which radioactivity remains hybridized following stringent washing.

  5. 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.

  6. 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.

  7. Combined electrophoresis-electrospray interface and method

    DOEpatents

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

    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. 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.

  9. Hybrid slab-microchannel gel electrophoresis system

    DOEpatents

    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.

  10. Applications of capillary electrophoresis in biotechnology.

    PubMed

    Lagu, A L

    1999-10-01

    Capillary electrophoresis (CE)-related techniques are increasingly being used as a matter of routine practice in the biotechnology discipline. Since recombinant DNA-derived proteins and the antisense oligonucleotides constitute a large portion of the applications of these techniques, they have been emphasized in this review. Analyses by CE of Escherichia coli-derived proteins and glycosylated proteins derived from mammalian cell cultures are summarized, as well as those of the carbohydrate chains that have been enzymatically removed from the protein. Applications of CE in the analysis of the antisense oligonucleotides for the determination of purity and the analytical studies on the metabolism of these modified oligonucleotides, by CE are reviewed. The literature mainly covers the period from 1996. PMID:10596822

  11. 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.

  12. Precise, fast, and flexible determination of protein interactions by affinity capillary electrophoresis: part 3: anions.

    PubMed

    Xu, Yuanhong; Redweik, Sabine; El-Hady, Deia Abd; Albishri, Hassan M; Preu, Lutz; Wätzig, Hermann

    2014-08-01

    The binding of physiologically anionic species or negatively charged drug molecules to proteins is of great importance in biochemistry and medicine. Since affinity capillary electrophoresis (ACE) has already proven to be a suitable analytical tool to study the influence of ions on proteins, this technique was applied here for comprehensively studying the influence of various anions on proteins of BSA, β-lactoglobulin, ovalbumin, myoglobin, and lysozyme. The analysis was performed using different selected anions of succinate, glutamate, phosphate, acetate, nitrate, iodide, thiocyanate, and pharmaceuticals (salicylic acid, aspirin, and ibuprofen) that exist in the anionic form at physiological pH 7.4. Due to the excellent repeatability and precision of the ACE measurements, not necessarily strong but significant influences of the anions on the proteins were found in many cases. Different influences in the observed bindings indicated change of charge, mass, or conformational changes of the proteins due to the binding with the studied anions. Combining the mobility-shift and pre-equilibrium ACE modes, rapidity and reversibility of the protein-anion bindings were discussed. Further, circular dichroism has been used as an orthogonal approach to characterize the interactions between the studied proteins and anions to confirm the ACE results. Since phosphate and various anions from amino acids and small organic acids such as succinate or acetate are present in very high concentrations in the cellular environment, even weak influences are certainly relevant as well. PMID:24436007

  13. Capillary zone electrophoresis as a tool for the quality control of goldenseal extracts.

    PubMed

    Unger, Matthias; Laug, Stefanie; Holzgrabe, Ulrike

    2005-06-01

    The root extracts of goldenseal (Hydrastis canadensis L.) are popular phytomedicines for the treatment of gastrointestinal disorders and upper respiratory tract infections. Here we describe a simple and fast capillary zone electrophoresis (CZE) method with ultraviolet detection at 225 nm for the quantification of the major goldenseal constituents, berberine and hydrastine, in herbal remedies containing goldenseal root extracts. Tritoqualine, an antihistaminic drug with a hydrastine-like phthalidisoquinoline structure, was applied as an internal standard. The running buffer was a 1:5 mixture of 500 mM ammonium acetate (adjusted to pH 3.4 with acetic acid) and methanol. Our newly developed CZE method was validated regarding limit of detection (LOD), limit of quantification, linearity, accuracy and precision. For both berberine and hydrastine, the LOD was 1.0 microg/mL and the linearity was obtained between 2.5 and 500 microg/mL. Using our newly developed method, both the alkaloids could be analysed in herbal remedies containing goldenseal root extracts within 8 min. PMID:15912542

  14. Adrenocortical suppression in cats given megestrol acetate.

    PubMed

    Chastain, C B; Graham, C L; Nichols, C E

    1981-12-01

    Megestrol acetate was given orally to 8 cats at a dose of 2.5 mg every other day for 2 weeks and to 8 cats at a dose of 5.0 mg every day for 2 weeks. Four cats were designated nontreated controls. Pre-ACTH-stimulated plasma concentrations of cortisol (hydrocortisone) and ACTH-stimulated cortisol and tolerance to large-dose glucose infusion (IV) were determined on each of the 20 cats given megestrol acetate. Cats were restrained with acepromazine maleate and ketamine hydrochloride during blood sample collection and large-dose glucose infusion. Adrenocortical function and tolerance to large-dose glucose infusion were reevaluated for 4 weeks--after 1st and 2nd weeks of megestrol acetate treatment of the treated groups, and after 1st and 2nd weeks when treatment was stopped (ie, experiment weeks 3 and 4). Each week a cat from the control group and 2 cats from the 2 treated groups were selected to determine the changes occurring during the experiment for that week; after collection of plasma samples, each week's 5 selected cats were euthanatized and necropsied. Significant impairment of adrenocortical function and alteration of adrenocortical morphology occurred with both treated groups. The most severe adrenocortical alterations occurred in the cats 1 week after megestrol acetate was no longer given (ie, experiment week 3). Megestrol acetate-induced adrenocortical suppression contributed to the death of 1 cat. It was concluded that if stress occurs to cats on treatment or soon after treatment with megestrol acetate, glucocorticoids should be supplemented. The effects of megestrol acetate on glucose tolerance were overshadowed by the unforeseen intolerance caused by chemical restraint with acepromazine maleate and ketamine hydrochloride. PMID:6280517

  15. Analysis of starch structure using fluorophore-assisted carbohydrate electrophoresis.

    PubMed

    Morell, M K; Samuel, M S; O'Shea, M G

    1998-11-01

    The analysis of the fine structure of starches is important to the investigation of linkages between starch structure and function and to the investigation of the properties and roles of starch biosynthetic, modifying and degradation enzymes. Fluorophore-assisted carbohydrate electrophoresis has recently been introduced as a method for the analysis of the oligosaccharide populations released by the enzymatic digestion of starches, which has advantages in resolution and sensitivity over previously used methods, and provides the capacity for the facile analysis of oligosaccharide populations on either a molar or mass basis. The use of fluorophore-assisted carbohydrate electrophoresis for the analysis of oligosaccharides is reviewed with particular reference to the choice of label, efficiency of labeling and separation techniques. Examples of separations using slab gel electrophoresis, DNA sequencer analysis and capillary electrophoresis are presented and we conclude that on the basis of resolution and reproducibility, capillary electrophoresis is the method of choice for the separation of oligosaccharides of degree of polymerization from 1 to 100. Examples of isoamylase-debranched starches and glycogens analyzed by capillary electrophoresis are presented. The capillary electrophoresis analysis of starch structure through the analysis of oligosaccharides released by the debranching of limit dextrins derived from starches and glycogens is introduced as a useful diagnostic of starch structure. The potential for future development of novel diagnostics for starch structure using fluorophore-assisted carbohydrate electrophoresis is discussed. PMID:9848667

  16. 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…

  17. 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…

  18. Simultaneous electrophoretic analysis of proteins of very high and low molecular mass using Tris-acetate polyacrylamide gels.

    PubMed

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

    2010-04-01

    To separate and analyze giant and small proteins in the same electrophoresis gel, we have used a 3-15% polyacrylamide gradient gel containing 2.6% of the crosslinker bisacrylamide and 0.2 M of Tris-acetate buffer (pH 7.0). Samples were prepared in a sample buffer containing lithium dodecyl sulphate and were run in the gel described above using Tris-Tricine-SDS-sodium bisulfite buffer, pH 8.2, as electrophoresis buffer. Here, we show that this system can be successfully used for general applications of SDS-PAGE such as CBB staining and immunoblot. Thus, by using Tris-acetate 3-15% polyacrylamide gels, it is possible to simultaneously analyze proteins, in the mass range of 10-500 kDa, such as HERC1 (532 kDa), HERC2 (528 kDa), mTOR (289 kDa), Clathrin heavy chain (192 kDa), RSK (90 kDa), S6K (70 kDa), beta-actin (42 kDa), Ran (24 kDa) and LC3 (18 kDa). This system is highly sensitive since it allows detection from as low as 10 microg of total protein per lane. Moreover, it has a good resolution, low cost, high reproducibility and allows for analysis of proteins in a wide range of weights within a short period of time. All these features together with the use of a standard electrophoresis apparatus make the Tris-acetate-PAGE system a very helpful tool for protein analysis. PMID:20309890

  19. Membrane tethering

    PubMed Central

    Chia, Pei Zhi Cheryl

    2014-01-01

    Membrane trafficking depends on transport vesicles and carriers docking and fusing with the target organelle for the delivery of cargo. Membrane tethers and small guanosine triphosphatases (GTPases) mediate the docking of transport vesicles/carriers to enhance the efficiency of the subsequent SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)-mediated fusion event with the target membrane bilayer. Different classes of membrane tethers and their specific intracellular location throughout the endomembrane system are now well defined. Recent biochemical and structural studies have led to a deeper understanding of the mechanism by which membrane tethers mediate docking of membrane carriers as well as an appreciation of the role of tethers in coordinating the correct SNARE complex and in regulating the organization of membrane compartments. This review will summarize the properties and roles of membrane tethers of both secretory and endocytic systems. PMID:25343031

  20. Acetate Transport and Utilization in the Rat Brain

    PubMed Central

    Deelchand, Dinesh K.; Shestov, Alexander A.; Koski, Dee M.; Uğurbil, Kâmil; Henry, Pierre-Gilles

    2009-01-01

    Acetate, a glial-specific substrate, is an attractive alternative to glucose for the study of neuronal-glial interactions. The present study investigates the kinetics of acetate uptake and utilization in the rat brain in vivo during infusion of [2-13C]acetate using NMR spectroscopy. When plasma acetate concentration was increased, the rate of brain acetate utilization (CMRace) increased progressively and reached close to saturation for plasma acetate concentration > 2-3 mM, whereas brain acetate concentration continued to increase. The Michaelis-Menten constant for brain acetate utilization ( KMutil=0.01±0.14mM) was much smaller than for acetate transport through the blood-brain barrier ( KMt=4.18±0.83mM). The maximum transport capacity of acetate through the blood-brain barrier ( Vmaxt=0.96±0.18μmol/g/min) was nearly two-fold higher than the maximum rate of brain acetate utilization ( Vmaxutil=0.50±0.08μmol/g/min). We conclude that, under our experimental conditions, brain acetate utilization is saturated when plasma acetate concentrations increase above 2-3 mM. At such high plasma acetate concentration, the rate-limiting step for glial acetate metabolism is not the blood-brain barrier, but occurs after entry of acetate into the brain. PMID:19393008

  1. 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.

  2. Glycobiology of the cell surface: Its debt to cell electrophoresis 1940-65.

    PubMed

    Cook, Geoffrey M W

    2016-06-01

    This Review describes how in the period 1940-1959 cell electrophoresis (in the earlier literature often referred to as 'microelectrophoresis') was used to explore the surface chemistry of cells. Using the erythrocyte as a suitable model for the study of biological membranes, the early investigators were agreed on the presence of negatively charged groups at the surface of this cell. The contemporary dogma was that these were phosphate groups associated with phospholipids. Work in the 1960s, particularly on changes in the electrokinetic properties of erythrocytes following treatment with proteolytic enzymes, lead to the realization that the negatively charged groups at the red cell surface are predominantly due to sialic acids carried on glycoproteins. It quickly became apparent from cell electrophoresis that sialic acids have a ubiquitous presence on the surface of animal cells. This finding required that any complete model of the plasma membrane must include glycosylated molecules at the cell periphery, thus laying the foundations for the field termed 'Glycobiology of the Cell Surface'. PMID:26717803

  3. Nanofiltration of rhodium tris(triphenylphosphine) catalyst in ethyl acetate solution

    NASA Astrophysics Data System (ADS)

    Shaharun, Maizatul S.; Mustafa, Ahmad K.; Taha, Mohd F.

    2012-09-01

    Solvent resistant nanofiltration (SRNF) using polymer membranes has recently received enhanced attention due to the search for cleaner and more energy-efficient technologies. The large size of the rhodium tris(triphenylphosphine) [HRh(CO)(PPh3)3] catalyst (>400 Da) - relative to other components of the hydroformylation reaction provides the opportunity for a membrane separation based on retention of the catalyst species while permeating the solvent. The compatibility of the solvent-polyimide membrane (DuraMem{trade mark, serif} 200 and DuraMem{trade mark, serif} 500) combinations was assessed in terms of the membrane stability in solvent plus non-zero solvent flux at 2.0 MPa. Good HRh(CO)(PPh3)3 rejection (>0.95) and solvent fluxes of 9.9 L/m2ṡh1 at 2.0 MPa were obtained in the catalyst-ethyl acetate-DuraMem 500 system. The effect of pressure and catalyst concentration on the solvent flux and catalyst rejection was conducted on the catalyst-ethyl acetate-membrane systems. Increasing pressure substantially improved both solvent flux and catalyst rejection, while increasing catalyst concentration was found to be beneficial in terms of substantial increases in catalyst rejection without significantly affecting solvent flux.

  4. Association and release of the major intrinsic membrane glycoprotein from peripheral nerve myelin.

    PubMed Central

    Poduslo, J F; Yao, J K

    1985-01-01

    Hypo-osmotic homogenization of the endoneurium from the adult-rat sciatic nerve and subsequent evaluation of the 197 000 g aqueous supernatant by sodium dodecyl sulphate pore-gradient electrophoresis (SDS-p.g.e.) revealed a release of the major glycoprotein (P0) (29 000 Mr) from peripheral nerve myelin. Immunological verification of the presence of this asparagine-linked glycoprotein in the aqueous supernatant was obtained by immune overlay after SDS-p.g.e. and electrophoretic transfer to nitrocellulose using anti-P0 gamma-globulin followed by autoradiographic detection with 125I-protein A. A comparison of successive hypo- and iso-osmotic extractions of the endoneurium revealed that the hypo-osmotic extraction released increasing amounts of P0 into the supernatant fraction, whereas the iso-osmotic treatment revealed lower levels of P0 extracted from the myelin and lesser amounts with each successive extraction. Three successive hypo-osmotic extractions resulted in a 2.0-, 2.9-, and 9.5-fold increase in the amount of P0 released compared with the successive iso-osmotic extractions. Although these results suggest that this major myelin glycoprotein has properties similar to those of extrinsic membrane proteins, temperature-dependent phase-partitioning experiments with Triton X-114 revealed that this glycoprotein is recovered in the detergent-enriched lower phase. These results indicate that this major myelin glycoprotein is an amphipathic integral membrane protein with a distinct hydrophobic domain and yet has solubility characteristics typical of an extrinsic membrane protein. P0 labelled in vitro with [3H]mannose could be immunoprecipitated from the aqueous supernatant with anti-P0 gamma-globulin by centrifugation at 197000g without the addition of second antibody or protein A. Analysis of such an immune precipitate after incorporation in vitro with [14C]acetate to label endoneurial lipids revealed that all major endoneurial lipid classes contained radioactive

  5. 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)

  6. 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 ...

  7. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... new uses subject to reporting. (1) The chemical substances identified as 2-ethoxyethanol (CAS No. 110-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and 2-methoxyethanol acetate (CAS No. 110-49-6) are subject to reporting under this section for the significant new...

  8. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... new uses subject to reporting. (1) The chemical substances identified as 2-ethoxyethanol (CAS No. 110-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and 2-methoxyethanol acetate (CAS No. 110-49-6) are subject to reporting under this section for the significant new...

  9. [Degradation of thiometon in ethyl acetate].

    PubMed

    Satoh, M; Shimokawa, S; Kobata, M; Tanaka, T; Nakanishi, Y

    2001-04-01

    When performing multiresidue analysis of pesticides, the recovery of thiometon was less than 20% from carrots and eggplants, but about 100% from garlic chives and welsh onions. The recovery of thiometon was found to depend on the lot of ethyl acetate. A 2-year-old lot of ethyl acetate caused degradation of thiometon, but a fresh lot of ethyl acetate did not. Analysis showed that ethyl acetate stored for 2 years contained about 5 microL/mL of acetaldehyde. Thiometon was also degraded by acetone or acetonitrile, when acetaldehyde was added to them, in the same manner as by aged ethyl acetate. The fact that the recovery of thiometon from welsh onions was about 100% indicated that some of the mercaptans in allium vegetables may prevent thiometon degradation. Mercaptans such as L-cysteine and 3-mercaptoproionic acid were confirmed to prevent the degradation of thiometon and disulfoton. These findings show that mercaptans may be useful additives for analyzing thiometon and disulfoton. PMID:11486375

  10. 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.

  11. Relaxometry, luminescence measurements, electrophoresis, and animal biodistribution of lanthanide(III) complexes of some polyaza macrocyclic acetates containing pyridine

    SciTech Connect

    Kim, W.D.; Sherry, A.D.; Kiefer, G.E.; McMillan, K.; Maton, F.; Muller, R.N.

    1995-04-12

    Four Gd{sup 3+} complexes [Gd(BP2A){sup +}, Gd(PC2A){sup +}, Gd(PCTA){sup 0}, and Gd(BPO4A){sup {minus}}] with polyazamacrocyclic ligands that contain a pyridine moiety were prepared and examined for possible use as MRI contrast enhancement agents. The authors estimated the number of inner sphere water molecules (q{sub Gd}) for the Gd{sup 3+} complexes from the values of q found for the Tb{sup 3+} and/or Eu{sup 3+} complexes by luminescence lifetime measurements. It was estimated that q{sub Gd} = 3.5, 3.3, 2.4, and 0.2 for Gd(BP2A){sup +}, Gd(PC2A){sup +}, Gd(PCTA){sup 0}, and Gd(BPO4A){sup {minus}}, respectively. The inner sphere relaxivities (r{sub 1,inner}) of these tetraaza macrocyclic complexes were higher than that of Gd(DOTA){sup {minus}} [i.e. 6.79 for Gd(BP2A){sup +}, 6.21 for Gd(PC2A){sup +}, and 4.60 for Gd(PCTA){sup 0} mM{sup {minus}1}s{sup {minus}1} at 40 MHz and 25{degrees}C], but the normalized relaxivities per q{sub Gd} (1.94, 1.88, and 1.92 mM{sup {minus}1}s{sup {minus}1}, respectively) were comparable to that of Gd(DOTA){sup {minus}}. A quantitative treatment of the NMRD profiles based on Solomon-Bloembergen-Morgan theory, using the NMRD profile of Gd(BPO4A){sup {minus}} to correct for an outer sphere contribution, showed that the complexes exhibit characteristics similar to that of Gd(DOTA){sup {minus}} but with shorter electronic relaxation times. Tissue biodistribution results using radioactive {sup 153}Sm and {sup 159}Gd complexes in rats indicate that the cationic [{sup 153}Sm-(BP2A){sup +} and {sup 153}Sm(PC2A){sup +}] complexes accumulate preferably in the bone tissue while the neutral [{sup 153}Sm-(PCTA){sup 0}] and anionic [{sup 153}Sm(BPO4A){sup {minus}}] complexes appear to have renal clearances similar to those of other low molecular weight contrast agents [i.e. Gd(DTPA){sup 2{minus}} and Gd(DOTA){sup {minus}}].

  12. 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

  13. Megestrol acetate for treatment of endometriosis.

    PubMed

    Schlaff, W D; Dugoff, L; Damewood, M D; Rock, J A

    1990-04-01

    Between 1977-1989, 29 women with symptomatic endometriosis were treated with megestrol acetate by the Johns Hopkins Division of Reproductive Endocrinology. All had previously received one or more alternative medical treatments for endometriosis, in each case discontinued because of poor response or development of unacceptable side effects. Treatment consisted of a daily dose of 40 mg megestrol acetate orally for up to 24 months. Disease-related symptoms (dysmenorrhea, noncyclic pelvic pain, and dyspareunia) were relieved in 86% of the subjects treated with an adequate course of therapy. Side effects were fairly well tolerated, although eight women discontinued treatment within 2 months and two others stopped the drug by 4 months. These preliminary findings suggest that megestrol acetate may be an effective treatment for patients with endometriosis, even those who have been unresponsive to other modes of therapy. PMID:2314784

  14. Butyl acetate and yeasts interact in adhesion and germination of Botrytis cinerea conidia in vitro and in fungal decay of golden delicious apple.

    PubMed

    Filonow, A B

    2001-04-01

    Butyl acetate is a volatile aroma and flavor compound in apple. Conidia of three strains of Botrytis cinerea, a fungus that causes decay of apple fruit in postharvest storage, had greater adhesion to and greater germination on polycarbonate membrane filters on water inside sealed 500 cc glass jars that were injected with 4 microliters butyl acetate than conidia not so exposed. Conidial germination was highly correlated with conidial adhesion. The yeasts Sporobolomyces roseus and Cryptococcus laurentii, but not Saccharomyces cerevisiae, reduced the adhesion and germination promoting effect of butyl acetate. Conidia did not readily utilize butyl acetate as a food source, as shown by lack of tetrazolium violet reduction, whereas S. roseus and C. laurentii, but not S. cerevisiae did. Butyl acetate added to suspensions of conidia increased the electrical conductivity of the suspensions and increased the loss of 14C from 14C-labeled conidia compared to conidia unexposed to butyl acetate. Uptake of [14C]glucose by conidia was not increased by butyl acetate. Wounds of Golden Delicious apples inoculated with conidia (strain F-J-4) in a dilute solution of butyl acetate had greater decay than unexposed wounds. S. roseus and C. laurentii, but not S. cerevisiae, added with the conidia decreased the incidence or size of decay. Results indicated that butyl acetate increased conidial adhesion, stimulating conidial germination, and some yeasts can reduce this effect. PMID:11446303

  15. Validation of STR typing by capillary electrophoresis.

    PubMed

    Moretti, T R; Baumstark, A L; Defenbaugh, D A; Keys, K M; Brown, A L; Budowle, B

    2001-05-01

    With the use of capillary electrophoresis (CE), high-resolution electrophoretic separation of short tandem repeat (STR) loci can be achieved in a semiautomated fashion. Laser-induced detection of fluorescently labeled PCR products and multicolor analysis enable the rapid generation of multilocus DNA profiles. In this study, conditions for typing PCR-amplified STR loci by capillary electrophoresis were investigated using the ABI Prism 310 Genetic Analyzer (Applied Biosystems). An internal size standard was used with each run to effectively normalize mobility differences among injections. Alleles were designated by comparison to allelic ladders that were run with each sample set. Multiple runs of allelic ladders and of amplified samples demonstrate that allele sizes were reproducible, with standard deviations typically less than 0.12 bases for fragments up to 317 bases in length (largest allele analyzed) separated in a 47 cm capillary. Therefore, 99.7% of all alleles that are the same length should fall within the measurement error window of +/- 0.36 bases. Microvariants of the tetranucleotide repeats were also accurately typed by the analytical software. Alleles differing in size by one base could be resolved in two-donor DNA mixtures in which the minor component comprised > or = 5% of the total DNA. Furthermore, the quantitative data format (i.e., peak amplitude) can in some instances assist in determining individual STR profiles in mixed samples. DNA samples from previously typed cases (typed for RFLP, AmpliType PM+DQA1, and/or D1S80) were amplified using AmpFlSTR Profiler Plus and COfiler and were evaluated using the ABI Prism 310. Most samples yielded typable results. Compared with previously determined results for other loci, there were no discrepancies as to the inclusion or exclusion of suspects or victims. CE thus provides efficient separation, resolution, sensitivity and precision, and the analytical software provides reliable genotyping of STR loci. The

  16. 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.

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

    DOEpatents

    Davidson, James C.; Balch, Joseph W.

    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.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. Simulating Electrophoresis with Discrete Charge and Drag

    NASA Astrophysics Data System (ADS)

    Mowitz, Aaron J.; Witten, Thomas A.

    A charged asymmetric rigid cluster of colloidal particles in saline solution can respond in exotic ways to an electric field: it may spin or move transversely. These distinctive motions arise from the drag force of the neutralizing countercharge surrounding the cluster. Because of this drag, calculating the motion of arbitrary asymmetric objects with nonuniform charge is impractical by conventional methods. Here we present a new method of simulating electrophoresis, in which we replace the continuous object and the surrounding countercharge with discrete point-draggers, called Stokeslets. The balance of forces imposes a linear, self-consistent relation among the drag and Coulomb forces on the Stokeslets, which allows us to easily determine the object's motion via matrix inversion. By explicitly enforcing charge+countercharge neutrality, the simulation recovers the distinctive features of electrophoretic motion to few-percent accuracy using as few as 1000 Stokeslets. In particular, for uniformly charged objects, we observe the characteristic Smoluchowski independence of mobility on object size and shape. We then discuss electrophoretic motion of asymmetric objects, where our simulation method is particularly advantageous. This work is supported by a Grant from the US-Israel Binational Science Foundation.

  4. Unexpected surface chemistry in capillaries for electrophoresis.

    PubMed

    Kaupp, S; Bubert, H; Baur, L; Nelson, G; Wätzig, H

    2000-10-13

    Good and reproducible capillary quality is needed to develop robust methods and to facilitate method transfer in CE. Physical surface defects no longer play a major role in variability of fused-silica capillaries. Nevertheless, problems are frequently being reported when buffers in the pH range between 4 and 7 are used. Thus the surface chemistry has been studied by X-ray photoelectron spectroscopy. Silicon-carbon bindings have been found on inner capillary surfaces for electrophoresis. This binding type is not completely removed by pre-conditioning with 1 M NaOH for 30 min. This corresponds to the result, that capillaries provide more stable migration times, especially in the pH range 4-7, when they are pre-conditioned for longer than 1 h. The origin of this Si-C bond is still not quite clear. They could be caused by graphite which is used during the fabrication of the raw cylinders prior to capillary drawing. Further investigations are intended in order to understand if there are any differences in surface carbon content from batch to batch and if this can influence experimental results in CE. A better understanding of the surface chemistry should not only improve robustness in CE, but also help to facilitate and accelerate capillary pre-conditioning and rinsing procedures to remove strongly adsorbed analytes or matrices. PMID:11100849

  5. Analysis of spiramycin by capillary electrophoresis.

    PubMed

    González-Hernández, R; Li, Y M; Van Schepdael, A; Roets, E; Hoogmartens, J

    1999-09-01

    The development and validation of an analytical method for the determination of spiramycin I in the presence of its related substances by capillary electrophoresis is shown. The separation, performed in a phosphate buffer (80 mM, pH 7.5) containing 12 mM cetyltrimethylammonium bromide (CTAB) and 20 mM sodium cholate, with a 50 microm ID and 44 cm long fused-silica capillary (36 cm effective length), applying a voltage of 12 kV (l approximately 80 microA), at 25 degrees C, is achieved in 15 min. Good selectivity among spiramycin I and its related substances was obtained. The influence of the buffer pH, and of the CTAB and sodium cholate concentrations was investigated. The method robustness, examined by means of a full-fraction factorial design, shows that it can be used within the limits set for the three parameters that were investigated. The method is linear (r = 0.9992) and precise (day-to-day corrected peak area repeatability, n = 18, relative standard deviation = 1.3%). The limits of detection and quantitation are 7 pg (0.025%) and 22 pg (0.08%), respectively, relative to a 2 mg/mL solution. PMID:10499332

  6. Capillary electrophoresis for total glycosaminoglycan analysis

    PubMed Central

    Ucakturk, Ebru; Cai, Chao; Li, Lingyun; Li, Guoyun; Zhang, Fuming; Linhardt, Robert J.

    2014-01-01

    A capillary zone electrophoresis-laser induced fluorescence detection (CZE-LIF) method was developed for the simultaneous analysis of disaccharides derived from heparan sulfate, chondroitin sulfate/dermatan sulfate, hyaluronan and keratan sulfate. Glycosaminoglycans (GAGs) were first depolymerized with the mixture of GAG lyases (heparinase I, II, III and chondroitinase ABC and chondroitinase AC II) and GAG endohydrolase (keratinase II) and the resulting disaccharides were derivatized by reductive amination with 2-aminoacridone. Nineteen fluorescently labeled disaccharides were separated using 50 mM phosphate buffer (pH 3.3) under reversed polarity at 25 kV. Using these conditions, all the disaccharides examined were baseline-separated in less then 25 min. This CZE-LIF method gave good reproducibility both migration time (≤ 1.03% for intra-day and ≤ 4.4% for inter-day) and the peak area values (≤ 5.6% for intra- and ≤ 8.69% for inter-day). This CZE-LIF method was used for profiling and quantification of GAG derivative disaccharides in bovine cornea. The results shows that the current CZE-LIF method offers fast, simple, sensitive, reproducible determination of disaccharides derived from total GAGs in a single run. PMID:24817364

  7. Contact charge electrophoresis: experiment and theory.

    PubMed

    Drews, Aaron M; Cartier, Charles A; Bishop, Kyle J M

    2015-04-01

    Contact charge electrophoresis (CCEP) uses steady electric fields to drive the continuous, oscillatory motion of conductive particles and droplets between two or more electrodes. These rapid oscillations can be rectified to direct the motion of objects within microfluidic environments using low-power, dc voltage. Here, we compare high precision experimental measurements of CCEP within a microfluidic system to equally detailed theoretical predictions on the motion of a conductive particle between parallel electrodes. We use a simple, capillary microfluidic platform that combines high-speed imaging with precision electrical measurements to enable the synchronized acquisition of both the particle location and the electric current due to particle motion. The experimental results are compared to those of a theoretical model, which relies on a Stokesian dynamics approach to accurately describe both the electrostatic and hydrodynamic problems governing particle motion. We find remarkable agreement between theory and experiment, suggesting that particle motion can be accurately captured by a combination of classical electrostatics and low-Reynolds number hydrodynamics. Building on this agreement, we offer new insight into the charge transfer process that occurs when the particle nears contact with an electrode surface. In particular, we find that the particle does not make mechanical contact with the electrode but rather that charge transfer occurs at finite surface separations of >0.1 μm by means of an electric discharge through a thin lubricating film. We discuss the implications of these findings on the charging of the particle and its subsequent dynamics. PMID:25785396

  8. Nonlinear electrophoresis of ideally polarizable particles

    NASA Astrophysics Data System (ADS)

    Figliuzzi, Bruno; Chan, Wai Hong Ronald; Buie, Cullen R.

    2013-11-01

    We focus in this presentation on the nonlinear electrophoresis of ideally polarizable particles. At high applied voltages, significant ionic exchanges occur between the EDL which surrounders the particle and the bulk solution. In this situation, the velocity field, the electric potential and the ionic concentration at the immediate vicinity of the particle are described by a complicated set of coupled nonlinear partial differential equations. These equations are classically considered in the limit of a weak applied field, which enables further analytical progress (Khair and Squires, Phys. Fluids, 2010). However, in the general case, the equation governing the electrophoretic motion of the particle must be solved numerically. In this study, we rely on a numerical approach to determine the electric potential, ionic concentration and velocity field in the bulk solution surrounding the particle. The numerical simulations use a pseudo-spectral which was used successfully by Chu and Bazant to determine the electric potential and the ionic concentration around an ideally polarizable metallic sphere (Physical Review E, 2006). Our numerical model also incorporates the steric model developed by Kilic et al. in 2007 to account for crowding effects in the electric double layer.

  9. Integrated polymerase chain reaction/electrophoresis instrument

    DOEpatents

    Andresen, Brian D.

    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.

  10. Injector-concentrator electrodes for microchannel electrophoresis

    DOEpatents

    Swierkowski, Stefan P.

    2003-05-06

    An input port geometry, with injector-concentrator electrodes, for planar microchannel array for electrophoresis. This input port geometry enables efficient extraction and injection of the DNA sample from a single input port. The geometry, which utilizes injector-concentrator electrodes, allows simultaneous concentration, in different channels, of the sample into a longitudinally narrow strip just before releasing it for a run with enhanced injection spatial resolution, and time resolution. Optional multiple electrodes, at a different bias than the concentrator electrodes, may be used to discriminate against sample impurity ions. Electrode passivation can be utilized to prevent electrolysis. An additional electrode in or on the input hole can better define the initial loading. The injector-concentrator electrodes are positioned so that they cross the drift channel in a narrow strip at the bond plane between the top and bottom plates of the instrument and are located close to the inlet hole. The optional sample purification electrodes are located at a greater distance from the input hole than the injector-concentrate electrodes.

  11. 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

  12. 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.

  13. Robotics in biomedical chromatography and electrophoresis.

    PubMed

    Fouda, H G

    1989-08-11

    The ideal laboratory robot can be viewed as "an indefatigable assistant capable of working continuously for 24 h a day with constant efficiency". The development of a system approaching that promise requires considerable skill and time commitment, a thorough understanding of the capabilities and limitations of the robot and its specialized modules and an intimate knowledge of the functions to be automated. The robot need not emulate every manual step. Effective substitutes for difficult steps must be devised. The future of laboratory robots depends not only on technological advances in other fields, but also on the skill and creativity of chromatographers and other scientists. The robot has been applied to automate numerous biomedical chromatography and electrophoresis methods. The quality of its data can approach, and in some cases exceed, that of manual methods. Maintaining high data quality during continuous operation requires frequent maintenance and validation. Well designed robotic systems can yield substantial increase in the laboratory productivity without a corresponding increase in manpower. They can free skilled personnel from mundane tasks and can enhance the safety of the laboratory environment. The integration of robotics, chromatography systems and laboratory information management systems permits full automation and affords opportunities for unattended method development and for future incorporation of artificial intelligence techniques and the evolution of expert systems. Finally, humanoid attributes aside, robotic utilization in the laboratory should not be an end in itself. The robot is a useful tool that should be utilized only when it is prudent and cost-effective to do so. PMID:2671006

  14. 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...

  15. 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.

  16. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium acetate. 184.1185 Section 184.1185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  17. 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 Specific Tolerances for Residues of New Animal Drugs §...

  18. 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.

  19. 21 CFR 522.1881 - Prednisolone acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Prednisolone acetate. 522.1881 Section 522.1881 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... used as supportive therapy pre- and postoperatively and for various stress conditions...

  20. Reactions of germanium tetrahalides with ketene acetals

    SciTech Connect

    Efimova, I.V.; Kazankova, M.A.; Lutsenko, I.F.

    1985-05-01

    Recently, the authors reported that alkyl vinyl ethers and terminal alkynes are readily germylated by germanium tetrahalides in the presence of a tertiary amine. To extend the range of applicability of this reaction and to obtain additional information on its mechanism, the authors study reactions of ketene acetals with germanium tetrachloride and tetrabromide in the presence of triethylamine.

  1. 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 Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  2. 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.

  3. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles; Zoeller, Joseph Robert; Depew, Leslie Sharon

    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.

  4. Suppressed conductometric capillary electrophoresis separation systems

    SciTech Connect

    Dasgupta, P.K.; Bao, L. )

    1993-04-15

    A tubular cation-exchange membrane is installed at the end of a 60-cm-long 75-[mu]m-bore fused-silica capillary. A static dilute acid regenerant solution surrounds the membranes that functions as a suppressor. With positive high voltage applied to the capillary inlet and the regenerant solution grounded, effective suppression of electrolytes such as solutions of alkalic metal borate, glycinate, or cyanide is observed. Electroosmotic flow carries the capillary effluent past the suppressor into a conductivity detection cell constituted by two platinum wires inserted through the wall of a poly(vinyl chloride) capillary. The system provides detection limits in the 10--20 [mu]g/L range for a variety of anions; a typical separation requires 15 min. Applicability to a variety of real samples is demonstrated. 26 refs., 10 figs.

  5. 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

  6. Membrane Processes.

    PubMed

    Pellegrin, Marie-Laure; Burbano, Marie S; Sadler, Mary E; Diamond, Jason; Baker, Simon; Greiner, Anthony D; Arabi, Sara; Wong, Joseph; Doody, Alexandra; Padhye, Lokesh P; Sears, Keith; Kistenmacher, Peter; Kent, Fraser; Tootchi, Leila; Aguinaldo, Jorge; Saddredini, Sara; Schilling, Bill; Min, Kyungnan; McCandless, Robert; Danker, Bryce; Gamage, Neranga P; Wang, Sunny; Aerts, Peter

    2016-10-01

    This review, for literature published in 2015, 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, 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:27620084

  7. 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.

  8. Multicomponent membranes

    DOEpatents

    Kulprathipanja, Santi; Kulkarni, Sudhir S.; Funk, Edward W.

    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.

  9. 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...

  10. 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.

  11. Integration of amperometric sensors for microchip capillary electrophoresis application

    NASA Astrophysics Data System (ADS)

    Dicorato, F.; Moore, E.; Glennon, J.

    2011-08-01

    Capillary electrophoresis is a technique for the separation and analysis of chemical compounds. Techniques adopted from the microchip technology knowledge have led to recent developments of electrophoresis system with integration on microchip. Microchip Capillary Electrophoresis (μCE) systems offer a series of advantages as easy integration for Lab-on-a-chip applications, high performance, portability, speed, minimal solvent and sample requirements. A new technological challenge aims at the development of an economic modular microchip capillary electrophoresis systems using separable and independent units concerning the sensor. In this project we worked on the development of an interchangeable amperometric sensor in order to provide a solution to such electrode passivation and facilitating the use of tailored sensors for specific analyte detection besides. Fluidic chips have been machined from cyclic olefin polymer pallets (Zeonor®) using a micro-injection molding machine.

  12. 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...

  13. 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

  14. 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)

  15. Nonlinear electrophoresis of ideally polarizable particles

    NASA Astrophysics Data System (ADS)

    Figliuzzi, B.; Chan, W. H. R.; Moran, J. L.; Buie, C. R.

    2014-10-01

    We focus in this paper on the nonlinear electrophoresis of ideally polarizable particles. At high applied voltages, significant ionic exchange occurs between the electric double layer, which surrounds the particle, and the bulk solution. In addition, steric effects due to the finite size of ions drastically modify the electric potential distribution in the electric double layer. In this situation, the velocity field, the electric potential, and the ionic concentration in the immediate vicinity of the particle are described by a complicated set of coupled nonlinear partial differential equations. In the general case, these equations must be solved numerically. In this study, we rely on a numerical approach to determine the electric potential, the ionic concentration, and the velocity field in the bulk solution surrounding the particle. The numerical simulations rely on a pseudo-spectral method which was used successfully by Chu and Bazant [J. Colloid Interface Sci. 315(1), 319-329 (2007)] to determine the electric potential and the ionic concentration around an ideally polarizable metallic sphere. Our numerical simulations also incorporate the steric model developed by Kilic et al. [Phys. Rev. E 75, 021502 (2007)] to account for crowding effects in the electric double layer, advective transport, and for the presence of a body force in the bulk electrolyte. The simulations demonstrate that surface conduction significantly decreases the electrophoretic mobility of polarizable particles at high zeta potential and at high applied electric field. Advective transport in the electric double layer and in the bulk solution is also shown to significantly impact surface conduction.

  16. Band broadening of DNA fragments isolated by polyacrylamide gel electrophoresis in capillary electrophoresis.

    PubMed

    Kaneta, Takashi; Ogura, Takehito; Yamato, Shuhei; Imasaka, Totaro

    2012-02-01

    Polyacrylamide gel electrophoresis (PAGE) is used frequently for isolation and purification of DNA fragments. In the present study, DNA fragments extracted from polyacrylamide gels showed significant band broadening in capillary electrophoresis (CE). A pHY300PLK (a shuttle vector functioning in Escherichia coli and Bacillus subtilis) marker, which contained nine fragments ranging from 80 to 4870 bp, was separated by PAGE, and each fragment was isolated by phenol/chloroform extraction and ethanol precipitation. After extraction from the polyacrylamide gel, the peaks of the isolated DNA fragments exhibited band broadening in CE, where a linear poly(ethylene oxide) was used as a sieving matrix. The theoretical plate numbers of the DNA fragments contained in the pHY300PLK marker were >10(6) for all the fragments before extraction. However, the DNA fragments extracted from the polyacrylamide gel showed decreased theoretical plate numbers (5-20 times smaller). The degradation of the theoretical plate number was significant for middle sizes of the DNA fragments ranging from 489 to 1360 bp, whereas the largest and smallest fragments (80 and 4870 bp) had no obvious influence. The band broadening was attributed to contamination of the DNA fragments by polyacrylamide fibers during the separation and extraction process. PMID:22258810

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 21 CFR 582.5892 - a-Tocopherol acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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....

  2. 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. Cat

  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. 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 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.

  5. Monitoring antigenic protein integrity during glycoconjugate vaccine synthesis using capillary electrophoresis-mass spectrometry.

    PubMed

    Tengattini, Sara; Domínguez-Vega, Elena; Temporini, Caterina; Terreni, Marco; Somsen, Govert W

    2016-09-01

    A capillary electrophoresis-mass spectrometry (CE-MS) method was developed for the characterization and integrity assessment of the Mycobacterium tuberculosis (MTB) antigens TB10.4 and Ag85B and their chemically produced glycoconjugates, which are glycovaccine candidates against tuberculosis (TB). In order to prevent protein adsorption to the inner capillary wall and to achieve efficient separation of the antigen proteoforms, a polyionic multilayer coating of polybrene-dextran sulfate-polybrene (PB-DS-PB) was used in combination with 1.5 M acetic acid as background electrolyte (BGE). Coupling of CE to high-resolution time-of-flight MS was achieved by a coaxial interface employing a sheath liquid of isopropanol-water (50:50, v/v) containing 0.1 % formic acid. The MTB antigens were exposed to experimental conditions used for chemical glycosylation (but no activated saccharide was added) in order to investigate their stability during glycovaccine production. CE-MS analysis revealed the presence of several closely related degradation products, including truncated, oxidized and conformational variants, which were assigned by accurate mass. Analysis of synthesized mannose conjugates of TB10.4 and Ag85B allowed the determination of the glycoform composition of the neo-glycoproteins next to the characterization of degradation products which were shown to be partly glycoconjugated. Moreover, the selectivity of CE-MS allowed specific detection of deamidated species (protein mass change of 1.0 Da only), indicating that chemical glycosylation increased susceptibility to deamidation. Overall, the results show that CE-MS represents a useful analytical tool for the detailed characterization and optimization of neo-glycoconjugate products. Graphical Abstract Flowchart illustrating Mycobacterium tuberculosis (MTB) antigen glycosylation, glycoconjugate variant and degradation product separation by capillary electrophoresis (CE) and their characterization by intact mass

  6. Separating acetic acid from furol (furfural) by electrodialysis method

    SciTech Connect

    Guan, S.F.; Li, C.S. Ye, S.T.; Shen, S.Y.; Wang, Y.T.; Yu, S.H.

    1981-01-01

    Furfural production by hydrolysis of fibrous plant materials is accompanied by formation of acetic acid in amounts depending on the material used. The amount of acetic formed in the hydrolysis of the fruit shell of oil-tea camellia (Camellia oleosa) (an oilseed-bearing tree) is equal to the amount of furfural. The acetic acid can be separated from the furfural and concentrated to 10% by electrodialysis. A smaller amount of furfural is separated with acetic acid.

  7. Cyproterone acetate in treatment of precocious puberty.

    PubMed Central

    Kauli, R; Pertzelan, A; Prager-Lewin, R; Grünebaum, M; Laron, Z

    1976-01-01

    Twenty-nine children (23 girls, 6 boys) with precocious puberty were treated with cyproterone acetate for various periods of time ranging from 6 months to 3 years 4 months. They received an oral dose ranging from 70-150 mg/m2 per day, or an intramuscular depot injection once a fortnight or once a month at a dose ranging from 107-230 mg/m2. Both forms of therapy were found to suppress the signs of sexual maturation, but the oral form proved to be superior. Only the younger patients with a bone age under 11 years showed a beneficial effect upon linear growth and bone maturation. No side effects were noted, but additional advantageous effects upon behaviour and sociability were. It is concluded that at present cyproterone acetate by mouth is the drug of choice in the treatment of precocious puberty. The treatment should be initiated as early as possible to attain maximum benefit. PMID:952553

  8. Facile hydrolysis and alcoholysis of palladium acetate.

    PubMed

    Bedford, Robin B; Bowen, John G; Davidson, Russell B; Haddow, Mairi F; Seymour-Julen, Annabelle E; Sparkes, Hazel A; Webster, Ruth L

    2015-05-26

    Palladium(II) acetate is readily converted into [Pd3 (μ(2) -OH)(OAc)5 ] (1) in the presence of water in a range of organic solvents and is also slowly converted in the solid state. Complex 1 can also be formed in nominally anhydrous solvents. Similarly, the analogous alkoxide complexes [Pd3 (μ(2) -OR)(OAc)5 ] (3) are easily formed in solutions of palladium(II) acetate containing a range of alcohols. An examination of a representative Wacker-type oxidation shows that the Pd-OH complex 1 and a related Pd-oxo complex 4 can be excluded as potential catalytic intermediates in the absence of exogenous water. PMID:25865439

  9. Evaluation of a novel hydrophilic derivatized capillary for protein analysis by capillary electrophoresis-electrospray mass spectrometry.

    PubMed

    Cole, R B; Varghese, J; McCormick, R M; Kadlecek, D

    1994-10-01

    A new type of hydrophilic derivatized capillary has been used to enable the on-line capillary electrophoresis separation and electrospray mass spectrometric detection of a mixture of proteins containing bovine cytochrome c, tuna cytochrome c and horse heart myoglobin. Less than 40 fmol of each compound were loaded into the capillary. Baseline resolution of components was achieved, as were accurate assignments of molecular masses. The hydrophilic derivatized capillaries were taken through extensive testing procedures to characterize their performance and capabilities for protein analysis. A mixture of six proteins (cytochrome c, ribonuclease A, alpha-chymotrypsinogen, myoglobin, carbonic anhydrase II and alpha-lactalbumin) in acetic acid-sodium acetate buffer was used to delineate the relationships between migration time and pH, along with migration time and buffer concentration for each protein. The variations in capillary efficiency as a function of pH and as a function of buffer concentration were also characterized for the same six proteins in the acetic acid-sodium acetate system. A pH of 4.8 was found to offer an excellent compromise between separation efficiency (up to 500,000 theoretical plates) and analysis time. Capillary efficiencies were also found to be very good when employing a Tris.HCl electrolyte adjusted to pH 4.8. Lastly, electropherogram reproducibility and capillary durability were examined with the finding that little deterioration of the capillary occurred over the course of 400 injections (200 h run time). This represents a notable improvement over previously documented derivatization procedures designed to reduce protein adsorption to fused-silica capillary walls. PMID:7981821

  10. 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.

  11. 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.

  12. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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 2013-04-01 2013-04-01 false Ethyl alcohol containing ethyl acetate....

  13. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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 2012-04-01 2012-04-01 false Ethyl alcohol containing ethyl acetate....

  14. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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 2014-04-01 2014-04-01 false Ethyl alcohol containing ethyl acetate....

  15. 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....

  16. 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....

  17. 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…

  18. 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....

  19. 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....

  20. 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....

  1. 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....

  2. 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....

  3. 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

  4. 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

  5. Novel cationic polyelectrolyte coatings for capillary electrophoresis.

    PubMed

    Duša, 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 β-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

  6. 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).

  7. An Alternating Current Electroosmotic Pump Based on Conical Nanopore Membranes.

    PubMed

    Wu, Xiaojian; Ramiah Rajasekaran, Pradeep; Martin, Charles R

    2016-04-26

    Electroosmotic flow (EOF) is used to pump solutions through microfluidic devices and capillary electrophoresis columns. We describe here an EOF pump based on membrane EOF rectification, an electrokinetic phenomenon we recently described. EOF rectification requires membranes with asymmetrically shaped pores, and conical pores in a polymeric membrane were used here. We show here that solution flow through the membrane can be achieved by applying a symmetrical sinusoidal voltage waveform across the membrane. This is possible because the alternating current (AC) carried by ions through the pore is rectified, and we previously showed that rectified currents yield EOF rectification. We have investigated the effect of both the magnitude and frequency of the voltage waveform on flow rate through the membrane, and we have measured the maximum operating pressure. Finally, we show that operating in AC mode offers potential advantages relative to conventional DC-mode EOF pumps. PMID:27046145

  8. 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.

  9. Resistance of Streptococcus bovis to acetic acid at low pH: relationship between intracellular pH and anion accumulation.

    PubMed Central

    Russell, J B

    1991-01-01

    Streptococcus bovis JB1, an acid-tolerant ruminal bacterium, was able to grow 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). YATP (grams of cells per mole of ATP) was not decreased significantly even by high concentrations of acetate. Cultures supplemented with 100 mM sodium acetate took up [14C]acetate and [14C]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. PMID:2036013

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. Optimization of in-line fritless solid-phase extraction for capillary electrophoresis-mass spectrometry.

    PubMed

    Tak, Yvonne H; Toraño, 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 μl (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

  16. 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 255 nm 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 280 nm. Good linearities over 3 orders of magnitude were obtained. The noise level recorded was as low as 50 μAU and the drift typically <200 μAU/5 min. PMID:26091783

  17. Separation and determination of degradation products of acid orange 7 by capillary electrophoresis/capacitively coupled contactless conductivity detector.

    PubMed

    Wang, Xin; Xiong, Ya; Xie, Tianyao; Sharma, Virender K; Tu, Yuting; Yang, Jiannan; Tian, Shuanghong; He, Chun

    2013-07-15

    Capillary electrophoresis (CE) with capacitively coupled contactless conductivity detector (C(4)D) was developed to separate azo-dyestuff acid orange 7 (AO7) and its six degradation products. The analyzed products were sulfamic acid, oxalic acid, benzenesulfonic acid, 4-hydroxybenzene sulfonic acid, phthalic acid, and 4-aminobenzene sulfonic acid. In developing the method, types and concentrations of running buffers, injecting voltage and time, and applied voltage were tested to obtain optimum conditions to analyze target compounds. The separation was successfully achieved within 10 min using a fused-silica capillary under the following conditions: 20 mmol L(-1) acetate acid buffer, electrokinetic injection of -12 kV × 10 s, and applied voltage of -13 kV. The developed method was applied to analyze degradation products in situ during the reaction of AO7 with Fenton reagent (Fe(II)+H2O2 at pH 4.0). PMID:23622525

  18. 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.

  19. 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

  20. Membranous nephropathy

    MedlinePlus

    ... to reduce cholesterol and triglyceride levels (most often statins) may be recommended. A low-salt diet may ... of membranous nephropathy Your symptoms get worse or don't go away You develop new symptoms You have ...

  1. Metalless electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips.

    PubMed

    Duarte Junior, Gerson F; Fracassi da Silva, José Alberto; Mendonça Francisco, Kelliton José; 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 μmol/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

  2. Nonlinear electrophoresis for purification of soil DNA for metagenomics.

    PubMed

    Engel, Katja; Pinnell, Lee; Cheng, Jiujun; Charles, Trevor C; Neufeld, Josh D

    2012-01-01

    Purification of microbial DNA from soil is challenging due to the co-extraction of humic acids and associated phenolic compounds that inhibit subsequent cloning, amplification or sequencing. Removal of these contaminants is critical for the success of metagenomic library construction and high-throughput sequencing of extracted DNA. Using three different composite soil samples, we compared a novel DNA purification technique using nonlinear electrophoresis on the synchronous coefficient of drag alteration (SCODA) instrument with alternate purification methods such as direct current (DC) agarose gel electrophoresis followed by gel filtration or anion exchange chromatography, Wizard DNA Clean-Up System, and the PowerSoil DNA Isolation kit. Both nonlinear and DC electrophoresis were effective at retrieving high-molecular weight DNA with high purity, suitable for construction of large-insert libraries. The PowerSoil DNA Isolation kit and the nonlinear electrophoresis had high recovery of high purity DNA suitable for sequencing purposes. All methods demonstrated high consistency in the bacterial community profiles generated from the DNA extracts. Nonlinear electrophoresis using the SCODA instrument was the ideal methodology for the preparation of soil DNA samples suitable for both high-throughput sequencing and large-insert cloning applications. PMID:22056233

  3. Electrophoresis of DNA and other polyelectrolytes: Physical mechanisms

    NASA Astrophysics Data System (ADS)

    Viovy, Jean-Louis

    2000-07-01

    The dramatic recent advances in molecular biology, which have opened a new era in medicine and biotechnology, rely on improved techniques to study large molecules. Electrophoresis is one of the most important of these. Separation of DNA by size, in particular, is at the heart of genome mapping and sequencing and is likely to play an increasing role in diagnosis. This article reviews, from the point of view of a physicist, the mechanisms responsible for electrophoretic separation of polyelectrolytes. This separation is mainly performed in gels, and a wide variety of migration mechanisms can come into play, depending on the polyelectrolyte's architecture, on the electric fields applied, and on the properties of the gel. After a brief review of the thermodynamic and electrohydrodynamic principles relating to polyelectrolyte solutions, the author treats the phenomenology of electrophoresis and describes the conceptual and theoretical tools in the field. The reptation mechanisms, by which large flexible polyelectrolytes thread their way through the pores of the gel matrix, play a prominent role. Biased reptation, the extension of this model to electrophoresis, provides a very intuitive framework within which numerous physical ideas can be introduced and discussed. It has been the most popular theory in this domain, and it remains an inspiring concept for current development. There have also been important advances in experimental techniques such as single-molecule viodeomicroscopy and the development of nongel separation media and mechanisms. These, in turn, form the basis for fast-developing and innovative technologies like capillary electrophoresis, electrophoresis on microchips, and molecular ratchets.

  4. [Degradation of oxytetracycline with ozonation in acetic acid solvent].

    PubMed

    Li, Shi-Yin; Li, Xiao-Rong; Zhu, Yi-Ping; Zhu, Jiang-Peng; Wang, Guo-Xiang

    2012-12-01

    Use acetic acid as the media of ozone degradation of oxytetracycline (OTC), and effects of the initial dosing ratio of ozone/OTC, ozone flow, free radical scavenger, metal ions on the removal rate of OTC were investigated respectively. The results showed that acetic acid had a high ozone stability and solubility. OTC had a high removal rate and degradation rate in acetic acid solution. With the increase of OTC dosage, the removal rate of OTC decreased in acetic acid. Removal rate of OTC was increased distinctly when ozone flow increased properly. It was also observed that free radical scavenger had a significantly negative effect on OTC ozonation degradation in acetic acid. Furthermore the main reactions of OTC ozone oxidation were direct oxidation and indirect oxidation in acetic acid. When Fe3+ and Co2+ were existent in acetic acid, the degradation of OTC was inhibited significantly. PMID:23379161

  5. Acetic acid removal from corn stover hydrolysate using ethyl acetate and the impact on Saccharomyces cerevisiae bioethanol fermentation.

    PubMed

    Aghazadeh, Mahdieh; Ladisch, Michael R; Engelberth, Abigail S

    2016-07-01

    Acetic acid is introduced into cellulose conversion processes as a consequence of composition of lignocellulose feedstocks, causing significant inhibition of adapted, genetically modified and wild-type S. cerevisiae in bioethanol fermentation. While adaptation or modification of yeast may reduce inhibition, the most effective approach is to remove the acetic acid prior to fermentation. This work addresses liquid-liquid extraction of acetic acid from biomass hydrolysate through a pathway that mitigates acetic acid inhibition while avoiding the negative effects of the extractant, which itself may exhibit inhibition. Candidate solvents were selected using simulation results from Aspen Plus™, based on their ability to extract acetic acid which was confirmed by experimentation. All solvents showed varying degrees of toxicity toward yeast, but the relative volatility of ethyl acetate enabled its use as simple vacuum evaporation could reduce small concentrations of aqueous ethyl acetate to minimally inhibitory levels. The toxicity threshold of ethyl acetate, in the presence of acetic acid, was found to be 10 g L(-1) . The fermentation was enhanced by extracting 90% of the acetic acid using ethyl acetate, followed by vacuum evaporation to remove 88% removal of residual ethyl acetate along with 10% of the broth. NRRL Y-1546 yeast was used to demonstrate a 13% increase in concentration, 14% in ethanol specific production rate, and 11% ethanol yield. This study demonstrated that extraction of acetic acid with ethyl acetate followed by evaporative removal of ethyl acetate from the raffinate phase has potential to significantly enhance ethanol fermentation in a corn stover bioethanol facility. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:929-937, 2016. PMID:27090191

  6. Electrophoresis of proteins and protein-protein complexes in native polyacrylamide gels using a horizontal gel apparatus.

    PubMed

    Su, C; Wang, F; Ciolek, D; Pan, Y C

    1994-11-15

    Electrophoresis of proteins and protein-protein complexes in polyacrylamide gels under native conditions using a horizontal gel apparatus is described. The advantage of this system is that it permits the detection of both negatively and positively charged proteins as well as protein-protein complexes in the same gel. During electrophoresis, a continuous gel sandwiched between two glass plates is placed horizontally on the platform and submerged in a reservoir buffer. The sample wells are made along the center of the gel, allowing positively and negatively charged proteins to migrate toward the cathode and anode, respectively. Several proteins with varying molecular weights and isoelectric point (pI) values and pairs of proteins capable of forming protein-protein complexes were chosen as model systems to illustrate the methodology. The effects of several parameters on the performance of the gel system including protein molecular weight, pI, and gel concentration were also examined and the results obtained by this method are comparable to those obtained by the vertical system. Following electrophoresis, both negatively and positively charged proteins as well as protein-protein complexes can be transferred by electroblotting onto polyvinylidene difluoride membranes for further analyses. PMID:7695108

  7. Study of capillary electrophoresis chip with conductivity detection

    NASA Astrophysics Data System (ADS)

    Wei, Wang; Li, Tian; Liu, Xiao-wei; Lei, Xuan

    2006-04-01

    Microchip electrophoresis technique have been developed fully these years, especially the detection methods have been the research focuses. With the help of MEMS technique, the system integrating function are more and more. This paper presented a novel design and fabrication method about this electrophoresis chip with the detection electrodes. The two-layer structure, one is PDMS substrate to fabricate the electrophoresis microchannel, the other is the glass substrate with the Pt electrodes, are bonded together. The soft lithography with the two molds is developed to accommodate the PDMS curing and peeling off. Then the inorganic cation Cu 2+ is introduced and tested the project feasibility. All these works are laid a stable foundation for the chip appliance.

  8. THERMAL DETECTION OF DNA AND PROTEINS DURING GEL ELECTROPHORESIS

    SciTech Connect

    R. JOHNSTON

    2000-08-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to try to detect unstained, untagged, unlabeled DNA bands in real-time during gel electrophoresis using simple thermal measurements. The technical and ES&H advantages to this approach could potentially be quite significant, especially given the extreme importance of gel electrophoresis to a wide variety of practical and research fields. The project was unable to demonstrate sufficient thermal sensitivity to detect DNA bands. It is clear that we still do not understand the gel electrophoresis phenomenon very well. The temperature control techniques developed during the course of this project have other useful applications.

  9. Nonlinear electrophoresis in the presence of dielectric decrement.

    PubMed

    Figliuzzi, B; Chan, W H R; Buie, C R; Moran, J L

    2016-08-01

    The nonlinear phenomena that occur in the electric double layer (EDL) that forms at charged surfaces strongly influence electrokinetic effects, including electro-osmosis and electrophoresis. In particular, saturation effects due to either dielectric decrement or ion crowding effects are of paramount importance. Dielectric decrement significantly influences the ionic concentration in the EDL at high ζ potential, leading to the formation of a condensed layer near the particle's surface. In this article, we present a model incorporating both steric effects due to the finite size of ions and dielectric decrement to describe the physics in the electric double layer. The model remains valid in both weakly and strongly nonlinear regimes, as long as the electric double layer remains in quasiequilibrium. We apply this model to the study of two archetypal problems in electrokinetics, namely the electrophoresis of particles with fixed surface charges and the electrophoresis of ideally polarizable particles. PMID:27627400

  10. Enantiomeric resolution of multiple chiral centres racemates by capillary electrophoresis.

    PubMed

    Ali, Imran; Suhail, Mohd; Al-Othman, Zeid A; Alwarthan, Abdulrahman; Aboul-Enein, Hassan Y

    2016-05-01

    Enantiomeric resolution of multichiral centre racemates is an important area as some multichiral centre racemates are of great medicinal importance. However, enantioseparation of such types of racemates is a challenging task. Amongst many analytical techniques, capillary electrophoresis is a powerful technique and may be used to resolve such racemates. Only few papers are available describing enantiomeric resolution of such racemates. Therefore, efforts have been made to describe the enantiomeric resolution of multichiral centre racemates by capillary electrophoresis. This article discusses the importance of multichiral racemates, the need for capillary electrophoresis in enantiomeric resolution and chiral resolution of multichiral centre racemates using various chiral selectors. Further, attempts have been made to discuss the future challenges and prospects of enantiomeric resolution of multichiral racemates. The various chiral selectors used for the purpose are chiral crown ether, cyclodextrins, polysaccharides, macrocyclic glycopeptide antibiotics and ligand exchange. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26840015

  11. Inexpensive and safe DNA gel electrophoresis using household materials.

    PubMed

    Ens, S; Olson, A B; Dudley, C; Ross, N D; 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 containers are fitted with aluminum foil electrodes and 9-V batteries to run food-grade agar-agar gels using aquarium pH buffers and then stained with gentian violet. This activity was tested in a high school biology classroom with significantly positive responses on postactivity reflective surveys. The electrophoresis activity addresses several Life Science Content Standard C criteria, including aspects of cell biology, genetics, and evolution. It also can be used to teach aspects of motion and force in the physical science classroom. PMID:22615228

  12. 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 (μFFE) 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 μFFE. Separations using various modes such as zone electrophoresis, isoelectric focusing, isotachophoresis, and field-step electrophoresis have been demonstrated. PMID:19290514

  13. Capillary and microchip electrophoresis: challenging the common conceptions.

    PubMed

    Breadmore, Michael C

    2012-01-20

    Capillary electrophoresis (CE) has long been regarded as a powerful analytical separation technique that is an alternative to more traditional methods such as gel electrophoresis (GE) and liquid chromatography (LC). It is often touted as having a number of advantages over both of these, such as speed, flexibility, portability, sample and reagent requirements and cost, but also a number of disadvantages such as reproducibility and sensitivity. Microchip electrophoresis (ME), the next evolutionary step, miniaturised CE further providing improvements in speed and sample requirements as well as the possibility to perform more complex and highly integrated analyses. CE and ME are seen as a viable alternative to GE, but are often considered to be inferior to LC. This review will consider the strengths and weaknesses of both CE and ME and will challenge the common conceptions held about these. PMID:22000781

  14. 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.

  15. Temperature dependence of ion transport in dilute tetrabutylammonium triflate-acetate solutions and self-diffusion in pure acetate liquids.

    PubMed

    Bopege, Dharshani N; Petrowsky, Matt; Fleshman, Allison M; Frech, Roger; Johnson, Matthew B

    2012-01-12

    Conductivities and static dielectric constants for 0.0055 M tetrabutylammonium trifluoromethanesulfonate in n-butyl acetate, n-pentyl acetate, n-hexyl acetate, n-octyl acetate, and n-decyl acetate have been collected over the temperature range of 0-80 °C. Self-diffusion coefficients and static dielectric constants of pure acetates were obtained over the same temperature range. Both temperature-dependent diffusion coefficients and ionic conductivities of these pure acetates and dilute acetate solutions can be accurately described by the compensated Arrhenius formalism. Activation energies were calculated from compensated Arrhenius plots for both conductivity and diffusion data. Activation energies are higher for conductivity data of 0.0055 M TbaTf-acetates compared to diffusion data of pure acetates. The plot of the exponential prefactor versus the dielectric constant yields a single master curve for both conductivity and diffusion data. These data support the argument that mass and charge transport are thermally activated processes in the acetates, as previously observed in alcohol-based electrolytes. PMID:22145961

  16. Chemoselectivities in acetalization, thioacetalization, oxathioacetalization and azathioacetalization.

    PubMed

    Roy, Ram Kinkar; Bagaria, Priyanka; Naik, Sarala; Kavala, Veerababurao; Patel, Bhisma K

    2006-02-16

    In the present article (experimental as well theoretical) the relative yields of cyclic (O,O), (S,S), (S,O), and (S,N) acetals, formed from p-(NO2)C6H4CHO and p-(OH)C6H4CHO, are compared. Atomic charges, global electrophilicity descriptor (w) [as proposed by Parr et al., J. Am. Chem. Soc. 1999, 121, 1922] and hard-soft acid-base concept of Pearson (J. Am. Chem. Soc. 1963, 85, 3533) are used to explain the experimental observations. Although the w values can explain the yields, charge and local softness values of the interacting sites explain the plausible reaction mechanism. The bisnucleophiles chosen for acetalization are CH2(OH)-CH2(OH) (glycol), CH2(SH)-CH2(SH) (dithiol), CH2(OH)-CH2(SH) (oxathiol) and CH2(SH)-CH2(NH2) (azathiol). For p-(NO2)C6H4CHO, the experimental yield of cyclic acetals were found to follow the trend as (S,N) > (S,O) > (O,O) > (S,S), which is also supported by theoretical explanation based on the w values and applying the concept of hard-hard (i.e., charge-controlled) and soft-soft (i.e., orbital-controlled) interaction between the interacting sites of the substrates (i.e., aldehydes) and the reactants (bisnucleophiles). Similarly, for p-(OH)C6H4CHO the relative yields of cyclic acetals follow the trend (S,N) approximately (S,S) > (S,O) > (O,O). It is argued that the attack on C(CHO) (i.e., C-atom of the CHO group) in p-(NO2)C6H4CHO by O(OH) (i.e., O-atom of OH group) or N(NH2) (i.e., N-atom of NH2 group) is mainly charge-controlled but the attack on C(CHO) in p-(OH)C6H4CHO) by S(SH) (i.e., S-atom of SH group) is orbital-controlled. PMID:16466254

  17. Phosphorus removal using nanofiltration membranes.

    PubMed

    Leo, C P; Chai, W K; Mohammad, A W; Qi, Y; Hoedley, A F A; Chai, S P

    2011-01-01

    A high concentration of phosphorus in wastewater may lead to excessive algae growth and deoxygenation of the water. In this work, nanofiltration (NF) of phosphorus-rich solutions is studied in order to investigate its potential in removing and recycling phosphorus. Wastewater samples from a pulp and paper plant were first analyzed. Commercial membranes (DK5, MPF34, NF90, NF270, NF200) were characterized and tested in permeability and phosphorus removal experiments. NF90 membranes offer the highest rejection of phosphorus; a rejection of more than 70% phosphorus was achieved for a feed containing 2.5 g/L of phosphorus at a pH <2. Additionally, NF90, NF200 and NF270 membranes show higher permeability than DK5 and MPF34 membranes. The separation performance of NF90 is slightly affected by phosphorus concentration and pressure, which may be due to concentration polarization and fouling. By adjusting the pH to 2 or adding sulfuric acid, the separation performance of NF90 was improved in removing phosphorus. However, the presence of acetic acid significantly impairs the rejection of phosphorus. PMID:22053475

  18. Utilization of pyrolytic substrate by microalga Chlamydomonas reinhardtii: cell membrane property change as a response of the substrate toxicity.

    PubMed

    Zhao, Xuefei; Jarboe, Laura; Wen, Zhiyou

    2016-05-01

    Acetic acid derived from fast pyrolysis of lignocellulosic biomass is a promising substrate for microalgae fermentation for producing lipid-rich biomass. However, crude pyrolytic acetic acid solution contains various toxic compounds inhibiting algal growth. It was hypothesized that such an inhibition was mainly due to the cell membrane damage. In this work, the cell membrane property of algal cells was evaluated at various conditions to elucidate the mechanisms of inhibition caused by the pyrolytic substrate solution. It was found that acetic acid itself served a carbon source for boosting algal cell growth but also caused cell membrane leakage. The acetic acid concentration for highest cell density was 4 g/L. Over-liming treatment of crude pyrolytic acetic acid increased the algal growth with a concurrent reduction of cell membrane leakage. Directed evolution of algal strain enhanced cell membrane integrity and thus increased its tolerance to the toxicity of the crude substrate. Statistical analysis shows that there was a significant correlation between the cell growth performance and the cell membrane integrity (leakage) but not membrane fluidity. The addition of cyto-protectants such as Pluronic F68 and Pluronic F127 enhanced the cell membrane integrity and thus, resulted in enhanced cell growth. The transmission electron microscopy (TEM) of algal cells visually confirmed the cell membrane damage as the mechanism of the pyrolytic substrate inhibition. Collectively, this work indicates that the cell membrane is one major reason for the toxicity of pyrolytic acetic acid when being used for algal culture. To better use this pyrolytic substrate, cell membrane of the microorganism needs to be strengthened through either strain improvement or addition of membrane protectant reagents. PMID:26995605

  19. Chiral recognition of dapoxetine enantiomers with methylated-gamma-cyclodextrin: a validated capillary electrophoresis method.

    PubMed

    Neumajer, Gábor; Sohajda, Tamás; Darcsi, András; Tóth, Gergő; Szente, Lajos; Noszál, Béla; Béni, Szabolcs

    2012-03-25

    The enantiomers of dapoxetine, a serotonin transporter inhibitor for the treatment of premature ejaculation have been separated by cyclodextrin modified capillary zone electrophoresis using uncoated fused-silica capillary. Over 20 cyclodextrins were screened as chiral selectors, investigating the stability of the inclusion complexes and enantioseparating properties. According to the preliminary experiments as chiral selector randomly methylated-γ-cyclodextrin was chosen. The basic chemical and instrumental parameters of enantioseparation as concentration of buffer, chiral selector and organic additive, pH, temperature and applied voltage were optimized afterwards using an orthogonal experimental design. Using this methodology not only the optimal parameter values for chiral separation (15 °C, +15 kV, 70 mM acetate, 20 v/v% MeOH, pH*=4.5, 3 mM methylated-γ-CyD) but also the significance order of factors on resolution was determined. Applying these parameters an optimal resolution of 7.01 was achieved. The optimized method was then validated according to the ICH guideline Q2 (R1) with regard to repeatability, linearity range, LOD, LOQ, accuracy and robustness. PMID:22280959

  20. Capillary electrophoresis for the analysis of short-chain organic acids in coffee.

    PubMed

    Galli, Verónica; Barbas, Coral

    2004-04-01

    A simple and rapid capillary electrophoresis method for low-molecular mass carboxylic acids measurement in coffee has been optimised and validated. Regarding separation conditions, phosphate concentration in the background electrolyte, surfactant type [cetyltrimethylammonium bromide (CTAB), tetradecyltri methylammonium bromide (TTAB) and hexadimethrine bromide (HDB)], percentages of organic modifier and pH were assayed. The best conditions were: 500 mM phosphate buffer at pH 6.25 with CTAB 0.5 mM. The separation was carried out with an uncoated fused-silica capillary (57 cm x 50 microm i.d.) which was operated at -10 kV potential. Detection was performed at 200 nm. In such conditions 17 short-chain organic acids: oxalic, formic, fumaric, mesaconic, succinic, maleic, malic, isocitric, citric, acetic, citraconic, glycolic, propionic, lactic, furanoic, pyroglutamic, quinic acids plus nitrate were separated, identified and measured. Validation parameters of the method allow us to consider it lineal, accurate and precise and, therefore, reliable for its employment in food composition studies or for quality control. Results in coffees with different industrial treatment allow the detection of important differences in the organic acid profile. PMID:15065808

  1. Determination of five nitroimidazole residues in artificial porcine muscle tissue samples by capillary electrophoresis.

    PubMed

    Lin, Yingyun; Su, Yan; Liao, Xiulin; Yang, Na; Yang, Xiupei; Choi, Martin M F

    2012-01-15

    A capillary electrophoresis (CE) method with ultraviolet detection has been developed for simultaneous detection and quantification of five nitroimidazoles including benzoylmetronidazole, dimetridazole, metronidazole, ronidazole, and secnidazole in porcine muscles. Nitroimidazoles in samples were extracted by ethyl acetate with subsequent clean-up by a strong cation exchange solid phase extraction column. The clean extracts were subjected to CE separation with optimal experimental conditions: pH 3.0 running buffer containing 25mM sodium phosphate and 0.10mM tetrabutylammonium bromide, 5s hydrodynamic injection at 0.5psi and 28kV separation voltage. The nitroimidazoles could be monitored and detected at 320nm within 18min. The limits of detection were below 1.0μg/kg and limits of quantification were lower than 3.2μg/kg for all nitroimidazoles in the muscle samples. The recoveries and relative standard deviations were 85.4-96.0, 83.5-92.5, 1.3-3.9, and 1.1-4.2%, respectively for the intra-day and inter-day analyses. The proposed CE method has been successfully applied to determine nitroimidazoles in artificial porcine muscle samples with good accuracy and recovery, demonstrating that it has potential for detection and quantification of multi-nitroimidazole residue in real muscle samples. PMID:22265553

  2. Quantitative Determination of Lercanidipine Enantiomers in Commercial Formulations by Capillary Electrophoresis

    PubMed Central

    Lourenço, Luciana Pereira; Aguiar, Fernando Armani; de Oliveira, Anderson Rodrigo Moraes; de Gaitani, Cristiane Masetto

    2015-01-01

    An enantioselective method based on capillary electrophoresis (CE) using cyclodextrin (CD) as chiral selector was developed and validated for determination of lercanidipine (LER) enantiomers, a drug calcium channel blocker which exerts antihypertensive effects of long duration, in a pharmaceutical formulation. Optimum separation of LER enantiomers was obtained on a 50 cm × 50 μm id capillary using a sodium acetate buffer solution 200 mmol/L pH 4.0 containing 10 mmol/L of 2,3,6-o-methyl-β-cyclodextrin (TM-β-CD) as background electrolyte. The capillary temperature and voltage were 15°C and 25 kV, respectively, hydrodynamic injection and detection at 237 nm. Linearity was obtained in the range 12.5–100 μg/mL for both enantiomers (r ≥ 0.995). The RSD (%) and relative errors (E, %) obtained in precision and accuracy studies (intraday and interday) were lower than 5%. After validation, the method was applied to quantify the enantiomers of LER in commercial tablets and the results were satisfactory in terms of accuracy and precision, both less than 5%. Therefore, this method was found to be appropriate for enantioselective quality control of LER enantiomers in pharmaceutical formulations. PMID:25821632

  3. Evaluation of a sheathless capillary electrophoresis/electrospray ionization interface on an ion trap mass spectrometer

    SciTech Connect

    Kriger, M.S.; Cook, K.D.; Ramsey, R.S.

    1994-12-31

    The use of small diameter fused silica capillaries has proven advantageous in several electrospray (ES) mass spectrometric (MS) applications. Enhanced sensitivity and reduced background provide very low limits of detection. Prompted by these findings, the authors have developed an improved capillary electrophoresis (CE)/ES interface and evaluated its performance on a quadrupole ion trap MS using specially prepared fused silica capillary columns. The capillary tip is tapered, then gold-coated using a proprietary process that provides physical and chemical stability. (This process will be described in a subsequent publication, following determination of its patent status by the University of Tennessee Research Corporation). Tapering focuses the electric field, enabling electrospray of highly conductive aqueous solutions prior to the onset of a corona discharge. These capillaries have been used for CE/ES without a sheath solvent, thus avoiding dilution and increased background. The gold coating is not removed from the capillary by application and removal of cellophane adhesive tape, demonstrating excellent physical adhesion. Microscopic inspection has revealed that the coating remains uncompromised when sonicated in water, methanol, ethanol, propanol, acetic acid buffer (10 mM; pH 3.5), concentrated HCl (12.1 M), or potassium hydroxide (1 M). The coating did not survive sonication in aqua regia or piranha solution (30% H{sub 2}O{sub 2}/H{sub 2}SO{sub 4} 1:4).

  4. Application of an external contactless conductivity detector for the analysis of beverages by microchip capillary electrophoresis.

    PubMed

    Kubán, Pavel; Hauser, Peter C

    2005-08-01

    Quantitative total ionic analysis of alcoholic and nonalcoholic beverages was performed by microchip capillary electrophoresis with external contactless conductivity detection. An electrolyte solution consisting of 10.5 mM histidine, 50 mM acetic acid, and 2 mM 18-crown-6 at pH 4.1 was used for the determination of NH(4) (+), K(+), Ca(2+), Na(+), and Mg(2+). Fast analysis of Cl(-), NO(3) (-), and SO(4) (2-) was achieved in 20 mM 2-(N-morpholino)ethanesulfonic acid /histidine electrolyte solution at pH 6.0 and the simultaneous separation of up to 12 inorganic and organic anions was performed in a solution containing 10 mM His and 7 mM glutamic acid at pH 5.75. Limits of detection ranged from 90 to 250 mug/L for inorganic cations and anions, and from 200 to 2000 mug/L for organic anions and phosphate. Calibration curves showed linear dependencies over one to two orders of magnitude when the stacking effect was minimized by injecting standard solutions prepared in background electrolyte solutions. Total analysis times of 35 and 90 s were achieved for the determination of 5 inorganic cations and for the simultaneous determination of 12 inorganic and organic anions, respectively, which represents a considerable reduction of analysis time compared to conventional separation methods used in food analysis. PMID:16047312

  5. Rapid determination of salbutamol in pharmaceutical preparations by chiral capillary electrophoresis.

    PubMed

    Ekiert, Ela; García-Ruiz, Carmen; García, Maria A; Marina, Maria L

    2003-08-01

    A fast and simple method of chiral capillary electrophoresis (CE) has been applied to the analysis of salbutamol in different pharmaceutical preparations. Using of a 25 mM acetate buffer (pH 5.0), containing 13.1 mg/mL carboxymethyl-beta-cyclodextrin (CM-beta-CD), an applied voltage of 20 kV and a temperature of 25 degrees C, the enantiomers of salbutamol could be separated in about 2 min. Three different pharmaceutical preparations (two syrups, one oral solution, and two kind of tablets) containing a racemate of salbutamol were injected directly in the CE system, following dilution in dimethyl sulfoxide (DMSO). Appreciable differences in the retention times were observed for salbutamol enantiomers in the different formulations studied, which were attributed to the effect of the matrix components on the electrophoretic mobility. The standard addition method was used for the calibration due to the existence of matrix interferences. Finally, the stability of the enantiomers of salbutamol in the oral solution was studied calculating the enantiomeric ratio values when the solution was injected immediately after being opened in the first case and after being opened and stored in the fridge for two months in the second case. PMID:12900882

  6. Bacterial community dynamics of salted and fermented shrimp based on denaturing gradient gel electrophoresis.

    PubMed

    Han, Kook-Il; Kim, Yong Hyun; Hwang, Seon Gu; Jung, Eui-Gil; Patnaik, Bharat Bhusan; Han, Yeon Soo; Nam, Kung-Woo; Kim, Wan-Jong; Han, Man-Deuk

    2014-12-01

    The Korean traditional seafood jeotgal is consumed directly or as an additive in other foods to improve flavor or fermentation efficiency. Saeujot, made from salted and fermented tiny shrimp (SFS; Acetes japonicus), is the best-selling jeotgal in Korea. In this study, we reveal the microbial diversity and dynamics in naturally fermented shrimp by denaturing gradient gel electrophoresis (DGGE). The population fingerprints of the predominant microbiota and its succession were generated by DGGE analysis of universal V3 16S rDNA polymerase chain reaction (PCR) amplicons. Overall, 17 strains were identified from sequencing of 30 DGGE bands. The DGGE profiles showed diverse bacterial populations in the sample, throughout the fermentation of SFS. Staphylococcus equorum, Halanaerobium saccharolyticum, Salimicrobium luteum, and Halomonas jeotgali were the dominant bacteria, and their levels steadily increased during the fermentation process. Certain other bacteria, such as Psychrobacter jeotgali and Halomonas alimentaria appeared during the early-fermentation process, while Alkalibacterium putridalgicola, Tetragenococcus muriaticus, and Salinicoccus jeotgali appeared during the late-fermentation process. The members of the order Bacillales were found to be predominant during the fermentation of SFS. Furthermore, S. equorum was identified as the dominant bacterial isolate by the traditional method of culturing under aerobic and facultative anaerobic conditions. We expect that this information will facilitate the design of autochthonous starter cultures for the production of SFS with desired characteristic sensory profiles and shorter ripening times. PMID:25393163

  7. Development of a fast capillary electrophoresis method to determine inorganic cations in biodiesel samples.

    PubMed

    Piovezan, Marcel; Costa, Ana Carolina O; Jager, Alessandra Vincenzi; de Oliveira, Marcone Augusto Leal; Micke, Gustavo Amadeu

    2010-07-19

    The aim of this study was to develop a fast capillary electrophoresis method for the determination of inorganic cations (Na(+), K(+), Ca(2+), Mg(2+)) in biodiesel samples, using barium (Ba(2+)) as the internal standard. The running electrolyte was optimized through effective mobility curves in order to select the co-ion and Peakmaster software was used to determine electromigration dispersion and buffer capacity. The optimum background electrolyte was composed of 10 mmol L(-1) imidazole and 40 mmol L(-1) of acetic acid. Separation was conducted in a fused-silica capillary (32 cm total length and 23.5 cm effective length, 50 microm I.D.), with indirect UV detection at 214 nm. The migration time was only 36 s. In order to obtain the optimized conditions for extraction, a fractional factorial experimental design was used. The variables investigated were biodiesel mass, pH, extractant volume, agitation and sonication time. The optimum conditions were: biodiesel mass of 200 mg, extractant volume of 200 microL and agitation of 20 min. The method is characterized by good linearity in the concentration range of 0.5-20 mg kg(-1) (r>0.999), limit of detection was equal to 0.3 mg kg(-1), inter-day precision was equal to 1.88% and recovery in the range of 88.0-120%. The developed method was successfully applied to the determination of cations in biodiesel samples. PMID:20599036

  8. The separation of chondroitin sulfate disaccharides and hyaluronan oligosaccharides by capillary zone electrophoresis.

    PubMed

    Carney, S L; Osborne, D J

    1991-05-15

    We have developed techniques for the separation of unsulfated (2-acetamido-2-deoxy-3-O-(4-deoxy-alpha-L-threo- hex-4-enopyranosyluronicacid)-D-galactose and -D-glucose), monosulfated (2-acetamido-2-deoxy-3- O-(4-deoxy-2-O-sulfo-alpha-L-threo-hex-4-enopyranosyluronic acid)-D-galactose and 2-acetamido-2-deoxy-3-O-(4-deoxy-alpha-L-threo-hex- 4-enopyranosyluronic acid)-4-sulfo-D-galactose and -6-sulfo-D-galactose),disulfated (2-acetamido-2-deoxy-3-O-(4-deoxy-2-O-sulfo-alpha-L-threo-hex-4- enopyranosyluronic acid)-4-sulfo-D-galactose and -6-sulfo-D-galactose and 2-acet-amido-2-deoxy-3-O-(4-deoxy-alpha-L-threo-hex-4-enopy- ranosyluronic acid)-4,6-di-O-sulfo-D-galactose), and trisulfated (2-acetamido-2-deoxy-3-O-(4-deoxy-2-O- sulfo-alpha-L-threo-hex-4-enopyranosyluronic acid)-4,6-di-O-sulfo-D-galactose) isomers of chondroitin using capillary zone electrophoresis. In addition, it is possible to separate oligomers of hyaluronan by similar protocols. These techniques represent a rapid, sensitive, and reproducible technique for the assay of these molecules from digests of connective tissues. PMID:1909507

  9. Measurements of serotonin and related indoles using capillary electrophoresis with multiphoton-induced hyperluminescence.

    PubMed

    Gostkowski, M L; Wei, J; Shear, J B

    1998-07-01

    We report the use of multiphoton-excited photochemistry to generate highly fluorescent products from hydroxyindoles fractionated in submicron capillary electrophoresis channels. In this approach, the near-infrared (750 nm) output from a modelocked titanium:sapphire laser is focused at the outlet of a 0.6-micron i.d. capillary, producing pulse intensities of approximately 10(12) W cm-2 within a femtoliter focal volume. Hydroxyindole molecules migrating through the outlet aperture of the capillary intersect the beam focus, where absorption of three to four photons (approximately 1.65 eV photon-1) initiates a photobleaching reaction. The resultant hydroxyindole photoproducts produce broadband visible emission (lambdamax approximately 500 nm) when excited with two additional near-IR photons and appear substantially more resistant to photobleaching than the parent hydroxyindoles. This multiphoton-induced conversion of analytes to hyperluminescent derivatives thus offers a more sensitive approach than UV fluorescence for detecting extremely small quantities of material. Mixtures of the hydroxyindoles serotonin (5-hydroxytryptamine), 5-hydroxytryptophan, and 5-hydroxyindole acetic acid are reliably characterized (relative error approximately 10%) in 100 s, with detection limits as low as approximately 70 zmol (approximately 42,000 molecules). The sensitivity of this measurement strategy improves on the best previously reported results for capillary separations of indoles by more than one order of magnitude. PMID:9657885

  10. Centimeter-scale characterization of biogeochemical gradients at a wetland-aquifer interface using capillary electrophoresis

    USGS Publications Warehouse

    Baez-Cazull, S.; McGuire, J.T.; Cozzarelli, I.M.; Raymond, A.; Welsh, L.

    2007-01-01

    Steep biogeochemical gradients were measured at mixing interfaces in a wetland-aquifer system impacted by landfill leachate in Norman, Oklahoma. The system lies within a reworked alluvial plain and is characterized by layered low hydraulic conductivity wetland sediments interbedded with sandy aquifer material. Using cm-scale passive diffusion samplers, "peepers", water samples were collected in a depth profile to span interfaces between surface water and a sequence of deeper sedimentary layers. Geochemical indicators including electron acceptors, low-molecular-weight organic acids, base cations, and NH4+ were analyzed by capillary electrophoresis (CE) and field techniques to maximize the small sample volumes available from the centimeter-scale peepers. Steep concentration gradients of biogeochemical indicators were observed at various interfaces including those created at sedimentary boundaries and boundaries created by heterogeneities in organic C and available electron acceptors. At the sediment-water interface, chemical profiles with depth suggest that SO42 - and Fe reduction dominate driven by inputs of organic C from the wetland and availability of electron acceptors. Deeper in the sediments (not associated with a lithologic boundary), a steep gradient of organic acids (acetate maximum 8.8 mM) and NH4+ (maximum 36 mM) is observed due to a localized source of organic matter coupled with the lack of electron acceptor inputs. These findings highlight the importance of quantifying the redox reactions occurring in small interface zones and assessing their role on biogeochemical cycling at the system scale. ?? 2007 Elsevier Ltd. All rights reserved.

  11. Analysis of silica nanoparticles by capillary electrophoresis coupled to an evaporative light scattering detector.

    PubMed

    Adelantado, Carlos; Rodríguez-Fariñas, Nuria; Rodríguez Martín-Doimeadios, Rosa C; Zougagh, Mohammed; Ríos, Ángel

    2016-06-01

    A simple and rapid methodology has been developed to identify and separate silica nanoparticles (SiO2NPs) of different sizes in aqueous solution by capillary zone electrophoresis coupled to an evaporative light scattering detector (CE-ELSD). SiO2NPs were separated using 3 mM ammonium acetate buffer, containing 1% methanol at pH 6.9. SiO2NPs of 20, 50 and 100 nm were successfully separated under the optimum experimental conditions. CE coupled to ELSD has been proven to be an effective separation technique to determine particles with such small sizes, although the peaks are very close to each other, and it is a promising technique that may allow the separation of other types of nanoparticles. Confirmation by TEM and quantification of the SiO2 content was also carried out by inductively coupled plasma-mass spectrometry (ICP-MS). The new method was applied to the analysis of real samples, in order to assess its ability to avoid matrix effects in the determination of SiO2NPs in these kinds of samples. PMID:27155305

  12. Determination of biogenic amines in beer and wine by capillary electrophoresis-tandem mass spectrometry.

    PubMed

    Daniel, Daniela; Dos Santos, Vagner Bezerra; Vidal, Denis Tadeu Rajh; do Lago, Claudimir Lucio

    2015-10-16

    A capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) method for the simultaneous assessment of nine biogenic amines (spermine, spermidine, putrescine, cadaverine, histamine, phenylethylamine, tryptamine, tyramine, and urocanic acid) in commercial samples of beer and wine is introduced. The samples were submitted to a simple clean-up step with poly(vinylpolypyrrolidone) followed by filtration. Electrophoretic separation in a polyvinyl alcohol (PVA)-coated capillary using 0.5 mol L(-1) acetic acid (pH 2.5) as background electrolyte and detection by electrospray-tandem mass spectrometry was employed. The range of the correlation coefficients of the calibration curves of the analyzed compounds was 0.996-0.999, and the limits of detection and limits of quantification were in the range of 1-2 μg L(-1) and 3-8 μg L(-1), respectively. The recovery values for samples spiked at three concentration levels (0.2, 0.5, and 1.0 mg L(-1)) ranged from 87 to 113% with standard deviation not greater than 5.8%. The use of a PVA-coated silica capillary allows suppressing the electroosmotic flow and, consequently, increasing of the separation efficiency. The method was successfully used to determine biogenic amines in commercial samples of beer and wine. PMID:26362807

  13. Further characterization of filarial antigens by SDS polyacrylamide gel electrophoresis

    PubMed Central

    Dissanayake, S.; Galahitiyawa, S. C.; Ismail, M. M.

    1983-01-01

    SDS (sodium dodecyl sulfate)-polyacrylamide gel electrophoresis of an antigen isolated from sera of Wuchereria bancrofti-infected patients and Setaria digitata antigen SD2-4 is reported. Both antigens showed carbohydrate (glycoprotein) staining. The W. bancrofti antigen had an apparent relative molecular mass of 35 000 while the S. digitata antigen SD2-4 migrated at the marker dye position on SDS-polyacrylamide gel electrophoresis. SDS treatment of these antigens did not abolish the precipitation reaction with antibody. In the case of W. bancrofti antigen, SDS treatment probably exposed hitherto hidden antigen epitopes. PMID:6354508

  14. Separation of DNA by free flow electrophoresis in space.

    PubMed

    Kobayashi, H; Ishii, N

    2001-10-01

    Free flow electrophoresis of a nematode C. elegans DNA was carried out on the space shuttle flight in International Microgravity Laboratory No. 2 (IML-2)., 1994. We selected the C. elegans DNA as the sample of the space experiment for free flow electrophoresis separation. This worm is a useful animal for the study of development and behavior by genetic analysis, and is a good candidate for a complete DNA sequence analysis because the haploid genome size consists of approximately 100 Mb (megabase) distributed on the six chromosomes, only 1/30 of human genome size. (Recently, the entire genomic DNA (97 Mb) sequences of C. elegans have been completed at the last December, 1998, as the first organism of multicellular system. In addition, many of the genes in C. elegans have extensive similarity to their mammalian counterparts. It may be possible to use the technology of free flow electrophoresis to contribute to the DNA analysis of the eukaryote. In this mission we attempted to make real-time communication between the space shuttle and on the ground during the electrophoresis processing. Because the separation tendency of the sample in space was not predicted so perfectly, the requests to the crews of the space shuttle was needed for selecting the fractions to be separated. According to the three dimensional electropherogram (3DEP) figured out the electrophoresis behavior, we were able to recover those fractions and kept in the deep freezer until landing. This real-time monitoring of the electrophoresis was the first evidence during space electrophoresis experiments which was started at Apollo 14, 1974. Unfortunately, some troubles occurred by contamination of bubbles in space nevertheless the post flight analyses of the fractionated samples were succeeded. The DNAs estimated by the DNA probes were not isolated one but the migration tendencies were differ from each other. It was clear that certain parts of the process in this study are advanced; that is, the precise

  15. Construction and evaluation of a capillary electrophoresis DNA sequencer

    SciTech Connect

    Drossman, H.

    1992-01-01

    This dissertation describes the construction and evaluation of an automated DNA sequencer using capillary gel electrophoresis (CGE) for separating single-strand DNA fragments and a fluorescence detector for analyzing labeled fragments. Theories governing the electrophoretic separation of DNA, dispersion processes in CGE and high sensitivity fluorescence detection are reviewed. The CGE DNA sequencer is compared with current DNA sequencing instruments and with projections of future DNA sequencing instruments. Parameters affecting the limits of detection, DNA sample loading, sample mobility and resolution are evaluated. Predictions for the future of capillary electrophoresis for large-scale sequencing projects are presented.

  16. EOS production on the Space Station. [Electrophoresis Operations/Space

    NASA Technical Reports Server (NTRS)

    Runge, F. C.; Gleason, M.

    1986-01-01

    The paper discusses a conceptual integration of the equipment for EOS (Electrophoresis Operations/Space) on the Space Station in the early 1990s. Electrophoresis is a fluid-constituent separation technique which uses forces created by an electrical field. Aspects covered include EOS equipment and operations, and Space Station installations involving a pressurized module, a resupply module, utility provisions and umbilicals and crew involvement. Accommodation feasibility is generally established, and interfaces are defined. Space Station production of EOS-derived pharmaceuticals will constitute a significant increase in capability compared to precursor flights on the Shuttle in the 1980s.

  17. Definition of performance specifications for automated Analytical Electrophoresis Facility (AAEF)

    NASA Technical Reports Server (NTRS)

    Brooks, D. E.

    1976-01-01

    In order to provide specifications for the automated Analytical Electrophoresis Facility (AAEF) that would satisfy the broadest variety of demands of a future user community, a survey was carried out of all those people who were identified as having published papers on cell electrophoresis in the past four years. A computer search was conducted of the relevant literature from which a list of 87 investigators was derived and defined as the user community for purposes of the mailing. A questionnaire was developed covering the areas of performance which required definition which was subsequently circulated to the user community. Based on the response to this survey performance specifications were assembled.

  18. Gel Electrophoresis of Gold-DNA Nano-Conjugates

    SciTech Connect

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

    2006-01-10

    Single stranded DNA of different lengths and different amounts was attached to colloidal phosphine stabilized Au nanoparticles. The resulting conjugates were investigated in detail by a gel electrophoresis study based on 1200 gels. We demonstrate how these experiments help to understand the binding of DNA to Au particles. In particular we compare specific attachment of DNA via gold-thiol bonds with nonspecific adsorption of DNA. The maximum number of DNA molecules that can be bound per particle was determined. We also compare several methods to used gel electrophoresis for investigating the effective diameter of DNA-Au conjugates, such as using a calibration curve of particles with known diameters and Ferguson plots.

  19. Automatic registration and segmentation algorithm for multiple electrophoresis images

    NASA Astrophysics Data System (ADS)

    Baker, Matthew S.; Busse, Harald; Vogt, Martin

    2000-06-01

    We present an algorithm for registering, segmenting and quantifying multiple scanned electrophoresis images. (2D gel) Electrophoresis is a technique for separating proteins or other macromolecules in organic material according to net charge and molecular mass and results in scanned grayscale images with dark spots against a light background marking the presence of such macromolecules. The algorithm begins by registering each of the images using a non-rigid registration algorithm. The registered images are then jointly segmented using a Markov random field approach to obtain a single segmentation. By using multiple images, the effect of noise is greatly reduced. We demonstrate the algorithm on several sets of real data.

  20. EVALUATION OF MEMBRANE PERFORMANCE AND FOULING BY PYROLYSIS-GC/MS

    EPA Science Inventory

    Pyrolysis-GC/MS is used to evaluate the organic foulants found on two types of membranes for three natural waters. olyamide and cellulose acetate membranes are used. aters from Manatee Lake, Harsha Lake, and the Ohio River are used as feed waters. he pyrolysis fragments are class...