The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Andrew L. Zydney - One of the best experts on this subject based on the ideXlab platform.
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Size Exclusion Chromatography of plasmid DNA isoforms.
Journal of Chromatography A, 2009Co-Authors: David R. Latulippe, Andrew L. ZydneyAbstract:Abstract There is considerable interest in using Size Exclusion Chromatography (SEC) to analyze and purify specific plasmid isoforms, but there is currently no fundamental understanding of the effects of plasmid Size and morphology on plasmid behavior in SEC. Experiments were performed for plasmids from 3.0 to 17.0 kbp in Size. The linear and open-circular isoforms were generated from the supercoiled plasmid by appropriate enzymatic digestion. SEC retention data were obtained using a Sephacryl S-1000 SF resin packed column and an Agilent HPLC system over a range of flow rates using buffers of different ionic strength and composition. The plasmid partition coefficients, K P , were evaluated from the first statistical moment of the chromatographic peak. The partition coefficient decreased with increasing plasmid Size as expected; K P varied from 0.299 to 0.045 for supercoiled plasmids of 3.0 to 17.0 kbp. The partition coefficient also increased with increasing ionic strength due to the compaction of the DNA associated with the shielding of the intramolecular electrostatic interactions. For any plasmid Size, the supercoiled isoform had the highest K P followed by the open-circular and then the linear isoform, consistent with independent estimates of the plasmid radius of gyration as determined by static light scattering. The experimental data were analyzed using available theoretical models for the partitioning of linear and cyclic polymer chains in well-defined pore geometries. These results provide important insights into the behavior of different plasmid isoforms in Size Exclusion Chromatography.
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Electrostatic effects on protein partitioning in Size-Exclusion Chromatography and membrane ultrafiltration.
Journal of Chromatography A, 1998Co-Authors: Narahari S. Pujar, Andrew L. ZydneyAbstract:Although Size-Exclusion Chromatography and membrane ultrafiltration are generally viewed as Size-based separation processes, there is considerable evidence for the importance of electrostatic interactions. Experimental studies of Size-Exclusion Chromatography and membrane ultrafiltration were performed in parallel using both neutral dextrans and charged proteins. Data for protein retention time and membrane sieving clearly indicate that the effective protein Size increases with decreasing ionic strength due to the reduction in electrostatic shielding. These results were quantified using available theoretical models for the partitioning of charged solutes. The data clearly demonstrate the similarity of the electrostatic interactions and partitioning effects in Size-Exclusion Chromatography and membrane ultrafiltration.
JOHANNES THEODORUS FAUSTINUS KEURENTJES - One of the best experts on this subject based on the ideXlab platform.
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Viral clearance using surfactant‐aided Size‐Exclusion Chromatography
Aiche Journal, 2007Co-Authors: D.a. Horneman, Marcel Ottens, Luuk A.m. Van Der Wielen, JOHANNES THEODORUS FAUSTINUS KEURENTJESAbstract:Surfactant-aided Size-Exclusion Chromatography (SASEC) is applied to the viral clearance of blood proteins, taking BSA as an example. Fixed bed systems as well as simulated moving bed (SMB) systems are examined. SASEC shows a better performance of this separation in terms of log reduction value (LRV), productivity of BSA, yield on BSA and solvent consumption compared to normal Size-Exclusion Chromatography (SEC) in fixed bed as well as in SMB systems. © 2007 American Institute of Chemical Engineers AIChE J, 2007
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Surfactant-aided Size Exclusion Chromatography
Journal of Chromatography B, 2004Co-Authors: D.a. Horneman, M.w. Wolbers, M. Zomerdijk, Marcel Ottens, JOHANNES THEODORUS FAUSTINUS KEURENTJES, Luuk A.m. Van Der WielenAbstract:The flexibility and selectivity of Size Exclusion Chromatography (SEC) for protein purification can be modified by adding non-ionic micelle-forming surfactants to the mobile phase. The micelles exclude proteins from a liquid phase similar to the Exclusion effect of the polymer fibers of the Size Exclusion resin. This surfactant-aided Size Exclusion Chromatography technology (SASEC) is demonstrated on the separation of two model proteins; bovine serum albumin (BSA) and myoglobin (Myo). The effect of the added surfactants on the distribution behavior of the proteins is predicted adequately by a Size Exclusion model presented in this paper.
Yi-ming Shao - One of the best experts on this subject based on the ideXlab platform.
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Effect of salt on purification of plasmid DNA using Size-Exclusion Chromatography.
Journal of Chromatography A, 2006Co-Authors: Liang-zhu Li, Yi-ming ShaoAbstract:Abstract In the present study, we compared the performances of Size-Exclusion Chromatography for the purification of plasmid DNA when different concentrations (0.5 M, 1 M, 2 M, respectively) of two types of salt (NaCl and (NH4)2SO4) are present in running buffers. Our experiment results displayed that it is not only the resolution of RNA but also those of supercoiled plasmid DNA and host's genomic DNA were increased greatly in the presence of high concentration of water-structure salt. We deduce that two separation modes may be involved in the process: The supercoiled plasmid DNA is influenced mainly by compaction effect and eluted in the Size-Exclusion mode; whereas, RNA and genomic DNA are influenced mainly by hydrophobic effect due to their stretched and loose structures and eluted in the interaction mode. This method led to an improved efficiency of Size-Exclusion Chromatography.
D.a. Horneman - One of the best experts on this subject based on the ideXlab platform.
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Viral clearance using surfactant‐aided Size‐Exclusion Chromatography
Aiche Journal, 2007Co-Authors: D.a. Horneman, Marcel Ottens, Luuk A.m. Van Der Wielen, JOHANNES THEODORUS FAUSTINUS KEURENTJESAbstract:Surfactant-aided Size-Exclusion Chromatography (SASEC) is applied to the viral clearance of blood proteins, taking BSA as an example. Fixed bed systems as well as simulated moving bed (SMB) systems are examined. SASEC shows a better performance of this separation in terms of log reduction value (LRV), productivity of BSA, yield on BSA and solvent consumption compared to normal Size-Exclusion Chromatography (SEC) in fixed bed as well as in SMB systems. © 2007 American Institute of Chemical Engineers AIChE J, 2007
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Surfactant-aided Size Exclusion Chromatography
Journal of Chromatography B, 2004Co-Authors: D.a. Horneman, M.w. Wolbers, M. Zomerdijk, Marcel Ottens, JOHANNES THEODORUS FAUSTINUS KEURENTJES, Luuk A.m. Van Der WielenAbstract:The flexibility and selectivity of Size Exclusion Chromatography (SEC) for protein purification can be modified by adding non-ionic micelle-forming surfactants to the mobile phase. The micelles exclude proteins from a liquid phase similar to the Exclusion effect of the polymer fibers of the Size Exclusion resin. This surfactant-aided Size Exclusion Chromatography technology (SASEC) is demonstrated on the separation of two model proteins; bovine serum albumin (BSA) and myoglobin (Myo). The effect of the added surfactants on the distribution behavior of the proteins is predicted adequately by a Size Exclusion model presented in this paper.
Luuk A.m. Van Der Wielen - One of the best experts on this subject based on the ideXlab platform.
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Viral clearance using surfactant‐aided Size‐Exclusion Chromatography
Aiche Journal, 2007Co-Authors: D.a. Horneman, Marcel Ottens, Luuk A.m. Van Der Wielen, JOHANNES THEODORUS FAUSTINUS KEURENTJESAbstract:Surfactant-aided Size-Exclusion Chromatography (SASEC) is applied to the viral clearance of blood proteins, taking BSA as an example. Fixed bed systems as well as simulated moving bed (SMB) systems are examined. SASEC shows a better performance of this separation in terms of log reduction value (LRV), productivity of BSA, yield on BSA and solvent consumption compared to normal Size-Exclusion Chromatography (SEC) in fixed bed as well as in SMB systems. © 2007 American Institute of Chemical Engineers AIChE J, 2007
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Surfactant-aided Size Exclusion Chromatography
Journal of Chromatography B, 2004Co-Authors: D.a. Horneman, M.w. Wolbers, M. Zomerdijk, Marcel Ottens, JOHANNES THEODORUS FAUSTINUS KEURENTJES, Luuk A.m. Van Der WielenAbstract:The flexibility and selectivity of Size Exclusion Chromatography (SEC) for protein purification can be modified by adding non-ionic micelle-forming surfactants to the mobile phase. The micelles exclude proteins from a liquid phase similar to the Exclusion effect of the polymer fibers of the Size Exclusion resin. This surfactant-aided Size Exclusion Chromatography technology (SASEC) is demonstrated on the separation of two model proteins; bovine serum albumin (BSA) and myoglobin (Myo). The effect of the added surfactants on the distribution behavior of the proteins is predicted adequately by a Size Exclusion model presented in this paper.
