| 1. |
- Izumrudov, Vladimir, et al.
(author)
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Factors Controlling Phase Separation in Water-Salt Solutions of DNA and Polycations.
- 2003
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In: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 19:11, s. 4733-4739
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Journal article (peer-reviewed)abstract
- Factors affecting phase separation in water-salt solutions of polyelectrolyte complexes (PECs), formed by DNA and integral or pendant polycations with a quaternary amino group in every monomer unit, have been studied. When no salt was added, quantitative DNA precipitation occurred at a stoichiometric charge ratio, = [+]/[-] 1. In DNA mixtures with poly(N,N'-dimethyldiallylammonium chloride) (PDMDAAC, a pendant polycation), insoluble PECs formed in the range 0.7 < < 2. This suggests the formation of soluble, negatively charged PECs at 0 < < 0.7 and soluble, positively charged PECs at > 2. For different aliphatic ionene bromides (integral polycations), the range of corresponding to insoluble PECs was significantly broader, mainly due to the poor ability of the ionenes to form soluble, positively charged PECs. The range was also relatively broad for poly(N-ethyl-4-vinylpyridinium bromide) (a pendant polycation) and became broader with decreasing degree of polymerization of the polycation. The formation of insoluble PECs was favored by the addition of salt (NaCl), and the effect was more pronounced when decreasing the relative content of the solubilizing component, i.e., the nucleic acid at < 1 and the polycation at > 1. At moderate ionic strength, 0.12 M < [NaCl] < 0.6 M, quantitative precipitation of DNA was attained by addition of PDMAAC in the whole region studied: 1 < < 4.5. The data obtained strongly suggest that phase separation in solutions of DNA-containing PECs follows general rules revealed by studying PECs formed by flexible vinyl polyanions. However, the high rigidity of the DNA double helix appears to be responsible for the key feature revealed in the phase diagrams, i.e., significant broadening of the region for insoluble PECs at the expense of the region in which soluble DNA-containing PECs are formed. This feature may severely limit the application of DNA-containing PECs in medicine and biology but could be beneficial in the development of simple and effective procedures for DNA separation in biotechnology.
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| 2. |
- Sjöberg, Mats, 1965-, et al.
(author)
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Infliximab or cyclosporine as rescue therapy in hospitalized patients with steroid-refractory ulcerative colitis : a retrospective observational study
- 2012
-
In: Inflammatory Bowel Diseases. - : John Wiley & Sons. - 1078-0998 .- 1536-4844. ; 18:2, s. 212-218
-
Journal article (peer-reviewed)abstract
- Background: Cyclosporine (CsA) or infliximab (IFX) are used as rescue therapies in steroid-refractory, severe attacks of ulcerative colitis (UC). There are no data comparing the efficacy of these two alternatives. Methods: Outcome of rescue therapy was retrospectively studied in two cohorts of patients hospitalized due to steroid-refractory moderate to severe UC: 1) a Swedish-Danish cohort (n 49) treated with a single infusion of IFX; 2) an Austrian cohort (n 43) treated with intravenous CsA. After successful rescue therapy, maintenance immunomodulator treatment was given to 27/33 (82%) of IFX patients and to 31/40 (78%) of CsA patients. Endpoints were colectomy-free survival at 3 and 12 months. Kaplan-Meier and Cox regression models were used to evaluate the association between treatment groups and colectomy. Results: At 15 days, colectomy-free survival in the IFX cohort was 36/49 (73%) versus 41/43 (95%) in the CsA cohort (P = 0.005), at 3 months 33/49 (67%) versus 40/43 (93%) (P = 0.002), and at 12 months 28/49 (57%) versus 33/43 (77%) (P = 0.034). After adjusting for potential confounding factors, Cox regression analysis yielded adjusted hazard ratios for risk of colectomy in IFX-treated patients of 11.2 (95% confidence interval [CI] 2.4-53.1, P = 0.002) at 3 months and of 3.0 (95% CI 1.1-8.2, P = 0.030) at 12 months in comparison with CsA-treated patients. There were no opportunistic infections or mortality. Conclusions: Colectomy frequencies were significantly lower after rescue therapy with CsA than with a single infusion of IFX both at 3 and 12 months' follow-up. The superiority of CsA was seen principally during the first 15 days.
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| 3. |
- Wahlund, Per-Olof, et al.
(author)
-
Phase Separations in Water-Salt Solutions of Polyelectrolyte Complexes Formed by RNA and Polycations: Comparison with DNA Complexes.
- 2003
-
In: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 3:8, s. 404-411
-
Journal article (peer-reviewed)abstract
- Formation of insoluble polyelectrolyte complexes (PECs) between RNA and polycations was followed by measuring the residual RNA absorbance in the solution after separation of the precipitate. The polycations studied were poly(N,N-dimethyldiallylammonium) chloride (pendant type) and 2,5-ionene bromide (integral type) with quaternary amino groups in every monomer unit. The data obtained were compared with the results of analogous studies of DNA-containing PECs. This study is a part of a project aimed at the specific separation of plasmid DNA from RNA, a major problem in the preparative isolation of plasmid DNA. We thus deliberately chose a heterogenous RNA sample as it represents the RNA present in a real cell extract. In contrast to the exhaustive precipitation of DNA observed at certain values, a significant part of RNA was nonprecipitated at any = [+]/[-], that is, at any ratio of positively charged quaternary amino groups and negatively charged phosphate groups. The addition of sodium chloride increased the nonprecipitated fraction of RNA. DNA, on the other hand, was completely precipitated by both polycations at > 0.7. The less effective precipitation of RNA was probably due to the presence of a considerable fraction of short-chained molecules, incapable of forming a sufficient cooperative system of salt bonds with the polycation. This assumption was supported by a separate experiment, in which the precipitation behavior of RNA fractions of different molecular masses was investigated. The same tendency, while less pronounced, was also ascertained for PECs formed by polycations with DNA fractions of different molecular masses. The possibility of using the revealed differences between DNA and RNA behavior for effective precipitation procedure useful in bioseparation is discussed. The difference in the precipitation behavior of nucleic acids of different molecular masses means there is a possibility for developing an enzymatic assay for DNAase and RNAase activity.
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| 4. |
- Wahlund, Per-Olof, et al.
(author)
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Polyelectrolyte complexes as a tool for purification of plasmid DNA background and development
- 2004
-
In: Journal of Chromatography. B. - : Elsevier BV. - 1873-376X .- 1570-0232. ; 807:1, s. 121-127
-
Journal article (peer-reviewed)abstract
- The demand for highly purified plasmids in gene therapy and plasmid-based vaccines requires large-scale production of pharmaceutical-grade plasmid. Plasmid DNA was selectively precipitated from a clarified alkaline lysate using the polycation poly(N,N'-dimethyldiallylammonium) chloride which formed insoluble polyelectrolyte complex (PEC) with the plasmid DNA. Soluble PECs of DNA with polycations have earlier been used for cell transformation, but now the focus has been on insoluble PECs. Both DNA and RNA form stable PECs with synthetic polycations. However, it was possible to find a range of salt concentration where plasmid DNA was quantitatively precipitated whereas RNA remained in solution. The precipitated plasmid DNA was resolubilised at high salt concentration and the polycation was removed by gel-filtration. (C) 2004 Elsevier B.V. All rights reserved.
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| 5. |
- Wahlund, Per-Olof, et al.
(author)
-
Precipitation by polycation as capture step in purification of plasmid DNA from a clarified lysate
- 2004
-
In: Biotechnology and Bioengineering. - : Wiley. - 1097-0290 .- 0006-3592. ; 87:5, s. 675-684
-
Journal article (peer-reviewed)abstract
- The demand for highly purified plasmids in gene therapy and plasmid-based vaccines requires large-scale production of pharmaceutical-grade plasmid. Large-scale purification of plasmid DNA from bacterial cell culture normally includes one or several chromatographic steps. Prechromatographic steps include precipitation with solvents, salts, and polymers combined with enzymatic degradation of nucleic acids. No method alone has so far been able to selectively capture plasmid DNA directly from a clarified alkaline lysate. We present a method for selective precipitation of plasmid DNA from a clarified alkaline lysate using polycation poly(N,N'-dimethyldiallylammonium) chloride (PDMDAAC). The specific interaction between the polycation and the plasmid DNA resulted in the formation of a stoichiometric insoluble complex. Efficient removal of contaminants such as RNA, by far the major contaminant in a clarified lysate, and proteins as well as 20-fold plasmid concentration has been obtained with about 80% recovery. The method utilizes a inexpensive, commercially available polymer and thus provides a capture step suitable for large-scale production. (C) 2004 Wiley Periodicals, Inc.
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| 6. |
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| 7. |
- Blais, Curtis, et al.
(author)
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Design and Development of an Architecture for Demonstrating the Interplay of Emerging SISO Standards
- 2007
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In: Simulation Interoperability Standards Organization - Spring Simulation Interoperability Workshop 2007, 07 Spring SIW. - 9781604239232 ; , s. 302-309
-
Conference paper (peer-reviewed)abstract
- The Simulation Interoperability Standards Organization (SISO) focuses on facilitating simulation interoperability across government and non-government applications worldwide. A number of standards are emerging that will individually have great impact on the development and operation of simulation systems, as well as interoperation across simulation systems and command and control systems. Taken together, however, the emerging standards represent a set of capabilities and technologies which can revolutionize the simulation industry, radically improving the way we develop and deliver interoperable systems.In the Fall 2006 Simulation Interoperability Workshop, an architecture for demonstrating the interplay of several current and emerging SISO standards was presented. The following standards were selected for development of an initial demonstration system: (1) the Coalition Battle Management Language (C-BML) for unambiguous expression of plans and orders for live, constructive, and robotic forces; (2) the Military Scenario Definition Language (MSDL) for describing a scenarios that can be shared across multiple systems; (3) Base Object Models (BOMs) for specifying building blocks for composing larger model sets; (4) the Simulation Reference Markup Language (SRML) for platform-independent representation of executable behavior models; and (5) the Distributed Interactive Simulation Extensible Markup Language (DIS-XML) initiative for representing DIS Protocol Data Units in XML to enhance interchange of dynamic entity state and entity interactions across diverse systems in web-based network centric architectures.This paper discusses how the framework can be used by the SISO community as a means for educating the community on emerging standards and as a platform for demonstration of new concepts and capabilities as a precursor to a new standardization effort. It describes work performed to design and develop an initial test case demonstrating the integration of these standards, including problems encountered, problem resolutions, lessons learned, and future work.
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| 8. |
- Bodin, Theo, et al.
(author)
-
Road traffic noise, air pollution and myocardial infarction: a prospective cohort study.
- 2016
-
In: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 1432-1246 .- 0340-0131. ; 89:5, s. 793-802
-
Journal article (peer-reviewed)abstract
- Both road traffic noise and air pollution have been linked to cardiovascular disease. However, there are few prospective epidemiological studies available where both road traffic noise and air pollution have been analyzed simultaneously. The aim of this study was to investigate the relation between road traffic noise, air pollution and incident myocardial infarction in both current (1-year average) and medium-term (3-year average) perspective.
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| 9. |
- Budnik, Lygia Therese, et al.
(author)
-
Diagnosis, monitoring and prevention of exposure-related non-communicable diseases in the living and working environment : DiMoPEx-project is designed to determine the impacts of environmental exposure on human health
- 2018
-
In: Journal of Occupational Medicine and Toxicology. - : Springer Science and Business Media LLC. - 1745-6673. ; 13:1
-
Research review (peer-reviewed)abstract
- The WHO has ranked environmental hazardous exposures in the living and working environment among the top risk factors for chronic disease mortality. Worldwide, about 40 million people die each year from noncommunicable diseases (NCDs) including cancer, diabetes, and chronic cardiovascular, neurological and lung diseases. The exposure to ambient pollution in the living and working environment is exacerbated by individual susceptibilities and lifestyle-driven factors to produce complex and complicated NCD etiologies. Research addressing the links between environmental exposure and disease prevalence is key for prevention of the pandemic increase in NCD morbidity and mortality. However, the long latency, the chronic course of some diseases and the necessity to address cumulative exposures over very long periods does mean that it is often difficult to identify causal environmental exposures. EU-funded COST Action DiMoPEx is developing new concepts for a better understanding of health-environment (including gene-environment) interactions in the etiology of NCDs. The overarching idea is to teach and train scientists and physicians to learn how to include efficient and valid exposure assessments in their research and in their clinical practice in current and future cooperative projects. DiMoPEx partners have identified some of the emerging research needs, which include the lack of evidence-based exposure data and the need for human-equivalent animal models mirroring human lifespan and low-dose cumulative exposures. Utilizing an interdisciplinary approach incorporating seven working groups, DiMoPEx will focus on aspects of air pollution with particulate matter including dust and fibers and on exposure to low doses of solvents and sensitizing agents. Biomarkers of early exposure and their associated effects as indicators of disease-derived information will be tested and standardized within individual projects. Risks arising from some NCDs, like pneumoconioses, cancers and allergies, are predictable and preventable. Consequently, preventative action could lead to decreasing disease morbidity and mortality for many of the NCDs that are of major public concern. DiMoPEx plans to catalyze and stimulate interaction of scientists with policy-makers in attacking these exposure-related diseases.
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| 10. |
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| 11. |
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| 12. |
- de Ståhl, Teresita Diaz, et al.
(author)
-
The Swedish childhood tumor biobank : systematic collection and molecular characterization of all pediatric CNS and other solid tumors in Sweden
- 2023
-
In: Journal of Translational Medicine. - : BioMed Central (BMC). - 1479-5876. ; 21
-
Journal article (peer-reviewed)abstract
- The Swedish Childhood Tumor Biobank (BTB) is a nonprofit national infrastructure for collecting tissue samples and genomic data from pediatric patients diagnosed with central nervous system (CNS) and other solid tumors. The BTB is built on a multidisciplinary network established to provide the scientific community with standardized biospecimens and genomic data, thereby improving knowledge of the biology, treatment and outcome of childhood tumors. As of 2022, over 1100 fresh-frozen tumor samples are available for researchers. We present the workflow of the BTB from sample collection and processing to the generation of genomic data and services offered. To determine the research and clinical utility of the data, we performed bioinformatics analyses on next-generation sequencing (NGS) data obtained from a subset of 82 brain tumors and patient blood-derived DNA combined with methylation profiling to enhance the diagnostic accuracy and identified germline and somatic alterations with potential biological or clinical significance. The BTB procedures for collection, processing, sequencing, and bioinformatics deliver high-quality data. We observed that the findings could impact patient management by confirming or clarifying the diagnosis in 79 of the 82 tumors and detecting known or likely driver mutations in 68 of 79 patients. In addition to revealing known mutations in a broad spectrum of genes implicated in pediatric cancer, we discovered numerous alterations that may represent novel driver events and specific tumor entities. In summary, these examples reveal the power of NGS to identify a wide number of actionable gene alterations. Making the power of NGS available in healthcare is a challenging task requiring the integration of the work of clinical specialists and cancer biologists; this approach requires a dedicated infrastructure, as exemplified here by the BTB.
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| 13. |
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| 14. |
- Ganowiak, Katarzyna, et al.
(author)
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Fibrils from Synthetic Amyloid-Related Peptides Enhance Development of Experimental AA-Amyloidosis in Mice
- 1994
-
In: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 199:1, s. 306-312
-
Journal article (peer-reviewed)abstract
- Amyloid enhancing factor is an incompletely characterized activity of extracts from many amyloid-containing tissues and which greatly shortens the preamyloidotic phase during experimental induction of AA-amyloidosis. In this communication we show that amyloid-like fibrils made in vitro from synthetic peptides, corresponding to segments of amyloid fibril proteins, have amyloid enhancing factor-like activity. Thus, there is a possibility that amyloid enhancing factor activity depends on small fibrils serving as nucleation centers for fibril elongation.
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| 15. |
- Gottschalk, Ingo, et al.
(author)
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Improved lectin-mediated immobilization of human red blood cells in superporous agarose beads
- 2003
-
In: Journal of chromatography. B. - 1570-0232 .- 1873-376X. ; 784:1, s. 203-208
-
Journal article (peer-reviewed)abstract
- A new type of agarose bead, superporous agarose, was used as a gel support for immobilization of human red blood cells (RBCs) mediated by wheat germ lectin. The number of immobilized cells was similar to that obtained with commercial wheat germ lectin–agarose but the cell stability appeared to be superior. This allowed improved frontal affinity chromatographic analyses of cytochalasin B (CB)-binding to the glucose transporter GLUT1 which established a ratio of one CB-binding site per GLUT1 dimer for both plain RBCs or those treated with different poly amino acids. The measured dissociation constants, 70±14 nM for CB and 12±3 mM for glucose binding to GLUT1, are similar to those reported earlier.
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| 16. |
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| 17. |
- Gustavsson, Per-Erik, et al.
(author)
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Continuous superporous agarose beds for chromatography and electrophoresis
- 1999
-
In: Journal of chromatography. A. - 0021-9673. ; 832:1-2, s. 29-39
-
Journal article (peer-reviewed)abstract
- Continuous agarose beds (monoliths) were prepared by casting agarose emulsions designed to generate superporous agarose. The gel structures obtained were transected by superpores (diameters could be varied in the range 20–200 μm) through which liquids could be pumped. The pore structure and the basic properties of the continuous gel were investigated by microscopy and size exclusion chromatography. The chromatographic behaviour was approximately the same as for beds packed with homogeneous agarose beads with a particle diameter equivalent to the distance between the superpores. In one application, the superporous continuous agarose bed was derivatized with a NAD+ analogue and used in the affinity purification of bovine lactate dehydrogenase from a crude extract. In another application, a new superporous composite gel material was prepared by adding hydroxyapatite particles to the agarose phase. The composite bed was used to separate a protein mixture by hydroxyapatite chromatography. In a third application, the continuous superporous agarose material was used as an electrophoresis gel. Here, a water-immiscible organic liquid was pumped through the superpores to dissipate the joule heat evolved, thus allowing high current densities.
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| 18. |
- Gustavsson, Per-Erik, et al.
(author)
-
Continuous superporous agarose beds in radial flow columns
- 2001
-
In: Journal of chromatography. A. - 0021-9673. ; 925:1-2, s. 69-78
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Journal article (peer-reviewed)abstract
- Continuous superporous agarose beds constitute a new support material for chromatography, biocatalysis and electrophoresis. The bed consists of a single piece of agarose gel, homogeneously transected by flow-carrying pores, which easily can be varied in the range of 10–100 μm. In this work, large diameter beds (60 mm) were prepared and used in specially designed radial flow columns. The basic chromatographic properties of the beds were investigated by size-exclusion chromatography experiments. In an affinity chromatography application one bed was derivatized with Cibacron Blue 3GA and used for the purification of lactate dehydrogenase from a crude bovine heart extract. In a biotransformation application one bed was provided with immobilized β-galactosidase and used in the production of lactose-free milk.
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| 19. |
- Gustavsson, Per-Erik, et al.
(author)
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Direct measurements of convective fluid velocities in superporous agarose beads
- 1998
-
In: Journal of Chromatography A. - 0021-9673. ; 795:2, s. 199-210
-
Journal article (peer-reviewed)abstract
- Superporous agarose beads contain two sets of pores, diffusion pores and so-called superpores or flow pores, in which the chromatographic flow can transport substances to the interior of each individual bead [Gustavsson and Larsson, J. Chromatogr. A 734 (1996) 231]. The existence of pore flow may be proven indirectly by the chromatographic performance of beads but it has never been directly demonstrated in a chromatographic bed. In this report, pore flow was directly measured by following the movement of micro-particles (dyed yeast cells) in a packed bed. The passage of the micro-particles through the superpores and through the interstitial pores was followed by a microscope/video camera focused on beads which were situated four layers from the glass wall. The video recordings were subsequently used to determine the convective fluid velocities in both the superpores and the interstitial pores. Experiments were carried out with three different bead size ranges, all of which contained superporous beads having an average superpore diameter of 30 mu m. The superpore fluid velocity as % of interstitial fluid velocity was determined to be 2-5% for columns packed with 300-500-mu m beads (3% average value), 6-12% for columns packed with 180-300 mu m beads (7% average value) and 11-24% for columns packed with 106-180-mu m beads (17% average value). These data were compared to and found to agree with theoretically calculated values based on the Kozeny-Carman equation. In order to observe and accurately measure fluid velocities within a chromatographic bed, special techniques were adopted. Also, precautions were made to ensure that the experimental conditions used were representative of normal chromatography runs. (C) 1998 Elsevier Science B.V.
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| 20. |
- Gustavsson, Per-Erik, et al.
(author)
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Fast Chromatography of Proteins.
- 2003
-
In: Isolation and Purification of proteins. (Biotechnology and Bioprocessing ; 27). - 0824707265 ; , s. 423-454
-
Book chapter (other academic/artistic)abstract
- Abstract is not available
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| 21. |
- Gustavsson, Per-Erik, et al.
(author)
-
Monolithic Polysaccharide Materials.
- 2003
-
In: Monolithic Materials: Preparation, Properties and Applications (Journal of Chromatography Library ; 67). - 0444508791 ; 67
-
Book chapter (other academic/artistic)abstract
- Abstract is not available
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| 22. |
- Gustavsson, Per-Erik, et al.
(author)
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Purification of plasmid DNA with a new type of anion-exchange beads having a non-charged surface
- 2004
-
In: Journal of Chromatography A. - : Elsevier BV. - 0021-9673. ; 1038:1-2, s. 131-140
-
Journal article (peer-reviewed)abstract
- We have prepared a new type of anion exchanger, which effectively discriminates between RNA and plasmid DNA. The material is based on a Sephacryl S-500 HR matrix provided with quartenary amine anion-exchange groups. A distinguishing feature of the beads is that a thin (2-3 mum) outer layer of the beads lacks ion-exchange groups. In the synthesis of these beads the vinyl groups in the outer layer of vinylalkyl substituted Sephacryl S-500 HR beads are reacted with bromine. The resulting layer of bromoalkyl groups are hydrolysed, creating an inert outer layer of hydroxyalkyl groups. Finally, bromination and trimethylamine reactions of the inner vinyl groups provide the beads with a core of cationic groups. Large plasmid molecules will not bind to such beads since they are too large to enter the pores and therefore cannot come into contact with the charged matrix in the inner parts of the beads. RNA and protein molecules present in a cleared lysate, on the other hand, readily enter the pores and become adsorbed. A two-column strategy was developed for plasmid purification (recombinant pBluescript, 5.9 kilo base pairs, kbp). The first column was packed with the restricted access anion-exchanger beads (lid beads) and the second column with normal ion-exchange material (same ligand density as the lid beads). Diluted (3 x), cleared lysate was pumped through the tandem columns. The first column was subsequently disconnected from the system and the purified plasmid adsorbed on the second column was eluted in a concentrated form (6x) and with 89% recovery. The two-column procedure removed 99.5% of the RNA and 96% of the proteins. (C) 2004 Elsevier B.V. All rights reserved.
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| 23. |
- Gustavsson, Per-Erik, et al.
(author)
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Superporous agarose, a new material for chromatography
- 1996
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In: Journal of chromatography. A. - : Elsevier BV. - 0021-9673. ; 734:2, s. 231-240
-
Journal article (peer-reviewed)abstract
- This paper reports on a new type of spherical agarose chromatography particles characterized by two sets of pores, normal diffusion pores, characteristic of all agarose materials and very wide pores, so-called superpores or flow pores. These superpores allow part of the chromatographic flow to pass through each individual particle, which gives improved mass transfer, especially in situations where diffusion is the limiting factor for the overall performance of a chromatographic separation. The particles were prepared by a double emulsification procedure. Observations under a microscope and size-exclusion chromatography were used in order to demonstrate pore flow. The chromatographic behaviour of the new particles was as efficient as that of homogeneous particles which were several times smaller. The agarose particles were derivatized with polyethyleneimine and used for an ion-exchange chromatographic separation of three model proteins. As expected from a perfusion material, the superporous beads resolved the protein mixture more efficiently than homogeneous beads of the same size.
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| 24. |
- Gustavsson, Per-Erik, et al.
(author)
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Superporous agarose as an affinity chromatography support
- 1997
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In: Journal of chromatography. A. - 0021-9673. ; 776:2, s. 197-203
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Journal article (peer-reviewed)abstract
- Superporous agarose beads were used as an affinity support in column chromatography. These beads characteristically possess two sets of pores, normal diffusion pores and flow pores, so-called superpores. The superpores, whose diameter is a substantial fraction of the particle diameter (i.e. 1/3 to 1/10 of the particle diameter), allow part of the chromatographic flow to pass through each individual bead. Consequently, significant improvement in mass transfer is observed in superporous beads as compared with homogeneous beads, especially at high flow-rates [Gustavsson and Larsson, J. Chromatogr. A, 734 (1996) 231–240.]Superporous agarose beads and homogeneous agarose beads were each derivatized with two types of affinity ligands. A NAD+ analogue was used for the purification of bovine lactate dehydrogenase and protein A was used for the adsorption of rabbit IgG. The performances of superporous beads and homogeneous beads were compared. Superporous bead columns derivatized with protein A and NAD+ analogue could be operated 5 times and 3 times, respectively, as fast as corresponding homogeneous bead columns.
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| 25. |
- Gustavsson, Per-Erik, et al.
(author)
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Superporous agarose beads as a hydrophobic interaction chromatography support
- 1999
-
In: Journal of Chromatography A. - 0021-9673. ; 830:2, s. 275-284
-
Journal article (peer-reviewed)abstract
- Superporous agarose beads were used as a support for hydrophobic interaction chromatography. These beads have large connecting flow pores in addition to their normal diffusion pores. The flow pores, which are approximately one fifth of the overall diameter of the superporous agarose beads, were earlier shown to give the beads improved mass transfer properties relative to homogeneous agarose beads (Gustavsson and Larsson, J. Chromatogr. A, 734 (1996) 231-240). Superporous agarose beads and homogeneous agarose beads of the same particle size range (106-180 mu m) were derivatized with phenyl groups. The properties of the superporous beads were then compared with the homogeneous beads in the separation of a mixture of three model proteins (ribonuclease A, lysozyme and bovine serum albumin) at various superficial flow velocities from 30 to 600 cm/h. The superporous beads gave satisfactory separation at flow velocities five times higher than was possible for homogeneous beads. The performance of the two types of beads was also compared in the purification of lactate dehydrogenase from a beef heart extract at a superficial flow velocity of 150 cm/h. The superporous beads performed considerably better, leading to twice the purification factor and twice the concentration of the desired product. The results were interpreted using the theoretical treatment given by Carta and Rodrigues (Carta and Rodrigues, Chem. Eng. Sci., 48 (1993) 3927). (C) 1999 Elsevier Science B.V. All rights reserved.
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