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Author

Aleš Štrancar

Bio: Aleš Štrancar is an academic researcher from BIA Separations (Slovenia). The author has contributed to research in topics: Monolithic HPLC column & Monolith. The author has an hindex of 38, co-authored 122 publications receiving 3748 citations.


Papers
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Journal ArticleDOI
TL;DR: A heat release during the polymerization is analyzed and a mathematical model is derived for the prediction of the maximal thickness of the monolithic annulus having a uniform structure for GMA-EDMA monoliths.
Abstract: Monolithic supports have become the subject of extensive study in the past years. Despite their advantageous features and many successful chromatographic applications in the analytical scale, only a very few examples of larger volume monoliths were described. In the case of GMA−EDMA monoliths, this can be attributed to the fact that due to the exothermic polymerization a pronounced temperature increase inside the monolith significantly affects the structure. The temperature increase depends on the thickness of the monolith, and consequently, there is an upper limit that allows the preparation of a unit with a uniform structure. In the present work, we have analyzed a heat release during the polymerization and have derived a mathematical model for the prediction of the maximal thickness of the monolithic annulus having a uniform structure. On the basis of the calculations, two annuluses of different diameters were polymerized and merged into a single monolithic unit with a volume of 80 mL. In addition, a s...

167 citations

Journal ArticleDOI
TL;DR: It could be shown, that up-scaling to the production scale using 800 ml CIM Convective Interaction Media radial flow monoliths is possible under low pressure conditions and CIM DEAE was successfully implemented as intermediate step of the cGMP pDNA manufacturing process.

156 citations

Book ChapterDOI
TL;DR: Short Monolithic Columns (SMC) were engineered to combine both features and have the potential of becoming the method of choice for the purification of larger biomolecules and nanopartides on the semi-preparative scale.
Abstract: Monolithic supports represent a novel type of stationary phases for liquid and gas chromatography, for capillary electrochromatography, and as supports for bioconversion and solid phase synthesis. As opposed to individual particles packed into chromatographic columns, monolithic supports are cast as continuous homogeneous phases. They represent an approach that provides high rates of mass transfer at lower pressure drops as well as high efficiencies even at elevated flow rates. Therefore, much faster separations are possible and the productivity of chromatographic processes can be increased by at least one order of magnitude as compared to traditional chromatographic columns packed with porous particles. Besides the speed, the nature of the pores allows easy access even in the case of large molecules, which make monolithic supports a method of choice for the separation of nanoparticles like pDNA and viruses. Finally, for the optimal purification of larger biomolecules, the chromatographic column needs to be short. This enhances the speed of the separation process and reduces backpressure, unspecific binding, product degradation and minor changes in the structure of the biomolecule, without sacrificing resolution. Short Monolithic Columns (SMC) were engineered to combine both features and have the potential of becoming the method of choice for the purification of larger biomolecules and nanoparticles on the semi-preparative scale.

105 citations

Journal ArticleDOI
TL;DR: Such units can be used for in-process control in production and downstream processing of biopolymers, as was shown in experiments involving the purification of α(1)-antitrypsin and clotting factor IX and the immobilization of enzyme glucose oxidase on an epoxy-activated compact porous disk.
Abstract: Production and downstream processing in biotechnology requires fast and accurate control of each step in the process. Improved techniques which can be validated are required in order to meet these ...

104 citations

Journal ArticleDOI
TL;DR: The results demonstrated that nanoparticle tracking analysis is a method for fast estimation of virus concentration in different samples and it can provide a better insight into the sample status, regarding the level of virus aggregation.
Abstract: The NanoSight LM10 with Nanoparticle tracking analysis (NTA) software was evaluated for the quantification of latex particles, adenovirus 5, and influenza virus. The inter-day variability was determined by measuring the same sample over several consecutive days and the method’s accuracy was demonstrated by using known concentrations of the subject particles. NTA analysis was also used to quantify chromatographic fractions of adenovirus and influenza virus after purification on a CIM monolithic column. NTA results were compared and evaluated against hemagglutination (HA) and end point dilution assay, determining total and infection virus particle number, respectively. The results demonstrated that nanoparticle tracking analysis is a method for fast estimation of virus concentration in different samples. In addition, it can provide a better insight into the sample status, regarding the level of virus aggregation.

95 citations


Cited by
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Journal ArticleDOI
TL;DR: Various purification techniques for higher recovery of glucose oxidase are described here, and issues of enzyme kinetics, stability studies and characterization are addressed.

976 citations

Journal ArticleDOI
TL;DR: The actual and potential performance of monolithic columns are compared with those of packed columns andMonolithic columns have considerable advantages, which makes them most useful in many applications of liquid chromatography.

782 citations

Journal ArticleDOI
TL;DR: This paper is a review of the recent literatures on enzyme immobilization by various techniques, the need for immobilization and different applications in industry, covering the last two decades.
Abstract: Compared to free enzymes in solution, immobilized enzymes are more robust and more resistant to environmental changes. More importantly, the heterogeneity of the immo-bilized enzyme systems allows an easy recovery of both enzymes and products, multiple re-use of enzymes, continuous operation of enzymatic processes, rapid termination of reactions, and greater variety of bioreactor designs. This paper is a review of the recent literatures on enzyme immobilization by various techniques, the need for immobilization and different applications in industry, covering the last two decades. The most recent papers, patents, and reviews on immobilization strategies and application are reviewed.

657 citations

Journal ArticleDOI
Raja Ghosh1
TL;DR: The current state of development in the area of membrane chromatographic separation of proteins is reviewed and the technical challenges facing membrane chromatography are highlighted and the scope for future work is discussed.

539 citations

Journal ArticleDOI
TL;DR: A vast variety of methods that have meanwhile emerged for the preparation of monoliths comprising standard free radical polymerizations, including stable free radicals, atom transfer radical polymerization, and ring-opening metathesis polymerization are presented.

528 citations