1
|
Huang RZ, Chen KH, Ooi CW, Hoe BC, Lai YR, Hsu M, Chiu CY, Wang SSS, Chang YK. Direct recovery of malate dehydrogenase from highly viscous yeast cell homogenate by a fluidized bed contactor equipped with an agitator. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
2
|
Koppejan V, Ferreira G, Lin D, Ottens M. Mathematical modelling of expanded bed adsorption - a perspective on in silico process design. JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY (OXFORD, OXFORDSHIRE : 1986) 2018; 93:1815-1826. [PMID: 30008502 PMCID: PMC6032964 DOI: 10.1002/jctb.5595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/22/2018] [Accepted: 01/24/2018] [Indexed: 06/08/2023]
Abstract
Expanded bed adsorption (EBA) emerged in the early 1990s in an attempt to integrate the clarification, capture and initial product concentration/purification process. Several mathematical models have been put forward to describe its operation. However, none of the models developed specifically for EBA allows simultaneous prediction of bed hydrodynamics, mass transfer/adsorption and (unwanted) interactions and fouling. This currently limits the development and early optimization of EBA-based separation processes. In multiphase reactor engineering, the use of multiphase computational fluid dynamics has been shown to improve fundamental understanding of fluidized beds. To advance EBA technology, a combination of particle, equipment and process scale models should be used. By employing a cascade of multiscale simulations, the various challenges EBA currently faces can be addressed. This allows for optimal design and selection of equipment, materials and process conditions, and reduces risks and development times of downstream processes involving EBA. © 2018 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- Victor Koppejan
- Delft University of TechnologyDepartment of Biotechnology, Van der Maasweg 9, 2629 HZDelftThe Netherlands
| | - Guilherme Ferreira
- DSM Biotechnology CenterCenter of Integrated BioProcessing, Alexander Fleminglaan 12613AXDelftThe Netherlands
| | - Dong‐Qiang Lin
- College of Chemical and Biological EngineeringZhejiang UniversityHangzhouChina
| | - Marcel Ottens
- Delft University of TechnologyDepartment of Biotechnology, Van der Maasweg 9, 2629 HZDelftThe Netherlands
| |
Collapse
|
3
|
de Araújo Padilha CE, de Araújo Padilha CA, de Santana Souza DF, de Oliveira JA, de Macedo GR, dos Santos ES. Recurrent neural network modeling applied to expanded bed adsorption chromatography of chitosanases produced by Paenibacillus ehimensis. Chem Eng Res Des 2017. [DOI: 10.1016/j.cherd.2016.09.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
4
|
de Araújo Padilha CE, Fortunato Dantas PV, de sousa FC, de Santana Souza DF, de Oliveira JA, de Macedo GR, dos Santos ES. Mathematical modeling of the whole expanded bed adsorption process to recover and purify chitosanases from the unclarified fermentation broth of Paenibacillus ehimensis. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1039:44-50. [DOI: 10.1016/j.jchromb.2016.10.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/17/2016] [Accepted: 10/23/2016] [Indexed: 12/25/2022]
|
5
|
de Araújo Padilha CE, de Araújo NK, de Santana Souza DF, de Oliveira JA, de Macedo GR, dos Santos ES. Modeling and simulation of Bacillus cereus chitosanase activity during purification using expanded bed chromatography. KOREAN J CHEM ENG 2016. [DOI: 10.1007/s11814-016-0127-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
6
|
Lin DQ, Shi W, Tong HF, van de Sandt EJAX, Boer PD, Ferreira GNM, Yao SJ. Evaluation and characterization of axial distribution in expanded bed: II. Liquid mixing and local effective axial dispersion. J Chromatogr A 2015; 1393:65-72. [PMID: 25817706 DOI: 10.1016/j.chroma.2015.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/03/2015] [Accepted: 03/07/2015] [Indexed: 11/30/2022]
Abstract
Expanded bed adsorption (EBA) is a promising technology to capture proteins directly from unclarified feedstock. In order to better understand liquid mixing along the bed height in expanded beds, an in-bed sampling method was used to measure residence time distribution at different bed heights. A 2cm diameter nozzle column was tested with agarose raw beads (3% crosslinked agarose containing tungsten carbide). Two settled bed heights (11.5 and 23.1cm) with different expansion factors (1.4-2.6) were investigated and the number of theoretical plates (N), the height equivalent of theoretical plate (HETP) and the local effective axial dispersion coefficient (Dax) were calculated for each bed height-defined zone. The effects of expansion factor, settled bed height and mobile phase were evaluated. The results showed that N increased with the increase of expansion factors, but Dax was unaffected under fixed bed heights. Dax and HETP were found similar as a function of relative bed height for two settled bed heights tested. Higher mobile phase viscosity resulted in stronger axial dispersion. In addition, the local effective Dax under the expansion factor near 2.0 had a different profile which showed minimum values at 0.6-0.8 relative bed height, and the potential mechanism was discussed. These results would be useful for the characterization of axial dispersion and modeling protein adsorption in expanded beds under varying operation conditions.
Collapse
Affiliation(s)
- Dong-Qiang Lin
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
| | - Wei Shi
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Hong-Fei Tong
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Emile J A X van de Sandt
- DSM Biotechnology Center, Center of Integrated BioProcessing, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands.
| | - Piet den Boer
- Patheon Biologics, Zuiderweg 72/2, 9744 AP Groningen, The Netherlands
| | - Guilherme N M Ferreira
- DSM Biotechnology Center, Center of Integrated BioProcessing, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands
| | - Shan-Jing Yao
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| |
Collapse
|
7
|
Kelly W, Garcia P, McDermott S, Mullen P, Kamguia G, Jones G, Ubiera A, Göklen K. Experimental characterization of next-generation expanded-bed adsorbents for capture of a recombinant protein expressed in high-cell-density yeast fermentation. Biotechnol Appl Biochem 2013; 60:510-20. [PMID: 23745765 DOI: 10.1002/bab.1133] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 05/29/2013] [Indexed: 11/06/2022]
Abstract
Expanded-bed adsorption (EBA) can be particularly useful in protein recovery from high-cell-density fermentation broth where conventional methods for harvest and clarification, such as continuous centrifugation and depth filtration, demand long processing times and are associated with high costs. In this work, the use of next-generation high-particle-density EBA adsorbents, including two mixed-mode resins, for the direct capture of a recombinant protein expressed in yeast at high cell densities is evaluated. Using classical experimental approaches and under different conditions (pH, salt, etc.), Langmuir isotherm parameters for these resins are obtained along with pore diffusivity values. Additional batch adsorption studies with Fastline® MabDirect, the resin that demonstrated the highest static binding capacity for the recombinant protein of interest under the conditions evaluated in this study, indicate competitive binding of nontarget proteins and approximately a 30% reduction in equilibrium binding capacity to 50 mg/mL settled bed in the presence of a 5%-10% cell concentration. Packed-bed (PB) dynamic binding capacities for the MabDirect resin (25-40 mg/mL PB) were significantly higher than for the Fastline® HSA resin and for the MabDirect MM resin in expanded-bed mode (5-10 mg/mL settled bed). Bed expansion behavior for the mMabDirect MM resin along with process yield and eluate purity are identified as a function of linear velocity and cell density, demonstrating process feasibility for pilot scale use.
Collapse
Affiliation(s)
- William Kelly
- College of Engineering, Villanova University, Villanova, PA, USA
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Kelly W, Kamguia G, Mullen P, Ubiera A, Göklen K, Huang Z, Jones G. Using a two species competitive binding model to predict expanded bed breakthrough of a recombinant protein expressed in a high cell density fermentation. BIOTECHNOL BIOPROC E 2013. [DOI: 10.1007/s12257-012-0754-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
9
|
Simulation of the breakthrough curves for the adsorption of α-lactalbumin and β-lactoglobulin to SP Sepharose FF cation-exchanger. Biochem Eng J 2010. [DOI: 10.1016/j.bej.2009.12.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
10
|
Rolland D, Raymond F, Gauthier M, Fournier C, Charrier JP, Jolivet M, Dantigny P. Strategies for improving production and purification of a recombinant protein: rP30 of Toxoplasma gondii expressed in the yeast Schizosaccharomyces pombe. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 861:186-95. [PMID: 17728194 DOI: 10.1016/j.jchromb.2007.07.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 06/08/2007] [Accepted: 07/23/2007] [Indexed: 11/26/2022]
Abstract
Many problems concerned with the production and the purification of recombinant proteins must be addressed prior to launching an industrial production process. Among these problems, attention is focused on low-level expression that complicates the purification step and can jeopardise the process. The expression of a membrane protein, rP30, of Toxoplasma gondii in the yeast Schizosaccharomyces pombe led to a secretion of only 0.5 microg ml(-1). In order to obtain a sufficient quantity for biochemical characterization and evaluation in vitro diagnostic test development, strategies for both production and purification had to be optimized. First, the influence of four nitrogen sources (three peptones and yeast extract) on the growth rate, but also on the separation between the protein and the components of the fermentation broth was assessed. Second, batch and fed-batch fermentations were compared in terms of final biomass and rP30 concentrations. Third, three different protocols that included fixed and expanded bed ion exchange chromatography were compared for processing a large volume of feedstock. By using the most appropriate strategies, i.e. fed-batch fermentation, capture on EBA cation exchanger and affinity chromatography polishing, a purification factor of 1778 and a yield of 49% were achieved. These performances allowed a 12.5-fold increase for the overall rP30 process productivity.
Collapse
Affiliation(s)
- D Rolland
- R&D Department, bioMérieux, Marcy l'Etoile, F-69280, France.
| | | | | | | | | | | | | |
Collapse
|
11
|
Ng YL, Chase HA. Separation and enrichment of neural stem cells using segregation in an expanded bed. Biotechnol Lett 2007; 29:1745-51. [PMID: 17611723 DOI: 10.1007/s10529-007-9458-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 06/11/2007] [Accepted: 06/18/2007] [Indexed: 10/23/2022]
Abstract
An expanded bed system has been developed for a novel application in which the separation and enrichment of neural stem cells from a sample containing a mixture of stem and progenitor cells is achieved based on the difference in the sizes of the aggregates of these types of cells. Inert Sephadex beads and flocculated yeast cells were used as experimental controls and references. The characteristics of the separation of neural stem cell aggregates based on size are similar to those achieved with flocculated yeast where cell-to-cell aggregation controls the pattern of size separation different from those of inert Sephadex beads.
Collapse
Affiliation(s)
- Yuen Ling Ng
- Department of Chemical Engineering, University of Cambridge, Pembroke Street, Cambridge, CB2 3RA, UK
| | | |
Collapse
|
12
|
Liu X, Liu L, Chen H, Chen X. Separation and determination of four active components in medicinal preparations by flow injection-capillary electrophoresis. J Pharm Biomed Anal 2007; 43:1700-5. [PMID: 17337151 DOI: 10.1016/j.jpba.2007.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2006] [Revised: 12/24/2006] [Accepted: 01/02/2007] [Indexed: 11/26/2022]
Abstract
A simple, rapid and accurate method for the separation and determination of paracetamol (Par), pseudoephedrine hydrochloride (Pse), dextromethorphan hydrobromide (Dex) and chlorphenamine hydrogen maleate (Chl) was developed by combination of flow injection and capillary zone electrophoresis for the first time. The analysis was carried out using an unmodified fused-silica capillary (75 mm x 75 microm i.d. x 375 microm o.d., effective separation length of 45 mm) and direct ultraviolet detection at 214 nm, 1.0 kV applied voltage. The optimized running buffer composed of 75 mM sodium borate-15% (v/v) acetonitrile (ACN) (pH* 9.30) was applied for the separation of the four analytes. The separation was achieved in 4.5 min. The sample throughput rate could reach up to 19 h(-1). The repeatability (defined as relative standard deviation) was 0.6%, 1.0%, 2.1%, 1.9% with peak height evaluation and 0.7%, 1.8%, 0.7%, 1.1% with peak area evaluation for Par, Pse, Dex and Chl, respectively. The limits of detection (S/N=3) were 0.22 microg/ml, 0.29 microg/ml, 0.42 microg/ml and 0.70 microg/ml for Par, Pse, Dex and Chl, respectively. The method was successfully applied to determine the four compounds in three cold medicines with recoveries in the range of 97.18-105.15%.
Collapse
Affiliation(s)
- Xiumei Liu
- Department of Chemistry, Lanzhou University, Lanzhou 730000, China
| | | | | | | |
Collapse
|
13
|
Chen WD, Hu HH, Wang YD. Analysis of steric mass-action model for protein adsorption equilibrium onto porous anion-exchange adsorbent. Chem Eng Sci 2006. [DOI: 10.1016/j.ces.2006.07.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
14
|
Rojas EEG, dos Reis Coimbra JS, Minim LA, Saraiva SH, da Silva CAS. Hydrophobic interaction adsorption of hen egg white proteins albumin, conalbumin, and lysozyme. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 840:85-93. [PMID: 16750942 DOI: 10.1016/j.jchromb.2006.04.033] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 03/28/2006] [Accepted: 04/27/2006] [Indexed: 11/26/2022]
Abstract
Hydrophobic adsorption equilibrium data of the hen egg white proteins albumin, conalbumin, and lysozyme were obtained in batch systems, at 25 degrees C, using the Streamline Phenyl resin as adsorbent. The influence of three types of salt, NaCl, Na(2)SO(4), or (NH(4))(2)SO(4), and their concentration on the equilibrium data were evaluated. The salt Na(2)SO(4) showed the higher interaction with the studied proteins, thus favoring the adsorption of proteins by the adsorbent, even though each type of salt interacted in a distinct manner with each protein. The isotherm models of Langmuir, Langmuir exponential, and Chen and Sun were well fitted to the equilibrium data, with no significant difference being observed at the 5% level of significance. The mass transfer model applied simulated correctly adsorption kinetics of the proteins under the studied conditions.
Collapse
Affiliation(s)
- Edwin E Garcia Rojas
- Laboratório de Processos de Separação, LPS, Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, UFV, 36571-000-Viçosa, MG, Brazil
| | | | | | | | | |
Collapse
|
15
|
Chang YK, Horng JT, Huang RZ, Lin SY. Direct recovery of clotting factor IX from unclarified human plasma by expanded bed ion exchange chromatography. Biochem Eng J 2006. [DOI: 10.1016/j.bej.2006.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
16
|
Chang YK, Chen JP, Sheu JR, Cheng PJ, Su CH, Chou SY. Direct recovery of alcohol dehydrogenase from unclarified yeast cell homogenate by IDEBAC using an improved scheme for elution. Biochem Eng J 2006. [DOI: 10.1016/j.bej.2006.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
17
|
Graumann K, Premstaller A. Manufacturing of recombinant therapeutic proteins in microbial systems. Biotechnol J 2006; 1:164-86. [PMID: 16892246 DOI: 10.1002/biot.200500051] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Recombinant therapeutic proteins have gained enormous importance for clinical applications. The first recombinant products have been produced in E. coli more than 20 years ago. Although with the advent of antibody-based therapeutics mammalian expression systems have experienced a major boost, microbial expression systems continue to be widely used in industry. Their intrinsic advantages, such as rapid growth, high yields and ease of manipulation, make them the premier choice for expression of non-glycosylated peptides and proteins. Innovative product classes such as antibody fragments or alternative binding molecules will further expand the use of microbial systems. Even more, novel, engineered production hosts and integrated technology platforms hold enormous potential for future applications. This review summarizes current applications and trends for development, production and analytical characterization of recombinant therapeutic proteins in microbial systems.
Collapse
Affiliation(s)
- Klaus Graumann
- Novartis Biopharmaceutical Operations, Sandoz GmbH, Biochemiestrasse 10, 6250 Kundl, Austria.
| | | |
Collapse
|
18
|
Li P, Xiu G, Mata VG, Grande CA, Rodrigues AE. Expanded bed adsorption/desorption of proteins with Streamline Direct CST I adsorbent. Biotechnol Bioeng 2006; 94:1155-63. [PMID: 16572450 DOI: 10.1002/bit.20952] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Streamline Direct CST I is a new type of ion exchanger with multi-modal functional groups, specially designed for an expanded bed adsorption (EBA) process, which can capture directly the proteins from the high ionic strength feedstocks with a high binding capacity. In this study, an experimental study is carried out for two-component proteins (BSA and myoglobin) competitive adsorption and desorption in an expanded bed packed with Streamline Direct CST I. Based on the measurements of the single- and two-component bovine serum albumin (BSA)/myoglobin adsorption isotherm on Streamline Direct CST I, the binding and elution conditions for the whole EBA process are selected; and then frontal analysis for a longer timescale and column displacement experiments in a fixed bed (XK16/20 column) are carried out to evaluate the two-component proteins (BSA and myoglobin) competitive adsorption and displacement on Streamline Direct CST I. Finally, the feasibility of capturing both BSA and myoglobin by an expanded bed packed with Streamline Direct CST I is addressed in a Streamline 50 column packed with 300 mL Streamline Direct CST I.
Collapse
Affiliation(s)
- Ping Li
- Department of Chemical Engineering, Laboratory of Separation and Reaction Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, s/n 4200-465 Porto, Portugal
| | | | | | | | | |
Collapse
|
19
|
Yun J, Lin DQ, Yao SJ. Predictive modeling of protein adsorption along the bed height by taking into account the axial nonuniform liquid dispersion and particle classification in expanded beds. J Chromatogr A 2005; 1095:16-26. [PMID: 16275279 DOI: 10.1016/j.chroma.2005.07.120] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2005] [Revised: 07/22/2005] [Accepted: 07/25/2005] [Indexed: 11/24/2022]
Abstract
Expanded bed adsorption (EBA) is a special chromatography technique with perfect classification of adsorbent particles in the column, thus the performance of protein adsorption in expanded beds is particular, obviously nonuniform and complex along the column. Detailed description of the complex adsorption kinetics of proteins in expanded bed is essential for better analyzing of adsorptive mechanisms, the design of chromatographic processes and the optimization of operation parameters of EBA processes. In this work, a theoretical model for the prediction of protein adsorption kinetics in expanded beds was developed by taking into account the classified distribution of adsorbent particles along the bed height, the nonuniform behaviors of axial liquid dispersion, the axial variation of local bed voidage as well as the axial changes of target component mass transfer. The model was solved using the implicit finite difference scheme combining with the orthogonal collocation method, and then applied to predict the breakthrough behaviors of bovine serum albumin (BSA) on Streamline DEAE and lysozyme on Streamline SP along the bed height in expanded beds under various conditions. In addition, the experiments of front adsorption of BSA on Streamline DEAE at different axial column positions were carried out to reveal the adsorption kinetics of BSA along the bed height in a 20 mm I.D. expanded bed, and the influences of liquid velocity and feed concentration on the breakthrough behaviors were also analyzed. The breakthrough behaviors predicted by the present model were compared with the experimental data obtained in this work and in the literature published. The agreement between the prediction and the experimental breakthrough curves is satisfied.
Collapse
Affiliation(s)
- Junxian Yun
- Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, PR China
| | | | | |
Collapse
|
20
|
The influence of bakers’ yeast cells on protein adsorption in anion exchange expanded bed chromatography. BIOTECHNOL BIOPROC E 2005. [DOI: 10.1007/bf02932026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
21
|
Johnson ME, Landers JP. Fundamentals and practice for ultrasensitive laser-induced fluorescence detection in microanalytical systems. Electrophoresis 2005; 25:3513-27. [PMID: 15565706 DOI: 10.1002/elps.200406086] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Laser-induced fluorescence is an extremely sensitive method for detection in chemical separations. In addition, it is well-suited to detection in small volumes, and as such is widely used for capillary electrophoresis and microchip-based separations. This review explores the detailed instrumental conditions required for sub-zeptomole, sub-picomolar detection limits. The key to achieving the best sensitivity is to use an excitation and emission volume that is matched to the separation system and that, simultaneously, will keep scattering and luminescence background to a minimum. We discuss how this is accomplished with confocal detection, 90 degrees on-capillary detection, and sheath-flow detection. It is shown that each of these methods have their advantages and disadvantages, but that all can be used to produce extremely sensitive detectors for capillary- or microchip-based separations. Analysis of these capabilities allows prediction of the optimal means of achieving ultrasensitive detection on microchips.
Collapse
Affiliation(s)
- Mitchell E Johnson
- Duquesne University, Department of Chemistry and Biochemistry, Pittsburgh, PA 15282, USA.
| | | |
Collapse
|
22
|
Li P, Xiu G, Rodrigues AE. Experimental and modeling study of protein adsorption in expanded bed. AIChE J 2005. [DOI: 10.1002/aic.10536] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
23
|
|