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Song X, Ju Y, Chen L, Zhang W. Construction of Xylose-Utilizing Cyanobacterial Chassis for Bioproduction Under Photomixotrophic Conditions. Methods Mol Biol 2024; 2760:57-75. [PMID: 38468082 DOI: 10.1007/978-1-0716-3658-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Xylose is a major component of lignocellulose and the second most abundant sugar present in nature after glucose; it, therefore, has been considered to be a promising renewable resource for the production of biofuels and chemicals. However, no natural cyanobacterial strain is known capable of utilizing xylose. Here, we take the fast-growing cyanobacteria Synechococcus elongatus UTEX 2973 as an example to develop the synthetic biology-based methodology of constructing a new xylose-utilizing cyanobacterial chassis with increased acetyl-CoA for bioproduction.
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Affiliation(s)
- Xinyu Song
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, People's Republic of China
- Key Laboratory of Systems Bioengineering and Frontier Science Center of Synthetic Biology, The Ministry of Education of China, Tianjin University, Tianjin, People's Republic of China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, People's Republic of China
| | - Yue Ju
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, People's Republic of China
- Key Laboratory of Systems Bioengineering and Frontier Science Center of Synthetic Biology, The Ministry of Education of China, Tianjin University, Tianjin, People's Republic of China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, People's Republic of China
- Key Laboratory of Systems Bioengineering and Frontier Science Center of Synthetic Biology, The Ministry of Education of China, Tianjin University, Tianjin, People's Republic of China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, People's Republic of China.
- Key Laboratory of Systems Bioengineering and Frontier Science Center of Synthetic Biology, The Ministry of Education of China, Tianjin University, Tianjin, People's Republic of China.
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, People's Republic of China.
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2
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Dauer K, Pfeiffer-Marek S, Kamm W, Wagner KG. Microwell Plate-Based Dynamic Light Scattering as a High-Throughput Characterization Tool in Biopharmaceutical Development. Pharmaceutics 2021; 13:pharmaceutics13020172. [PMID: 33514069 PMCID: PMC7911513 DOI: 10.3390/pharmaceutics13020172] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 01/03/2023] Open
Abstract
High-throughput light scattering instruments are widely used in screening of biopharmaceutical formulations and can be easily incorporated into processes by utilizing multi-well plate formats. High-throughput plate readers are helpful tools to assess the aggregation tendency and colloidal stability of biological drug candidates based on the diffusion self-interaction parameter (kD). However, plate readers evoke issues about the precision and variability of determined data. In this article, we report about the statistical evaluation of intra- and inter-plate variability (384-well plates) for the kD analysis of protein and peptide solutions. ANOVA revealed no significant differences between the runs. In conclusion, the reliability and precision of kD was dependent on the plate position of the sample replicates and kD value. Positive kD values (57.0 mL/g, coefficients of variation (CV) 8.9%) showed a lower variability compared to negative kD values (−14.8 mL/g, CV 13.4%). The variability of kD was not reduced using more data points (120 vs. 30). A kD analysis exclusively based on center wells showed a lower CV (<2%) compared to edge wells (5–12%) or a combination of edge and center wells (2–5%). We present plate designs for kD analysis within the early formulation development, screening up to 20 formulations consuming less than 50 mg of active pharmaceutical ingredient (API).
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Affiliation(s)
- Katharina Dauer
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Bonn, 53121 Bonn, Germany;
- Tides Drug Product Pre-Development Sciences, Sanofi-Aventis Deutschland GmbH, Industrial Park Hoechst, 65926 Frankfurt am Main, Germany; (S.P.-M.); (W.K.)
| | - Stefania Pfeiffer-Marek
- Tides Drug Product Pre-Development Sciences, Sanofi-Aventis Deutschland GmbH, Industrial Park Hoechst, 65926 Frankfurt am Main, Germany; (S.P.-M.); (W.K.)
| | - Walter Kamm
- Tides Drug Product Pre-Development Sciences, Sanofi-Aventis Deutschland GmbH, Industrial Park Hoechst, 65926 Frankfurt am Main, Germany; (S.P.-M.); (W.K.)
| | - Karl G. Wagner
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Bonn, 53121 Bonn, Germany;
- Correspondence:
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Tegally H, San JE, Giandhari J, de Oliveira T. Unlocking the efficiency of genomics laboratories with robotic liquid-handling. BMC Genomics 2020; 21:729. [PMID: 33081689 PMCID: PMC7576741 DOI: 10.1186/s12864-020-07137-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 10/11/2020] [Indexed: 02/08/2023] Open
Abstract
In research and clinical genomics laboratories today, sample preparation is the bottleneck of experiments, particularly when it comes to high-throughput next generation sequencing (NGS). More genomics laboratories are now considering liquid-handling automation to make the sequencing workflow more efficient and cost effective. The question remains as to its suitability and return on investment. A number of points need to be carefully considered before introducing robots into biological laboratories. Here, we describe the state-of-the-art technology of both sophisticated and do-it-yourself (DIY) robotic liquid-handlers and provide a practical review of the motivation, implications and requirements of laboratory automation for genome sequencing experiments.
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Affiliation(s)
- Houriiyah Tegally
- Kwazulu-Natal Research and Innovation Sequencing Platform (KRISP), College of Health Sciences, K-RITH Tower Building, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 719 Umbilo Road, Durban, South Africa.
| | - James Emmanuel San
- Kwazulu-Natal Research and Innovation Sequencing Platform (KRISP), College of Health Sciences, K-RITH Tower Building, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 719 Umbilo Road, Durban, South Africa
| | - Jennifer Giandhari
- Kwazulu-Natal Research and Innovation Sequencing Platform (KRISP), College of Health Sciences, K-RITH Tower Building, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 719 Umbilo Road, Durban, South Africa
| | - Tulio de Oliveira
- Kwazulu-Natal Research and Innovation Sequencing Platform (KRISP), College of Health Sciences, K-RITH Tower Building, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 719 Umbilo Road, Durban, South Africa.
- Department of Global Health, University of Washington, 908 Jefferson Street, 13th Floor, Seattle, WA, 98104, USA.
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4
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The Microfluidic Trainer: Design, Fabrication and Validation of a Tool for Testing and Improving Manual Skills. MICROMACHINES 2020; 11:mi11090872. [PMID: 32961810 PMCID: PMC7570042 DOI: 10.3390/mi11090872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/17/2020] [Accepted: 09/17/2020] [Indexed: 11/16/2022]
Abstract
Microfluidic principles have been widely applied for more than 30 years to solve biological and micro-electromechanical problems. Despite the numerous advantages, microfluidic devices are difficult to manage as their handling comes with several technical challenges. We developed a new portable tool, the microfluidic trainer (MT), that assesses the operator handling skills and that may be used for maintaining or improving the ability to inject fluid in the inlet of microfluidic devices for in vitro cell culture applications. After several tests, we optimized the MT tester cell to reproduce the real technical challenges of a microfluidic device. In addition to an exercise path, we included an overfilling indicator and a correct infilling indicator at the inlet (control path). We manufactured the MT by engraving a 3 mm-high sheet of methacrylate with 60W CO2 laser plotter to create multiple capillary paths. We validated the device by enrolling 21 volunteers (median age 33) to fill both the MT and a commercial microfluidic device. The success rate obtained with MT significantly correlated with those of a commercial microfluidic culture plate, and its 30 min-continuous use for three times significantly improved the performance. Overall, our data demonstrate that MT is a valid assessment tool of individual performances in using microfluidic devices and may represent a low-cost solution to training, improve or warm up microfluidic handling skills.
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Fan J, Men Y, Hao Tseng K, Ding Y, Ding Y, Villarreal F, Tan C, Li B, Pan T. Dotette: Programmable, high-precision, plug-and-play droplet pipetting. BIOMICROFLUIDICS 2018; 12:034107. [PMID: 29861810 PMCID: PMC5962442 DOI: 10.1063/1.5030629] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 05/09/2018] [Indexed: 05/19/2023]
Abstract
Manual micropipettes are the most heavily used liquid handling devices in biological and chemical laboratories; however, they suffer from low precision for volumes under 1 μl and inevitable human errors. For a manual device, the human errors introduced pose potential risks of failed experiments, inaccurate results, and financial costs. Meanwhile, low precision under 1 μl can cause severe quantification errors and high heterogeneity of outcomes, becoming a bottleneck of reaction miniaturization for quantitative research in biochemical labs. Here, we report Dotette, a programmable, plug-and-play microfluidic pipetting device based on nanoliter liquid printing. With automated control, protocols designed on computers can be directly downloaded into Dotette, enabling programmable operation processes. Utilizing continuous nanoliter droplet dispensing, the precision of the volume control has been successfully improved from traditional 20%-50% to less than 5% in the range of 100 nl to 1000 nl. Such a highly automated, plug-and-play add-on to existing pipetting devices not only improves precise quantification in low-volume liquid handling and reduces chemical consumptions but also facilitates and automates a variety of biochemical and biological operations.
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Affiliation(s)
- Jinzhen Fan
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | | | - Kuo Hao Tseng
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | - Yi Ding
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | - Yunfeng Ding
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | - Fernando Villarreal
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | - Cheemeng Tan
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | - Baoqing Li
- Authors to whom correspondence should be addressed: and
| | - Tingrui Pan
- Authors to whom correspondence should be addressed: and
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6
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Influence of the experimental setup on the determination of enzyme kinetic parameters. Biotechnol Prog 2016; 33:87-95. [DOI: 10.1002/btpr.2390] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 06/21/2016] [Indexed: 11/07/2022]
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7
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Reproducibility of Uniform Spheroid Formation in 384-Well Plates. ACTA ACUST UNITED AC 2016; 21:923-30. [DOI: 10.1177/1087057116651867] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/06/2016] [Indexed: 12/29/2022]
Abstract
Spheroid cultures of cancer cells reproduce the spatial dimension–induced in vivo tumor traits more effectively than the conventional two-dimensional cell cultures. With growing interest in spheroids for high-throughput screening (HTS) assays, there is an increasing demand for cost-effective miniaturization of reproducible spheroids in microtiter plates (MPs). However, well-to-well variability in spheroid size, shape, and growth is a frequently encountered problem with almost every culture method that has prevented the transfer of spheroids to the HTS platform. This variability partly arises due to increased susceptibility of MPs to edge effects and evaporation-induced changes in the growth of spheroids. In this study, we examined the effect of evaporation on the reproducibility of spheroids of tumor and nontumor cell lines in 384-well plates, and show that culture conditions that prevent evaporation-induced medium loss result in the formation of uniform spheroids across the plate. Additionally, we also present a few technical improvements to increase the scalability of the liquid-overlay spheroid culturing technique in MPs, together with a simple software routine for the quantification of spheroid size. We believe that these cost-effective improvements will aid in further improvement of spheroid cultures for HTS drug discovery.
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Rhode H, Schulze M, Renard S, Zimmermann P, Moore T, Cumme GA, Horn A. An Improved Method for Checking HTS/uHTS Liquid-Handling Systems. ACTA ACUST UNITED AC 2016; 9:726-33. [PMID: 15634800 DOI: 10.1177/1087057104269496] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An efficient method is presented to determine precision and accuracy of multichannel liquid-handling systems under conditions near to application. Themethod consists of gravimetrical determination of accuracy and optical determination of precision based on the dilution of absorbing and fluorescent dye solutions in microplates. Mean delivery volume per well can be determined with precision better than a 0.04% coefficient of variation (CV). Optical signal precision, CV( S), is improved by multiwavelength measurements. Precision of absorbance measurement yields a better resolution than precision of fluorescence measurement (0.3% and 1.5%, respectively), indicating that absorbance measurements should be preferred. From CV( S), an upper bound of the precision of the volumes delivered is derived. Method performance is demonstrated with the dispenser CyBi™-Drop and the pipettor CyBi™-Well using different ejection principles; with commonly used fluids; with 96-, 384-, and 1536-well microplates; and with photometric and fluorometric indicators. Precision of the volumes delivered, as obtained with optimized methods, all plate formats, and both devices, is better than 2% CV with 2 µ L set volume and about 1% CV with higher set volumes.
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Affiliation(s)
- Heidrun Rhode
- Institute of Biochemistry, Friedrich Schiller University, Medical Faculty, D-07740 Jena, Germany.
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Hentz NG, Knaide TR. Effect of Liquid-Handling Accuracy on Assay Performance. ACTA ACUST UNITED AC 2014; 19:153-62. [DOI: 10.1177/2211068213504095] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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10
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Bushway PJ, Azimi B, Heynen-Genel S. Optimization and application of median filter corrections to relieve diverse spatial patterns in microtiter plate data. ACTA ACUST UNITED AC 2011; 16:1068-80. [PMID: 21900202 DOI: 10.1177/1087057111419028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The standard (STD) 5 × 5 hybrid median filter (HMF) was previously described as a nonparametric local backestimator of spatially arrayed microtiter plate (MTP) data. As such, the HMF is a useful tool for mitigating global and sporadic systematic error in MTP data arrays. Presented here is the first known HMF correction of a primary screen suffering from systematic error best described as gradient vectors. Application of the STD 5 × 5 HMF to the primary screen raw data reduced background signal deviation, thereby improving the assay dynamic range and hit confirmation rate. While this HMF can correct gradient vectors, it does not properly correct periodic patterns that may present in other screening campaigns. To address this issue, 1 × 7 median and a row/column 5 × 5 hybrid median filter kernels (1 × 7 MF and RC 5 × 5 HMF) were designed ad hoc, to better fit periodic error patterns. The correction data show periodic error in simulated MTP data arrays is reduced by these alternative filter designs and that multiple corrective filters can be combined in serial operations for progressive reduction of complex error patterns in a MTP data array.
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Affiliation(s)
- Paul J Bushway
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA.
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11
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Microlitre/millilitre shaken bioreactors in fermentative and biotransformation processes – a review. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420600667684] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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12
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Capelle MAH, Gurny R, Arvinte T. A high throughput protein formulation platform: case study of salmon calcitonin. Pharm Res 2008; 26:118-28. [PMID: 18600433 DOI: 10.1007/s11095-008-9662-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Accepted: 06/10/2008] [Indexed: 11/26/2022]
Abstract
PURPOSE The feasibility of using high throughput spectroscopy for characterization and selection of physically stable protein formulations was studied. MATERIALS AND METHODS A hundred aqueous formulations of salmon calcitonin (sCT) were prepared using 20 buffer compositions. The solutions had pH values between 2.5 and 10.5. The stability of the sCT formulations was analyzed over 1 week by the following assays: (1) protein concentration, (2) volume control by measuring pathlength, (3) turbidity (absorbance at 350 nm), (4) intrinsic tyrosine fluorescence, (5) 1-anilino-naphthalene-8-sulfonate (ANS) fluorescence, (6) Nile Red fluorescence. Addition of the dyes (Nile Red and ANS) was used to study protein conformational changes. RESULTS After 1 day, 27 out of the 100 formulations of salmon calcitonin were stable. After 7 days, 12 stable sCT formulations remained. The best salmon calcitonin formulation was in 10 mM sodium acetate buffer with pH values between 3.5 and 5.5. CONCLUSIONS The findings are in accordance with the sCT formulations that were patented and used commercially. This can be considered as a proof of concept for the high throughput protein formulation platform.
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Affiliation(s)
- Martinus A H Capelle
- Department of Pharmaceutics and Biopharmaceutics, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Quai E-Ansermet 30, 1211, Geneva 4, Switzerland
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Quintero C, Rosenstein C, Hughes B, Middleton R, Kariv I. Quality Control Procedures for Dose-Response Curve Generation Using Nanoliter Dispense Technologies. ACTA ACUST UNITED AC 2007; 12:891-9. [PMID: 17517899 DOI: 10.1177/1087057107302114] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
With the advancement of high-throughput biomolecular screening techniques to the lead optimization stage, there is a critical need to quality control (QC) dose-response curves generated by robotic liquid handlers to ensure accurate affinity determinations. One challenge in evaluating the performance of liquid handlers is identifying and validating a robust method for testing dispense volumes across different instruments. Although traditional automated liquid handlers are still considered the standard platform in many laboratories, nanoliter dispensers are becoming more common and pose new challenges for routine quality control procedures. For example, standard gravimetric measurements are unreliable for testing the accuracy of nanoliter liquid dispenses. However, nanoliter dispensing technology allows for the conservation of compound, reduces compound carryover from well to well through discrete dispenses, and eliminates the need for intermediate compound dilution steps to achieve a low final DMSO assay concentration. Moreover, an intermediate dilution step in aqueous solution might result in compound precipitation at high concentrations. This study compared representative automation procedures done on a variety of liquid dispensers, including manual, traditional, and nanodispense volumes. The data confirmed the importance of establishing robust QC procedures for dose-response generation in addition to accuracy and precision determinations for each instrument, and they validated the use of nanoliter pipettors for dose-response testing. The results of this study also support the requirement for thorough mixing during serial compound dilutions prepared for high-throughput lead optimization strategies using traditional liquid handlers. ( Journal of Biomolecular Screening 2007:891-899)
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Capelle MAH, Gurny R, Arvinte T. High throughput screening of protein formulation stability: practical considerations. Eur J Pharm Biopharm 2006; 65:131-48. [PMID: 17107777 DOI: 10.1016/j.ejpb.2006.09.009] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Revised: 09/01/2006] [Accepted: 09/18/2006] [Indexed: 11/28/2022]
Abstract
The formulation of protein drugs is a difficult and time-consuming process, mainly due to the complexity of protein structure and the very specific physical and chemical properties involved. Understanding protein degradation pathways is essential for the success of a biopharmaceutical drug. The present review concerns the application of high throughput screening techniques in protein formulation development. A protein high throughput formulation (HTF) platform is based on the use of microplates. Basically, the HTF platform consists of two parts: (i) sample preparation and (ii) sample analysis. Sample preparation involves automated systems for dispensing the drug and the formulation ingredients in both liquid and powder form. The sample analysis involves specific methods developed for each protein to investigate physical and chemical properties of the formulations in microplates. Examples are presented of the use of protein intrinsic fluorescence for the analysis of protein aqueous properties (e.g., conformation and aggregation). Different techniques suitable for HTF analysis are discussed and some of the issues concerning implementation are presented with reference to the use of microplates.
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Affiliation(s)
- Martinus A H Capelle
- Department of Pharmaceutics and Biopharmaceutics, University of Geneva, University of Lausanne, CH-1211 Geneva 4, Switzerland
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15
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Nealon AJ, O’Kennedy RD, Titchener-Hooker NJ, Lye GJ. Quantification and prediction of jet macro-mixing times in static microwell plates. Chem Eng Sci 2006. [DOI: 10.1016/j.ces.2006.02.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Kensy F, Zimmermann HF, Knabben I, Anderlei T, Trauthwein H, Dingerdissen U, Büchs J. Oxygen transfer phenomena in 48-well microtiter plates: determination by optical monitoring of sulfite oxidation and verification by real-time measurement during microbial growth. Biotechnol Bioeng 2005; 89:698-708. [PMID: 15696519 DOI: 10.1002/bit.20373] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oxygen limitation is one of the most frequent problems associated with the application of shaking bioreactors. The gas-liquid oxygen transfer properties of shaken 48-well microtiter plates (MTPs) were analyzed at different filling volumes, shaking diameters, and shaking frequencies. On the one hand, an optical method based on sulfite oxidation was used as a chemical model system to determine the maximum oxygen transfer capacity (OTR(max)). On the other hand, the Respiration Activity Monitoring System (RAMOS) was applied for online measurement of the oxygen transfer rate (OTR) during growth of the methylotropic yeast Hansenula polymorpha. A proportionality constant between the OTR(max) of the biological system and the OTR(max) of the chemical system were indicated from these data, offering the possibility to transform the whole set of chemical data to biologically relevant conditions. The results exposed "out of phase" shaking conditions at a shaking diameter of 1 mm, which were confirmed by theoretical consideration with the phase number (Ph). At larger shaking diameters (2-50 mm) the oxygen transfer rate in MTPs shaken at high frequencies reached values of up to 0.28 mol/L/h, corresponding to a volumetric mass transfer coefficient (k(L)a) of 1,600 1/h. The specific mass transfer area (a) increases exponentially with the shaking frequency up to values of 2,400 1/m. On the contrary, the mass transfer coefficient (k(L)) is constant at a level of about 0.15 m/h over a wide range of shaking frequencies and shaking diameters. However, at high shaking frequencies, when the complete liquid volume forms a thin film on the cylindric wall of the well, the mass transfer coefficient (k(L)) increases linearly to values of up to 0.76 m/h. Essentially, the present investigation demonstrates that the 48-well plate outperforms the 96-well MTP and shake flasks at widely used operating conditions with respect to oxygen supply. The 48-well plates emerge, therefore, as an excellent alternative for microbial cultivation and expression studies combining the advantages of both the high-throughput 96-well MTP and the classical shaken Erlenmeyer flask.
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Affiliation(s)
- Frank Kensy
- Biochemical Engineering, RWTH Aachen University, Sammelbau Biologie, Worringerweg 1, D-52074 Aachen, Germany
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Taylor PB, Ashman S, Baddeley SM, Bartram SL, Battle CD, Bond BC, Clements YM, Gaul NJ, McAllister WE, Mostacero JA, Ramon F, Wilson JM, Hertzberg RP, Pope AJ, Macarron R. A standard operating procedure for assessing liquid handler performance in high-throughput screening. ACTA ACUST UNITED AC 2003; 7:554-69. [PMID: 14599354 DOI: 10.1177/1087057102238630] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The thrust of early drug discovery in recent years has been toward the configuration of homogeneous miniaturized assays. This has allowed organizations to contain costs in the face of exponential increases in the number of screening assays that need to be run to remain competitive. Miniaturization brings with it an increasing dependence on instrumentation, which over the past several years has seen the development of nanodispensing capability and sophisticated detection strategies. To maintain confidence in the data generated from miniaturized assays, it is critical to ensure that both compounds and reagents have been delivered as expected to the target wells. The authors have developed a standard operating procedure for liquid-handling quality control that has enabled them to evaluate performance on 2 levels. The first level provides for routine daily testing on existing instrumentation, and the second allows for more rigorous testing of new dispensing technologies. The procedure has shown itself to be useful in identifying both method programming and instrumentation performance shortcomings and has provided a means to harmonizing instrumentation usage by assay development and screening groups. The goal is that this type of procedure be used for facilitating the exchange of liquid handler performance data across the industry.
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Affiliation(s)
- Paul B Taylor
- GlaxoSmithKline Pharmaceuticals, Department of Molecular Screening, King of Prussia, PA, USA
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Abstract
The transition from slow, manual, low-throughput screening to industrialized robotic ultra-high throughput screening (uHTS) in the past few years has made it possible to screen hundreds of thousands of chemical entities against a biological target in a short time-frame. The need to minimize the cost of screening has been addressed primarily by reducing the volume of sample to be screened. This, in turn, has resulted in the miniaturization of HTS technology as a whole. Miniaturization requires new technologies and strategies for compound handling, assay development, assay adaptation, liquid handling and automation in addition to refinement of the technologies used for detection systems and data management. This review summarizes current trends in the field of uHTS and illustrates the technological developments that are necessary to enable the routine application of miniaturized uHTS systems within an industrial environment.
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Affiliation(s)
- J Wölcke
- Drug Discovery Services, Screening Operations, Evotec OAI, Schnackenburgallee 114, D-22525, Hamburg, Germany
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