A High Cell Density Transient Transfection System for Therapeutic Protein Expression Based on a CHO GS-Knockout Cell Line: Process Development and Product Quality AssessmentRajendra Y, et al., Biotechnol Bioeng, 112(5):977-86, 2015
Overexpression of Serpinb1 in Chinese Hamster Ovary Cells Increases Recombinant IgG ProductivityLin N, et al., J Biotechnol, 193:91-9, 2015
Microbial Strain Development Using BioLayer InterferometryCantin G, BioProcess International, 12(4):54-57, 2014
New LIC Vectors for Production of Proteins from Genes Containing Rare CodonsEschenfeldt WH, et al., J Struct Funct Genomics, 14, 135-144, 2013
A High-throughput Media Design Approach for High Performance Mammalian Fed-batch CulturesRouiller, Y, et al., mAbs, 5(3), 501-511, 2013
A High-Yielding, CHO-K1-Based Transient Transfection SystemAgrawal, V, et al., BioProcess International, 11(1), 28-35, 2013
Reliable Protein Production in a Pseudomonas Fluorescens Expression SystemRetallack, D., Jin, H., Chew, L., Protein Expression and Purification, 81(2), 157-65, 2012
Recombinant Fab Expression and Secretion in Escherichia Coli Continuous Culture at Medium Cell Densities: Influence of TemperatureCarmona, E. et al., Process Biochemistry, 2012, 47 (3), 446-452, 2012
Identifying Bottlenecks in Transient and Stable Production of Recombinant Monoclonal-antibody Sequence Variants in Chinese Hamster Ovary CellsMason, M., et al., Biotechnology Progress, 28(3), 846-855, 2012
Estimation of Raw Material Performance in Mammalian Cell Culture Using Near infrared Spectra Combined with Chemometrics ApproachesLee, H.W, et al., Biotechnology Progress, 28(3), 824-832, 2012
Impact of Gene Vector Design on the Control of Recombinant Monoclonal Antibody Production by Chinese Hamster Ovary CellsDavies, S.L., et al., Biotechnology Progress, 27 (6), 1689-1699, 2011
Role of Iron and Sodium Citrate in Animal Protein-Free CHO Cell Culture Medium on Cell Growth and Monoclonal Antibody ProductionBai, Y., et al., Biotechnology Progress, 27(1), 209-219, 2011
Soluble Periplasmic Production of Human Granulocyte Colony-stimulating Factor (G-CSF) in Pseudomonas fluorescensJin, H., et al., Protein Expression and Purification, 78(1), 69-77, 2011
High-end pH-controlled Delivery of Glucose Effectively Suppresses Lactate Accumulation in CHO Fed-batch CulturesGagnon, M., et al., Biotechnology and Bioengineering, 108(6), 1328-1337, 2011
Binding Rate Screen - A High-Throughput Assay in Soluble Lysate for Prioritizing Protein Expression ConstructsTian-Yu, J., et al., Analytical Biochemistry, 399(2), 276-283, 2010
A Predictive High-Throughput Scale-Down Model of Monoclonal Antibody Production in CHO CellsLegmann, R., et al., Biotechnology and Bioengineering, 104(6), 1107-1120, 2009
Characterization of the Antibody Quantitation Assay with the Octet RED
Amy Bass, Research Associate, Takeda Pharmaceuticals, at the 2nd Annual Workshop on Label-Free Assays for Bioprocessing Ligand Binding and Antibody Characterization, Boston MA, August 2011 For cell line development, it is ideal to have a quick and robust method to accurately determine antibody titer from crude supernatant. We have incorporated the ForteBio quantitation assay into the Takeda San Francisco cell line development platform. The quantitation assay was shown to have high specificity, precision and accuracy as judged by correlation of Octet platform data to HPLC data. The antibody quantitation assay is used in our cell line development platform at the 96 well, fed batch shake flask and bioreactor stages to streamline the evaluation of clones.
The Three A's of Biologicals: Activity, Activity, Activity: Guiding Process Development Using Bioactivity Measurements
Oren Beske, Vice President, Aragen Biosciences at the 2nd Annual Workshop on Label-Free Assays for Bioprocessing Ligand Binding and Antibody Characterization, Boston MA, August 2011 This case study presents an example of a protein therapeutic expressed in mammalian cells that lost significant bioactivity when adapted to an industrial CHO production platform. Further investigation using various bioassays revealed that the reduction in specific activity was due to a fraction of the protein being expressed by the cells in an inactive form. Alternative purification processes were developed to identify and remove the inactive protein species in the preparation. Using the ForteBio Octet platform, an in vitro binding assay was rapidly developed and a kinetic analysis of the interaction revealed that the inactive form of the product possessed a faster dissociation constant from the target, resulting in a reduced affinity constant. With the source of the inactivity understood, a cell culture process was developed to increase specific activity of the expressed protein and identify clones producing product with high specific activity. Both the bioactivity assay and the ForteBio kinetic assay were used to track product quality during process development.
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