Microscale acoustic disruption of mammalian cells for intracellular product release.

High-throughput microscale models for cell culture are critical for biopharmaceutical process development and drug discovery compound screening. While analytical methods are readily available for quantifying cell number and secreted product concentration, the recovery and measurement of intracellular products are significantly affected by the method of cell disruption. For example, the detergents often used in product extraction are incompatible with lipid-enveloped viruses.

Automated dynamic fed-batch process and media optimization for high productivity cell culture process development.

Current industry practices for large-scale mammalian cell cultures typically employ a standard platform fed-batch process with fixed volume bolus feeding. Although widely used, these processes are unable to respond to actual nutrient consumption demands from the culture, which can result in accumulation of by-products and depletion of certain nutrients. This work demonstrates the application of a fully automated cell culture control, monitoring, and data processing system to achieve significant productivity improvement via dynamic feeding and media optimization.

Characterization of the basic charge variants of a human IgG1: effect of copper concentration in cell culture media.

We report a case study of an IgG1 with a unique basic charge variant profile caused by C-terminal proline amidation on either one or two heavy chains. The proline amidation was sensitive to copper ion concentration in the production media during cell culture: the higher the Cu ( 2+) ion concentration, the higher the level of proline amidation detected. This conclusion was supported by the analysis of samples that revealed direct correlation between the proline amidation level observed from peptide maps and the level of basic peaks measured by imaged capillary isoelectric focusing and a pH gradient ion-exchange chromatography method.

Twin-arginine translocation of active human tissue plasminogen activator in Escherichia coli.

When eukaryotic proteins with multiple disulfide bonds are expressed at high levels in Escherichia coli, the efficiency of thiol oxidation and isomerization is typically not sufficient to yield soluble products with native structures. Even when such proteins are secreted into the oxidizing periplasm or expressed in the cytoplasm of cells carrying mutations in the major intracellular disulfide bond reduction systems (e.g.