Sponsored by: GE Healthcare
Session ends: February 21st, 2014, 3:00pm MST
Answers by: Peggy Lio, Director of Process Science, GE Healthcare
Cell culture media, including basal media and feeds, are key elements impacting the performance of bioprocesses. Advancements in cellular and metabolic understanding, coupled with high throughput applications, have led to evolved approaches in medium development and optimization resulting in innovative cell culture media with desired characteristics to meet specific needs.
However, challenges associated with the use of cell culture media still exist. Examples include manufacturability, subpar stability, inconsistent performance and/or underperformance in terms of productivity and quality attributes. In some cases, troubleshooting efforts can be guided by learned know-how but in other circumstances a systematic approach is necessary to identify the root cause. In this Ask the Expert session, we invite you to participate in discussions on experience and lessons learned around cell culture media troubleshooting. Please submit your questions about cell culture media for bioprocessing.
Questions & Answers
Mammalian cells can synthesize fatty acids however they cannot introduce double bonds into fatty acids beyond C9. Therefore, unsaturated fatty acids, such as linoleic acid and linolenic acid, are beneficial for mammalian cell culture. Cholesterol is not essential for mammalian cells except for auxotrophic mutants (e.g. NS0).» Read MoreThere are approaches, such as alternating pH (either acidic or basic) and temperature (mostly warm), that can accelerate/facilitate solubilizing media compounds. However, they don’t necessarily improve solubility (maximum concentration in a saturated solution)issues. Therefore, it is important to also evaluate the composition of your media formulation to assess whether there are components that are at […]» Read MoreThere are several ways of utilizing cell metabolism characteristics for medium optimization. Firstly, the metabolism rate of key medium components such as amino acids and vitamins can easily be determined by spent media analysis. The metabolic profiles can then be used for design of stoichiometrically balanced medium formulations. Since metabolic characteristics are dynamic, utilization of […]» Read MoreThe concentration of glutamine and/or asparagine in your cell culture media should be assessed and limited since both amino acids can be deaminated leading to ammonia as the byproduct. During late stationary phase of mammalian cell culture, cells may utilize alanine to generate pyruvate and this process also produces ammonia. Supplementation of pyruvate into the […]» Read MoreMammalian cells can synthesize fatty acids however they cannot introduce double bonds into fatty acids beyond C9. Therefore, unsaturated fatty acids, such as linoleic acid and linolenic acid, are beneficial for mammalian cell culture. Cholesterol is not essential for mammalian cells except for auxotrophic mutants (e.g.,NS0 cells).» Read MoreThere are commercially available serum free media suitable for the optimization of recombinant blood factor expression in CHO or BHK cells. Depending on the cell type and specific molecule of interest, the media may need to be supplemented with other components (e.g., growth factors, cell protection agents, and product dependent factors). Media optimization should always […]» Read MoreFor recombinant protein and monoclonal antibody production, there are commercially available chemically defined cell culture media with equivalent or better performance than non-defined media. For vaccine production applications, media with non-defined components are still widely used.» Read MoreNutrient depletion causes cell apoptosis which can impact productivity levels and/or product quality therefore it is important to supplement media with depleted components. In order to achieve the best performance, a metabolically balanced feed formulation and an optimal feeding schedule should be designed and applied.» Read MoreApoptosis is typically caused by nutrient depletion and/or metabolite accumulation. Nutrient depletion can be prevented by proper feeding strategies. Metabolite accumulation is less of concern in a perfusion process but is often challenging to tackle in a fed-batch process. Media optimization approaches to control the accumulation of metabolites may include: reducing glutamine to control ammonia, […]» Read MoreYes, there are media with alternate carbon sources. For example, galactose, which has a lower metabolizing rate than glucose, may be supplemented into cell culture media to remedy the issue of high lactate generation in certain cell culture situations. Disaccharides are also commonly used in culture media for non-mammalian cells.» Read MoreThere are medium components known for impacting protein glycosylation through different mechanisms. For example, manganese serves as a cofactor in the glycosylation pathway and can improve glycosylation; galactose impacts glycan precursors and may improve glycosylation; high glutamine in medium formulation can cause less glycosylation due to ammonia generation.» Read MorePowder media are typically more stable than liquid media and therefore tend to have a longer shelf life. The salts in liquid media exist in ionized forms and are subject to reaction and degradation. Another common stability issue for liquid media is precipitation of components that are less soluble or formulated at high concentrations. In […]» Read More