Culture Development

Nutrient Supplementation Strategies for Biopharmaceutical Production, Part 2

Some of the numerous feeding strategies are more appropriate than others for certain types of cell culture production systems. Once a nutrient supplement has been identified as described in Part 1 of this three-part review (1), a supplementation strategy must be chosen. Supplementing at too great a rate may expose log-phase cells to stresses such as increased osmolality and lactate levels that would inhibit biomass expansion. But inadequate supplementation can lead to early apoptosis through rapid depletion of selected important…

Nutrient Supplementation Strategies for Biopharmaceutical Production

Cell-culture–related in vitro recombinant protein production is currently a $70-billion/year business. In 2007, biotech drug sales grew by 12.5%, twice as fast as standard pharmaceuticals (1). Current ongoing efforts to maximize productivity in both time and volume directly affect the scale and capital investment required for a bioreactor suite. As cells reach higher concentrations more quickly while each cell pumps out more product than ever before, the number and scale of bioreactors can be reduced. To that end, not only…

DoE Helps Optimize a Cell Culture Bioproduction System

    Typical serum-free culture media used in bioprocessing can have 60–90 components at differing concentrations to feed a single cell line. Media used to grow different cell lines for bioprocessing applications may each require unique optimal chemical formulations. Adding complexity, optimal process conditions such as pH and stirring rate may also differ from cell line to cell line depending on the unique characteristics of process performance. To tackle all those variables, we at Invitrogen Corporation of Carlsbad, CA (www.invitrogen.com/pddirect)…

Rethinking Media Performance

    Fetal bovine serum (FBS) was — and in many cases still is — the supplement of choice to maintain the viability of mammalian cells in culture. However, there are considerable limitations to its use. In the early days of cell culture, the issues surrounding serum were mainly its variable performance and the potential to contaminate cultures with fungi, viruses, and bacteria. Early attempts to produce a serum-free medium (SFM) were academic exercises that usually relied on the use…

Medium and Process Optimization for High Yield, High Density Suspension Cultures: From Low Throughput Spinner Flasks to High Throughput Millilitre Reactors

    The most important contributions to high-yield manufacturing processes for the production of recombinant proteins from cultivated mammalian cells have come from the identification of highly enriched and well-balanced media formulations, and fine tuning the process conditions that support high cell culture densities with high specific productivity. The industry standard yield for immunoglobulins or similar molecules derived from suspension-cultivated mammalian cells in bioreactors has risen during the past 20 years from the tens of mg/L to g/L. The more…

Many Considerations in Selecting Bioproduction Culture Media

    Not long ago, the ability to support efficient large-scale culture of cells was the main factor in choice and development of production media. However, a number of new performance demands have been imposed on production media (as listed in the “Key Factors” box). These new criteria arise from such sources as the demand for increased efficiency in a number of production operations, goals invoked by new quality initiatives, and a more science-based approach to process development. Not only…

Considering Cell Culture Automation in Upstream Bioprocess Development

Cell culture automation has become more common in drug discovery and research applications, thereby freeing bench scientists from repetitive work as well as improving the consistency of their cell culture processes (1). Mammalian cell culture is used in the production of biopharmaceuticals, where developing a production cell line requires a large amount of repetitive manual work for bench scientists. With the increasing importance of biologics in today’s pharmaceutical market, throughput and efficiency are crucial in developing a production cell line.…

Carbohydrates and Their Analysis, Part Three

A large proportion of the therapeutic biotechnology products already in the market or under development are glycoproteins. Therapeutic glycoproteins are produced as recombinant products in cell culture systems, which raises the importance of understanding the biosynthetic events described in the previous installments of this three-part article. Lack of control in a bioprocess could easily change glycosylation patterns by distorting the activities taking place in the Golgi apparatus. Disruption of the delicate balance among substrate availability, optimum pH for specific activities,…

Determining the Effect of Raw Materials on Manufacturing-Scale Cell-Culture Performance

Large-scale cell culture production processes routinely involve multicomponent cell culture media formulations including both chemically defined raw materials and complex raw materials such as hydrolysates (1). Even minor variations in the compositions of either can lead to variability in protein productivity or product quality. That often persists despite the use of a raw material lot-blending strategy at large scales to “average out” raw material trends. And a raw material lot-blending strategy can makes it more difficult to identify which single…