Application of Taguchi experimental design to the optimisation of a baculovirus expression system.
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Biomedical subjects
Publications and source records attributed to C H Ferguson.
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Spodoptera frugiperda (Sf-9) insect cells have been grown in serum-free medium in 250-ml spinner flasks. The maximum cell density obtained in these cultures was dependent on the aeration rate of the culture. Similar yields of uninfected cells were obtained when cultures were stirred in spinner flasks at 80 rev min-1 and in a 4-1 stirred-tank bioreactor and the dissolved oxygen in the bioreactor was controlled at 20% of air saturation. Cells were infected with a recombinant baculovirus at different multiplicities of infection: the timing and maximum level of expression of the recombinant protein were dependent on the multiplicity of infection, the cell density at infection, and on the aeration rate of the culture. Oxygen-limited growth resulted in undetectable levels of recombinant protein (< 6 ng recombinant protein 10(-7) cells). Compared with the maximum yields observed in spinner flask cultures, higher levels of recombinant protein were produced when cells were grown and infected in the bioreactor. The level of dissolved oxygen in the bioreactor was controlled at 50% of air saturation.
Signs of revolutionary transformation in the global computer industry are everywhere. A roll call of the major industry players reads like a waiting list in the emergency room. The usual explanations for the industry's turmoil are at best inadequate. Scale, friendly government policies, manufacturing capabilities, a strong position in desktop markets, excellent software, top design skills--none of these is sufficient, either by itself or in combination, to ensure competitive success in information technology. A new paradigm is required to explain patterns of success and failure. Simply stated, success flows to the company that manages to establish proprietary architectural control over a broad, fast-moving, competitive space. Architectural strategies have become crucial to information technology because of the astonishing rate of improvement in microprocessors and other semiconductor components. Since no single vendor can keep pace with the outpouring of cheap, powerful, mass-produced components, customers insist on stitching together their own local systems solutions. Architectures impose order on the system and make the interconnections possible. The architectural controller is the company that controls the standard by which the entire information package is assembled. Microsoft's Windows is an excellent example of this. Because of the popularity of Windows, companies like Lotus must conform their software to its parameters in order to compete for market share. In the 1990s, proprietary architectural control is not only possible but indispensable to competitive success. What's more, it has broader implications for organizational structure: architectural competition is giving rise to a new form of business organization.