Assay requirements for cell culture process development.

Because the structural parameters which influence product "quality" will vary from protein to protein, the screening methods used during development of each production process will also differ. Thus, not all of the methods described above will be needed for each product. One of the challenges of cell culture process development is choosing the correct structural features to monitor. The next level of process development may involve on-line control of many of the parameters discussed above. This would allow product quality-driven manipulations of culture conditions. The major factor limiting this advance may not be the techniques for real-time analysis, but rather a more thorough understanding of the structural features which describe a high-quality pharmaceutical protein.