Author Archives: Weichang Zhou

Development, Qualification, and Application of a Bioreactor Scale-Down Process: Modeling Large-Scale Microcarrier Perfusion Cell Culture

Qualified scale-down models of large-scale cell culture processes are essential to conducting studies for applications such as investigating manufacturing deviations, enhancing process understanding, and improving process robustness. For example, scale-down models can be used for raw material investigations as well as evaluation and qualification of new good manufacturing practice (GMP) cell banks for manufacturing implementation. Process characterization studies are performed also with qualified scale-down models to improve process consistency (1, 2). Often it is impractical to conduct investigational studies at…

A Novel Seed-Train Process: Using High-Density Cell Banking, a Disposable Bioreactor, and Perfusion Technologies

A typical cell culture process begins with thawing of a cryopreserved cell-bank vial, followed by successive expansions into larger culture vessels such as shake flasks, spinners, Wave bags, and stirred bioreactors (1). When culture volume and cell density meet predetermined criteria, the culture is transferred to a production bioreactor in which cells continue to grow and express product. This approach presents several challenges. Shake flasks or spinners used in the initial stages require manual manipulations inside a laminar flow hood,…