Representative mammalian cell culture test materials for assessment of primary recovery technologies: A rapid method with industrial applicability

Mammalian cell culture material is often difficult to produce accurately and reproducibly for downstream studies. This article presents a methodology for the creation of a set of cell culture test materials where key variables including cell density, cell viability, product, and the host cell protein (HCP) load can be manipulated individually. The methodology was developed using a glutamine synthetase Chinese hamster ovary cell line cultured at 5‐L and 70‐L scales. Cell concentration post‐cell growth was manipulated using tangential flow filtration to generate a range of target cell densities of up to 100 × 106 cells/mL. A method to prepare an apoptotic cell stock to achieve target viabilities of 40–90% is also described. In addition, a range of IgG1 and HCP concentrations was achieved. The results illustrate that the proposed methodology is able to mimic different cell culture profiles by decoupling the control of the key variables. The cell culture test materials were shown to be representative of typical cell culture feed material in terms of particle size distribution and HCP population. This provides a rapid method to create the required feeds for assessing the feasibility of primary recovery technologies designed to cope with higher cell density cultures. The authors report a method of developing cell culture test materials where the variables, including cell density, viability, product and impurity loads, can be independently controlled. This has industrial and academic potential in overcoming practical obstacles often faced in the testing of