Figure 1.
Effect of settling time and culture cell concentration on the retention of cells, and the resulting pH and dissolved oxygen (DO) effect. (a) Diagrammatic representation of microscale vessel dimensions detailing the location of optical sensors on the internal base of the vessel. Measurements for vessel geometry taken from Nienow et al (2013). (b) Photograph of two microscale vessels populated with Chinese hamster ovary cell cultures of concentrations of 2 × 107 cells/ml (on the left) and 1 × 108 cells/ml (on the right). The top image (B1) displays a homogenous culture at the initiation of gravity settling whilst the bottom one (B2) displays the same vessels after 30 min of settling. A sediment layer and a cleared fraction are visible in the vessels settled for 30 min indicated by the dashed box. (c) Percentage cell loss from microscale reactor vessel following cell retention by incrementally increasing the gravity settling time from 15 to 30 min, with starting concentration of 6.08 × 106 cells/ml across replicates. Data show mean ± SD, n = 6 [Color figure can be viewed at wileyonlinelibrary.com]