Regardless of medium and cell line, growth kinetics and mAb production of CHO cell lines in INK 128 cell line 24DW plates was comparable to those grown in shake flasks (Fig. 1). As shown in Fig. 2, cell viabilities were maintained above 80% on Day
7 of culture for all cell lines in both shake flask and 24DW plates. These results indicate that 24DW plates may simulate the performance and dynamics of shake flask and can be used for cell culture process development studies. In order to assess well-to-well variation, CHO line 3 was cultured in all wells of a 24DW plate in a basal medium supplemented with 3 g/L of PP3 peptone. Samples were collected on Day 4 and 7 for assessment of growth. As shown in Table 1, the percent coefficient of variation (%CV) for VCD and viability was <10%, which was consistent with the shake flask culture system (<15%) as observed in our laboratory (data not shown). As shown in Table 2, growth data was uniform across Procaspase activation the plate on various days of culture
and edge effect was not observed. Protein production was determined on the last day of culture and %CV for protein production was less than 5% for entire plate (Table 3). Together, these results show well-to-well consistency and lack of edge effect in 24DW cultures with Duetz sandwich-covers. To assess plate-to-plate variation, a peptone titration study was performed in three 24DW plates with CHO line 5 as described in Materials and Methods. Each plate contained six different concentrations of TCY peptone in duplicate wells. Sample locations were identical across three plates as shown in the plate map (Table 4). Samples were collected and analyzed for growth (Day 5) and production (Day 7). In Fig. 3, growth and production data is presented in a multivariate charts, where each panel represents a plate. Peptone showed a dose dependent effect on growth and protein production in all plates. All three cAMP plates did not show significant differences in mean VCD or production, indicating that the average response was similar across plates, regardless of titration point. Two
way ANOVA analyses were performed to determine the effect of plates and titration on growth. There was a significant difference among titration points (P = 0.00) while plate effect was insignificant (P < 0.081). These results demonstrate 24DW plate-to-plate consistency. Common strategies for enhancing cell performance for biologics production include batch or fed batch supplementation with peptone and/or CD supplements to provide sufficient nutrition. Studies were performed to assess the applicability of 24DW plates for batch and fed batch processes and to determine the correlation between 24DW plate and shake flask culture systems. To compare the performance of 24DW plates and shake flasks in a batch culture process, CHO line 4 was grown in both culture systems in the presence of various concentrations of PP3 peptone. Samples were collected on various days of culture and data is shown (Fig.