Control of dissolved carbon dioxide levels is very important to the performance of CHO cell culture processes. Increasing pCO₂ levels are a common problem with large-scale cell culture operations. This study investigated the relationship between pCO₂, pH, lactate levels, and NaOH additions. While attempting to study affects of pCO₂, it became difficult to understand experimental results due to pH variations that affected the pCO₂ readings. To better understand the system, Abbott Laboratories media was studied in cell-free experiments to examine how the bicarbonate buffering system works, and how it responds to additions of acids and bases. This lead to the creation of a method to normalize pCO₂ with respect to pH. The method was tested at both lab and large scale cell culture.

This method of normalizing pCO₂ data, eliminates the most complicated, nonlinear interaction from analysis, resulting in improved data analysis and process troubleshooting with pCO₂ related problems.