Near Infrared Spectroscopy as an In-Situ PAT Tool to Monitor Adherent VERO Cell Culture Processes

Based on the regulation agency requirements, one of the main challenges for biological production is to improve in-situ monitoring of animal cell industrial processes (PAT approach). Further than pH, pO2 and cell density which are already on-line monitored, the medium component concentrations are key information to improve the process efficiency and ensure the final product quality. Near infrared spectroscopy (NIRS) was proved to be a good candidate to in-situ monitor these parameters in biochemical processes. Nevertheless, only few works reported NIRS use for animal cell cultures and they were only focused on single suspension cells. Consequently, our study was interested in proposing NIRS as a new in-situ tool to quantify glucose and lactate levels, in the particular case of adherent Vero cells highly used in vaccine production. The NIRS quantification technique was challenged with the implementation of various operating conditions close to the industrial process, such as punctual exchange of culture medium with cells grown on microcarriers in stirred bioreactors.