May 8-13, 2016
Near-infrared spectroscopy (NIR) has been used to monitor glycerol and methanol, non-invasively during cultures of Pichia pastoris1, 2. In this work, glucose and lactate were measured in Chinese Hamster Ovary (CHO) perfusion culture, in real time, using an online advanced NIR monitor and a reference offline biochemical analyzer. The 1.8-L culture started in the batch phase at 4 g/L glucose with 0.3 x 106 cells/mL and reached 1.5 x 106 cells/mL after 90 hours. Perfusion was then initiated and conducted for 10 days at 0.7 vvd, using a spiral membrane-less microfluidic device3. The maximum cell concentration was 4 x106 cells/mL at 160 hours and was maintained until the termination of the experiment. Online and offline trends were similar (Figure 1). Final concentrations of glucose and lactate were 2.2 g/L and 1.8 g/L, respectively. High performance liquid chromatography (HPLC) was used to measure IgG1.
1 Pasquini, Celio. (2003). Near Infrared Spectroscopy: fundamentals, practical aspects and analytical applications. Journal of the Brazilian Chemical Society, 14(2), 198-219. doi.org/10.1590/S0103-50532003000200006 2 Goldfeld, M., Christensen, J., Pollard, D., Gibson, E. R., Olesberg, J. T., Koerperick, E. J., Lanz, K., Small, G. W., Arnold, M. A. and Evans, C. E. (2014), Advanced near-infrared monitor for stable real-time measurement and control of Pichia pastoris bioprocesses. Biotechnol Progress, 30: 749–759. doi:10.1002/btpr.1890 3Warkiani, M.E., Kah, A., Tay P., Guan, G., Han, J. (2015). Membrane-less microfiltration using inertial microfluidics. Scientific Reports, 5:11018. doi: 10-1038/srep11018