Figure 4.
Continuous online protein size monitoring during steady-state IgG1 production. (A) Viable cell concentration and viability during perfusion culture. Perfusion began around day 3. (B) Viable cell and IgG1 concentrations. The online monitoring was performed from day 11 to day 16. (C) Protein signals in the Target group (including IgG1) measured by the online monitoring system and IgG1 concentration obtained by affinity chromatography (HPLC). From day 12 to 13, analysis of culture supernatant was intentionally stopped (no data points) due to maintenance and validation of sample preparation system. (D) Trend of total amount of proteins measured by the online monitoring system and the offline gel electrophoresis microchip. (E) and (F) Characteristics of proteins in three size groups (LMWP, Target, HMWP) over cultivation time measured by the nanofluidic device (E) and the offline gel electrophoresis microchip (F). For the viable concentration, viability, and offline microchip, error bars are data range (n = 3, technical replicates); For the nanofluidic device, error bars are standard deviation (n = 12).