Sodium dodecyl sulfate-polymer capillary electrophoresis for the analysis of cell culture proteins

The application of sodium dodecyl sulfate (SDS)-polymer capillary electrophoresis (CE) to the analysis of proteins of hybridoma cell culture supernatant is demonstrated. All steps of the developed analysis are shown and discussed. Following optimization of sample preparation and concentration, as well as of the mode of injection all main protein components were separated with high resolution and selectivity. Proteolytic degradation of IgG, due to microbial contamination, was observed on SDS-gel CE and capillary zone electrophoresis (CZE). The technique was applied to monitor the cell cultivation process and concentrations of main components are demonstrated. IgG was found to increase from initially 5 mg/L to 20 mg/L after 4 days and to > 130 mg/L after 14 days of cultivation. The techniques may be applied to other biotechnological processes for the production or purification of proteins.