Monitoring Glycosylation Profile and Protein Titer in Cell Culture Samples UsingZipChip CE-MS

Rapid and sensitive product quality analysis is important for real-time monitoring during biopharmaceutical development and manufacturing. However, low level of protein concentration and complex cell culture matrix pose challenges for product quality characterization at early stages of cell line selection and process development. Here, we describe a fast and simple microfluidic ZipChip CE-MS method to measure quality attributes of monoclonal antibody protein directly from cell culture supernatant. Cell culture supernatant samples were characterized with charge-based separation using microfluidic capillary electrophoresis coupled to a high-resolution mass spectrometer. Under sample reducing conditions, multiple protein glycosylation attributes were determined on the heavy chain, whereas titer information was obtained from comparison of light chain signal intensity following sample spiking-in with heavy labeled mAb. Therefore, the protein expression and product quality can be monitored using the same method with a single microfluidic device. A total volume of ten to fifty microliter of cell culture supernatant is needed, whereas analysis time is within three minutes per sample. In addition, comparison of new method with traditional RP-LC-MS method using a set of time-course bioreactor cell culture samples has been performed. A good correlation of the levels of N-glycosylation attributes between ZipChip CE-MS of crude samples and RPLCMS analysis following Protein A (ProA) purification step has been demonstrated.