(74f) High-Throughput Quantification of Glycoprotein Sialylation

Sialic acid can improve qualities of therapeutic glycoproteins, such as circulatory half life, biological activity, and solubility. In production of therapeutic glycoproteins, a high-throughput method is required for process monitoring and optimization to ensure consistent and optimal sialic acid content. Current methods for quantifying sialic acid, however, require chromatographic purification that is time consuming and cannot rapidly analyze many samples in parallel. Here we present a novel high-throughput method for quantifying glycoprotein sialylation. The method does not require protein purification. It can accurately, rapidly (15 mins), and specifically analyze many samples in parallel. It requires only 45 μL of sample and has a quantitation limit of 2 μM sialic acid. It has also been validated for monitoring sialylation of recombinant interferon-gamma (IFN-γ) produced in Chinese Hamster Ovary (CHO) cell culture. It is currently used for optimization culture conditions to increase sialylation of IFN-γ. This method is useful for various applications in upstream and downstream bioprocesses.