Traditional Host Cell Protein (HCP) ELISA assays depend on the quality of the assay antibodies and provide overall HCP population data only. However, the levels of individual HCP may be independently affected by adjustments in cell culture and purification conditions during process development, suggesting that there is a need consider additional technologies.
Biacore™ systems use a label-free technology with immobilized antibodies for direct detection of HCPs that allows fast assay turnaround with good precision and accuracy. Two-dimensional Fluorescence Difference Gel Electrophoresis does not depend on antibody recognition but relies on pre-labeling of samples and multiplexed fluorescence detection of proteins in a 2-D electrophoresis gel. This technology was used to characterize the effect of different culture conditions on MAb expressing CHO cells in terms of almost 1700 individual host cell protein profiles and overall patterns in harvest material as well as MabSelect SuRe™ flowthrough and eluate fractions.