Recombinant production of biopharmaceuticals leaves contaminating residual proteins from the expression host in the final product in minute amounts, despite multiple purification steps. These host-cell proteins must be identified and quantified.

Using two-dimensional gel electrophoresis (2DE) we elucidate those minor abundant species and identify them by mass spectrometry. If desired targeted quantification is feasible for precise analysis across different product batches and over time.