Fast quantitative determination of monoclonal antibody in infusion bags using protein A nano liquid chromatography

Staphylococcus aureus Protein A was immobilized on an in‐house made neutravidin poly (glycidyl methacrylate‐co‐ethylene dimethacrylate) capillary column with a 25 µm internal diameter, a length of 30 mm and a mass loadability of 60 ng. The immobilized quantity of protein A on the organic monolith was very low, in the pico mole range (1.80 pmol). This was of significance importance when working with less available or expensive purified enzyme. This capillary column was integrated into a nano liquid chromatographic system and used for the fast determination without dilution of the doses of therapeutic monoclonal antibodies (mAbs) in standardized infusion bags prepared in advance in a pharmacy department. This chromatographic method was linear in the studied concentration range with good precision and accuracy. Heat stressed studies indicated that the protein A affinity capillary column was able to monitor degraded mAbs. As well, the high specificity of this column to capture immunoglobulin G2 in cell culture supernatant was visualized. As the mAbs are produced through genetic engineering of animal cells this last result demonstrated that this novel protein A column could be used in the feature for rapid screening of immunoglobulin G concentration in cell culture.