A protocol for setting-up robust hydrophobic interaction chromatography targeting the analysis of intact proteins and monoclonal antibodies.

Hydrophobic interaction chromatography (HIC) is a chromatographic technique that mainly targets the separation of biomolecules (intact proteins, monoclonal antibodies, etc.) based on the difference in surface hydrophobicity while applying non-denaturing conditions. This protocol paper provides guidelines for setting-up robust HIC analysis and considers the instrument configuration, mobile-phase and sample preparation, as well as chromatographic conditions and settings. The separation of a mixture of intact proteins and monoclonal antibodies is demonstrated by applying conventional HIC conditions, that is, using a mildly hydrophobic (C) stationary phase in combination with an inverse ammonium sulphate gradient dissolved in aqueous phosphate buffer. The effect of sample-preparation conditions on sample breakthroughs is presented. Finally, good run-to-run repeatability (relative standard deviation < 2%) is demonstrated for five different columns obtained from three different column lots, considering chromatographic retention, peak width, peak area and column pressure.