Abstract: The present invention relates to a method for the purification of antibodies from a protein mixture produced in a bioreactor, at least comprising the steps of intermediate purification and polishing, wherein the intermediate purification and polishing step comprises in-line anion exchange chromatography (AEX) treatment and hydrophobic interaction chromatography (HIC) treatment in flow through mode. The present invention further relates to a single operational unit comprising both an anion exchange chromatography part and a hydrophobic interaction chromatography part, which are serially connected, wherein the unit comprises an inlet at the upstream end of the anion exchange chromatography part and an outlet at the downstream end of the hydrophobic interaction chromatography part and wherein the unit also comprises an inlet between the anion exchange chromatography part and the hydrophobic interaction chromatography part.