Monoclonal antibodies are usually purified using protein A media for capture. Protein A media are expensive and leaching of the toxic protein A is a disadvantage. Therefore, a purification process avoiding protein A chromatography is an attractive alternative. The goal of the project was to analyse three different chromatography types (cation exchange, anion exchange, HIC) for their ability to purify mAb from cell culture supernatant with a special focus on depletion of host cell proteins and DNA. Different ion exchange and hydrophobic interaction media (all Merck KGaA) were used for purification of a mAb from CHO cell culture supernatant. For each chromatography medium, optimal purification conditions were evaluated and the depletion of host cell proteins (HCP), ssDNA and dsDNA were analysed.
The experiments demonstrate that all three chromatography types are capable of significantly reducing the host cell protein and DNA content. The results also show that a purification process comprising a sequence of these three chromatography steps can become a suitable alternative to a purification process with an integrated protein A affinity chromatography.