The European Agency for the Evaluation of Medicinal Products Human Medicines Evaluation Unit

Biotechnology products, in many cases recombinant proteins, are derived from a complex expression/production system involving a genetically modified host cell (bacteria, yeast or mammalian cell). Among impurities to be eliminated during the downstream purification process, two components which are of major interest for safety and tolerance reasons are residual host cell DNA and residual host cell proteins (HCP).