National regulatory authorizations, such as FDA and EMA, require that biopharmaceuticals must be analysed and purified to reduce HCPs to an acceptable level. The HCP acceptance level is evaluated case-by-case and depends on multiple factors including; dose, frequency of drug administration, type of drug and severity of disease. Analysis of HCPs is not simple, since the HCP mixture consists of a large number of protein species, which are unique to the specific host and not related to the intended recombinant protein.[4]