Recent challenges in the field include those associated with the application of traditional methods to new types of molecules and manufacturing processes. The advent of “ ” production of biologics in lieu of harvesting animal proteins has revolutionized the treatment of disease. While the fruits of the biotechnology revolution are widely acknowledged, the realization of the differences in the means of production and changes in the manner of control of potential impurities and contaminants in regard to the new versus the old are less widely appreciated.