Current and future pharmaceutical products of biotechnology include proteins, nucleic acids, and viral gene vectors. Example 1.4 identified five physical and biochemical features of these biological species by which they could be distinguished in a bioseparation; identified a bioseparation operation that could be used to selectively remove or retain each species from a mixture of the other two; and summarized important considerations in maintaining the activity of each species that would constrain the operating parameters of each bioseparation. Extend that example by listing the purity requirements for FDA approval of each of these three purified species as a parenteral product, which is one that is introduced into a human organism by intravenous, subcutaneous, intramuscular, or intramedullary injection.