In the case of mammalian cell culture where inherent viruses must be removed during purification, to what extent does the equipment suites, etc. need to be segregated?

It’s important when you plan this kind of a facility to think about how you are going to segregate the equipment and the HVAC systems such that you do not get forward flow of any potential contaminants as a result. Many of the facilities that do this work, in fact, are designed with multiple separate HVAC systems to provide this level of insurance.