1. INTRODUCTION
This general chapter is intended to provide users with practical guidelines regarding the derivation, production, storage, characterization, and qualification of bacterial and mammalian cell banks used in the manufacture of biological drug products. The chapter is primarily focused on the characterization of cell banks used to produce biological products that are subject to approval by the US FDA. Cell banking characterization and qualification should be based on sound scientific principles and current regulatory guidance. The relevant requirements and guidances for generating cell banks for biotherapeutics seeking FDA approval include the US Code of Federal Regulations (21 CFR Part 610.18) (1), FDA Points to Consider documents (2–4), FDA Guidance for Industry documents, and International Council for Harmonisation (ICH) guidelines (5–8). These guidances state that the final biological product and production should be consistent, uniform, and free from cellular and adventitious contaminants.