Cell Bank Preparation and Characterization

One or more properties of a cell line are likely to change during an extended period of continuous passage. In order to ensure consistency of the properties of a cell line or of a product derived from it, it is, therefore, necessary to cryopreserve and characterize a reference stock of cells. Thereafter, throughout a research, development, or manufacturing program cell cultures are discarded after a defined passage interval and the cryopreserved stock used to reinitiate fresh cultures. Although a small number of ampoules in a single bank may be sufficient for a small research program, to ensure continuity of supply of a cell line from a culture collection or for the manufacture of a biopharmaceutical, it is usual to prepare a two-tiered cell bank system. This consists of a master cell bank (MCB) of 50–400 ampoules and manufacturer’s working cell banks (WCB) each derived in an identical manner from one ampoule of the MCB (Table 1 ). In this chapter the methods of preparation, storage, and characterization of such cell banks are described.