A Working Cell Bank (WCB) is a cryopreserved collection of cells derived directly from the Master Cell Bank (MCB), prepared in multiple aliquots and used as the direct starting material for individual manufacturing runs of a biopharmaceutical product. By drawing from the WCB for routine production rather than from the MCB, the integrity and longevity of the master stock are preserved throughout the product lifecycle. The WCB must be fully characterized for identity, viability, purity, genetic stability, and absence of adventitious agents in compliance with ICH Q5D and GMP requirements, and multiple WCBs can be generated from a single Master Cell Bank (MCB) to support long-term clinical and commercial manufacturing without risk of genetic drift.
