Protocol for the validation of microbiological control of cellular products according to German regulators recommendations--Boon and Bane for the manufacturer.

In order to generate standardized conditions for the microbiological control of HPCs, the PEI recommended defined steps for validation that will lead to extensive validation as shown in this study, where a possible validation principle for the microbiological control of allogeneic SCPs is presented. Although it could be demonstrated that automated culture improves microbial safety of cellular products, the requirement for extensive validation studies needs to be considered.