Expansion of suspension cell culture from cell bank to bioreactor is performed through passages of successively larger Erlenmeyer shake flasks. A traditional cap must be unscrewed for each fluid transfer. Risk of contamination is mitigated by performing these fluid transfers in a biosafety cabinet (BSC) or laminar flow hood. Work in a BSC is not preferred because of high maintenance and operating costs, intensive cleaning and decontamination procedures, and the inconvenience of performing operations in the BSC. Despite the use…