Abstract: A method of using an aseptic sampling arrangement. The sampling arrangement includes a septum cartridge and a securing element for use with a fluid enclosure. A locking arrangement is provided to allow selective access to the septum cartridge and the securing element. The sampling arrangement further includes a needle, a tube, and a collection bag. The sampling arrangement can be used to monitor the quality of a fluid product. The method of monitoring includes obtaining a fluid product sample from the fluid enclosure within the collection bag. The collection bag is then incubated for a period of time during which oxygen permeates the bag to simulate post-pasteurizing conditions and/or pre-pasteurizing conditions of the fluid product. The method further includes monitoring the level of contamination detected within the fluid product sample.