The present invention relates to a method of providing a filled product bag of sterile fluid, the method comprising:providing a product bag having multiple bladders, a stem fluidly connected to the multiple bladders, and a filter disposed in-line with the stem；at least partially filling the multiple bladders with a fluid, wherein at least partially filling the multiple bladders includes passing the fluid through the filter and into the multiple bladders；after filling, sealing the multiple bladders；performing an integrity test on the filter； andcorrelating an integrity of the contents of the filled multiple bladders to an integrity of the filter based on an outcome of the integrity test.
