A chamfered holding seal member has an edge including an inclined surface. A variety of dials, transmission mechanisms and dilating elements are disclosed which may be combined in a variety of ways. Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium were selected as target organisms in various matrices including ground beef homogenate, apple juice, milk, and phosphate-buffered saline. The device includes means for releasing the rolled protective cover from the storage bag so that, upon release from the storage bag, the protective cover can roll down the inclined top surface by gravity. Also provided are methods for assembling and using components of the animal containment systems. The inlet connection includes an inlet probe having an opening defined by an arc at a downstream side.