The present disclosure relates to a filter capsule that supports direct integrity testing of an internal filter element. The filter capsule includes a filter housing having an inlet port, an outlet port, a passage running longitudinally between the inlet port and outlet port and holding a filter element, and an aseptic vent assembly. The filter housing also includes an integrity test assembly that can be used as a direct connection for integrity testing hardware, as opposed to upstream of the filter capsule. In one embodiment, the integrity test assembly comprises a body having a bore formed through its interior and a movable plunger within the bore. The plunger includes a handle to move the plunger between a closed position and an open position. Various seals between the plunger and the bore form a fluid tight seal between various portions of the plunger and the bore.