Abstract: A sterilizable passageway for a sterilizable enclosure which includes an enclosure having an outer wall, which has a passageway therethrough. A collar lines a periphery of the passageway, the collar having a sealing surface and a heated surface. A heater is positioned to deliver heat to the heated surface of the collar to selectively heat the collar for sterilization. A selectively positionable door is moveable between an operating position wherein it is spaced away from the passageway to permit the passage of articles into or out of the enclosure and a sterilizing position wherein it substantially seals the passageway. This door optimally includes a gasket positioned to contact the sealing surface of the collar when the door is in its sterilizing position.