Apparatus and methods are provided for cleaning, disinfecting, and/or sterilizing a device. More specifically, a first treatment chamber can be configured to conduct a first treatment stage therein at a first pressure, a first temperature, and a first sterilant concentration. A first passage can be operatively connected to the first treatment chamber and a second treatment chamber can be operatively connected to the first passage and in communication with the first chamber via the first passage. The second chamber can be configured to conduct a second treatment stage therein at a second pressure, a second temperature, and a second sterilant concentration. An object can be treated in the first treatment chamber and moved to the second treatment chamber via the first passage to be treated in the second treatment chamber.