Abstract: Pass through interlock systems for sanitized environments or "clean rooms" are disclosed which allow for the transfer of objects from outside the sanitized environment without introducing undesirable contaminants therein. The system comprises a frame, box like structure juxtaposed on the back end of a frame, two doors oppositely disposed to each other, an electric mortise lock with solenoid or electric motor, first and second sensors and an electronic controller with power source, that is programmed to automatically lock one door when the opposite door is opened.