Pre-assembled medical fluid flow system and method of making same

A pre-assembled disposable medical fluid flow system comprising,

• a first sterilized fluid flow system component;
• a second sterilized fluid flow system component;
• a flow path fixedly connected to the first and second sterilized fluid flow system components for providing fluid communication therebetween, the flow path including an isolated portion between the first and second sterilized fluid flow system components;
• an openable closure isolating the first sterilized fluid system component from the isolated portion of the flow path;
• and
• a micro-organism filter disposed between and isolating the isolated portion of the flow path and the second sterilized fluid flow system component such that any fluid from the isolated portion of the flow path must flow through the micro-organism filter to reach the second sterilized fluid flow system component.