A fluid plug for use with sterile processes such as the manufacture or production of pharmaceuticals and biologics is disclosed. The fluid plug is made of a material or materials that will tolerate sterilizing processes such as gamma irradiation. The fluid plug is used to selectively plug the ends of flexible polymer conduits that may be connected to fluids, reagents, or products used or generated as part of the manufacturing process. Also disclosed is the use of the plugs in combination with a series of valves in a block-and-bleed arrangement to enable the sterile transfer and connection of fluids, reagents, or products within a process flow.