Abstract: A fluid collection assembly (10) and method for use thereof is provided including a fluid collection cartridge (20) having a tubular member (21) with a plunger assembly slidably inserted. The plunger assembly includes a stopper (32) and a plunger rod (31). The stopper and plunger rod are removably interlocked together which enables the plunger rod to exert a force in a distal direction on the stopper and to be removed from the stopper upon the application of a proximal force thereto. The fluid collection assembly is particular useful in the collection of arterial blood. In use, the assembly is primed with a liquid anticoagulant, the plunger rod is removed, and a blood sample is collected with the arterial pressure causing the stopper to travel in a proximal direction along the cartridge.

Abstract: A container assembly with improved mixing dynamics for mixing substances in preparation for injection by an injection device or for the dispersion of additives in the collection and analysis of biological samples is disclosed. In one configuration, the container assembly includes a first mixing element protruding into an interior of a container. With the container rotated about its longitudinal axis, the first mixing element forms at least one vortex which effectuates mixing of a first substance provided within the container interior and a second substance provided within the container interior.