A container for storing donated blood plasma has a neck and an attachable locking cap. The cap may be rotatably attached to the neck. The cap and the neck are configured to lock the cap in at least one, and preferably two, rotational positions. In one position, tubes connected to the container are accessible. After the plasma has been collected and the tubes have been cut off and sealed, in the other position, the tube stubs are protected by the cap. The bottle and the cap may define structures that facilitate storing and protecting tubing wrapped longitudinally around the container, until the container is used to collect and store plasma.