Container systems for mixing fluids with a magnetic stir bar

A container system includes a substantially rigid container having a floor and a side wall upstanding therefrom. The side wall and floor bound a chamber. A magnetic mixer is disposed below the floor of the container. A mixing bag assembly is disposed within the chamber of the container. The mixing bag assembly includes a collapsible body having a first end and an opposing second end. The collapsible body bounds a compartment. A mixing dish is disposed at the second end of the collapsible body so as to communicate with the compartment thereof. A magnetic stir bar is disposed on the mixing dish.