A system for use in rapid sample analysis that includes a biosensor reagent, wherein the biosensor reagent includes living biological cells; a reservoir card, wherein the reservoir card stores the biosensor reagent; and a test cartridge base, wherein the test cartridge base is configured to accept the reservoir card, and wherein the test cartridge base further includes a reaction chamber having a central axis, wherein the reaction chamber has the shape of a revolved half ellipse; and an inlet channel connected to the reaction chamber, wherein the inlet channel is positioned above the reaction chamber at an angle of 15-60 degrees above the horizontal, and wherein the inlet channel is offset from the central axis of the reaction chamber.