A refrigeration appliance includes a housing and toothed profiles which are fixed to the housing. The liquid crystal dispensing apparatus includes a frame, a table, at least one liquid crystal discharge device, and a liquid crystal amount inspecting portion. Each chamber may include an analyte-specific reagent effective to react with a selected analyte that may be present in the sample, and detection means for detecting the signal. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. The passive interlock structure feature includes recesses formed in the tops or bottoms of the containers, and corresponding complementary low planar projections in the bottoms or tops of the containers.