Abstract: A cassette for arranging and loading reagent containers into a staining apparatus includes a housing with a base and walls upstanding from the base to define a plurality of compartments. Each compartment is configured for receiving a reagent container. The housing includes two portions, pivotably coupled together at respective first ends thereof, and configured to pivot between an open configuration and a closed configuration. Each portion of the housing in the closed configuration is received within a corresponding one of an adjacent pair of channels located within the staining apparatus when the cassette is loaded therewithin.