A retaining clip for retaining reagent test slides in a stacked arrangement is formed as a unitary member and has first, second and third plates, each having an inner surface and an outer surface. The inner surface of the first plate pivots towards the inner surface of the second plate, and the inner surface of the third plate also pivots such that the inner surfaces of the first and third plates at least partially face each other upon pivoting. The inner surfaces of the first and third plates are separated by a distance to accommodate the reagent test slides in a stacked arrangement. Alternatively, the third and second plates can be fixed rigidly to each other with only the first plate pivoting to at least partially face the third plate upon pivoting.
