<p>A filling apparatus for filling a microplate. The microplate having a plurality of wells each sized to receive an assay. The filling apparatus can comprise an assay input layer having a first surface and an opposing second surface. The assay input layer can comprise an assay input port extending from the first surface to the second surface and at least one pressure nodule extending from the second surface. An output layer can comprise a plurality of staging capillaries each having an inlet and an outlet. The output layer can further comprise a capillary plane disposed above the plurality of staging capillaries in fluid communication with the assay input port. The capillary plane can be sized to draw the assay from the assay input port to generally flood fill the plurality of staging capillaries.</p>