A device for performing lateral capillary flow may comprise a housing having a proximal end and a distal end, said housing comprising an interior defined between a lower base portion and an upper portion coupled to the lower base portion, wherein the interior includes a region sized and shaped to receive a capillary flow matrix. A reservoir may be located in the upper portion of the housing proximate the proximal end of the housing, the reservoir having an inlet accessible from an exterior of the housing and an outlet in flow communication with an interior of the housing at a location above the region. The device may further comprise a support system disposed in the interior of the housing, the support system comprising a surface positioned in the region sized and shaped to receive a capillary flow matrix and in alignment with the outlet of the reservoir, the surface being configured to receive and support a capillary flow matrix received in the region. An elastically compressible structure may be located between the surface and the lower base portion, the elastically compressible structure being biased to urge the surface toward the outlet of the reservoir in response to a force exerted on the surface in a direction toward the lower base portion.