A system for conducting an assay comprises a power source (16), a controller (13) for controlling the assay and a plurality of assay units (14) operatively connected to one another such that the controller can communicate with the assay units and the system is capable of conducting the assay. An assay device comprises a substantially circular body (24) having a plurality of chambers in fluid connection such that fluid can pass between said chambers and a central hub (200) having a sample inlet (202) disposed therein for receiving a sample.