Apparatus for performing assays on liquid samples accurately, rapidly and simply

An apparatus for performing an assay of a liquid sample comprising a reaction element, said reaction element comprising therein a channel structure defining a sample well and a reaction chamber in fluid communication with each other, said channel structure having a geometry causing a liquid sample placed in said sample well to be drawn into and fill said reaction chamber via capillary action, wherein after said reaction chamber is filled said liquid sample remains stationary in said reaction chamber, wherein said apparatus further comprises a means for monitoring a reaction in the reaction chamber, a means for detecting scattered or reflected light emitted from said reaction chamber, a permanent magnet and an electromagnet, wherein said permanent magnet and said electromagnet are in close enough proximity to said reaction element that said permanent magnet and said electromagnet exert their magnetic fields on said reaction element, with said permanent magnet being situated between said electromagnet and said element.