When running a test, blood flows into micro-fluidic channels, where plasma is separated from red blood cells by centrifugation. Plasma is then transferred into the reaction and readout chambers, where it dissolves the reagents, blocking buffer and dry magnetic nanoparticles. Magnetic nanoparticles, coated with a specific antigen or antibody, trap the target analyte. A magnetic field is then repeatedly applied to align the nanoparticles into chains and to increase the chains in size and in number.
Finally, a blue laser light is shone through the sample while an oscillating magnetic field is applied. In a negative sample, single particles do not produce a measurable signal.  In a positive sample, nanoparticle chains rotate, scattering the light and producing a signal. The more the analyte, the more the nanoclusters, the higher the signal.