Reveal 2.0 for DSP is a single-step lateral flow device based on a competitive immunoassay format. In summary, the shellfish extract is wicked through a reagent zone, containing antibodies specific for OA-group toxins that have been conjugated to colored particles. If the toxins are present in the sample, the toxin will be captured by the particle-antibody complex. The complex then is wicked onto a membrane, which contains a stationary capture zone of a toxin-protein conjugate. This zone captures any uncomplexed toxin particle-antibody. Therefore, as the concentration of toxins in the sample increases, the test line intensity decreases. The membrane also contains a stationary control zone which always will form regardless of the level of toxins.