Reveal 2.0 for PSP is a single-step lateral flow device based on a competitive immunoassay format. Shellfish extract is wicked through a reagent zone containing antibodies specific for PSTs that have been conjugated to colored particles. If PSTs 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 PST particle-antibody. Therefore, as the concentration of PSTs in the sample increases, the test line intensity decreases. The membrane also contains a stationary control zone which will always form regardless of the level of PSTs.