Figure 3.

Scheme of a lateral flow test across with (A) standard and (B) competitive immunoassay. In the standard assay, when the sample is added the liquid start flowing to the conjugate pad where the analytes, if present on the sample, can bind to the label particles. The conjugate can flow by capillarity forces across the detection pad where they are captured only if the conjugate has the analytes attached. Instead, in competitive model the analyte and the label particles compete for being captured on the detection pad obtaining a response inversely proportional to the concentration of analytes. Reproduced with permission from ref. [63].