Thioflavin T (ThT, Thioflavine T, Basic Yellow 1) is a benzothiazole dye that exhibits enhanced fluorescence upon binding to amyloid fibrils and is commonly used to diagnose amyloid fibrils. Thioflavin T is found to exist as micelles at concentrations commonly used to monitor fibrils by fluorescence assay. The micelles of Thioflavin T bind to amyloid fibrils leading to enhancement of fluorescence emission.