To address these questions outlined above, we have studied the fluorescence of ThT across a wide range of concentrations, from 0.2 to 500 μM, in the presence of three amyloid proteins, Aβ40 and Aβ42 involved in Alzheimer's disease [25], and yeast prion protein Ure2 [26]. This evidence concerns the gene PRNP and early-onset autosomal dominant Alzheimer disease.