Type 1 alpha synuclein pre-formed fibrils (SPR-322) seed the formation of new alpha synuclein fibrils from the pool of alpha synuclein monomers (SPR-321). Thioflavin T is a fluorescent dye that binds to beta sheet-rich structures, such as those in alpha synuclein fibrils. Upon binding, the emission spectrum of the dye experiences a red-shift, and increased fluorescence intensity. Thioflavin T emission curves show increased fluorescence (correlated to alpha synuclein protein aggregation) over time when 10 nM of Type 1 alpha synuclein pre-formed fibrils (SPR-322) is combined with 100 µM of alpha synuclein monomer (SPR-321), as compared to when 10 nM of Type 1 alpha synuclein pre-formed fibrils (SPR-322) is combined with 100 µM of alpha Synuclein monomer (SPR-316). Thioflavin T ex = 450 nm, em = 485 nm.