Thioflavin T is a fluorescent dye that binds to beta sheet-rich structures, such as those in alpha synuclein monomers and fibrils. Upon binding, the emission spectrum of the dye experiences a red-shift, and increased fluorescence intensity. The Rat Alpha Synuclein monomer (SPR-481) is very active and was able to form more beta-sheet structure alone than with the combination of monomer and fibril. In combination, the fibril (SPR-482) is the majority of the seed.