Formation of a new fluorescence of human neuronal tau protein

A new fluorescence at 333 nm formed when the solution of human neuronal tau protein was incubated at 37°C. The maximum excitation was at 230 and 280 nm respectively with the quantum yield of about 0.02. It took about 30 h for the complete formation of the new fluorescence and the light scattering increased with the formation procedure. It suggests that the fluorescence resulted from the aggregation of tau molecules in solution.