The reaction is monitored by Thioflavin-T (ThT) fluorescence and enabled detection of PrP seeds in the cerebrospinal fluid (CSF) of patients with sporadic CJD (sCJD) or genetic forms of prion disease (e.g. GSS and FFI) either in the symptomatic19 or pre-symptomatic stage of the disease20, 21. Here, PRNP is linked to prion disease.