The basis of amplifying PrPSc
with RT-QuIC. (a) Schematic illustration of RT-QuIC. PrPSc converts rPrPsen to rPrPres thereby increasing the total amount of β-sheeted PrP. This increase can be demonstrated by the increased value of ThT-fluorescence. Therefore, the sample containing PrPSc (prion) is distinguished from that without PrPSc (non-prion). RFU, relative fluorescence units. (b) However, it was not the amount of newly formed rPrPres but the time to reach the steep increase of amplification (ascendant curves) that was related to the seeded quantity of PK-treated PrPSc (PrP27-30). Different amounts of purified mouse RML scrapie-prion PrP27-30 and normal mouse PrPC were seeded into reactions to perform 80 hours of RT-QuIC. PrPC did not cause ascendant curves.