Fig. 1: Overview of the Microfluidic-QuIC (Micro-QuIC) assay.
a Kinetic profile of the misfolded PrP, showing Thioflavin T fluorescence intensity as an indicator of prion amplification. The curve progresses from a lag phase to a rapid exponential increase, reflecting prion-induced rPrP misfolding, and culminates in a plateau phase. b Misfolded chronic wasting disease (CWD) prion seeds originating from biological samples are added to rPrP solutions and injected into a microfluidic device. This creates a liquid-air interface between the main channels and side channels. The application of high frequency sound waves (4.6 kHz) induces vibration of the liquid–air interface to create a vortex current. Acoustic waves are applied to these solutions for approximately 3 h while being incubated at 40 °C. If present, PrPRes induces conformational changes of the rPrP. Resulting products are labeled with Thioflavin T, which can be detected under fluorescent microscope (excitation wavelength ~450 nm, emission wavelength ~480 nm.). c Schematic of microfluidic-QuIC device. Double layers of PDMS devices are bonded to the thin glass slides. Mineral oil is injected between the two layers of PDMS to prevent solution evaporation. A piezoelectric transducer is attached on the back of the glass slide. d Photograph of a microfluidic-QuIC device.
