Related Experiment Video
Updated: Mar 20, 2026
Real-time Quaking-induced Conversion Assay for Detection of CWD Prions in Fecal Material
Published on: September 29, 2017
Factors That Improve RT-QuIC Detection of Prion Seeding Activity
Christina D Orrú1, Andrew G Hughson2, Bradley R Groveman3
1Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, 59840 MT, USA. christina.orru@nih.gov.
Abstract:
Rapid and sensitive detection of prions is important in managing prion diseases. The real-time quaking-induced conversion (RT-QuIC) assay for prion seeding activity has been applied to many prion diseases and provides for specific antemortem diagnostic testing. We evaluated RT-QuIC's long-term consistency and varied multiple reaction parameters. Repeated assays of a single scrapie sample using multiple plate readers and recombinant prion protein (rPrP(Sen)) substrates gave comparable results. N-terminal truncated hamster rPrP(Sen) (residues 90-231) hastened both prion-seeded and prion-independent reactions but maintained a clear kinetic distinction between the two. Raising temperatures or shaking speeds accelerated RT-QuIC reactions without compromising specificity. When applied to nasal brushings from Creutzfeldt-Jakob disease patients, higher temperatures accelerated RT-QuIC kinetics, and the use of hamster rPrP(Sen) (90-231) strengthened RT-QuIC responses. Elongation of shaking periods reduced scrapie-seeded reaction times, but continuous shaking promoted false-positive reactions. Furthermore, pH 7.4 provided for more rapid RT-QuIC reactions than more acidic pHs. Additionally, we show that small variations in the amount of sodium dodecyl sulfate (SDS) significantly impacted the assay. Finally, RT-QuIC performed in multiplate thermoshakers followed by fluorescence readings in separate plate readers enhanced assay throughput economically. Collectively, these results demonstrate improved speed, efficacy and practicality of RT-QuIC assays and highlight variables to be optimized for future applications.
Insights
Optimizing the real-time quaking-induced conversion (RT-QuIC) assay enhances prion detection speed and accuracy. Key factors like temperature, substrate, and shaking parameters improve diagnostic efficacy for prion diseases.
Area of Science:
- Neuroscience
- Biochemistry
- Medical Diagnostics
Background:
- Prion diseases require rapid and sensitive detection methods.
- The real-time quaking-induced conversion (RT-QuIC) assay is crucial for antemortem diagnosis.
- Assay consistency and parameter optimization are vital for reliable prion detection.
Purpose of the Study:
- To evaluate the long-term consistency of the RT-QuIC assay.
- To investigate the impact of various reaction parameters on RT-QuIC performance.
- To optimize RT-QuIC for improved speed, sensitivity, and practicality in prion disease diagnostics.
Main Methods:
- Assessed RT-QuIC consistency using repeated scrapie sample tests and multiple plate readers.
- Varied reaction parameters including temperature, shaking speed, pH, SDS concentration, and shaking duration.
- Utilized N-terminal truncated hamster recombinant prion protein (rPrP(Sen), residues 90-231) as a substrate.
- Applied optimized RT-QuIC to nasal brushings from Creutzfeldt-Jakob disease patients.
Main Results:
- Consistent results were obtained across repeated assays and different plate readers.
- N-terminal truncated hamster rPrP(Sen) (90-231) accelerated reactions while maintaining specificity.
- Increased temperature and shaking speed enhanced reaction kinetics without compromising specificity.
- Optimized parameters, including pH 7.4 and specific SDS concentrations, improved RT-QuIC speed and response.
- Multiplate thermoshakers with separate fluorescence readers increased assay throughput economically.
Conclusions:
- RT-QuIC assay parameters can be optimized to significantly improve speed, efficacy, and practicality.
- Optimized RT-QuIC offers enhanced diagnostic potential for prion diseases, including Creutzfeldt-Jakob disease.
- Further refinement of RT-QuIC variables will facilitate broader application in prion disease management.
