Wilham JM et al. 2010, Rapid end-point quantitation of prion seeding activity with sensitivity comparable to bioassays (PLoS Pathog 6(12):e1001217, doi 10.1371/journal.ppat.1001217)

This 2010 PLoS Pathogens paper introduced real-time quaking-induced conversion (RT-QuIC), a plate-based assay in which tiny amounts of prion seed trigger misfolding of recombinant prion protein, read out by a fluorescent dye in real time. The authors combined it with serial dilution and a statistical end-point calculation (SD50, the seeding dose giving positives in half of replicate reactions), so that seeding activity could be quantified in about two days instead of the months to years needed for animal bioassay. It was a methods paper tested on animal-derived samples, not a human diagnostic study. Full text is open access and was read in full for this entry. Information only, not medical advice.

Key facts

  • Bibliographic record verified: ten authors led by Jason M. Wilham and ending with Byron Caughey, PLoS Pathogens volume 6, issue 12, article e1001217, published 2 December 2010; PMID 21152012, PMCID PMC2996325.
  • The assay blends the earlier QuIC and amyloid seeding assay approaches, using bacterially expressed recombinant prion protein as the conversion substrate and a fluorescent amyloid dye as readout.
  • Quantitation uses end-point dilution: samples are diluted serially and the SD50 is estimated, analogous to infectivity titration in animals.
  • Brain tissue from hamsters with 263K scrapie gave SD50 values of roughly 10^11 to 10^12 per gram, which the authors presented as comparable to bioassay sensitivity.
  • Nasal lavage from hamsters with transmissible mink encephalopathy and CSF from 263K-infected hamsters contained detectable seeding activity, indicating these fluids carry measurable prion seed in that model.
  • The assay also separated deer chronic wasting disease and sheep scrapie brain samples from normal controls.
  • Rare apparent false positives occurred in negative controls (2 of 240 wells), which the authors attributed either to spontaneous fibril formation or to contamination and said could be handled by retesting.
  • The work came from the NIAID Rocky Mountain Laboratories with co-authors at Cagliari, Montana State, Nagasaki and Alberta, funded by the NIAID Intramural Research Program, with no competing interests declared.

Timeline

  1. 2010Manuscript received (4 May).
  2. 2010Accepted (3 November).
  3. 2010Published online 2 December in PLoS Pathogens 6(12).

Last checked 1 November 2026

Sources for this page