Table 1. Comparison of prion detection in a dilutional series of CWD+ cervid brain pool.
| Cervid brain pool homogenate dilution | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Assay | 10−1 | 10−2 | 10−3 | 10−4 | 10−5 | 10−6 | 10−7 | 10−8 | 10−9 | |
| Western Blot | ||||||||||
| BioRad ELISA | ||||||||||
| Mouse Bioassay | ND | *LD50 | ND | ND | ||||||
| sPMCA/WB | ND | ND | ||||||||
| RT-QuIC | NT | NA | ||||||||
| sPMCA/RT-QuIC | NT | |||||||||
CWD+ cervid brain pool homogenate (CBP6) was serially diluted and assayed for prion endpoint dilution. Conventional WB detected prions at 10−1 (unamplified; 500 μg). BioRad ELISA detected prions at 10−1 and 10−2 dilutions (unamplified; 3 mg-300 μg. Tg(CerPrP) 5037 mouse bioassay demonstrates prion infectivity within CBP6 dilutions 10−2–10−6 (300 μg-30 ng). sPMCA/WB detects amyloid seeding activity from 10−1–10−6 (20 μg-2 ng; 10−8–10−9 not done (ND)). Amyloid seeding activity is detected by RT-QuIC from 10−3–10−7 (2 μg-200 pg). RT-QuIC demonstrates no amplification (NA) at dilution 10−2 (20 μg). sPMCA/RT-QuIC detects amyloid seeding activity from 10−2–10−8 (20 μg-20 pg). No assay detected prions at CBP6 dilution 10−9. Bioassay not done (ND) at 10−1 or 10−8–10−9. 10−1 dilutions were not tested (NT) for RT-QuIC and sPMCA/RT-QuIC due to required dilution into PrPC substrate. Shaded squares indicate prion positivity. *LD50 = 105.5.