Table 1.
Synopsis of currently used prion strain differentiation assays
| Assay principle | Test substrate | Speed | Cost |
|---|---|---|---|
| Incubation period in indicator mice (6) | Mice | Years | +++ |
| Histological lesion profile (8, 9) | Mice | Years | +++ |
| Histoblots (24) | Immunohistology | Days | ++ |
| Conformation-dependent immunoassay (12) | ELISA | Days | + |
| Conformational stability assay (13) | Western blot | Days | ++ |
| PK cleavage site (4) | Western blot | Days | + |
| Detection with N-terminal antibodies (5) | Western blot | Days | + |
| Glycosylation profile on Western blot (11) | Western blot | Days | + |
| Amyloid detection by thioflavin and Congo red stains (7) | Histochemistry | Hours | + |
| Luminescent-conjugated polymers (21) | Histochemistry | Hours | + |
| Cell panel assay | Cell culture | Weeks | ++ |
Most assays sport high discriminatory power between few specific strains (e.g. glycosylation profiles for BSE and vCJD) but may perform poorly with other strains. +, low; ++, high; +++, extremely high.