Table 2

Biochemical analysis methods

MethodFunction of testAdvantagesDisadvantagesReferences
1. Western blot (WB)Detection of protease-resistant PrPSc Standard method used in the diagnosis of prion diseasesRelatively low analytical sensitivity 22–24
2. Sodium phosphotungstic acid (NaPTA) precipitation/western blottingConcentration and detection of protease-resistant PrPSc Can detect low levels of PrPSc, for example, in vCJD spleen and sCJD muscleNot tested for use in routine diagnostics or screening 2 25 26
3. Conformation-dependent immunoassay (CDI)Detection of PrPSc based on concealed epitopes that are exposed when PrPSc is denaturedCan detect protease-sensitive forms of PrPSc Not tested for use in routine diagnostics or screening 28 29
4. Real-time quaking-induced conversion (RT-QuIC)Uses incubation and shaking to recapitulate and accelerate prion replication in vitro using recombinant prion protein (PrP) substrateUltra-sensitive for detecting low levels of sCJD PrPSc Less able to detect vCJD PrPSc 32–34
5. Protein misfolded cyclic amplification (PMCA)Uses incubation and sonication to recapitulate and accelerate prion replication in vitro using brain cellular prion protein PrPC substrateUltra-sensitive for detecting low levels of vCJD PrPSc Less sensitive for sCJD PrPSc in our hands 30 31
  • CJD, Creutzfeldt-Jakob disease; PrP, prion protein; PrPSc, abnormal misfolded form of the PrP; sCJD, sporadic CJD; vCJD, Variant CJD.