Improved conformation-dependent immunoassay: suitability for human prion detection with enhanced sensitivity

J Gen Virol. 2003 Jul;84(Pt 7):1921-1925. doi: 10.1099/vir.0.18996-0.


The presence of pathogenic prion protein (PrP(Sc)) in lymphoid tissues of variant Creutzfeldt-Jakob disease (vCJD) patients raises questions as to whether prions may be present in bodily fluids as well. Currently, transgenic mice are highly sensitive in vivo tools for the study of prions in tissues or fluids containing high levels of normal prion protein (PrP(C)). We report here an in vitro assay with virtually equivalent sensitivity incorporating a capture antibody into a sandwich conformation-dependent immunoassay (CDI), resulting in 30- to 100-fold increased sensitivity compared with the original, direct CDI. Furthermore, spiking plasma with vCJD prions in different preparations demonstrated that sandwich CDI detects prions with different biophysical properties at high sensitivity, even without proteinase K pretreatment of samples. Thus, sandwich CDI represents a powerful tool to study prions in bodily fluids of CJD/vCJD patients, with a turnaround time of less than 24 h.

Publication types

  • Evaluation Study

MeSH terms

  • Animals
  • Body Fluids / chemistry*
  • Creutzfeldt-Jakob Syndrome / diagnosis
  • Humans
  • Immunoassay
  • Mice
  • Mice, Inbred BALB C
  • PrPC Proteins / analysis*
  • PrPC Proteins / blood
  • PrPSc Proteins / analysis*
  • PrPSc Proteins / blood
  • Prion Diseases / diagnosis*
  • Protein Conformation*
  • Sensitivity and Specificity


  • PrPC Proteins
  • PrPSc Proteins