HealthDay News — A timed in vitro prion protein (PrP) conversion protocol is sensitive for detecting elk chronic wasting disease (CWD) in brain tissues, according to research published in the Journal of Molecular Diagnostics.

As a novel technique for identification of prion disease, John G. Gray, from the Canadian Food Inspection Agency in Lethbridge, and colleagues present a timed in vitro PrP conversion protocol with accurate, well-defined analytical criteria based on probability density and mass functions of transmissible spongiform encephalopathy (TSE)+ and TSE associated thioflavin T signal times. The method was used in elk CWD in brain tissues.

The researchers found that the sensitivity of the protocol and analytical criteria were similar to those of two bioassay models, and more than 1.2 log10 more sensitive than the most sensitive rapid test for TSE. Timing in vitro PrP conversion could be used to titrate TSE infectivity.

“Our results further support that timing in vitro PrP conversion is a plausible method to titrate TSE infectivity,” the authors write. “This study embodies the first comprehensive analytical sensitivity comparison between an amyloid seeding assay, bioassay, and multiple TSE rapid tests, thus providing considerable insight into the operating range relation between these TSE detection methods.”

The study was supported by the Alberta Livestock and Meat Agency.


Gray JG, Graham C, Dudas S, Paxman E, Vuong B, Czub S. Defining and Assessing Analytical Performance Criteria for Transmissible Spongiform Encephalopathy-Detecting Amyloid Seeding Assays. J Mol Diagn. 2016; doi:10.1016/j.jmoldx.2016.01.005.