BSE: Science & research - Development of rapid biochemical tests for TSE infection (post-mortem)
Background information
Research has been funded in this area since the early stages of the BSE epidemic. This includes the investigation and optimisation of methods to detect the abnormal form of prion protein (PrPSc) in tissues.
Brain samples from suspect cases of TSEs that are identified through surveillance programmes are tested using biochemical methods. The tests used have to be approved by the EU.
Aims
- To improve the sensitivity and accuracy of post-mortem diagnostic tests currently used in cattle and sheep. This may also enable disease detection earlier in the incubation period.
Detection of the prion protein using antibodies and ligands
Current biochemical tests rely on detecting the proteinase K-resistant, abnormal prion protein (PrPSc). The normal prion protein usually found in the body (PrPc) is readily digested by proteinase K. Research has been conducted to look for chemicals or antibodies which can:
- Specifically bind to PrPSc and not PrPc; or
- Differentiate between different TSE strains (see strain typing).
Examples of Defra-funded research in this area include:
- Evaluation of Seprion, a commercial ligand (a chemical that binds to PrPSc), in collaboration with IDEXX (project SE1776). Seprion now forms the basis of the HerdchekTM TSE testing kit;
- Investigation of whether DNA aptamers (single stranded DNA sequences) specific for PrPSc could be developed (project SE1773);
- Isolation and characterisation of novel antibodies directed against the prion protein (project SE2009).
As well as research into developing novel antibodies and ligands, research has also been undertaken to optimise the test methods used to increase the sensitivity e.g. the use of more sensitive detection systems, optimised sample handling techniques.
Links to other information
- Post - mortem tests approved by the EU
- Research into tests that use surrogate markers for TSE infection i.e. non-PrPSc
Page last modified: 7 March, 2008