Prionics®-Check WESTERN
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About the Prionics®-Check WESTERN
The Prionics®-Check WESTERN is the gold standard of rapid BSE testing, and is used as a confirmatory test by most National Reference Laboratories across Europe. It owes its success to its precision and reliability.
Test procedure
- Preparation of the brain sample and isolation of the BSE prion protein
The test sample is a small piece of obex, a defined region of the brain stem. The homogenized brain sample is incubated with an optimized reagent mixture consisting of digestion enzymes and a buffer solution (I). This solution degrades the normal prion protein. Only the BSE-specific prion protein remains in the test sample. - Separation of proteins by gel electrophoresis and immunological detection of BSE prion protein
The proteins in the sample are then separated according to size by gel electrophoresis (II) and transferred to a special blot membrane for detection (III). The BSE-specific prion protein on the membrane is detected with specific antibodies and is visualized on a digital file or on a film.
Performance
The Prionics®-Check WESTERN was the first rapid BSE test officially recognized by the Swiss authorities in 1998. It was also the only test approved by the EU in 1999 which scored 100% sensitivity and 100% specificity, with no repetition of tests required. The Prionics®-Check WESTERN scored excellent results in all the evaluation studies. The test also allowed easy and clear-cut discrimination between positive and negative samples taken from fallen stock which were largely autolyzed (decaying). As the most sold rapid BSE test in the world, the Prionics®-Check WESTERN has also demonstrated its outstanding suitability for use under practical conditions. Under such field conditions, the test has furthermore proven to be able to detect a subclinical BSE infection even before the occurrence of pathological changes in the brain, i.e. the test is able to identify true BSE cases that are negative in histology but positive in immunohistochemistry.
Selected Reading
Chaplin MJ et al. Res Vet Sci 2002 Feb; 72:37-43
Evaluation of the effects of controlled autolysis on the immunodetection of PrPSc by immunoblotting and immunohistochemistry from natural cases of scrapie and BSE.
PubMed Abstract
Fingerprint
The signals generated by the Prionics®-Check WESTERN provide a protein-specific molecular fingerprint. Therefore, result interpretation is clear-cut, making the WESTERN completely reliable. Furthermore, the Western blot is currently the only method in routine testing suited for the discrimination of prion strains.
Prionics®-Check tests allowed for CWD testing in the EU.
EC Decision on a survey for chronic wasting disease in cervids, March 19, 2007
