Submitted to: Canadian Journal of Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2005
Publication Date: 8/1/2005
Citation: Huang, H., Rendulich, J., Stevenson, D., O'Rourke, K.I., Balachandran, A. 2005. Evaluation of Western blotting methods using samples with or without sodium phosphotungstic acid precipitation for diagnosis of scrapie and chronic wasting disease. Canadian Journal of Veterinary Research. 69(3):193-199.
Interpretive Summary: Scrapie and chronic wasting disease are fatal brain diseases of sheep, goats, deer and elk. Diagnosis of these diseases is made by examination of formalin fixed brain and lymph nodes. If the tissue is unsuitable for this assay or if confirmatory testing is needed, the western blot assay is used. In the paper, the authors describe the use of a modified western blot assay for elk and sheep tissues. The modified technique showed no false positive results and was shown to be a useful assay for confirming the diagnosis of scrapie and chronic wasting disease in deer and elk.
Technical Abstract: Scrapie and chronic wasting disease are fatal neurodegenerative diseases of sheep, deer and elk. The diseases are member of the transmissible spongiform encephalopathies or prion diseases of livestock. Diagnosis of disease is made by detection of the abnormal form of the prion protein (PrP-Sc) by various antibody-based assays. Immunohistochemistry is a gold standard, providing sensitive and specific identification of infected animals. Supplemental testing is useful when tissues are autolyzed or if confirmatory testing is needed. Western blot analysis can be a specific technique but may lack the sensitivity needed to identify animals during preclinical stages of disease. In this paper, the authors evaluate an enrichment technique applied to tissue lysates before western blot assay. The enrichment step increased the sensitivity of the assay 100 fold and produced no false positive results. The enrichment technique was shown to be a useful adjunct to western blot analysis of scrapie and chronic wasting disease tissues.