NR AXQZ
AU Leathers,V.; Koller,S.
TI Validation of a 1.5 Hour TSE Assay: An Ultra-short Microtiter Based EIA
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Epidemiology, Risk Assessment and Transmission P04.70
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
The IDEXX HerdChek* Bovine Spongiform Encephalopathy (BSE) and IDEXX HerdChek* BSE-Scrapie Antigen Test Kits are transmissible spongiform encephalopathy (TSE) antigen-capture enzyme immunoassays (EIAs) for the detection of the abnormal conformer of PrPsc in postmortem tissues. These assays have an approved "Short" protocol in which the EIA portion of the assay is completed in ~2.2 hours. For laboratories that require a fast turn-around time, IDEXX has validated an even shorter assay protocol in which the EIA part of the test is completed in 1.5 hours. This new "Ultra-Short" assay protocol uses increased temperature (32-37°) and a slow plate shaker during the sample incubation step to accelerate PrPsc capture from viscous brain homogenate samples. The enhanced binding kinetics from the elevated temperature and plate shaker allow for a significant reduction in sample and conjugate incubation times compared to the original "Standard" (4-hour) and "Short" (2.2- hour) protocols. In a study of >2,000 negative bovine brain samples and >2,000 small ruminant samples, the Ultra-Short assay protocol performed with 100% specificity and aligned closely with the original Standard protocol. The population mean OD to cutoff ratio was >15 standard deviations from the test cutoff for both populations. For evaluation of diagnostic sensitivity, twenty BSE positive bovine brain and twenty scrapie positive ovine samples were tested in quadruplicate on the Ultra-Short and Standard protocols, resulting in a diagnostic sensitivity of 100% on both methods. In addition, the OD relative to cutoff values for the positive samples strongly correlated between the two assay protocols with R2 values of > 0.97 for bovine samples and >
0.99 for ovine samples. For evaluation of analytical sensitivity, twenty BSE positive bovine brain samples and twenty scrapie positive ovine samples were serially diluted out to >1:1000 and tested on the Ultra-Short and Standard assay protocols. In all cases, the limit of detection for these samples was the same on both assay protocols. The IDEXX HerdChek* Ultra-Short (1.5-hour) assay protocol delivers the same high level of sensitivity and specificity as seen with the Standard and Short assay protocols. *HerdChek is a trademark or a registered trademark of IDEXX Laboratories, Inc. in the United States and/or other countries.
AD V. Leathers, S. Koller, IDEXX Laboratories, USA
SP englisch
PO Schottland
EA pdf-Datei und Poster (Posterautoren ergänzt um N. Djuranovic)