{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:08:37Z","timestamp":1760123317062,"version":"build-2065373602"},"reference-count":31,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,1,15]],"date-time":"2025-01-15T00:00:00Z","timestamp":1736899200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Veterinary Sciences"],"abstract":"<jats:p>Population-based sampling has improved pathogen monitoring in the US swine industry by increasing sensitivity while reducing costs. Postmortem tongue fluids (TF) have emerged as a practical option for monitoring porcine reproductive and respiratory syndrome virus (PRRSV) in breeding herds, but limited data exist on optimal storage conditions. This study evaluated PRRSV RNA detection via RT-qPCR in TF samples under various storage times, temperatures, and viral loads. Additionally, the porcine endogenous reference gene (internal sample control, ISC) was assessed for monitoring sample quality. Three studies were conducted: Study 1 compared fresh TF samples to freeze\u2013thaw TF samples, with significantly lower cycle threshold (Ct) values in fresh samples. Studies 2 and 3 evaluated PRRSV RNA stability across six time points (0 to 336 h) and four temperatures (\u221220 \u00b0C, 4 \u00b0C, 22 \u00b0C, and 34 \u00b0C). At 4 \u00b0C, Ct value variation was minimal (\u22641.1) over 14 days (336 h), with no significant changes within 48 h. In contrast, storage at 22 \u00b0C and 34 \u00b0C resulted in increased Ct values. The ISC RNA showed similar stability patterns, maintaining quality at 4 \u00b0C but degrading at higher temperatures. In conclusion, storing TF at \u22644 \u00b0C for up to 14 days for PRRSV and ISC RNA detection is the best scenario, ensuring optimal diagnostic quality.<\/jats:p>","DOI":"10.3390\/vetsci12010059","type":"journal-article","created":{"date-parts":[[2025,1,15]],"date-time":"2025-01-15T05:59:42Z","timestamp":1736920782000},"page":"59","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Effect of Time and Temperature on the Detection of PRRSV RNA and Endogenous Internal Sample Control in Porcine Tongue Fluids"],"prefix":"10.3390","volume":"12","author":[{"given":"Isadora F.","family":"Machado","sequence":"first","affiliation":[{"name":"Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Onyekachukwu H.","family":"Osemeke","sequence":"additional","affiliation":[{"name":"Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kent","family":"Doolittle","sequence":"additional","affiliation":[{"name":"IDEXX Laboratories Inc., Westbrook, ME 04092, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cesar A. A.","family":"Moura","sequence":"additional","affiliation":[{"name":"Iowa Select Farms, Iowa Falls, IA 50126, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lucina","family":"Galina Pantoja","sequence":"additional","affiliation":[{"name":"Genus plc PIC, Hendersonville, TN 37075, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4980-526X","authenticated-orcid":false,"given":"Giovani","family":"Trevisan","sequence":"additional","affiliation":[{"name":"Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2540-8769","authenticated-orcid":false,"given":"Phillip","family":"Gauger","sequence":"additional","affiliation":[{"name":"Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7788-9942","authenticated-orcid":false,"given":"Daniel C. L.","family":"Linhares","sequence":"additional","affiliation":[{"name":"Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,1,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Trevisan, G., Linhares, L.C.M., Crim, B., Dubey, P., Schwartz, K.J., Burrough, E.R., Main, R.G., Sundberg, P., Thurn, M., and Lages, P.T.F. (2019). Macroepidemiological aspects of porcine reproductive and respiratory syndrome virus detection by major United States veterinary diagnostic laboratories over time, age group, and specimen. 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