Detection of bovine viral diarrhea virus in formalin fixed paraffin embedded tissue sections by real time RT-PCR (Taqman)

Real time quantitative RT-PCR (Taqman(R)) identified specifically BVD virus in freshly processed formalin-fixed paraffin-embedded tissue sections and archival samples up to 7 years old. Samples included tissue from both acutely and persistently infected animals. To assess RNA degradation due to tissue handling and processing, freshly collected tissues from a calf persistently infected with BVD virus were stored at 4degreesC or room temperature for up to 1 week prior to 24 h formalin fixation and routine histologic processing. Samples stored at 4degreesC for up to a week prior to fixation were positive while samples stored at room temperature were positive at 74 h but became negative after 96 h. Fixation of fresh tissue in formalin for 1 week prior to processing resulted in a mild decrease in signal strength compared with tissue fixed for 24-48 h. Real time RT-PCR improves diagnosis of BVD infection by allowing prospective and retrospective identification of BVD virus in tissues processed routinely and stored for histologic evaluation. (C) 2003 Elsevier Science B.V. All rights reserved.