Storage of bovine viral diarrhoea virus samples on filter paper and detection of viral RNA by a RT-PCR method

Of four solid carriers tested, Whatman paper No 1 was the best for storing blood and serum samples for the diagnosis of bovine viral diarrhoea (BVD) b y means of viral RNA detection. The filter papers were impregnated with 10 mul of blood or serum, followed by air drying. Samples collected in this wa y from persistently infected animals had lost infectivity within a few days , but viral RNA could still be detected by RT-PCR for up to 6 months. When investigated by RT-PCR, 12 blood and 10 serum samples selected at random fr om animals persistently infected with BVD virus showed the same results whe ther samples had been spotted onto filters or examined directly from the li quid state. The filters spotted with blood or serum are convenient for stor age and transport of samples to a diagnostic laboratory without the need fo r cooling. Sequencing of amplified RNA can be used subsequently for genetic typing. (C) 2001 Elsevier Science B.V. All rights reserved.