Post-mortem immunodiagnosis of scrapie and bovine spongiform encephalopathy

Two polyclonal antisera were raised in rabbits against the scrapie-associated fibril protein (PrP) prepared from sheep and mice which were terminally infected with experimental scrapie. The anti-mouse PrP serum identifies the proteins of scrapie-associated fibrils (SAF) from all the host species studied (mouse, hamster, sheep and goat) and bovine spongiform encephalopathy (BSE) fibrils from cow. The anti-sheep PrP serum displays species restricted immunoreactivity. While it identifies several PrP polypeptides from terminally affected sheep, goat and cow material, only the highest molecular weight band is recognised from hamster and there is no detection of mouse PrP. The use of these antisera in routine laboratory testing at post mortem provides a highly sensitive test for scrapie and BSE and may allow the identification of infected animals prior to the onset of clinical signs.