The mouse anti-prion monoclonal antibody F99 has been shown to recognize a conserved epitope (QYQRES) on the ruminant prion protein in tissues from sheep, cattle, mule deer, elk and white-tailed deer. The antibody may be useful in detecting agents of transmissible spongiform encephalopathies (TSEs). The Prion IHC Assay Kit A consists of anti-prion antibody, blocking reagents, alkaline phosphatase polymer detection and chromogen reagents. The kit contains reagent quantities sufficient for immunohistochemistry of approximately 50 formalin-fixed paraffin-embedded tissues. The kit is configured for use on the intelliPATH Automated Slide Stainer. Prion IHC Assay Kit B (IPR5033KG80, provided separately) contains hematoxylin counterstain and bluing solution.