Tissues from bovine animals sent for laboratory testing pursuant to the provisions of Article 12(2) shall be subject to a histopathological examination as laid down in the latest edition of the Manual, except where the material is autolysed. Where the result of the histopathological examination is inconclusive or negative or where the material is autolysed, the tissues shall be subject to an examination by one of the other diagnostic methods laid down in the Manual (immunochemistry, immuno-blotting or demonstration of characteristic fibrils by electron microscopy).