Comparison of four fixatives for routine splenic histology and immunohistochemical staining for group II avian adenovirus.

Four different fixatives, A, B, C, and D, were compared for use in routine histology of splenic tissue and for immunohistochemical staining to detect group II avian adenoviral antigen. Sixteen pheasants were experimentally infected with type II adenovirus; spleens from each bird were harvested, divided, and treated with each of the four fixatives. All four fixatives were adequate for routine histology. Fixative B was significantly more sensitive for immunohistochemistry than the three other fixatives, and it also detected the viral antigens at the highest dilutions of the primary antibody.