Immunohistochemical detection of infectious bursal disease virus antigen in the bursa of fabricius of experimentally infected chickens

The indirect immunoperoxidase method (IP) with polyclonal antibodies was us ed for detecting infectious bursal disease (IBD) virus antigen in the bursa of chickens experimentally infected with a highly virulent vi,vs designate d as KA. Detection of IBD virus by the IP method on methanol fixed paraffin embedded tissue samples is possible ten days after infection (PI). Three t o seven days PI an intensive expression of IBDV antigen can be observed on lymphocytes in the cortex and medulla of bursal follicles, as well as on ma crophages in the follicles and interstitium. Ten days PI the immunohistoche mical reaction is very discreet, but IBD virus detection is still possible. The IP method, used in our work, is a sensitive and specific way of demons trating IBDV in the bursa of Fabricius of experimentally infected chickens.