Hog cholera. V. Demonstration of the antigen in swine tissues by the fluorescent antibody technique.

The fluorescent antibody technique was employed to detect hog cholera virus in tissue sections of various organs from experimentally infected swine. The method proved to be highly sensitive and infection could be detected in these animals as early as three days after inoculation with the virus. Best results were obtained when tissues were collected from young animals in advanced disease rather than from sows or from pigs in the early febrile phase. Tonsil, spleen and lymph node were the tissues of choice and were most satisfactory when removed from freshly killed animals rather than from those that had died.