Division 1 Fluorescent antibody test (FAT)

The principle of the test is the detection of viral antigen on thin cryosections of organ material from pigs suspected of being infected with classical swine fever virus. The intracellular antigen is detected by using a FITC conjugated antibody. A positive result should be confirmed by repeating the staining with a specific monoclonal antibody.

Suitable organs are tonsils, kidney, spleen, different lymph nodes and ileum. A smear of bone marrow cells might also be used in case of feral pigs, if these organs are not available or are autolysed.

The test can be performed within one day. As organ samples can only be obtained from dead animals its use for screening purposes is limited. Confidence in the test result may be limited by doubtful staining, particularly where considerable experience in performing the test has not been acquired or if the organs tested are autolysed.