EN
With immunofluorescence techniques large foci are visible in frozen sections of the tonsils and spleen of pigs infected with virulent strains of HCV. Low or moderate-virulent strains induce small, weakly fluorescent foci under the same conditions. This sometimes causes diagnostic problems. Therefore, under such conditions, isolation of virus in cell cultures should be applied for HC diagnosis. The culture might be examined for the presence of HCV by direct IFT using immunoenzymatic methods (PLA). The usefulness of the PLA for the diagnosis of HC was compared with IFT. Forty samples of tonsils, spleens and kidneys were collected from 10 pigs experimentally infected and from 5 field cases of HC. Isolation was performed on rapidly growing PK-15 cells seeded in flat bottomed microtitre plates. The cultures after 48 h were fixed and stained with hiperimmune porcine HC antiserum and after that with anti-porcine IgG-HRPO conjugate. The results were read microscopically using 50 X magnification. The results were considered positive if stained reddish-brown infected cells were detected. The applied immunoenzymatic method enables the detection of HCV in all samples, from experimentally infected pigs and field cases of HC. Using IFT, in some cases, it was difficult to determine exactly the results of examination.