Figure 1From: Pathogenesis of swine influenza virus (Thai isolates) in weanling pigs: an experimental trial SIV antigen staining by IHC, (A) negative control, (B) dark brown staining cells (arrow) of the SIV-positive control, (C) SIV-positive staining on alveolar epithelial cells and (D) bronchiolar epithelial cells. Back to article page