Figure 7.

Double immunohistochemical staining of swine influenza virus antigens and epithelial cells. Lung sections from swine influenza virus (SIV) H1N1 infected pig euthanized PID 4. Double immunohistochemical staining using polyclonal anti-influenza and anti-cytokeratin antibodies demonstrating SIV antigen positive cells (clear blue cells) and epithelial cells (clear red cells). Double positive cells (SIV antigen positive epithelial cells) are purple (counterstained with hematoxylin). A: Demonstration of double positive bronchioles (arrowhead). B: Demonstration of both double stained alveolar type I (arrow) and II epithelial cells (arrowhead). (Original magnifications A: x10, B: x40).