In situ hybridization on paraffin-embedded HeLa-OH cells. Visible (A to C) or fluorescent (D to E) labeling of infected cells. Hybridization with the PNA probe A/Ge/08 (A, D, C, and F) or negative control (B, E). The negative control is a random PNA probe (PNA ISH detection kit). Infections were performed with an HRV-64 strain (B, C, E and F), except for mock-infected (M.I.) strains (A, D).