Figure 1.

Detection of West Nile virus (WNV) RNA using reverse transcription polymerase chain reaction (RT-PCR) in virus-inoculated human corneal epithelial (HCE) cells in vitro. Subconfluent monolayers of (A-B) HCE cells and (C-D) Vero cells in 25-cm² flasks were inoculated with WNV at a multiplicity of infection of 0.1 (lanes 1–6) or they were inoculated with an equal amount of heat-inactivated virus (lanes 7–12). After 1 hour, the virus inocula were removed, and the cell monolayers were rinsed twice in phosphate-buffered saline and incubated in the appropriate cell culture media. Cells were homogenized in Trizol (Invitrogen) and total RNA was extracted at 1 (lanes 1 and 7), 2 (lanes 2 and 8), 3 (lanes 3 and 9), 4 (lanes 4 and 10), 5 (lanes 5 and 11), and 6 (lanes 6 and 12) days postinoculation. Equal amounts of total RNA (2 μg) were analyzed using RT-PCR with primers specific for (A–C) WNV, (B) human ribosomal protein RPL11, and (D) African green monkey β-actin.