Time course of PMN infiltration after a moderate SCI at T9, demonstrated by flow cytometry in the injured spinal cord. Cells isolated from spinal cord (T8-T10) were labeled with a FITC-conjugated anti-PMN antibody before analyzed on a FACS Calibur flow cytometer. Spinal cord tissues were collected from uninjured control or injured animal 30 minutes, 2 hours, 24 hours, 3 days, or 7 days after SCI. The number of PMNs detected in the injured or uninjured spinal cord was visualized by dot plots (A), and represented as the percent of cells in the spinal cord relative to uninjured control (B). All flow cytometric gates were set using control IgG isotype labeled cells. # = significantly (P < 0.05) different from uninjured control. n = 5. Number of experiment replication = 2.