Neutrophil migration requires flotillin microdomains. (a) fMLP (1 µg/mouse) was injected into subcutaneous air pouches. At the times indicated, mice were culled and the air pouch lavaged with PBS. Leukocyte counts were performed based on cell morphology after staining with Wright-Giemsa; a total of 200 cells were counted per slide. +/+, wild type; −/−, flotillin 1 knockout. Results are mean ± SEM (n = 3–7); these data are representative of three individual experiments. *, P < 0.05. (b) Cellular infiltration of the air pouch was monitored by flow cytometry using CD11b and Ly6G expression as markers of neutrophils (Ly6G^hiCD11b^+ve) and monocytes (Ly6G^loCD11b^+ve), as shown by the blue gating regions. Numbers in blue are the percentages of total cells in each gate. (c) Absolute cell numbers calculated from FACS analysis of infiltrating cells as in panel b. Results are mean ± SEM (n = 3–7); data are representative of three individual experiments. *, P < 0.05.