Dock8^−/− DCs fail to effectively transmigrate through the SCS floor. (A-C) Intravital 2-photon microscopy for LPS-stimulated DCs. (A) Velocities in the LN parenchyma and the SCS were compared between Dock8^+/− (n = 116 for parenchyma; n = 21 for SCS) and Dock8^−/− (n = 48 for parenchyma; n = 20 for SCS) DCs. Each symbol represents an individual DC; small horizontal lines indicate the average. (B) Localization of Dock8^+/− (red) and Dock8^−/− (blue) DCs in the LNs 48 hours after DC transfer. HEV (green) indicates high endothelial venule. The percentage of cells localized within outer 100 μm was compared between Dock8^+/− (n = 658) and Dock8^−/− (n = 171) DCs. Data are expressed as means ± SD *P < .05. (C) Morphology of Dock8^+/− (green) and Dock8^−/− (red) DCs migrating through the SCS floor (light blue). The length of cells located at the SCS floor was compared between Dock8^+/− (n = 65) and Dock8^−/− (n = 79) DCs. **P < .01. Elapsed time is presented as minutes:seconds. Each box plot exhibits the median (central line within each box), the 25th and 75th percentile values (box ends), and the 10th and 90th percentile values (error bars). In panels A through C, data are from 3 separate experiments.