Capture and migration of human primary neutrophils on endothelial cells. (A) Staining for E-selectin on a HUVEC monolayer and corresponding polymorphonuclear leukocyte (PMN) capture from whole blood. (B) PMN migration on HUVECs with red blood cells (RBCs) on the side; automated tracks generated with JEX. Colors represent the formation of the chemical gradient: red represents maximum chemoattractant source concentration; and yellow, the chemoattractant concentration in the sink. (C) Micrographs showing type I and type II neutrophil morphologies (also see supplemental Video 5). (D) Representative tracks of each neutrophil phenotype transposed to the origin. (E) Representative individual neutrophil tracks of chemotactic index and directional velocity toward the chemoattractant, illustrating the differences in chemotactic function. (F-G) Type I phenotype is significantly more directional and has a higher velocity toward the chemoattractant than type II. *P < .05. n = 3. (H) No significant difference in random migration speed between the 2 neutrophil phenotypes (n = 3). Direct comparisons of neutrophil chemotaxis with controls shown in supplemental Figure 8. (A-B) Scale bars represent 100 μm. (C) Scale bar represents 10 μm. Error bars represent SEM. Phase-contrast images acquired using Slidebook Version 5.0.0.14 software with an Olympus IX-81 microscope using a 10× objective (NA = 0.30) at 37°C, except for micrographs shown in panel C. Additional details on imaging are given in “Microscopy.”