Figure 2.

Examples of fluorescence images recorded for one donor. In the first row (A–D) are epi-fluorescence images recorded when the focus was positioned at the center of the cell. In images of the last two rows, cells are held in a pipette and pressed onto the glass to make similar contact areas (15.4 ± 1.3 μm²) and the focus was at the cell-glass interface. In the second row (E–H) are epi-fluorescence images and in the third row (I–L) are the corresponding TIRF images. Images of the first column (A, E, and I), the second column (B, F, and J), the third column (C, G, and K), and the fourth column (D, H, and L) illustrate L-selectin, PSGL-1, LFA-1, and Mac-1 labeling, respectively. For clarity of presentation, the range of grayscales in each image was adjusted, and the shaded values in the original image are given in the grayscale bars to the right of each image. All four cells (A–D) exhibited a similar epi-fluorescence intensity averaged over their bright edges (731 ± 25 per pixel).