Figure 1.

Typical images recorded for one cell. In these images, L-selectin is fluorescently labeled. The images in the first column (A, C, and F) are bright-field images, in the second column (B, D, and G) are epi-fluorescence images, and in the third column (E and H) are TIRF images. The focus was positioned at the center of the cell on the images of the first row and at the bottom of the cell on the images of the last two rows. The cell was held in a pipette for the images of the last row. For presentation, the contrast was adjusted to make the signal clearly visible. Note that the contact area was determined from the bright-field images (C and F). The area was that of a nearly circular ellipse drawn to just include the shaded central region and its boundary (as shown).