Figure 1.

Single molecules were tracked in three dimensions with spt-PALM and the DH-PSF. (A) A representative sequence of DH-PSF images, taken in series 70 ms apart, showing a single molecule as two lobes overlaid on a diffuse background stemming from a BamA fusion protein fluorescing in the periplasm. The rotation of the two lobes around the center of the distribution correlates with the molecule’s z position, here showing a decrease in z. These images were taken from consecutive frames in the track shown in (B). Scale bars, 1 μm. (B) Brightfield image of an E. coli cell from a tracking experiment. The trajectory in (C) is superimposed on the image at the bottom pole of the cell (boxed inset). (C) Visualization of 3D motion for the trajectory shown in (B). The color of the localization point corresponds with its z position, from blue (high z) to red (low z). To see this figure in color, go online.