Fig. 2: Localization precision as a function of z. | Communications Biology

Fig. 2: Localization precision as a function of z.

From: Three-dimensional localization and tracking of chromosomal loci throughout the Escherichia coli cell cycle

Fig. 2

a Scheme for repeated localization of beads. Beads were imaged 50 times per z height and were localized in each image using a neural network. For each bead the standard deviation in their localizations across all frames was used to calculate localization precision as a function of the z height. The signal-to-background ratio of the beads was matched to the signal-to-background ratio of the locus labels (Supplementary Fig. 8). b–d Localization precision in x, y, z as a function of z. N = 1311 beads were localized in >30 frames each. Bead localizations were binned into bins of 50 nm bin size on the z axis and mean and standard deviation of the bin are plotted for x, y and z axis. The red dashed curve in each plot corresponds to the Cramér-Rao lower bound on the localization precision of the cubic spline model of the PSF at a signal of ~1950 photons per emitter and background signal of ~5.8 photons/pixel. The photon count of the detected beads does however vary over the z-range and only the brightest beads were detected reliably (>30 frames) above +300 nm (Supplementary Fig. 9).

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