Dual-color SD-DNA-PAINT. (a,b) Single-color DNA-PAINT experiments
in SD-mode using COS-7 cells immunolabeled for either clathrin (R3)
or α-tubulin (R6). Recording modality: 20 000 frames,
100 ms exposure, 1 nM imager concentration. (a) Pseudocolor overlay
of the 2D intensity histograms from separate single-color experiments
(cyan: R6S-ATTO-655, magenta: R3S-ATTO-700, both: average of six experiments).
Color-separation masks (white lines) were manually designed within
the 2D intensity histogram based on the single-color experiments.
(b) The crosstalk was calculated as the percentage of localizations
from the source (i.e., ATTO-700) that were detected within the mask
of the recipient channel (i.e., ATTO-655) based on the single-color
ground truth and vice versa. Mean ± SEM, N =
4–5 images per channel. (c) COS-7 cells were immunolabeled
for clathrin (R3) or α-tubulin (R6) simultaneously. Samples
were imaged simultaneously in SD-mode (including color-filtering)
using the imagers from (a). Representative dual-color SD-DNA-PAINT
image of microtubules (R6S-655) and clathrin (R3S-700) with enlarged
regions (white boxes) are shown. Scale bar: 1 μm, zoom: 200
nm. Both enlarged regions have the same contrast. Recording modality:
30 000 frames, 100 ms exposure, 1 nM total imager concentration.
(d) Intensity line profiles across the indicated microtubules shown
in (c). The mean profile shows a “valley-to-peak” intensity
ratio of ∼50% (dotted red line).